diff options
Diffstat (limited to 'drivers/mailbox/bcm-pdc-mailbox.c')
| -rw-r--r-- | drivers/mailbox/bcm-pdc-mailbox.c | 1663 |
1 files changed, 1663 insertions, 0 deletions
diff --git a/drivers/mailbox/bcm-pdc-mailbox.c b/drivers/mailbox/bcm-pdc-mailbox.c new file mode 100644 index 000000000..4fe7be0bd --- /dev/null +++ b/drivers/mailbox/bcm-pdc-mailbox.c @@ -0,0 +1,1663 @@ +/* + * Copyright 2016 Broadcom + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation (the "GPL"). + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 (GPLv2) for more details. + * + * You should have received a copy of the GNU General Public License + * version 2 (GPLv2) along with this source code. + */ + +/* + * Broadcom PDC Mailbox Driver + * The PDC provides a ring based programming interface to one or more hardware + * offload engines. For example, the PDC driver works with both SPU-M and SPU2 + * cryptographic offload hardware. In some chips the PDC is referred to as MDE, + * and in others the FA2/FA+ hardware is used with this PDC driver. + * + * The PDC driver registers with the Linux mailbox framework as a mailbox + * controller, once for each PDC instance. Ring 0 for each PDC is registered as + * a mailbox channel. The PDC driver uses interrupts to determine when data + * transfers to and from an offload engine are complete. The PDC driver uses + * threaded IRQs so that response messages are handled outside of interrupt + * context. + * + * The PDC driver allows multiple messages to be pending in the descriptor + * rings. The tx_msg_start descriptor index indicates where the last message + * starts. The txin_numd value at this index indicates how many descriptor + * indexes make up the message. Similar state is kept on the receive side. When + * an rx interrupt indicates a response is ready, the PDC driver processes numd + * descriptors from the tx and rx ring, thus processing one response at a time. + */ + +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/debugfs.h> +#include <linux/interrupt.h> +#include <linux/wait.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/mailbox_controller.h> +#include <linux/mailbox/brcm-message.h> +#include <linux/scatterlist.h> +#include <linux/dma-direction.h> +#include <linux/dma-mapping.h> +#include <linux/dmapool.h> + +#define PDC_SUCCESS 0 + +#define RING_ENTRY_SIZE sizeof(struct dma64dd) + +/* # entries in PDC dma ring */ +#define PDC_RING_ENTRIES 512 +/* + * Minimum number of ring descriptor entries that must be free to tell mailbox + * framework that it can submit another request + */ +#define PDC_RING_SPACE_MIN 15 + +#define PDC_RING_SIZE (PDC_RING_ENTRIES * RING_ENTRY_SIZE) +/* Rings are 8k aligned */ +#define RING_ALIGN_ORDER 13 +#define RING_ALIGN BIT(RING_ALIGN_ORDER) + +#define RX_BUF_ALIGN_ORDER 5 +#define RX_BUF_ALIGN BIT(RX_BUF_ALIGN_ORDER) + +/* descriptor bumping macros */ +#define XXD(x, max_mask) ((x) & (max_mask)) +#define TXD(x, max_mask) XXD((x), (max_mask)) +#define RXD(x, max_mask) XXD((x), (max_mask)) +#define NEXTTXD(i, max_mask) TXD((i) + 1, (max_mask)) +#define PREVTXD(i, max_mask) TXD((i) - 1, (max_mask)) +#define NEXTRXD(i, max_mask) RXD((i) + 1, (max_mask)) +#define PREVRXD(i, max_mask) RXD((i) - 1, (max_mask)) +#define NTXDACTIVE(h, t, max_mask) TXD((t) - (h), (max_mask)) +#define