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Diffstat (limited to 'drivers/atm/horizon.c')
| -rw-r--r-- | drivers/atm/horizon.c | 2853 |
1 files changed, 2853 insertions, 0 deletions
diff --git a/drivers/atm/horizon.c b/drivers/atm/horizon.c new file mode 100644 index 000000000..4f2951cbe --- /dev/null +++ b/drivers/atm/horizon.c @@ -0,0 +1,2853 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + Madge Horizon ATM Adapter driver. + Copyright (C) 1995-1999 Madge Networks Ltd. + +*/ + +/* + IMPORTANT NOTE: Madge Networks no longer makes the adapters + supported by this driver and makes no commitment to maintain it. +*/ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/mm.h> +#include <linux/pci.h> +#include <linux/errno.h> +#include <linux/atm.h> +#include <linux/atmdev.h> +#include <linux/sonet.h> +#include <linux/skbuff.h> +#include <linux/time.h> +#include <linux/delay.h> +#include <linux/uio.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/wait.h> +#include <linux/slab.h> + +#include <asm/io.h> +#include <linux/atomic.h> +#include <linux/uaccess.h> +#include <asm/string.h> +#include <asm/byteorder.h> + +#include "horizon.h" + +#define maintainer_string "Giuliano Procida at Madge Networks <gprocida@madge.com>" +#define description_string "Madge ATM Horizon [Ultra] driver" +#define version_string "1.2.1" + +static inline void __init show_version (void) { + printk ("%s version %s\n", description_string, version_string); +} + +/* + + CREDITS + + Driver and documentation by: + + Chris Aston Madge Networks + Giuliano Procida Madge Networks + Simon Benham Madge Networks + Simon Johnson Madge Networks + Various Others Madge Networks + + Some inspiration taken from other drivers by: + + Alexandru Cucos UTBv + Kari Mettinen University of Helsinki + Werner Almesberger EPFL LRC + + Theory of Operation + + I Hardware, detection, initialisation and shutdown. + + 1. Supported Hardware + + This driver should handle all variants of the PCI Madge ATM adapters + with the Horizon chipset. These are all PCI cards supporting PIO, BM + DMA and a form of MMIO (registers only, not internal RAM). + + The driver is only known to work with SONET and UTP Horizon Ultra + cards at 155Mb/s. However, code is in place to deal with both the + original Horizon and 25Mb/s operation. + + There are two revisions of the Horizon ASIC: the original and the + Ultra. Details of hardware bugs are in section III. + + The ASIC version can be distinguished by chip markings but is NOT + indicated by the PCI revision (all adapters seem to have PCI rev 1). + + I believe that: + + Horizon => Collage 25 PCI Adapter (UTP and STP) + Horizon Ultra => Collage 155 PCI Client (UTP or SONET) + Ambassador x => Collage 155 PCI Server (completely different) + + Horizon (25Mb/s) is fitted with UTP and STP connectors. It seems to + have a Madge B154 plus glue logic serializer. I have also found a + really ancient version of this with slightly different glue. It + comes with the revision 0 (140-025-01) ASIC. + + Horizon Ultra (155Mb/s) is fitted with either a Pulse Medialink + output (UTP) or an HP HFBR 5205 output (SONET). It has either + Madge's SAMBA framer or a SUNI-lite device (early versions). It + comes with the revision 1 (140-027-01) ASIC. + + 2. Detection + + All Horizon-based cards present with the same PCI Vendor and Device + IDs. The standard Linux 2.2 PCI API is used to locate any cards and + to enable bus-mastering (with appropriate latency). + + ATM_LAYER_STATUS in the control register distinguishes between the + two possible physical layers (25 and 155). It is not clear whether + the 155 cards can also operate at 25Mbps. We rely on the fact that a + card operates at 155 if and only if it has the newer Horizon Ultra + ASIC. + + For 155 cards the two possible framers are probed for and then set + up for loop-timing. + + 3. Initialisation + + The card is reset and then put into a known state. The physical + layer is configured for normal operation at the appropriate speed; + in the case of the 155 cards, the framer is initialised with + line-based timing; the internal RAM is zeroed and the allocation of + buffers for RX and TX is made; the Burnt In Address is read and + copied to the ATM ESI; various policy settings for RX (VPI bits, + unknown VCs, oam cells) are made. Ideally all policy items should be + configurable at module load (if not actually on-demand), however, + only the vpi vs vci bit allocation can be specified at insmod. + + 4. Shutdown + + This is in response to module_cleaup. No VCs are in use and the card + should be idle; it is reset. + + II Driver software (as it should be) + + 0. Traffic Parameters + + The traffic classes (not an enumeration) are currently: ATM_NONE (no + traffic), ATM_UBR, ATM_CBR, ATM_VBR and ATM_ABR, ATM_ANYCLASS + (compatible with everything). Together with (perhaps only some of) + the following items they make up the traffic specification. + + struct atm_trafprm { + unsigned char traffic_class; traffic class (ATM_UBR, ...) + int max_pcr; maximum PCR in cells per second + int pcr; desired PCR in cells per second + int min_pcr; minimum PCR in cells per second + int max_cdv; maximum CDV in microseconds + int max_sdu; maximum SDU in bytes + }; + + Note that these denote bandwidth available not bandwidth used; the + possibilities according to ATMF are: + + Real Time (cdv and max CDT given) + + CBR(pcr) pcr bandwidth always available + rtVBR(pcr,scr,mbs) scr bandwidth always available, up to pcr at mbs too + + Non Real Time + + nrtVBR(pcr,scr,mbs) scr bandwidth always available, up to pcr at mbs too + UBR() + ABR(mcr,pcr) mcr bandwidth always available, up to pcr (depending) too + + mbs is max burst size (bucket) + pcr and scr have associated cdvt values + mcr is like scr but has no cdtv + cdtv may differ at each hop + + Some of the above items are qos items (as opposed to traffic + parameters). We have nothing to do with qos. All except ABR can have + their traffic parameters converted to GCRA parameters. The GCRA may + be implemented as a (real-number) leaky bucket. The GCRA can be used + in complicated ways by switches and in simpler ways by end-stations. + It can be used both to filter incoming cells and shape out-going + cells. + + ATM Linux actually supports: + + ATM_NONE() (no traffic in this direction) + ATM_UBR(max_frame_size) + ATM_CBR(max/min_pcr, max_cdv, max_frame_size) + + 0 or ATM_MAX_PCR are used to indicate maximum available PCR + + A traffic specification consists of the AAL type and separate + traffic specifications for either direction. In ATM Linux it is: + + struct atm_qos { + struct atm_trafprm txtp; + struct atm_trafprm rxtp; + unsigned char aal; + }; + + AAL types are: + + ATM_NO_AAL AAL not specified + ATM_AAL0 "raw" ATM cells + ATM_AAL1 AAL1 (CBR) + ATM_AAL2 AAL2 (VBR) + ATM_AAL34 AAL3/4 (data) + ATM_AAL5 AAL5 (data) + ATM_SAAL signaling AAL + + The Horizon has support for AAL frame types: 0, 3/4 and 5. However, + it does not implement AAL 3/4 SAR and it has a different notion of + "raw cell" to ATM Linux's (48 bytes vs. 52 bytes) so neither are + supported by this driver. + + The Horizon has limited support for ABR (including UBR), VBR and + CBR. Each TX channel has a bucket (containing up to 31 cell units) + and two timers (PCR and SCR) associated with it that can be used to + govern cell emissions and host notification (in the case of ABR this + is presumably so that RM cells may be emitted at appropriate times). + The timers may either be disabled or may be set to any of 240 values + (determined by the clock crystal, a fixed (?) per-device divider, a + configurable divider and a configurable timer preload value). + + At the moment only UBR and CBR are supported by the driver. VBR will + be supported as soon as ATM for Linux supports it. ABR support is + very unlikely as RM cell handling is completely up to the driver. + + 1. TX (TX channel setup and TX transfer) + + The TX half of the driver owns the TX Horizon registers. The TX + component in the IRQ handler is the BM completion handler. This can + only be entered when tx_busy is true (enforced by hardware). The + other TX component can only be entered when tx_busy is false + (enforced by driver). So TX is single-threaded. + + Apart from a minor optimisation to not re-select the last channel, + the TX send component works as follows: + + Atomic test and set tx_busy until we succeed; we should implement + some sort of timeout so that tx_busy will never be stuck at true. + + If no TX channel is set up for this VC we wait for an idle one (if + necessary) and set it up. + + At this point we have a TX channel ready for use. We wait for enough + buffers to become available then start a TX transmit (set the TX + descriptor, schedule transfer, exit). + + The IRQ component handles TX completion (stats, free buffer, tx_busy + unset, exit). We also re-schedule further transfers for the same + frame if needed. + + TX setup in more detail: + + TX open is a nop, the relevant information is held in the hrz_vcc + (vcc->dev_data) structure and is "cached" on the card. + + TX close gets the TX lock and clears the channel from the "cache". + + 2. RX (Data Available and RX transfer) + + The RX half of the driver owns the RX registers. There are two RX + components in the IRQ handler: the data available handler deals with + fresh data that has arrived on the card, the BM completion handler + is very similar to the TX completion handler. The data available + handler grabs the rx_lock and it is only released once the data has + been discarded or completely transferred to the host. The BM + completion handler only runs when the lock is held; the data + available handler is locked out over the same period. + + Data available on the card triggers an interrupt. If the data is not + suitable for our existing RX channels or we cannot allocate a buffer + it is flushed. Otherwise an RX receive is scheduled. Multiple RX + transfers may be scheduled for the same frame. + + RX setup in more detail: + + RX open... + RX close... + + III Hardware Bugs + + 0. Byte vs Word addressing of adapter RAM. + + A design feature; see the .h file (especially the memory map). + + 1. Bus Master Data Transfers (original Horizon only, fixed in Ultra) + + The host must not start a transmit direction transfer at a + non-four-byte boundary in host memory. Instead the host should + perform a byte, or a two byte, or one byte followed by two byte + transfer in order to start the rest of the transfer on a four byte + boundary. RX is OK. + + Simultaneous transmit and receive direction bus master transfers are + not allowed. + + The simplest solution to these two is to always do PIO (never DMA) + in the TX direction on the original Horizon. More complicated + solutions are likely to hurt my brain. + + 2. Loss of buffer on close VC + + When a VC is being closed, the buffer associated with it is not + returned to the pool. The host must store the reference to this + buffer and when opening a new VC then give it to that new VC. + + The host intervention currently consists of stacking such a buffer + pointer at VC close and checking the stack at VC open. + + 3. Failure to close a VC + + If a VC is currently receiving a frame then closing the VC may fail + and the frame continues to be received. + + The solution is to make sure any received frames are flushed when + ready. This is currently done just before the solution to 2. + + 4. PCI bus (original Horizon only, fixed in Ultra) + + Reading from the data port prior to initialisation will hang the PCI + bus. Just don't do that then! We don't. + + IV To Do List + + . Timer code may be broken. + + . Allow users to specify buffer allocation split for TX and RX. + + . Deal once and for all with buggy VC close. + + . Handle interrupted and/or non-blocking operations. + + . Change some macros to functions and move from .h to .c. + + . Try to limit the number of TX frames each VC may have queued, in + order to reduce the chances of TX buffer exhaustion. + + . Implement VBR (bucket and timers not understood) and ABR (need to + do RM cells manually); also no Linux support for either. + + . Implement QoS changes on open VCs (involves extracting parts of VC open + and close into separate functions and using them to make changes). + +*/ + +/********** globals **********/ + +static void do_housekeeping (struct timer_list *t); + +static unsigned short debug = 0; +static unsigned short vpi_bits = 0; +static int max_tx_size = 9000; +static int max_rx_size = 9000; +static unsigned char pci_lat = 0; + +/********** access functions **********/ + +/* Read / Write Horizon registers */ +static inline void wr_regl (const hrz_dev * dev, unsigned char reg, u32 data) { + outl (cpu_to_le32 (data), dev->iobase + reg); +} + +static inline u32 rd_regl (const hrz_dev * dev, unsigned char reg) { + return le32_to_cpu (inl (dev->iobase + reg)); +} + +static inline void wr_regw (const hrz_dev * dev, unsigned char reg, u16 data) { + outw (cpu_to_le16 (data), dev->iobase + reg); +} + +static inline u16 rd_regw (const hrz_dev * dev, unsigned char reg) { + return le16_to_cpu (inw (dev->iobase + reg)); +} + +static inline void wrs_regb (const hrz_dev * dev, unsigned char reg, void * addr, u32 len) { + outsb (dev->iobase + reg, addr, len); +} + +static inline void rds_regb (const hrz_dev * dev, unsigned char reg, void * addr, u32 len) { + insb (dev->iobase + reg, addr, len); +} + +/* Read / Write to a given address in Horizon buffer memory. + Interrupts must be disabled between the address register and data + port accesses as these must form an atomic operation. */ +static inline void wr_mem (const hrz_dev * dev, HDW * addr, u32 data) { + // wr_regl (dev, MEM_WR_ADDR_REG_OFF, (u32) addr); + wr_regl (dev, MEM_WR_ADDR_REG_OFF, (addr - (HDW *) 0) * sizeof(HDW)); + wr_regl (dev, MEMORY_PORT_OFF, data); +} + +static inline u32 rd_mem (const hrz_dev * dev, HDW * addr) { + // wr_regl (dev, MEM_RD_ADDR_REG_OFF, (u32) addr); + wr_regl (dev, MEM_RD_ADDR_REG_OFF, (addr - (HDW *) 0) * sizeof(HDW)); + return rd_regl (dev, MEMORY_PORT_OFF); +} + +static inline void wr_framer (const hrz_dev * dev, u32 addr, u32 data) { + wr_regl (dev, MEM_WR_ADDR_REG_OFF, (u32) addr | 0x80000000); + wr_regl (dev, MEMORY_PORT_OFF, data); +} + +static inline u32 rd_framer (const hrz_dev * dev, u32 addr) { + wr_regl (dev, MEM_RD_ADDR_REG_OFF, (u32) addr | 0x80000000); + return rd_regl (dev, MEMORY_PORT_OFF); +} + +/********** specialised access functions **********/ + +/* RX */ + +static inline void FLUSH_RX_CHANNEL (hrz_dev * dev, u16 channel) { + wr_regw (dev, RX_CHANNEL_PORT_OFF, FLUSH_CHANNEL | channel); + return; +} + +static void WAIT_FLUSH_RX_COMPLETE (hrz_dev * dev) { + while (rd_regw (dev, RX_CHANNEL_PORT_OFF) & FLUSH_CHANNEL) + ; + return; +} + +static inline void SELECT_RX_CHANNEL (hrz_dev * dev, u16 channel) { + wr_regw (dev, RX_CHANNEL_PORT_OFF, channel); + return; +} + +static void WAIT_UPDATE_COMPLETE (hrz_dev * dev) { + while (rd_regw (dev, RX_CHANNEL_PORT_OFF) & RX_CHANNEL_UPDATE_IN_PROGRESS) + ; + return; +} + +/* TX */ + +static inline void SELECT_TX_CHANNEL (hrz_dev * dev, u16 tx_channel) { + wr_regl (dev, TX_CHANNEL_PORT_OFF, tx_channel); + return; +} + +/* Update or query one configuration parameter of a particular channel. */ + +static inline void update_tx_channel_config (hrz_dev * dev, short chan, u8 mode, u16 value) { + wr_regw (dev, TX_CHANNEL_CONFIG_COMMAND_OFF, + chan * TX_CHANNEL_CONFIG_MULT | mode); + wr_regw (dev, TX_CHANNEL_CONFIG_DATA_OFF, value); + return; +} + +/********** dump functions **********/ + +static inline void dump_skb (char * prefix, unsigned int vc, struct sk_buff * skb) { +#ifdef DEBUG_HORIZON + unsigned int i; + unsigned char * data = skb->data; + PRINTDB (DBG_DATA, "%s(%u) ", prefix, vc); + for (i=0; i<skb->len && i < 256;i++) + PRINTDM (DBG_DATA, "%02x ", data[i]); + PRINTDE (DBG_DATA,""); +#else + (void) prefix; + (void) vc; + (void) skb; +#endif + return; +} + +static inline void dump_regs (hrz_dev * dev) { +#ifdef DEBUG_HORIZON + PRINTD (DBG_REGS, "CONTROL 0: %#x", rd_regl (dev, CONTROL_0_REG)); + PRINTD (DBG_REGS, "RX CONFIG: %#x", rd_regw (dev, RX_CONFIG_OFF)); + PRINTD (DBG_REGS, "TX CONFIG: %#x", rd_regw (dev, TX_CONFIG_OFF)); + PRINTD (DBG_REGS, "TX STATUS: %#x", rd_regw (dev, TX_STATUS_OFF)); + PRINTD (DBG_REGS, "IRQ ENBLE: %#x", rd_regl (dev, INT_ENABLE_REG_OFF)); + PRINTD (DBG_REGS, "IRQ SORCE: %#x", rd_regl (dev, INT_SOURCE_REG_OFF)); +#else + (void) dev; +#endif + return; +} + +static inline void dump_framer (hrz_dev * dev) { +#ifdef DEBUG_HORIZON + unsigned int i; + PRINTDB (DBG_REGS, "framer registers:"); + for (i = 0; i < 0x10; ++i) + PRINTDM (DBG_REGS, " %02x", rd_framer (dev, i)); + PRINTDE (DBG_REGS,""); +#else + (void) dev; +#endif + return; +} + +/********** VPI/VCI <-> (RX) channel conversions **********/ + +/* RX channels are 10 bit integers, these fns are quite paranoid */ + +static inline int vpivci_to_channel (u16 * channel, const short vpi, const int vci) { + unsigned short vci_bits = 10 - vpi_bits; + if (0 <= vpi && vpi < 1<<vpi_bits && 0 <= vci && vci < 1<<vci_bits) { + *channel = vpi<<vci_bits | vci; + return *channel ? 0 : -EINVAL; + } + return -EINVAL; +} + +/********** decode RX queue entries **********/ + +static inline u16 rx_q_entry_to_length (u32 x) { + return x & RX_Q_ENTRY_LENGTH_MASK; +} + +static inline u16 rx_q_entry_to_rx_channel (u32 x) { + return (x>>RX_Q_ENTRY_CHANNEL_SHIFT) & RX_CHANNEL_MASK; +} + +/* Cell Transmit Rate Values + * + * the cell transmit rate (cells per sec) can be set to a variety of + * different values by specifying two parameters: a timer preload from + * 1 to 16 (stored as 0 to 15) and a clock divider (2 to the power of + * an exponent from 0 to 14; the special value 15 disables the timer). + * + * cellrate = baserate / (preload * 2^divider) + * + * The maximum cell rate that can be specified is therefore just the + * base rate. Halving the preload is equivalent to adding 1 to the + * divider and so values 1 to 8 of the preload are redundant except + * in the case of a maximal divider (14). + * + * Given a desired cell rate, an algorithm to determine the preload + * and divider is: + * + * a) x = baserate / cellrate, want p * 2^d = x (as far as possible) + * b) if x > 16 * 2^14 then set p = 16, d = 14 (min rate), done + * if x <= 16 then set p = x, d = 0 (high rates), done + * c) now have 16 < x <= 2^18, or 1 < x/16 <= 2^14 and we want to + * know n such that 2^(n-1) < x/16 <= 2^n, so slide a bit until + * we find the range (n will be between 1 and 14), set d = n + * d) Also have 8 < x/2^n <= 16, so set p nearest x/2^n + * + * The algorithm used below is a minor variant of the above. + * + * The base rate is derived from the oscillator frequency (Hz) using a + * fixed divider: + * + * baserate = freq / 32 in the case of some Unknown Card + * baserate = freq / 8 in the case of the Horizon 25 + * baserate = freq / 8 in the case of the Horizon Ultra 155 + * + * The Horizon cards have oscillators and base rates as follows: + * + * Card Oscillator Base Rate + * Unknown Card 33 MHz 1.03125 MHz (33 MHz = PCI freq) + * Horizon 25 32 MHz 4 MHz + * Horizon Ultra 155 40 MHz 5 MHz + * + * The following defines give the base rates in Hz. These were + * previously a factor of 100 larger, no doubt someone was using + * cps*100. + */ + +#define BR_UKN 1031250l +#define BR_HRZ 4000000l +#define BR_ULT 5000000l + +// d is an exponent +#define CR_MIND 0 +#define CR_MAXD 14 + +// p ranges from 1 to a power of 2 +#define CR_MAXPEXP 4 + +static int make_rate (const hrz_dev * dev, u32 c, rounding r, + u16 * bits, unsigned int * actual) +{ + // note: rounding the rate down means rounding 'p' up + const unsigned long br = test_bit(ultra, &dev->flags) ? BR_ULT : BR_HRZ; + + u32 div = CR_MIND; + u32 pre; + + // br_exp and br_man are used to avoid overflowing (c*maxp*2^d) in + // the tests below. We could think harder about exact possibilities + // of failure... + + unsigned long br_man = br; + unsigned int br_exp = 0; + + PRINTD (DBG_QOS|DBG_FLOW, "make_rate b=%lu, c=%u, %s", br, c, + r == round_up ? "up" : r == round_down ? "down" : "nearest"); + + // avoid div by zero + if (!c) { + PRINTD (DBG_QOS|DBG_ERR, "zero rate is not allowed!"); + return -EINVAL; + } + + while (br_exp < CR_MAXPEXP + CR_MIND && (br_man % 2 == 