NRXDACTIVE(h, t, max_mask) RXD((t) - (h), (max_mask)) + +/* Length of BCM header at start of SPU msg, in bytes */ +#define BCM_HDR_LEN 8 + +/* + * PDC driver reserves ringset 0 on each SPU for its own use. The driver does + * not currently support use of multiple ringsets on a single PDC engine. + */ +#define PDC_RINGSET 0 + +/* + * Interrupt mask and status definitions. Enable interrupts for tx and rx on + * ring 0 + */ +#define PDC_RCVINT_0 (16 + PDC_RINGSET) +#define PDC_RCVINTEN_0 BIT(PDC_RCVINT_0) +#define PDC_INTMASK (PDC_RCVINTEN_0) +#define PDC_LAZY_FRAMECOUNT 1 +#define PDC_LAZY_TIMEOUT 10000 +#define PDC_LAZY_INT (PDC_LAZY_TIMEOUT | (PDC_LAZY_FRAMECOUNT << 24)) +#define PDC_INTMASK_OFFSET 0x24 +#define PDC_INTSTATUS_OFFSET 0x20 +#define PDC_RCVLAZY0_OFFSET (0x30 + 4 * PDC_RINGSET) +#define FA_RCVLAZY0_OFFSET 0x100 + +/* + * For SPU2, configure MDE_CKSUM_CONTROL to write 17 bytes of metadata + * before frame + */ +#define PDC_SPU2_RESP_HDR_LEN 17 +#define PDC_CKSUM_CTRL BIT(27) +#define PDC_CKSUM_CTRL_OFFSET 0x400 + +#define PDC_SPUM_RESP_HDR_LEN 32 + +/* + * Sets the following bits for write to transmit control reg: + * 11 - PtyChkDisable - parity check is disabled + * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory + */ +#define PDC_TX_CTL 0x000C0800 + +/* Bit in tx control reg to enable tx channel */ +#define PDC_TX_ENABLE 0x1 + +/* + * Sets the following bits for write to receive control reg: + * 7:1 - RcvOffset - size in bytes of status region at start of rx frame buf + * 9 - SepRxHdrDescEn - place start of new frames only in descriptors + * that have StartOfFrame set + * 10 - OflowContinue - on rx FIFO overflow, clear rx fifo, discard all + * remaining bytes in current frame, report error + * in rx frame status for current frame + * 11 - PtyChkDisable - parity check is disabled + * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory + */ +#define PDC_RX_CTL 0x000C0E00 + +/* Bit in rx control reg to enable rx channel */ +#define PDC_RX_ENABLE 0x1 + +#define CRYPTO_D64_RS0_CD_MASK ((PDC_RING_ENTRIES * RING_ENTRY_SIZE) - 1) + +/* descriptor flags */ +#define D64_CTRL1_EOT BIT(28) /* end of descriptor table */ +#define D64_CTRL1_IOC BIT(29) /* interrupt on complete */ +#define D64_CTRL1_EOF BIT(30) /* end of frame */ +#define D64_CTRL1_SOF BIT(31) /* start of frame */ + +#define RX_STATUS_OVERFLOW 0x00800000 +#define RX_STATUS_LEN 0x0000FFFF + +#define PDC_TXREGS_OFFSET 0x200 +#define PDC_RXREGS_OFFSET 0x220 + +/* Maximum size buffer the DMA engine can handle */ +#define PDC_DMA_BUF_MAX 16384 + +enum pdc_hw { + FA_HW, /* FA2/FA+ hardware (i.e. Northstar Plus) */ + PDC_HW /* PDC/MDE hardware (i.e. Northstar 2, Pegasus) */ +}; + +struct pdc_dma_map { + void *ctx; /* opaque context associated with frame */ +}; + +/* dma descriptor */ +struct dma64dd { + u32 ctrl1; /* misc control bits */ + u32 ctrl2; /* buffer count and address extension */ + u32 addrlow; /* memory address of the date buffer, bits 31:0 */ + u32 addrhigh; /* memory address of the date buffer, bits 63:32 */ +}; + +/* dma registers per channel(xmt or rcv) */ +struct dma64_regs { + u32 control; /* enable, et al */ + u32 ptr; /* last descriptor posted to chip */ + u32 addrlow; /* descriptor ring base address low 32-bits */ + u32 addrhigh; /* descriptor ring base address bits 63:32 */ + u32 status0; /* last rx descriptor written by hw */ + u32 status1; /* driver does not use */ +}; + +/* cpp contortions to concatenate w/arg prescan */ +#ifndef PAD +#define _PADLINE(line) pad ## line +#define _XSTR(line) _PADLINE(line) +#define PAD _XSTR(__LINE__) +#endif /* PAD */ + +/* dma registers. matches hw layout. */ +struct dma64 { + struct dma64_regs dmaxmt; /* dma tx */ + u32 PAD[2]; + struct dma64_regs dmarcv; /* dma rx */ + u32 PAD[2]; +}; + +/* PDC registers */ +struct pdc_regs { + u32 devcontrol; /* 0x000 */ + u32 devstatus; /* 0x004 */ + u32 PAD; + u32 biststatus; /* 0x00c */ + u32 PAD[4]; + u32 intstatus; /* 0x020 */ + u32 intmask; /* 0x024 */ + u32 gptimer; /* 0x028 */ + + u32 PAD; + u32 intrcvlazy_0; /* 0x030 (Only in PDC, not FA2) */ + u32 intrcvlazy_1; /* 0x034 (Only in PDC, not FA2) */ + u32 intrcvlazy_2; /* 0x038 (Only in PDC, not FA2) */ + u32 intrcvlazy_3; /* 0x03c (Only in PDC, not FA2) */ + + u32 PAD[48]; + u32 fa_intrecvlazy; /* 0x100 (Only in FA2, not PDC) */ + u32 flowctlthresh; /* 0x104 */ + u32 wrrthresh; /* 0x108 */ + u32 gmac_idle_cnt_thresh; /* 0x10c */ + + u32 PAD[4]; + u32 ifioaccessaddr; /* 0x120 */ + u32 ifioaccessbyte; /* 0x124 */ + u32 ifioaccessdata; /* 0x128 */ + + u32 PAD[21]; + u32 phyaccess; /* 0x180 */ + u32 PAD; + u32 phycontrol; /* 0x188 */ + u32 txqctl; /* 0x18c */ + u32 rxqctl; /* 0x190 */ + u32 gpioselect; /* 0x194 */ + u32 gpio_output_en; /* 0x198 */ + u32 PAD; /* 0x19c */ + u32 txq_rxq_mem_ctl; /* 0x1a0 */ + u32 memory_ecc_status; /* 0x1a4 */ + u32 serdes_ctl; /* 0x1a8 */ + u32 serdes_status0; /* 0x1ac */ + u32 serdes_status1; /* 0x1b0 */ + u32 PAD[11]; /* 0x1b4-1dc */ + u32 clk_ctl_st; /* 0x1e0 */ + u32 hw_war; /* 0x1e4 (Only in PDC, not FA2) */ + u32 pwrctl; /* 0x1e8 */ + u32 PAD[5]; + +#define PDC_NUM_DMA_RINGS 4 + struct dma64 dmaregs[PDC_NUM_DMA_RINGS]; /* 0x0200 - 0x2fc */ + + /* more registers follow, but we don't use them */ +}; + +/* structure for allocating/freeing DMA rings */ +struct pdc_ring_alloc { + dma_addr_t dmabase; /* DMA address of start of ring */ + void *vbase; /* base kernel virtual address of ring */ + u32 size; /* ring allocation size in bytes */ +}; + +/* + * context associated with a receive descriptor. + * @rxp_ctx: opaque context associated with frame that starts at each + * rx ring index. + * @dst_sg: Scatterlist used to form reply frames beginning at a given ring + * index. Retained in order to unmap each sg after reply is processed. + * @rxin_numd: Number of rx descriptors associated with the message that starts + * at a descriptor index. Not set for every index. For example, + * if descriptor index i points to a scatterlist with 4 entries, + * then the next three descriptor indexes don't have a value set. + * @resp_hdr: Virtual address of buffer used to catch DMA rx status + * @resp_hdr_daddr: physical address of DMA rx status buffer + */ +struct pdc_rx_ctx { + void *rxp_ctx; + struct scatterlist *dst_sg; + u32 rxin_numd; + void *resp_hdr; + dma_addr_t resp_hdr_daddr; +}; + +/* PDC state structure */ +struct pdc_state { + /* Index of the PDC whose state is in this structure instance */ + u8 pdc_idx; + + /* Platform device for this PDC instance */ + struct platform_device *pdev; + + /* + * Each PDC instance has a mailbox controller. PDC receives request + * messages through