0)) { + br_man = br_man >> 1; + ++br_exp; + } + // (br >>br_exp) <<br_exp == br and + // br_exp <= CR_MAXPEXP+CR_MIND + + if (br_man <= (c << (CR_MAXPEXP+CR_MIND-br_exp))) { + // Equivalent to: B <= (c << (MAXPEXP+MIND)) + // take care of rounding + switch (r) { + case round_down: + pre = DIV_ROUND_UP(br, c<<div); + // but p must be non-zero + if (!pre) + pre = 1; + break; + case round_nearest: + pre = DIV_ROUND_CLOSEST(br, c<<div); + // but p must be non-zero + if (!pre) + pre = 1; + break; + default: /* round_up */ + pre = br/(c<<div); + // but p must be non-zero + if (!pre) + return -EINVAL; + } + PRINTD (DBG_QOS, "A: p=%u, d=%u", pre, div); + goto got_it; + } + + // at this point we have + // d == MIND and (c << (MAXPEXP+MIND)) < B + while (div < CR_MAXD) { + div++; + if (br_man <= (c << (CR_MAXPEXP+div-br_exp))) { + // Equivalent to: B <= (c << (MAXPEXP+d)) + // c << (MAXPEXP+d-1) < B <= c << (MAXPEXP+d) + // 1 << (MAXPEXP-1) < B/2^d/c <= 1 << MAXPEXP + // MAXP/2 < B/c2^d <= MAXP + // take care of rounding + switch (r) { + case round_down: + pre = DIV_ROUND_UP(br, c<<div); + break; + case round_nearest: + pre = DIV_ROUND_CLOSEST(br, c<<div); + break; + default: /* round_up */ + pre = br/(c<<div); + } + PRINTD (DBG_QOS, "B: p=%u, d=%u", pre, div); + goto got_it; + } + } + // at this point we have + // d == MAXD and (c << (MAXPEXP+MAXD)) < B + // but we cannot go any higher + // take care of rounding + if (r == round_down) + return -EINVAL; + pre = 1 << CR_MAXPEXP; + PRINTD (DBG_QOS, "C: p=%u, d=%u", pre, div); +got_it: + // paranoia + if (div > CR_MAXD || (!pre) || pre > 1<<CR_MAXPEXP) { + PRINTD (DBG_QOS, "set_cr internal failure: d=%u p=%u", + div, pre); + return -EINVAL; + } else { + if (bits) + *bits = (div<<CLOCK_SELECT_SHIFT) | (pre-1); + if (actual) { + *actual = DIV_ROUND_UP(br, pre<<div); + PRINTD (DBG_QOS, "actual rate: %u", *actual); + } + return 0; + } +} + +static int make_rate_with_tolerance (const hrz_dev * dev, u32 c, rounding r, unsigned int tol, + u16 * bit_pattern, unsigned int * actual) { + unsigned int my_actual; + + PRINTD (DBG_QOS|DBG_FLOW, "make_rate_with_tolerance c=%u, %s, tol=%u", + c, (r == round_up) ? "up" : (r == round_down) ? "down" : "nearest", tol); + + if (!actual) + // actual rate is not returned + actual = &my_actual; + + if (make_rate (dev, c, round_nearest, bit_pattern, actual)) + // should never happen as round_nearest always succeeds + return -1; + + if (c - tol <= *actual && *actual <= c + tol) + // within tolerance + return 0; + else + // intolerant, try rounding instead + return make_rate (dev, c, r, bit_pattern, actual); +} + +/********** Listen on a VC **********/ + +static int hrz_open_rx (hrz_dev * dev, u16 channel) { + // is there any guarantee that we don't get two simulataneous + // identical calls of this function from different processes? yes + // rate_lock + unsigned long flags; + u32 channel_type; // u16? + + u16 buf_ptr = RX_CHANNEL_IDLE; + + rx_ch_desc * rx_desc = &memmap->rx_descs[channel]; + + PRINTD (DBG_FLOW, "hrz_open_rx %x", channel); + + spin_lock_irqsave (&dev->mem_lock, flags); + channel_type = rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK; + spin_unlock_irqrestore (&dev->mem_lock, flags); + + // very serious error, should never occur + if (channel_type != RX_CHANNEL_DISABLED) { + PRINTD (DBG_ERR|DBG_VCC, "RX channel for VC already open"); + return -EBUSY; // clean up? + } + + // Give back spare buffer + if (dev->noof_spare_buffers) { + buf_ptr = dev->spare_buffers[--dev->noof_spare_buffers]; + PRINTD (DBG_VCC, "using a spare buffer: %u", buf_ptr); + // should never occur + if (buf_ptr == RX_CHANNEL_DISABLED || buf_ptr == RX_CHANNEL_IDLE) { + // but easy to recover from + PRINTD (DBG_ERR|DBG_VCC, "bad spare buffer pointer, using IDLE"); + buf_ptr = RX_CHANNEL_IDLE; + } + } else { + PRINTD (DBG_VCC, "using IDLE buffer pointer"); + } + + // Channel is currently disabled so change its status to idle + + // do we really need to save the flags again? + spin_lock_irqsave (&dev->mem_lock, flags); + + wr_mem (dev, &rx_desc->wr_buf_type, + buf_ptr | CHANNEL_TYPE_AAL5 | FIRST_CELL_OF_AAL5_FRAME); + if (buf_ptr != RX_CHANNEL_IDLE) + wr_mem (dev, &rx_desc->rd_buf_type, buf_ptr); + + spin_unlock_irqrestore (&dev->mem_lock, flags); + + // rxer->rate = make_rate (qos->peak_cells); + + PRINTD (DBG_FLOW, "hrz_open_rx ok"); + + return 0; +} + +#if 0 +/********** change vc rate for a given vc **********/ + +static void hrz_change_vc_qos (ATM_RXER * rxer, MAAL_QOS * qos) { + rxer->rate = make_rate (qos->peak_cells); +} +#endif + +/********** free an skb (as per ATM device driver documentation) **********/ + +static void hrz_kfree_skb (struct sk_buff * skb) { + if (ATM_SKB(skb)->vcc->pop) { + ATM_SKB(skb)->vcc->pop (ATM_SKB(skb)->vcc, skb); + } else { + dev_kfree_skb_any (skb); + } +} + +/********** cancel listen on a VC **********/ + +static void hrz_close_rx (hrz_dev * dev, u16 vc) { + unsigned long flags; + + u32 value; + + u32 r1, r2; + + rx_ch_desc * rx_desc = &memmap->rx_descs[vc]; + + int was_idle = 0; + + spin_lock_irqsave (&dev->mem_lock, flags); + value = rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK; + spin_unlock_irqrestore (&dev->mem_lock, flags); + + if (value == RX_CHANNEL_DISABLED) { + // I suppose this could happen once we deal with _NONE traffic properly + PRINTD (DBG_VCC, "closing VC: RX channel %u already disabled", vc); + return; + } + if (value == RX_CHANNEL_IDLE) + was_idle = 1; + + spin_lock_irqsave (&dev->mem_lock, flags); + + for (;;) { + wr_mem (dev, &rx_desc->wr_buf_type, RX_CHANNEL_DISABLED); + + if ((rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK) == RX_CHANNEL_DISABLED) + break; + + was_idle = 0; + } + + if (was_idle) { + spin_unlock_irqrestore (&dev->mem_lock, flags); + return; + } + + WAIT_FLUSH_RX_COMPLETE(dev); + + // XXX Is this all really necessary? We can rely on the rx_data_av + // handler to discard frames that remain queued for delivery. If the + // worry is that immediately reopening the channel (perhaps by a + // different process) may cause some data to be mis-delivered then + // there may still be a simpler solution (such as busy-waiting on + // rx_busy once the channel is disabled or before a new one is + // opened - does this leave any holes?). Arguably setting up and + // tearing down the TX and RX halves of each virtual circuit could + // most safely be done within ?x_busy protected regions. + + // OK, current changes are that Simon's marker is disabled and we DO + // look for NULL rxer elsewhere. The code here seems flush frames + // and then remember the last dead cell belonging to the channel + // just disabled - the cell gets relinked at the next vc_open. + // However, when all VCs are closed or only a few opened there are a + // handful of buffers that are unusable. + + // Does anyone feel like documenting spare_buffers properly? + // Does anyone feel like fixing this in a nicer way? + + // Flush any data which is left in the channel + for (;;) { + // Change the rx channel port to something different to the RX + // channel we are trying to close to force Horizon to flush the rx + // channel read and write pointers. + + u16 other = vc^(RX_CHANS/2); + + SELECT_RX_CHANNEL (dev, other); + WAIT_UPDATE_COMPLETE (dev); + + r1 = rd_mem (dev, &rx_desc->rd_buf_type); + + // Select this RX channel. Flush doesn't seem to work unless we + // select an RX channel before hand + + SELECT_RX_CHANNEL (dev, vc); + WAIT_UPDATE_COMPLETE (dev); + + // Attempt to flush a frame on this RX channel + + FLUSH_RX_CHANNEL (dev, vc); + WAIT_FLUSH_RX_COMPLETE (dev); + + // Force Horizon to flush rx channel read and write pointers as before + + SELECT_RX_CHANNEL (dev, other); + WAIT_UPDATE_COMPLETE (dev); + + r2 = rd_mem (dev, &rx_desc->rd_buf_type); + + PRINTD (DBG_VCC|DBG_RX, "r1 = %u, r2 = %u", r1, r2); + + if (r1 == r2) { + dev->spare_buffers[dev->noof_spare_buffers++] = (u16)r1; + break; + } + } + +#if 0 + { + rx_q_entry * wr_ptr = &memmap->rx_q_entries[rd_regw (dev, RX_QUEUE_WR_PTR_OFF)]; + rx_q_entry * rd_ptr = dev->rx_q_entry; + + PRINTD (DBG_VCC|DBG_RX, "rd_ptr = %u, wr_ptr = %u", rd_ptr, wr_ptr); + + while (rd_ptr != wr_ptr) { + u32 x = rd_mem (dev, (HDW *) rd_ptr); + + if (vc == rx_q_entry_to_rx_channel (x)) { + x |= SIMONS_DODGEY_MARKER; + + PRINTD (DBG_RX|DBG_VCC|DBG_WARN, "marking a frame as dodgey"); + + wr_mem (dev, (HDW *) rd_ptr, x); + } + + if (rd_ptr == dev->rx_q_wrap) + rd_ptr = dev->rx_q_reset; + else + rd_ptr++; + } + } +#endif + + spin_unlock_irqrestore (&dev->mem_lock, flags); + + return; +} + +/********** schedule RX transfers **********/ + +// Note on tail recursion: a GCC developer said that it is not likely +// to be fixed soon, so do not define TAILRECUSRIONWORKS unless you +// are sure it does as you may otherwise overflow the kernel stack. + +// giving this fn a return value would help GCC, allegedly + +static void rx_schedule (hrz_dev * dev, int irq) { + unsigned int rx_bytes; + + int pio_instead = 0; +#ifndef TAILRECURSIONWORKS + pio_instead = 1; + while (pio_instead) { +#endif + // bytes waiting for RX transfer + rx_bytes = dev->rx_bytes; + +#if 0 + spin_count = 0; + while (rd_regl (dev, MASTER_RX_COUNT_REG_OFF)) { + PRINTD (DBG_RX|DBG_WARN, "RX error: other PCI Bus Master RX still in progress!"); + if (++spin_count > 10) { + PRINTD (DBG_RX|DBG_ERR, "spun out waiting PCI Bus Master RX completion"); + wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0); + clear_bit (rx_busy, &dev->flags); + hrz_kfree_skb (dev->rx_skb); + return; + } + } +#endif + + // this code follows the TX code but (at the moment) there is only + // one region - the skb itself. I don't know if this will change, + // but it doesn't hurt to have the code here, disabled. + + if (rx_bytes) { + // start next transfer within same region + if (rx_bytes <= MAX_PIO_COUNT) { + PRINTD (DBG_RX|DBG_BUS, "(pio)"); + pio_instead = 1; + } + if (rx_bytes <= MAX_TRANSFER_COUNT) { + PRINTD (DBG_RX|DBG_BUS, "(simple or last multi)"); + dev->rx_bytes = 0; + } else { + PRINTD (DBG_RX|DBG_BUS, "(continuing multi)"); + dev->rx_bytes = rx_bytes - MAX_TRANSFER_COUNT; + rx_bytes = MAX_TRANSFER_COUNT; + } + } else { + // rx_bytes == 0 -- we're between regions + // regions remaining to transfer +#if 0 + unsigned int rx_regions = dev->rx_regions; +#else + unsigned int rx_regions = 0; +#endif + + if (rx_regions) { +#if 0 + // start a new region + dev->rx_addr = dev->rx_iovec->iov_base; + rx_bytes = dev->rx_iovec->iov_len; + ++dev->rx_iovec; + dev->rx_regions = rx_regions - 1; + + if (rx_bytes <= MAX_PIO_COUNT) { + PRINTD (DBG_RX|DBG_BUS, "(pio)"); + pio_instead = 1; + } + if (rx_bytes <= MAX_TRANSFER_COUNT) { + PRINTD (DBG_RX|DBG_BUS, "(full region)"); + dev->rx_bytes = 0; + } else { + PRINTD (DBG_RX|DBG_BUS, "(start multi region)"); + dev->rx_bytes = rx_bytes - MAX_TRANSFER_COUNT; + rx_bytes = MAX_TRANSFER_COUNT; + } +#endif + } else { + // rx_regions == 0 + // that's all folks - end of frame + struct sk_buff * skb = dev->rx_skb; + // dev->rx_iovec = 0; + + FLUSH_RX_CHANNEL (dev, dev->rx_channel); + + dump_skb ("<<<", dev->rx_channel, skb); + + PRINTD (DBG_RX|DBG_SKB, "push %p %u", skb->data, skb->len); + + { + struct atm_vcc * vcc = ATM_SKB(skb)->vcc; + // VC layer stats + atomic_inc(&vcc->stats->rx); + __net_timestamp(skb); + // end of our responsibility + vcc->push (vcc, skb); + } + } + } + + // note: writing RX_COUNT clears any interrupt condition + if (rx_bytes) { + if (pio_instead) { + if (irq) + wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0); + rds_regb (dev, DATA_PORT_OFF, dev->rx_addr, rx_bytes); + } else { + wr_regl (dev, MASTER_RX_ADDR_REG_OFF, virt_to_bus (dev->rx_addr)); + wr_regl (dev, MASTER_RX_COUNT_REG_OFF, rx_bytes); + } + dev->rx_addr += rx_bytes; + } else { + if (irq) + wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0); + // allow another RX thread to start + YELLOW_LED_ON(dev); + clear_bit (rx_busy, &dev->flags); + PRINTD (DBG_RX, "cleared rx_busy for dev %p", dev); + } + +#ifdef TAILRECURSIONWORKS + // and we all bless optimised tail calls + if (pio_instead) + return rx_schedule (dev, 0); + return; +#else + // grrrrrrr! + irq = 0; + } + return; +#endif +} + +/********** handle RX bus master complete events **********/ + +static void rx_bus_master_complete_handler (hrz_dev * dev) { + if (test_bit (rx_busy, &dev->flags)) { + rx_schedule (dev, 1); + } else { + PRINTD (DBG_RX|DBG_ERR, "unexpected RX bus master completion"); + // clear interrupt condition on adapter + wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0); + } + return; +} + +/********** (queue to) become the next TX thread **********/ + +static int tx_hold (hrz_dev * dev) { + PRINTD (DBG_TX, "sleeping at tx lock %p %lu", dev, dev->flags); + wait_event_interruptible(dev->tx_queue, (!test_and_set_bit(tx_busy, &dev->flags))); + PRINTD (DBG_TX, "woken at tx lock %p %lu", dev, dev->flags); + if (signal_pending (current)) + return -1; + PRINTD (DBG_TX, "set tx_busy for dev %p", dev); + return 0; +} + +/********** allow another TX thread to start **********/ + +static inline void tx_release (hrz_dev * dev) { + clear_bit (tx_busy, &dev->flags); + PRINTD (DBG_TX, "cleared tx_busy for dev %p", dev); + wake_up_interruptible (&dev->tx_queue); +} + +/********** schedule TX transfers **********/ + +static void tx_schedule (hrz_dev * const dev, int irq) { + unsigned int tx_bytes; + + int append_desc = 0; + + int pio_instead = 0; +#ifndef TAILRECURSIONWORKS + pio_instead = 1; + while (pio_instead) { +#endif + // bytes in current region waiting for TX transfer + tx_bytes = dev->tx_bytes; + +#if 0 + spin_count = 0; + while (rd_regl (dev, MASTER_TX_COUNT_REG_OFF)) { + PRINTD (DBG_TX|DBG_WARN, "TX error: other PCI Bus Master TX still in progress!"); + if (++spin_count > 10) { + PRINTD (DBG_TX|DBG_ERR, "spun out waiting PCI Bus Master TX completion"); + wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0); + tx_release (dev); + hrz_kfree_skb (dev->tx_skb); + return; + } + } +#endif + + if (tx_bytes) { + // start next transfer within same region + if (!test_bit (ultra, &dev->flags) || tx_bytes <= MAX_PIO_COUNT) { + PRINTD (DBG_TX|DBG_BUS, "(pio)"); + pio_instead = 1; + } + if (tx_bytes <= MAX_TRANSFER_COUNT) { + PRINTD (DBG_TX|DBG_BUS, "(simple or last multi)"); + if (!dev->tx_iovec) { + // end of last region + append_desc = 1; + } + dev->tx_bytes = 0; + } else { + PRINTD (DBG_TX|DBG_BUS, "(continuing multi)"); + dev->tx_bytes = tx_bytes - MAX_TRANSFER_COUNT; + tx_bytes = MAX_TRANSFER_COUNT; + } + } else { + // tx_bytes == 0 -- we're between regions + // regions remaining to transfer + unsigned int tx_regions = dev->tx_regions; + + if (tx_regions) { + // start a new region + dev->tx_addr = dev->tx_iovec->iov_base; + tx_bytes = dev->tx_iovec->iov_len; + ++dev->tx_iovec; + dev->tx_regions = tx_regions - 1; + + if (!test_bit (ultra, &dev->flags) || tx_bytes <= MAX_PIO_COUNT) { + PRINTD (DBG_TX|DBG_BUS, "(pio)"); + pio_instead = 1; + } + if (tx_bytes <= MAX_TRANSFER_COUNT) { + PRINTD (DBG_TX|DBG_BUS, "(full region)"); + dev->tx_bytes = 0; + } else { + PRINTD (DBG_TX|DBG_BUS, "(start multi region)"); + dev->tx_bytes = tx_bytes - MAX_TRANSFER_COUNT; + tx_bytes = MAX_TRANSFER_COUNT; + } + } else { + // tx_regions == 0 + // that's all folks - end of frame + struct sk_buff * skb = dev->tx_skb; + dev->tx_iovec = NULL; + + // VC layer stats + atomic_inc(&ATM_SKB(skb)->vcc->stats->tx); + + // free the skb + hrz_kfree_skb (skb); + } + } + + // note: writing TX_COUNT clears any interrupt condition + if (tx_bytes) { + if (pio_instead) { + if (irq) + wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0); + wrs_regb (dev, DATA_PORT_OFF, dev->tx_addr, tx_bytes); + if (append_desc) + wr_regl (dev, TX_DESCRIPTOR_PORT_OFF, cpu_to_be32 (dev->tx_skb->len)); + } else { + wr_regl (dev, MASTER_TX_ADDR_REG_OFF, virt_to_bus (dev->tx_addr)); + if (append_desc) + wr_regl (dev, TX_DESCRIPTOR_REG_OFF, cpu_to_be32 (dev->tx_skb->len)); + wr_regl (dev, MASTER_TX_COUNT_REG_OFF, + append_desc + ? tx_bytes | MASTER_TX_AUTO_APPEND_DESC + : tx_bytes); + } + dev->tx_addr += tx_bytes; + } else { + if (irq) + wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0); + YELLOW_LED_ON(dev); + tx_release (dev); + } + +#ifdef TAILRECURSIONWORKS + // and we all bless optimised tail calls + if (pio_instead) + return tx_schedule (dev, 0); + return; +#else + // grrrrrrr! + irq = 0; + } + return; +#endif +} + +/********** handle TX bus master complete events **********/ + +static void tx_bus_master_complete_handler (hrz_dev * dev) { + if (test_bit (tx_busy, &dev->flags)) { + tx_schedule (dev, 1); + } else { + PRINTD (DBG_TX|DBG_ERR, "unexpected TX bus master completion"); + // clear interrupt condition on adapter + wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0); + } + return; +} + +/********** move RX Q pointer to next item in circular buffer **********/ + +// called only from IRQ sub-handler +static u32 rx_queue_entry_next (hrz_dev * dev) { + u32 rx_queue_entry; + spin_lock (&dev->mem_lock); + rx_queue_entry = rd_mem (dev, &dev->rx_q_entry->entry); + if (dev->rx_q_entry == dev->rx_q_wrap) + dev->rx_q_entry = dev->rx_q_reset; + else + dev->rx_q_entry++; + wr_regw (dev, RX_QUEUE_RD_PTR_OFF, dev->rx_q_entry - dev->rx_q_reset); + spin_unlock (&dev->mem_lock); + return rx_queue_entry; +} + +/********** handle RX data received by device **********/ + +// called from IRQ handler +static void rx_data_av_handler (hrz_dev * dev) { + u32 rx_queue_entry; + u32 rx_queue_entry_flags; + u16 rx_len; + u16 rx_channel; + + PRINTD (DBG_FLOW, "hrz_data_av_handler"); + + // try to grab rx lock (not possible during RX bus mastering) + if (test_and_set_bit (rx_busy, &dev->flags)) { + PRINTD (DBG_RX, "locked out of rx lock"); + return; + } + PRINTD (DBG_RX, "set rx_busy for dev %p", dev); + // lock is cleared if we fail now, o/w after bus master completion + + YELLOW_LED_OFF(dev); + + rx_queue_entry = rx_queue_entry_next (dev); + + rx_len = rx_q_entry_to_length (rx_queue_entry); + rx_channel = rx_q_entry_to_rx_channel (rx_queue_entry); + + WAIT_FLUSH_RX_COMPLETE (dev); + + SELECT_RX_CHANNEL (dev, rx_channel); + + PRINTD (DBG_RX, "rx_queue_entry is: %#x", rx_queue_entry); + rx_queue_entry_flags = rx_queue_entry & (RX_CRC_32_OK|RX_COMPLETE_FRAME|SIMONS_DODGEY_MARKER); + + if (!rx_len) { + // (at least) bus-mastering breaks if we try to handle a + // zero-length frame, besides AAL5 does not support them + PRINTK (KERN_ERR, "zero-length frame!"); + rx_queue_entry_flags &= ~RX_COMPLETE_FRAME; + } + + if (rx_queue_entry_flags & SIMONS_DODGEY_MARKER) { + PRINTD (DBG_RX|DBG_ERR, "Simon's marker detected!"); + } + if (rx_queue_entry_flags == (RX_CRC_32_OK | RX_COMPLETE_FRAME)) { + struct atm_vcc * atm_vcc; + + PRINTD (DBG_RX, "got a frame on rx_channel %x len %u", rx_channel, rx_len); + + atm_vcc = dev->rxer[rx_channel]; + // if no vcc is assigned to this channel, we should drop the frame + // (is this what SIMONS etc. was trying to achieve?) + + if (atm_vcc) { + + if (atm_vcc->qos.rxtp.traffic_class != ATM_NONE) { + + if (rx_len <= atm_vcc->qos.rxtp.max_sdu) { + + struct sk_buff * skb = atm_alloc_charge (atm_vcc, rx_len, GFP_ATOMIC); + if (skb) { + // remember this so we can push it later + dev->rx_skb = skb; + // remember this so we can flush it later + dev->rx_channel = rx_channel; + + // prepare socket buffer + skb_put (skb, rx_len); + ATM_SKB(skb)->vcc = atm_vcc; + + // simple transfer + // dev->rx_regions = 0; + // dev->rx_iovec = 0; + dev->rx_bytes = rx_len; + dev->rx_addr = skb->data; + PRINTD (DBG_RX, "RX start simple transfer (addr %p, len %d)", + skb->data, rx_len); + + // do the business + rx_schedule (dev, 0); + return; + + } else { + PRINTD (DBG_SKB|DBG_WARN, "failed to get skb"); + } + + } else { + PRINTK (KERN_INFO, "frame received on TX-only VC %x", rx_channel); + // do we count this? + } + + } else { + PRINTK (KERN_WARNING, "dropped over-size frame"); + // do we count this? + } + + } else { + PRINTD (DBG_WARN|DBG_VCC|DBG_RX, "no VCC for this frame (VC closed)"); + // do we count this? + } + + } else { + // Wait update complete ? SPONG + } + + // RX was aborted + YELLOW_LED_ON(dev); + + FLUSH_RX_CHANNEL (dev,rx_channel); + clear_bit (rx_busy, &dev->flags); + + return; +} + +/********** interrupt handler **********/ + +static irqreturn_t interrupt_handler(int irq, void *dev_id) +{ + hrz_dev *dev = dev_id; + u32 int_source; + unsigned int irq_ok; + + PRINTD (DBG_FLOW, "interrupt_handler: %p", dev_id); + + // definitely for us + irq_ok = 0; + while ((int_source = rd_regl (dev, INT_SOURCE_REG_OFF) + & INTERESTING_INTERRUPTS)) { + // In the interests of fairness, the handlers below are + // called in sequence and without immediate return to the head of + // the while loop. This is only of issue for slow hosts (or when + // debugging messages are on). Really slow hosts may find a fast + // sender keeps them permanently in the IRQ handler. :( + + // (only an issue for slow hosts) RX completion goes before + // rx_data_av as the former implies rx_busy and so the latter + // would just abort. If it reschedules another transfer + // (continuing the same frame) then it will not clear rx_busy. + + // (only an issue for slow hosts) TX completion goes before RX + // data available as it is a much shorter routine - there is the + // chance that any further transfers it schedules will be complete + // by the time of the return to the head of the while loop + + if (int_source & RX_BUS_MASTER_COMPLETE) { + ++irq_ok; + PRINTD (DBG_IRQ|DBG_BUS|DBG_RX, "rx_bus_master_complete asserted"); + rx_bus_master_complete_handler (dev); + } + if (int_source & TX_BUS_MASTER_COMPLETE) { + ++irq_ok; + PRINTD (DBG_IRQ|DBG_BUS|DBG_TX, "tx_bus_master_complete asserted"); + tx_bus_master_complete_handler (dev); + } + if (int_source & RX_DATA_AV) { + ++irq_ok; + PRINTD (DBG_IRQ|DBG_RX, "rx_data_av asserted"); + rx_data_av_handler (dev); + } + } + if (irq_ok) { + PRINTD (DBG_IRQ, "work done: %u", irq_ok); + } else { + PRINTD (DBG_IRQ|DBG_WARN, "spurious interrupt source: %#x", int_source); + } + + PRINTD (DBG_IRQ|DBG_FLOW, "interrupt_handler done: %p", dev_id); + if (irq_ok) + return IRQ_HANDLED; + return IRQ_NONE; +} + +/********** housekeeping **********/ + +static void do_housekeeping (struct timer_list *t) { + // just stats at the moment + hrz_dev * dev = from_timer(dev, t, housekeeping); + + // collect device-specific (not driver/atm-linux) stats here + dev->tx_cell_count += rd_regw (dev, TX_CELL_COUNT_OFF); + dev->rx_cell_count += rd_regw (dev, RX_CELL_COUNT_OFF); + dev->hec_error_count += rd_regw (dev, HEC_ERROR_COUNT_OFF); + dev->unassigned_cell_count += rd_regw (dev, UNASSIGNED_CELL_COUNT_OFF); + + mod_timer (&dev->housekeeping, jiffies + HZ/10); + + return; +} + +/********** find an idle channel for TX and set it up **********/ + +// called with tx_busy set +static short setup_idle_tx_channel (hrz_dev * dev, hrz_vcc * vcc) { + unsigned short idle_channels; + short tx_channel = -1; + unsigned int spin_count; + PRINTD (DBG_FLOW|DBG_TX, "setup_idle_tx_channel %p", dev); + + // better would be to fail immediately, the caller can then decide whether + // to wait or drop (depending on whether this is UBR etc.) + spin_count = 0; + while (!(idle_channels = rd_regw (dev, TX_STATUS_OFF) & IDLE_CHANNELS_MASK)) { + PRINTD (DBG_TX|DBG_WARN, "waiting for idle TX channel"); + // delay a bit here + if (++spin_count > 100) { + PRINTD (DBG_TX|DBG_ERR, "spun out waiting for idle TX channel"); + return -EBUSY; + } + } + + // got an idle channel + { + // tx_idle ensures we look for idle channels in RR order + int chan = dev->tx_idle; + + int keep_going = 1; + while (keep_going) { + if (idle_channels & (1<<chan)) { + tx_channel = chan; + keep_going = 0; + } + ++chan; + if (chan == TX_CHANS) + chan = 0; + } + + dev->tx_idle = chan; + } + + // set up the channel we found + { + // Initialise the cell header in the transmit channel descriptor + // a.k.a. prepare the channel and remember that we have done so. + + tx_ch_desc * tx_desc = &memmap->tx_descs[tx_channel]; + u32 rd_ptr; + u32 wr_ptr; + u16 channel = vcc->channel; + + unsigned long flags; + spin_lock_irqsave (&dev->mem_lock, flags); + + // Update the transmit channel record. + dev->tx_channel_record[tx_channel] = channel; + + // xBR channel + update_tx_channel_config (dev, tx_channel, RATE_TYPE_ACCESS, + vcc->tx_xbr_bits); + + // Update the PCR counter preload value etc. + update_tx_channel_config (dev, tx_channel, PCR_TIMER_ACCESS, + vcc->tx_pcr_bits); + +#if 0 + if (vcc->tx_xbr_bits == VBR_RATE_TYPE) { + // SCR timer + update_tx_channel_config (dev, tx_channel, SCR_TIMER_ACCESS, + vcc->tx_scr_bits); + + // Bucket size... + update_tx_channel_config (dev, tx_channel, BUCKET_CAPACITY_ACCESS, + vcc->tx_bucket_bits); + + // ... and fullness + update_tx_channel_config (dev, tx_channel, BUCKET_FULLNESS_ACCESS, + vcc->tx_bucket_bits); + } +#endif + + // Initialise the read and write buffer pointers + rd_ptr = rd_mem (dev, &tx_desc->rd_buf_type) & BUFFER_PTR_MASK; + wr_ptr = rd_mem (dev, &tx_desc->wr_buf_type) & BUFFER_PTR_MASK; + + // idle TX channels should have identical pointers + if (rd_ptr != wr_ptr) { + PRINTD (DBG_TX|DBG_ERR, "TX buffer pointers are broken!"); + // spin_unlock... return -E... + // I wonder if gcc would get rid of one of the pointer aliases + } + PRINTD (DBG_TX, "TX buffer pointers are: rd %x, wr %x.", + rd_ptr, wr_ptr); + + switch (vcc->aal) { + case aal0: + PRINTD (DBG_QOS|DBG_TX, "tx_channel: aal0"); + rd_ptr |= CHANNEL_TYPE_RAW_CELLS; + wr_ptr |= CHANNEL_TYPE_RAW_CELLS; + break; + case aal34: + PRINTD (DBG_QOS|DBG_TX, "tx_channel: aal34"); + rd_ptr |= CHANNEL_TYPE_AAL3_4; + wr_ptr |= CHANNEL_TYPE_AAL3_4; + break; + case aal5: + rd_ptr |= CHANNEL_TYPE_AAL5; + wr_ptr |= CHANNEL_TYPE_AAL5; + // Initialise the CRC + wr_mem (dev, &tx_desc->partial_crc, INITIAL_CRC); + break; + } + + wr_mem (dev, &tx_desc->rd_buf_type, rd_ptr); + wr_mem (dev, &tx_desc->wr_buf_type, wr_ptr); + + // Write the Cell Header + // Payload Type, CLP and GFC would go here if non-zero + wr_mem (dev, &tx_desc->cell_header, channel); + + spin_unlock_irqrestore (&dev->mem_lock, flags); + } + + return tx_channel; +} + +/********** send a frame **********/ + +static int hrz_send (struct atm_vcc * atm_vcc, struct sk_buff * skb) { + unsigned int spin_count; + int free_buffers; + hrz_dev * dev = HRZ_DEV(atm_vcc->dev); + hrz_vcc * vcc = HRZ_VCC(atm_vcc); + u16 channel = vcc->channel; + + u32 buffers_required; + + /* signed for error return */ + short tx_channel; + + PRINTD (DBG_FLOW|DBG_TX, "hrz_send vc %x data %p len %u", + channel, skb->data, skb->len); + + dump_skb (">>>", channel, skb); + + if (atm_vcc->qos.txtp.traffic_class == ATM_NONE) { + PRINTK (KERN_ERR, "attempt to send on RX-only VC %x", channel); + hrz_kfree_skb (skb); + return -EIO; + } + + // don't understand this + ATM_SKB(skb)->vcc = atm_vcc; + + if (skb->len > atm_vcc->qos.txtp.max_sdu) { + PRINTK (KERN_ERR, "sk_buff length greater than agreed max_sdu, dropping..."); + hrz_kfree_skb (skb); + return -EIO; + } + + if (!channel) { + PRINTD (DBG_ERR|DBG_TX, "attempt to transmit on zero (rx_)channel"); + hrz_kfree_skb (skb); + return -EIO; + } + +#if 0 + { + // where would be a better place for this? housekeeping? + u16 status; + pci_read_config_word (dev->pci_dev, PCI_STATUS, &status); + if (status & PCI_STATUS_REC_MASTER_ABORT) { + PRINTD (DBG_BUS|DBG_ERR, "Clearing PCI Master Abort (and cleaning up)"); + status &= ~PCI_STATUS_REC_MASTER_ABORT; + pci_write_config_word (dev->pci_dev, PCI_STATUS, status); + if (test_bit (tx_busy, &dev->flags)) { + hrz_kfree_skb (dev->tx_skb); + tx_release (dev); + } + } + } +#endif + +#ifdef DEBUG_HORIZON + /* wey-hey! */ + if (channel == 1023) { + unsigned int i; + unsigned short d = 0; + char * s = skb->data; + if (*s++ == 'D') { + for (i = 0; i < 4; ++i) + d = (d << 4) | hex_to_bin(*s++); + PRINTK (KERN_INFO, "debug bitmap is now %hx", debug = d); + } + } +#endif + + // wait until TX is free and grab lock + if (tx_hold (dev)) { + hrz_kfree_skb (skb); + return -ERESTARTSYS; + } + + // Wait for enough space to be available in transmit buffer memory. + + // should be number of cells needed + 2 (according to hardware docs) + // = ((framelen+8)+47) / 48 + 2 + // = (framelen+7) / 48 + 3, hmm... faster to put addition inside XXX + buffers_required = (skb->len+(ATM_AAL5_TRAILER-1)) / ATM_CELL_PAYLOAD + 3; + + // replace with timer and sleep, add dev->tx_buffers_queue (max 1 entry) + spin_count = 0; + while ((free_buffers = rd_regw (dev, TX_FREE_BUFFER_COUNT_OFF)) < buffers_required) { + PRINTD (DBG_TX, "waiting for free TX buffers, got %d of %d", + free_buffers, buffers_required); + // what is the appropriate delay? implement a timeout? (depending on line speed?) + // mdelay (1); + // what happens if we kill (current_pid, SIGKILL) ? + schedule(); + if (++spin_count > 1000) { + PRINTD (DBG_TX|DBG_ERR, "spun out waiting for tx buffers, got %d of %d", + free_buffers, buffers_required); + tx_release (dev); + hrz_kfree_skb (skb); + return -ERESTARTSYS; + } + } + + // Select a channel to transmit the frame on. + if (channel == dev->last_vc) { + PRINTD (DBG_TX, "last vc hack: hit"); + tx_channel = dev->tx_last; + } else { + PRINTD (DBG_TX, "last vc hack: miss"); + // Are we currently transmitting this VC on one of the channels? + for (tx_channel = 0; tx_channel < TX_CHANS; ++tx_channel) + if (dev->tx_channel_record[tx_channel] == channel) { + PRINTD (DBG_TX, "vc already on channel: hit"); + break; + } + if (tx_channel == TX_CHANS) { + PRINTD (DBG_TX, "vc already on channel: miss"); + // Find and set up an idle channel. + tx_channel = setup_idle_tx_channel (dev, vcc); + if (tx_channel < 0) { + PRINTD (DBG_TX|DBG_ERR, "failed to get channel"); + tx_release (dev); + return tx_channel; + } + } + + PRINTD (DBG_TX, "got channel"); + SELECT_TX_CHANNEL(dev, tx_channel); + + dev->last_vc = channel; + dev->tx_last = tx_channel; + } + + PRINTD (DBG_TX, "using channel %u", tx_channel); + + YELLOW_LED_OFF(dev); + + // TX start transfer + + { + unsigned int tx_len = skb->len; + unsigned int tx_iovcnt = skb_shinfo(skb)->nr_frags; + // remember this so we can free it later + dev->tx_skb = skb; + + if (tx_iovcnt) { + // scatter gather transfer + dev->tx_regions = tx_iovcnt; + dev->tx_iovec = NULL; /* @@@ needs rewritten */ + dev->tx_bytes = 0; + PRINTD (DBG_TX|DBG_BUS, "TX start scatter-gather transfer (iovec %p, len %d)", + skb->data, tx_len); + tx_release (dev); + hrz_kfree_skb (skb); + return -EIO; + } else { + // simple transfer + dev->tx_regions = 0; + dev->tx_iovec = NULL; + dev->tx_bytes = tx_len; + dev->tx_addr = skb->data; + PRINTD (DBG_TX|DBG_BUS, "TX start simple transfer (addr %p, len %d)", + skb->data, tx_len); + } + + // and do the business + tx_schedule (dev, 0); + + } + + return 0; +} + +/********** reset a card **********/ + +static void hrz_reset (const hrz_dev * dev) { + u32 control_0_reg = rd_regl (dev, CONTROL_0_REG); + + // why not set RESET_HORIZON to one and wait for the card to + // reassert that bit as zero? Like so: + control_0_reg = control_0_reg & RESET_HORIZON; + wr_regl (dev, CONTROL_0_REG, control_0_reg); + while (control_0_reg & RESET_HORIZON) + control_0_reg = rd_regl (dev, CONTROL_0_REG); + + // old reset code retained: + wr_regl (dev, CONTROL_0_REG, control_0_reg | + RESET_ATM | RESET_RX | RESET_TX | RESET_HOST); + // just guessing here + udelay (1000); + + wr_regl (dev, CONTROL_0_REG, control_0_reg); +} + +/********** read the burnt in address **********/ + +static void WRITE_IT_WAIT (const hrz_dev *dev, u32 ctrl) +{ + wr_regl (dev, CONTROL_0_REG, ctrl); + udelay (5); +} + +static void CLOCK_IT (const hrz_dev *dev, u32 ctrl) +{ + // DI must be valid around rising SK edge + WRITE_IT_WAIT(dev, ctrl & ~SEEPROM_SK); + WRITE_IT_WAIT(dev, ctrl | SEEPROM_SK); +} + +static u16 read_bia(const hrz_dev *dev, u16 addr) +{ + u32 ctrl = rd_regl (dev, CONTROL_0_REG); + + const unsigned int addr_bits = 6; + const unsigned int data_bits = 16; + + unsigned int i; + + u16 res; + + ctrl &= ~(SEEPROM_CS | SEEPROM_SK | SEEPROM_DI); + WRITE_IT_WAIT(dev, ctrl); + + // wake Serial EEPROM and send 110 (READ) command + ctrl |= (SEEPROM_CS | SEEPROM_DI); + CLOCK_IT(dev, ctrl); + + ctrl |= SEEPROM_DI; + CLOCK_IT(dev, ctrl); + + ctrl &= ~SEEPROM_DI; + CLOCK_IT(dev, ctrl); + + for (i=0; i<addr_bits; i++) { + if (addr & (1 << (addr_bits-1))) + ctrl |= SEEPROM_DI; + else + ctrl &= ~SEEPROM_DI; + + CLOCK_IT(dev, ctrl); + + addr = addr << 1; + } + + // we could check that we have DO = 0 here + ctrl &= ~SEEPROM_DI; + + res = 0; + for (i=0;i<data_bits;i++) { + res = res >> 1; + + CLOCK_IT(dev, ctrl); + + if (rd_regl (dev, CONTROL_0_REG) & SEEPROM_DO) + res |= (1 << (data_bits-1)); + } + + ctrl &= ~(SEEPROM_SK | SEEPROM_CS); + WRITE_IT_WAIT(dev, ctrl); + + return res; +} + +/********** initialise a card **********/ + +static int hrz_init(hrz_dev *dev) +{ + int onefivefive; + + u16 chan; + + int buff_count; + + HDW * mem; + + cell_buf * tx_desc; + cell_buf * rx_desc; + + u32 ctrl; + + ctrl = rd_regl (dev, CONTROL_0_REG); + PRINTD (DBG_INFO, "ctrl0reg is %#x", ctrl); + onefivefive = ctrl & ATM_LAYER_STATUS; + + if (onefivefive) + printk (DEV_LABEL ": Horizon Ultra (at 155.52 MBps)"); + else + printk (DEV_LABEL ": Horizon (at 25 MBps)"); + + printk (":"); + // Reset the card to get everything in a known state + + printk (" reset"); + hrz_reset (dev); + + // Clear all the buffer memory + + printk (" clearing memory"); + + for (mem = (HDW *) memmap; mem < (HDW *) (memmap + 1); ++mem) + wr_mem (dev, mem, 0); + + printk (" tx channels"); + + // All transmit eight channels are set up as AAL5 ABR channels with + // a 16us cell spacing. Why? + + // Channel 0 gets the free buffer at 100h, channel 1 gets the free + // buffer at 110h etc. + + for (chan = 0; chan < TX_CHANS; ++chan) { + tx_ch_desc * tx_desc = &memmap->tx_descs[chan]; + cell_buf * buf = &memmap->inittxbufs[chan]; + + // initialise the read and write buffer pointers + wr_mem (dev, &tx_desc->rd_buf_type, BUF_PTR(buf)); + wr_mem (dev, &tx_desc->wr_buf_type, BUF_PTR(buf)); + + // set the status of the initial buffers to empty + wr_mem (dev, &buf->next, BUFF_STATUS_EMPTY); + } + + // Use space bufn3 at the moment for tx buffers + + printk (" tx buffers"); + + tx_desc = memmap->bufn3; + + wr_mem (dev, &memmap->txfreebufstart.next, BUF_PTR(tx_desc) | BUFF_STATUS_EMPTY); + + for (buff_count = 0; buff_count < BUFN3_SIZE-1; buff_count++) { + wr_mem (dev, &tx_desc->next, BUF_PTR(tx_desc+1) | BUFF_STATUS_EMPTY); + tx_desc++; + } + + wr_mem (dev, &tx_desc->next, BUF_PTR(&memmap->txfreebufend) | BUFF_STATUS_EMPTY); + + // Initialise the transmit free buffer count + wr_regw (dev, TX_FREE_BUFFER_COUNT_OFF, BUFN3_SIZE); + + printk (" rx channels"); + + // Initialise all of the receive channels to be AAL5 disabled with + // an interrupt threshold of 0 + + for (chan = 0; chan < RX_CHANS; ++chan) { + rx_ch_desc * rx_desc = &memmap->rx_descs[chan]; + + wr_mem (dev, &rx_desc->wr_buf_type, CHANNEL_TYPE_AAL5 | RX_CHANNEL_DISABLED); + } + + printk (" rx buffers"); + + // Use space bufn4 at the moment for rx buffers + + rx_desc = memmap->bufn4; + + wr_mem (dev, &memmap->rxfreebufstart.next, BUF_PTR(rx_desc) | BUFF_STATUS_EMPTY); + + for (buff_count = 0; buff_count < BUFN4_SIZE-1; buff_count++) { + wr_mem (dev, &rx_desc->next, BUF_PTR(rx_desc+1) | BUFF_STATUS_EMPTY); + + rx_desc++; + } + + wr_mem (dev, &rx_desc->next, BUF_PTR(&memmap->rxfreebufend) | BUFF_STATUS_EMPTY); + + // Initialise the receive free buffer count + wr_regw (dev, RX_FREE_BUFFER_COUNT_OFF, BUFN4_SIZE); + + // Initialize Horizons registers + + // TX config + wr_regw (dev, TX_CONFIG_OFF, + ABR_ROUND_ROBIN | TX_NORMAL_OPERATION | DRVR_DRVRBAR_ENABLE); + + // RX config. Use 10-x VC bits, x VP bits, non user cells in channel 0. + wr_regw (dev, RX_CONFIG_OFF, + DISCARD_UNUSED_VPI_VCI_BITS_SET | NON_USER_CELLS_IN_ONE_CHANNEL | vpi_bits); + + // RX line config + wr_regw (dev, RX_LINE_CONFIG_OFF, + LOCK_DETECT_ENABLE | FREQUENCY_DETECT_ENABLE | GXTALOUT_SELECT_DIV4); + + // Set the max AAL5 cell count to be just enough to contain the + // largest AAL5 frame that the user wants to receive + wr_regw (dev, MAX_AAL5_CELL_COUNT_OFF, + DIV_ROUND_UP(max_rx_size + ATM_AAL5_TRAILER, ATM_CELL_PAYLOAD)); + + // Enable receive + wr_regw (dev, RX_CONFIG_OFF, rd_regw (dev, RX_CONFIG_OFF) | RX_ENABLE); + + printk (" control"); + + // Drive the OE of the LEDs then turn the green LED on + ctrl |= GREEN_LED_OE | YELLOW_LED_OE | GREEN_LED | YELLOW_LED; + wr_regl (dev, CONTROL_0_REG, ctrl); + + // Test for a 155-capable card + + if (onefivefive) { + // Select 155 mode... make this a choice (or: how do we detect + // external line speed and switch?) + ctrl |= ATM_LAYER_SELECT; + wr_regl (dev, CONTROL_0_REG, ctrl); + + // test SUNI-lite vs SAMBA + + // Register 0x00 in the SUNI will have some of bits 3-7 set, and + // they will always be zero for the SAMBA. Ha! Bloody hardware + // engineers. It'll never work. + + if (rd_framer (dev, 0) & 0x00f0) { + // SUNI + printk (" SUNI"); + + // Reset, just in case + wr_framer (dev, 0x00, 0x0080); + wr_framer (dev, 0x00, 0x0000); + + // Configure transmit FIFO + wr_framer (dev, 0x63, rd_framer (dev, 0x63) | 0x0002); + + // Set line timed mode + wr_framer (dev, 0x05, rd_framer (dev, 0x05) | 0x0001); + } else { + // SAMBA + printk (" SAMBA"); + + // Reset, just in case + wr_framer (dev, 0, rd_framer (dev, 0) | 0x0001); + wr_framer (dev, 0, rd_framer (dev, 0) &~ 0x0001); + + // Turn off diagnostic loopback and enable line-timed mode + wr_framer (dev, 0, 0x0002); + + // Turn on transmit outputs + wr_framer (dev, 2, 0x0B80); + } + } else { + // Select 25 mode + ctrl &= ~ATM_LAYER_SELECT; + + // Madge B154 setup + // none required? + } + + printk (" LEDs"); + + GREEN_LED_ON(dev); + YELLOW_LED_ON(dev); + + printk (" ESI="); + + { + u16 b = 0; + int i; + u8 * esi = dev->atm_dev->esi; + + // in the card I have, EEPROM + // addresses 0, 1, 2 contain 0 + // addresess 5, 6 etc. contain ffff + // NB: Madge prefix is 00 00 f6 (which is 00 00 6f in Ethernet bit order) + // the read_bia routine gets the BIA in Ethernet bit order + + for (i=0; i < ESI_LEN; ++i) { + if (i % 2 == 0) + b = read_bia (dev, i/2 + 2); + else + b = b >> 8; + esi[i] = b & 0xFF; + printk ("%02x", esi[i]); + } + } + + // Enable RX_Q and ?X_COMPLETE interrupts only + wr_regl (dev, INT_ENABLE_REG_OFF, INTERESTING_INTERRUPTS); + printk (" IRQ on"); + + printk (".\n"); + + return onefivefive; +} + +/********** check max_sdu **********/ + +static int check_max_sdu (hrz_aal aal, struct atm_trafprm * tp, unsigned int max_frame_size) { + PRINTD (DBG_FLOW|DBG_QOS, "check_max_sdu"); + + switch (aal) { + case aal0: + if (!(tp->max_sdu)) { + PRINTD (DBG_QOS, "defaulting max_sdu"); + tp->max_sdu = ATM_AAL0_SDU; + } else if (tp->max_sdu != ATM_AAL0_SDU) { + PRINTD (DBG_QOS|DBG_ERR, "rejecting max_sdu"); + return -EINVAL; + } + break; + case aal34: + if (tp->max_sdu == 0 || tp->max_sdu > ATM_MAX_AAL34_PDU) { + PRINTD (DBG_QOS, "%sing max_sdu", tp->max_sdu ? "capp" : "default"); + tp->max_sdu = ATM_MAX_AAL34_PDU; + } + break; + case aal5: + if (tp->max_sdu == 0 || tp->max_sdu > max_frame_size) { + PRINTD (DBG_QOS, "%sing max_sdu", tp->max_sdu ? "capp" : "default"); + tp->max_sdu = max_frame_size; + } + break; + } + return 0; +} + +/********** check pcr **********/ + +// something like this should be part of ATM Linux +static int atm_pcr_check (struct atm_trafprm * tp, unsigned int pcr) { + // we are assuming non-UBR, and non-special values of pcr + if (tp->min_pcr == ATM_MAX_PCR) + PRINTD (DBG_QOS, "luser gave min_pcr = ATM_MAX_PCR"); + else if (tp->min_pcr < 0) + PRINTD (DBG_QOS, "luser gave negative min_pcr"); + else if (tp->min_pcr && tp->min_pcr > pcr) + PRINTD (DBG_QOS, "pcr less than min_pcr"); + else + // !! max_pcr = UNSPEC (0) is equivalent to max_pcr = MAX (-1) + // easier to #define ATM_MAX_PCR 0 and have all rates unsigned? + // [this would get rid of next two conditionals] + if ((0) && tp->max_pcr == ATM_MAX_PCR) + PRINTD (DBG_QOS, "luser gave max_pcr = ATM_MAX_PCR"); + else if ((tp->max_pcr != ATM_MAX_PCR) && tp->max_pcr < 0) + PRINTD (DBG_QOS, "luser gave negative max_pcr"); + else if (tp->max_pcr && tp->max_pcr != ATM_MAX_PCR && tp->max_pcr < pcr) + PRINTD (DBG_QOS, "pcr greater than max_pcr"); + else { + // each limit unspecified or not violated + PRINTD (DBG_QOS, "xBR(pcr) OK"); + return 0; + } + PRINTD (DBG_QOS, "pcr=%u, tp: min_pcr=%d, pcr=%d, max_pcr=%d", + pcr, tp->min_pcr, tp->pcr, tp->max_pcr); + return -EINVAL; +} + +/********** open VC **********/ + +static int hrz_open (struct atm_vcc *atm_vcc) +{ + int error; + u16 channel; + + struct atm_qos * qos; + struct atm_trafprm * txtp; + struct atm_trafprm * rxtp; + + hrz_dev * dev = HRZ_DEV(atm_vcc->dev); + hrz_vcc vcc; + hrz_vcc * vccp; // allocated late + short vpi = atm_vcc->vpi; + int vci = atm_vcc->vci; + PRINTD (DBG_FLOW|DBG_VCC, "hrz_open %x %x", vpi, vci); + +#ifdef ATM_VPI_UNSPEC + // UNSPEC is deprecated, remove this code eventually + if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) { + PRINTK (KERN_WARNING, "rejecting open with unspecified VPI/VCI (deprecated)"); + return -EINVAL; + } +#endif + + error = vpivci_to_channel (&channel, vpi, vci); + if (error) { + PRINTD (DBG_WARN|DBG_VCC, "VPI/VCI out of range: %hd/%d", vpi, vci); + return error; + } + + vcc.channel = channel; + // max speed for the moment + vcc.tx_rate = 0x0; + + qos = &atm_vcc->qos; + + // check AAL and remember it + switch (qos->aal) { + case ATM_AAL0: + // we would if it were 48 bytes and not 52! + PRINTD (DBG_QOS|DBG_VCC, "AAL0"); + vcc.aal = aal0; + break; + case ATM_AAL34: + // we would if I knew how do the SAR! + PRINTD (DBG_QOS|DBG_VCC, "AAL3/4"); + vcc.aal = aal34; + break; + case ATM_AAL5: + PRINTD (DBG_QOS|DBG_VCC, "AAL5"); + vcc.aal = aal5; + break; + default: + PRINTD (DBG_QOS|DBG_VCC, "Bad AAL!"); + return -EINVAL; + } + + // TX traffic parameters + + // there are two, interrelated problems here: 1. the reservation of + // PCR is not a binary choice, we are given bounds and/or a + // desirable value; 2. the device is only capable of certain values, + // most of which are not integers. It is almost certainly acceptable + // to be off by a maximum of 1 to 10 cps. + + // Pragmatic choice: always store an integral PCR as that which has + // been allocated, even if we allocate a little (or a lot) less, + // after rounding. The actual allocation depends on what we can + // manage with our rate selection algorithm. The rate selection + // algorithm is given an integral PCR and a tolerance and told + // whether it should round the value up or down if the tolerance is + // exceeded; it returns: a) the actual rate selected (rounded up to + // the nearest integer), b) a bit pattern to feed to the timer + // register, and c) a failure value if no applicable rate exists. + + // Part of the job is done by atm_pcr_goal which gives us a PCR + // specification which says: EITHER grab the maximum available PCR + // (and perhaps a lower bound which we musn't pass), OR grab this + // amount, rounding down if you have to (and perhaps a lower bound + // which we musn't pass) OR grab this amount, rounding up if you + // have to (and perhaps an upper bound which we musn't pass). If any + // bounds ARE passed we fail. Note that rounding is only rounding to + // match device limitations, we do not round down to satisfy + // bandwidth availability even if this would not violate any given + // lower bound. + + // Note: telephony = 64kb/s = 48 byte cell payload @ 500/3 cells/s + // (say) so this is not even a binary fixpoint cell rate (but this + // device can do it). To avoid this sort of hassle we use a + // tolerance parameter (currently fixed at 10 cps). + + PRINTD (DBG_QOS, "TX:"); + + txtp = &qos->txtp; + + // set up defaults for no traffic + vcc.tx_rate = 0; + // who knows what would actually happen if you try and send on this? + vcc.tx_xbr_bits = IDLE_RATE_TYPE; + vcc.tx_pcr_bits = CLOCK_DISABLE; +#if 0 + vcc.tx_scr_bits = CLOCK_DISABLE; + vcc.tx_bucket_bits = 0; +#endif + + if (txtp->traffic_class != ATM_NONE) { + error = check_max_sdu (vcc.aal, txtp, max_tx_size); + if (error) { + PRINTD (DBG_QOS, "TX max_sdu check failed"); + return error; + } + + switch (txtp->traffic_class) { + case ATM_UBR: { + // we take "the PCR" as a rate-cap + // not reserved + vcc.tx_rate = 0; + make_rate (dev, 1<<30, round_nearest, &vcc.tx_pcr_bits, NULL); + vcc.tx_xbr_bits = ABR_RATE_TYPE; + break; + } +#if 0 + case ATM_ABR: { + // reserve min, allow up to max + vcc.tx_rate = 0; // ? + make_rate (dev, 1<<30, round_nearest, &vcc.tx_pcr_bits, 0); + vcc.tx_xbr_bits = ABR_RATE_TYPE; + break; + } +#endif + case ATM_CBR: { + int pcr = atm_pcr_goal (txtp); + rounding r; + if (!pcr) { + // down vs. up, remaining bandwidth vs. unlimited bandwidth!! + // should really have: once someone gets unlimited bandwidth + // that no more non-UBR channels can be opened until the + // unlimited one closes?? For the moment, round_down means + // greedy people actually get something and not nothing + r = round_down; + // slight race (no locking) here so we may get -EAGAIN + // later; the greedy bastards would deserve it :) + PRINTD (DBG_QOS, "snatching all remaining TX bandwidth"); + pcr = dev->tx_avail; + } else if (pcr < 0) { + r = round_down; + pcr = -pcr; + } else { + r = round_up; + } + error = make_rate_with_tolerance (dev, pcr, r, 10, + &vcc.tx_pcr_bits, &vcc.tx_rate); + if (error) { + PRINTD (DBG_QOS, "could not make rate from TX PCR"); + return error; + } + // not really clear what further checking is needed + error = atm_pcr_check (txtp, vcc.tx_rate); + if (error) { + PRINTD (DBG_QOS, "TX PCR failed consistency check"); + return error; + } + vcc.tx_xbr_bits = CBR_RATE_TYPE; + break; + } +#if 0 + case ATM_VBR: { + int pcr = atm_pcr_goal (txtp); + // int scr = atm_scr_goal (txtp); + int scr = pcr/2; // just for fun + unsigned int mbs = 60; // just for fun + rounding pr; + rounding sr; + unsigned int bucket; + if (!pcr) { + pr = round_nearest; + pcr = 1<<30; + } else if (pcr < 0) { + pr = round_down; + pcr = -pcr; + } else { + pr = round_up; + } + error = make_rate_with_tolerance (dev, pcr, pr, 10, + &vcc.tx_pcr_bits, 0); + if (!scr) { + // see comments for PCR with CBR above + sr = round_down; + // slight race (no locking) here so we may get -EAGAIN + // later; the greedy bastards would deserve it :) + PRINTD (DBG_QOS, "snatching all remaining TX bandwidth"); + scr = dev->tx_avail; + } else if (scr < 0) { + sr = round_down; + scr = -scr; + } else { + sr = round_up; + } + error = make_rate_with_tolerance (dev, scr, sr, 10, + &vcc.tx_scr_bits, &vcc.tx_rate); + if (error) { + PRINTD (DBG_QOS, "could not make rate from TX SCR"); + return error; + } + // not really clear what further checking is needed + // error = atm_scr_check (txtp, vcc.tx_rate); + if (error) { + PRINTD (DBG_QOS, "TX SCR failed consistency check"); + return error; + } + // bucket calculations (from a piece of paper...) cell bucket + // capacity must be largest integer smaller than m(p-s)/p + 1 + // where m = max burst size, p = pcr, s = scr + bucket = mbs*(pcr-scr)/pcr; + if (bucket*pcr != mbs*(pcr-scr)) + bucket += 1; + if (bucket > BUCKET_MAX_SIZE) { + PRINTD (DBG_QOS, "shrinking bucket from %u to %u", + bucket, BUCKET_MAX_SIZE); + bucket = BUCKET_MAX_SIZE; + } + vcc.tx_xbr_bits = VBR_RATE_TYPE; + vcc.tx_bucket_bits = bucket; + break; + } +#endif + default: { + PRINTD (DBG_QOS, "unsupported TX traffic class"); + return -EINVAL; + } + } + } + + // RX traffic parameters + + PRINTD (DBG_QOS, "RX:"); + + rxtp = &qos->rxtp; + + // set up defaults for no traffic + vcc.rx_rate = 0; + + if (rxtp->traffic_class != ATM_NONE) { + error = check_max_sdu (vcc.aal, rxtp, max_rx_size); + if (error) { + PRINTD (DBG_QOS, "RX max_sdu check failed"); + return error; + } + switch (rxtp->traffic_class) { + case ATM_UBR: { + // not reserved + break; + } +#if 0 + case ATM_ABR: { + // reserve min + vcc.rx_rate = 0; // ? + break; + } +#endif + case ATM_CBR: { + int pcr = atm_pcr_goal (rxtp); + if (!pcr) { + // slight race (no locking) here so we may get -EAGAIN + // later; the greedy bastards would deserve it :) + PRINTD (DBG_QOS, "snatching all remaining RX bandwidth"); + pcr = dev->rx_avail; + } else if (pcr < 0) { + pcr = -pcr; + } + vcc.rx_rate = pcr; + // not really clear what further checking is needed + error = atm_pcr_check (rxtp, vcc.rx_rate); + if (error) { + PRINTD (DBG_QOS, "RX PCR failed consistency check"); + return error; + } + break; + } +#if 0 + case ATM_VBR: { + // int scr = atm_scr_goal (rxtp); + int scr = 1<<16; // just for fun + if (!scr) { + // slight race (no locking) here so we may get -EAGAIN + // later; the greedy bastards would deserve it :) + PRINTD (DBG_QOS, "snatching all remaining RX bandwidth"); + scr = dev->rx_avail; + } else if (scr < 0) { + scr = -scr; + } + vcc.rx_rate = scr; + // not really clear what further checking is needed + // error = atm_scr_check (rxtp, vcc.rx_rate); + if (error) { + PRINTD (DBG_QOS, "RX SCR failed consistency check"); + return error; + } + break; + } +#endif + default: { + PRINTD (DBG_QOS, "unsupported RX traffic class"); + return -EINVAL; + } + } + } + + + // late abort useful for diagnostics + if (vcc.aal != aal5) { + PRINTD (DBG_QOS, "AAL not supported"); + return -EINVAL; + } + + // get space for our vcc stuff and copy parameters into it + vccp = kmalloc (sizeof(hrz_vcc), GFP_KERNEL); + if (!vccp) { + PRINTK (KERN_ERR, "out of memory!"); + return -ENOMEM; + } + *vccp = vcc; + + // clear error and grab cell rate resource lock + error = 0; + spin_lock (&dev->rate_lock); + + if (vcc.tx_rate > dev->tx_avail) { + PRINTD (DBG_QOS, "not enough TX PCR left"); + error = -EAGAIN; + } + + if (vcc.rx_rate > dev->rx_avail) { + PRINTD (DBG_QOS, "not enough RX PCR left"); + error = -EAGAIN; + } + + if (!error) { + // really consume cell rates + dev->tx_avail -= vcc.tx_rate; + dev->rx_avail -= vcc.rx_rate; + PRINTD (DBG_QOS|DBG_VCC, "reserving %u TX PCR and %u RX PCR", + vcc.tx_rate, vcc.rx_rate); + } + + // release lock and exit on error + spin_unlock (&dev->rate_lock); + if (error) { + PRINTD (DBG_QOS|DBG_VCC, "insufficient cell rate resources"); + kfree (vccp); + return error; + } + + // this is "immediately before allocating the connection identifier + // in hardware" - so long as the next call does not fail :) + set_bit(ATM_VF_ADDR,&atm_vcc->flags); + + // any errors here are very serious and should never occur + + if (rxtp->traffic_class != ATM_NONE) { + if (dev->rxer[channel]) { + PRINTD (DBG_ERR|DBG_VCC, "VC already open for RX"); + error = -EBUSY; + } + if (!error) + error = hrz_open_rx (dev, channel); + if (error) { + kfree (vccp); + return error; + } + // this link allows RX frames through + dev->rxer[channel] = atm_vcc; + } + + // success, set elements of atm_vcc + atm_vcc->dev_data = (void *) vccp; + + // indicate readiness + set_bit(ATM_VF_READY,&atm_vcc->flags); + + return 0; +} + +/********** close VC **********/ + +static void hrz_close (struct atm_vcc * atm_vcc) { + hrz_dev * dev = HRZ_DEV(atm_vcc->dev); + hrz_vcc * vcc = HRZ_VCC(atm_vcc); + u16 channel = vcc->channel; + PRINTD (DBG_VCC|DBG_FLOW, "hrz_close"); + + // indicate unreadiness + clear_bit(ATM_VF_READY,&atm_vcc->flags); + + if (atm_vcc->qos.txtp.traffic_class != ATM_NONE) { + unsigned int i; + + // let any TX on this channel that has started complete + // no restart, just keep trying + while (tx_hold (dev)) + ; + // remove record of any tx_channel having been setup for this channel + for (i = 0; i < TX_CHANS; ++i) + if (dev->tx_channel_record[i] == channel) { + dev->tx_channel_record[i] = -1; + break; + } + if (dev->last_vc == channel) + dev->tx_last = -1; + tx_release (dev); + } + + if (atm_vcc->qos.rxtp.traffic_class != ATM_NONE) { + // disable RXing - it tries quite hard + hrz_close_rx (dev, channel); + // forget the vcc - no more skbs will be pushed + if (atm_vcc != dev->rxer[channel]) + PRINTK (KERN_ERR, "%s atm_vcc=%p rxer[channel]=%p", + "arghhh! we're going to die!", + atm_vcc, dev->rxer[channel]); + dev->rxer[channel] = NULL; + } + + // atomically release our rate reservation + spin_lock (&dev->rate_lock); + PRINTD (DBG_QOS|DBG_VCC, "releasing %u TX PCR and %u RX PCR", + vcc->tx_rate, vcc->rx_rate); + dev->tx_avail += vcc->tx_rate; + dev->rx_avail += vcc->rx_rate; + spin_unlock (&dev->rate_lock); + + // free our structure + kfree (vcc); + // say the VPI/VCI is free again + clear_bit(ATM_VF_ADDR,&atm_vcc->flags); +} + +#if 0 +static int hrz_ioctl (struct atm_dev * atm_dev, unsigned int cmd, void *arg) { + hrz_dev * dev = HRZ_DEV(atm_dev); + PRINTD (DBG_FLOW, "hrz_ioctl"); + return -1; +} + +unsigned char hrz_phy_get (struct atm_dev * atm_dev, unsigned long addr) { + hrz_dev * dev = HRZ_DEV(atm_dev); + PRINTD (DBG_FLOW, "hrz_phy_get"); + return 0; +} + +static void hrz_phy_put (struct atm_dev * atm_dev, unsigned char value, + unsigned long addr) { + hrz_dev * dev = HRZ_DEV(atm_dev); + PRINTD (DBG_FLOW, "hrz_phy_put"); +} + +static int hrz_change_qos (struct atm_vcc * atm_vcc, struct atm_qos *qos, int flgs) { + hrz_dev * dev = HRZ_DEV(vcc->dev); + PRINTD (DBG_FLOW, "hrz_change_qos"); + return -1; +} +#endif + +/********** proc file contents **********/ + +static int hrz_proc_read (struct atm_dev * atm_dev, loff_t * pos, char * page) { + hrz_dev * dev = HRZ_DEV(atm_dev); + int left = *pos; + PRINTD (DBG_FLOW, "hrz_proc_read"); + + /* more diagnostics here? */ + +#if 0 + if (!left--) { + unsigned int count = sprintf (page, "vbr buckets:"); + unsigned int i; + for (i = 0; i < TX_CHANS; ++i) + count += sprintf (page, " %u/%u", + query_tx_channel_config (dev, i, BUCKET_FULLNESS_ACCESS), + query_tx_channel_config (dev, i, BUCKET_CAPACITY_ACCESS)); + count += sprintf (page+count, ".\n"); + return count; + } +#endif + + if (!left--) + return sprintf (page, + "cells: TX %lu, RX %lu, HEC errors %lu, unassigned %lu.\n", + dev->tx_cell_count, dev->rx_cell_count, + dev->hec_error_count, dev->unassigned_cell_count); + + if (!left--) + return sprintf (page, + "free cell buffers: TX %hu, RX %hu+%hu.\n", + rd_regw (dev, TX_FREE_BUFFER_COUNT_OFF), + rd_regw (dev, RX_FREE_BUFFER_COUNT_OFF), + dev->noof_spare_buffers); + + if (!left--) + return sprintf (page, + "cps remaining: TX %u, RX %u\n", + dev->tx_avail, dev->rx_avail); + + return 0; +} + +static const struct atmdev_ops hrz_ops = { + .open = hrz_open, + .close = hrz_close, + .send = hrz_send, + .proc_read = hrz_proc_read, + .owner = THIS_MODULE, +}; + +static int hrz_probe(struct pci_dev *pci_dev, + const struct pci_device_id *pci_ent) +{ + hrz_dev * dev; + int err = 0; + + // adapter slot free, read resources from PCI configuration space + u32 iobase = pci_resource_start (pci_dev, 0); + u32 * membase = bus_to_virt (pci_resource_start (pci_dev, 1)); + unsigned int irq; + unsigned char lat; + + PRINTD (DBG_FLOW, "hrz_probe"); + + if (pci_enable_device(pci_dev)) + return -EINVAL; + + /* XXX DEV_LABEL is a guess */ + if (!request_region(iobase, HRZ_IO_EXTENT, DEV_LABEL)) { + err = -EINVAL; + goto out_disable; + } + + dev = kzalloc(sizeof(hrz_dev), GFP_KERNEL); + if (!dev) { + // perhaps we should be nice: deregister all adapters and abort? + PRINTD(DBG_ERR, "out of memory"); + err = -ENOMEM; + goto out_release; + } + + pci_set_drvdata(pci_dev, dev); + + // grab IRQ and install handler - move this someplace more sensible + irq = pci_dev->irq; + if (request_irq(irq, + interrupt_handler, + IRQF_SHARED, /* irqflags guess */ + DEV_LABEL, /* name guess */ + dev)) { + PRINTD(DBG_WARN, "request IRQ failed!"); + err = -EINVAL; + goto out_free; + } + + PRINTD(DBG_INFO, "found Madge ATM adapter (hrz) at: IO %x, IRQ %u, MEM %p", + iobase, irq, membase); + + dev->atm_dev = atm_dev_register(DEV_LABEL, &pci_dev->dev, &hrz_ops, -1, + NULL); + if (!(dev->atm_dev)) { + PRINTD(DBG_ERR, "failed to register Madge ATM adapter"); + err = -EINVAL; + goto out_free_irq; + } + + PRINTD(DBG_INFO, "registered Madge ATM adapter (no. %d) (%p) at %p", + dev->atm_dev->number, dev, dev->atm_dev); + dev->atm_dev->dev_data = (void *) dev; + dev->pci_dev = pci_dev; + + // enable bus master accesses + pci_set_master(pci_dev); + + // frobnicate latency (upwards, usually) + pci_read_config_byte(pci_dev, PCI_LATENCY_TIMER, &lat); + if (pci_lat) { + PRINTD(DBG_INFO, "%s PCI latency timer from %hu to %hu", + "changing", lat, pci_lat); + pci_write_config_byte(pci_dev, PCI_LATENCY_TIMER, pci_lat); + } else if (lat < MIN_PCI_LATENCY) { + PRINTK(KERN_INFO, "%s PCI latency timer from %hu to %hu", + "increasing", lat, MIN_PCI_LATENCY); + pci_write_config_byte(pci_dev, PCI_LATENCY_TIMER, MIN_PCI_LATENCY); + } + + dev->iobase = iobase; + dev->irq = irq; + dev->membase = membase; + + dev->rx_q_entry = dev->rx_q_reset = &memmap->rx_q_entries[0]; + dev->rx_q_wrap = &memmap->rx_q_entries[RX_CHANS-1]; + + // these next three are performance hacks + dev->last_vc = -1; + dev->tx_last = -1; + dev->tx_idle = 0; + + dev->tx_regions = 0; + dev->tx_bytes = 0; + dev->tx_skb = NULL; + dev->tx_iovec = NULL; + + dev->tx_cell_count = 0; + dev->rx_cell_count = 0; + dev->hec_error_count = 0; + dev->unassigned_cell_count = 0; + + dev->noof_spare_buffers = 0; + + { + unsigned int i; + for (i = 0; i < TX_CHANS; ++i) + dev->tx_channel_record[i] = -1; + } + + dev->flags = 0; + + // Allocate cell rates and remember ASIC version + // Fibre: ATM_OC3_PCR = 1555200000/8/270*260/53 - 29/53 + // Copper: (WRONG) we want 6 into the above, close to 25Mb/s + // Copper: (plagarise!) 25600000/8/270*260/53 - n/53 + + if (hrz_init(dev)) { + // to be really pedantic, this should be ATM_OC3c_PCR + dev->tx_avail = ATM_OC3_PCR; + dev->rx_avail = ATM_OC3_PCR; + set_bit(ultra, &dev->flags); // NOT "|= ultra" ! + } else { + dev->tx_avail = ((25600000/8)*26)/(27*53); + dev->rx_avail = ((25600000/8)*26)/(27*53); + PRINTD(DBG_WARN, "Buggy ASIC: no TX bus-mastering."); + } + + // rate changes spinlock + spin_lock_init(&dev->rate_lock); + + // on-board memory access spinlock; we want atomic reads and + // writes to adapter memory (handles IRQ and SMP) + spin_lock_init(&dev->mem_lock); + + init_waitqueue_head(&dev->tx_queue); + + // vpi in 0..4, vci in 6..10 + dev->atm_dev->ci_range.vpi_bits = vpi_bits; + dev->atm_dev->ci_range.vci_bits = 10-vpi_bits; + + timer_setup(&dev->housekeeping, do_housekeeping, 0); + mod_timer(&dev->housekeeping, jiffies); + +out: + return err; + +out_free_irq: + free_irq(irq, dev); +out_free: + kfree(dev); +out_release: + release_region(iobase, HRZ_IO_EXTENT); +out_disable: + pci_disable_device(pci_dev); + goto out; +} + +static void hrz_remove_one(struct pci_dev *pci_dev) +{ + hrz_dev *dev; + + dev = pci_get_drvdata(pci_dev); + + PRINTD(DBG_INFO, "closing %p (atm_dev = %p)", dev, dev->atm_dev); + del_timer_sync(&dev->housekeeping); + hrz_reset(dev); + atm_dev_deregister(dev->atm_dev); + free_irq(dev->irq, dev); + release_region(dev->iobase, HRZ_IO_EXTENT); + kfree(dev); + + pci_disable_device(pci_dev); +} + +static void __init hrz_check_args (void) { +#ifdef DEBUG_HORIZON + PRINTK (KERN_NOTICE, "debug bitmap is %hx", debug &= DBG_MASK); +#else + if (debug) + PRINTK (KERN_NOTICE, "no debug support in this image"); +#endif + + if (vpi_bits > HRZ_MAX_VPI) + PRINTK (KERN_ERR, "vpi_bits has been limited to %hu", + vpi_bits = HRZ_MAX_VPI); + + if (max_tx_size < 0 || max_tx_size > TX_AAL5_LIMIT) + PRINTK (KERN_NOTICE, "max_tx_size has been limited to %hu", + max_tx_size = TX_AAL5_LIMIT); + + if (max_rx_size < 0 || max_rx_size > RX_AAL5_LIMIT) + PRINTK (KERN_NOTICE, "max_rx_size has been limited to %hu", + max_rx_size = RX_AAL5_LIMIT); + + return; +} + +MODULE_AUTHOR(maintainer_string); +MODULE_DESCRIPTION(description_string); +MODULE_LICENSE("GPL"); +module_param(debug, ushort, 0644); +module_param(vpi_bits, ushort, 0); +module_param(max_tx_size, int, 0); +module_param(max_rx_size, int, 0); +module_param(pci_lat, byte, 0); +MODULE_PARM_DESC(debug, "debug bitmap, see .h file"); +MODULE_PARM_DESC(vpi_bits, "number of bits (0..4) to allocate to VPIs"); +MODULE_PARM_DESC(max_tx_size, "maximum size of TX AAL5 frames"); +MODULE_PARM_DESC(max_rx_size, "maximum size of RX AAL5 frames"); +MODULE_PARM_DESC(pci_lat, "PCI latency in bus cycles"); + +static const struct pci_device_id hrz_pci_tbl[] = { + { PCI_VENDOR_ID_MADGE, PCI_DEVICE_ID_MADGE_HORIZON, PCI_ANY_ID, PCI_ANY_ID, + 0, 0, 0 }, + { 0, } +}; + +MODULE_DEVICE_TABLE(pci, hrz_pci_tbl); + +static struct pci_driver hrz_driver = { + .name = "horizon", + .probe = hrz_probe, + .remove = hrz_remove_one, + .id_table = hrz_pci_tbl, +}; + +/********** module entry **********/ + +static int __init hrz_module_init (void) { + BUILD_BUG_ON(sizeof(struct MEMMAP) != 128*1024/4); + + show_version(); + + // check arguments + hrz_check_args(); + + // get the juice + return pci_register_driver(&hrz_driver); +} + +/********** module exit **********/ + +static void __exit hrz_module_exit (void) { + PRINTD (DBG_FLOW, "cleanup_module"); + + pci_unregister_driver(&hrz_driver); +} + +module_init(hrz_module_init); +module_exit(hrz_module_exit); |