mailboxes, and sends response messages through the + * mailbox framework. + */ + struct mbox_controller mbc; + + unsigned int pdc_irq; + + /* tasklet for deferred processing after DMA rx interrupt */ + struct tasklet_struct rx_tasklet; + + /* Number of bytes of receive status prior to each rx frame */ + u32 rx_status_len; + /* Whether a BCM header is prepended to each frame */ + bool use_bcm_hdr; + /* Sum of length of BCM header and rx status header */ + u32 pdc_resp_hdr_len; + + /* The base virtual address of DMA hw registers */ + void __iomem *pdc_reg_vbase; + + /* Pool for allocation of DMA rings */ + struct dma_pool *ring_pool; + + /* Pool for allocation of metadata buffers for response messages */ + struct dma_pool *rx_buf_pool; + + /* + * The base virtual address of DMA tx/rx descriptor rings. Corresponding + * DMA address and size of ring allocation. + */ + struct pdc_ring_alloc tx_ring_alloc; + struct pdc_ring_alloc rx_ring_alloc; + + struct pdc_regs *regs; /* start of PDC registers */ + + struct dma64_regs *txregs_64; /* dma tx engine registers */ + struct dma64_regs *rxregs_64; /* dma rx engine registers */ + + /* + * Arrays of PDC_RING_ENTRIES descriptors + * To use multiple ringsets, this needs to be extended + */ + struct dma64dd *txd_64; /* tx descriptor ring */ + struct dma64dd *rxd_64; /* rx descriptor ring */ + + /* descriptor ring sizes */ + u32 ntxd; /* # tx descriptors */ + u32 nrxd; /* # rx descriptors */ + u32 nrxpost; /* # rx buffers to keep posted */ + u32 ntxpost; /* max number of tx buffers that can be posted */ + + /* + * Index of next tx descriptor to reclaim. That is, the descriptor + * index of the oldest tx buffer for which the host has yet to process + * the corresponding response. + */ + u32 txin; + + /* + * Index of the first receive descriptor for the sequence of + * message fragments currently under construction. Used to build up + * the rxin_numd count for a message. Updated to rxout when the host + * starts a new sequence of rx buffers for a new message. + */ + u32 tx_msg_start; + + /* Index of next tx descriptor to post. */ + u32 txout; + + /* + * Number of tx descriptors associated with the message that starts + * at this tx descriptor index. + */ + u32 txin_numd[PDC_RING_ENTRIES]; + + /* + * Index of next rx descriptor to reclaim. This is the index of + * the next descriptor whose data has yet to be processed by the host. + */ + u32 rxin; + + /* + * Index of the first receive descriptor for the sequence of + * message fragments currently under construction. Used to build up + * the rxin_numd count for a message. Updated to rxout when the host + * starts a new sequence of rx buffers for a new message. + */ + u32 rx_msg_start; + + /* + * Saved value of current hardware rx descriptor index. + * The last rx buffer written by the hw is the index previous to + * this one. + */ + u32 last_rx_curr; + + /* Index of next rx descriptor to post. */ + u32 rxout; + + struct pdc_rx_ctx rx_ctx[PDC_RING_ENTRIES]; + + /* + * Scatterlists used to form request and reply frames beginning at a + * given ring index. Retained in order to unmap each sg after reply + * is processed + */ + struct scatterlist *src_sg[PDC_RING_ENTRIES]; + + struct dentry *debugfs_stats; /* debug FS stats file for this PDC */ + + /* counters */ + u32 pdc_requests; /* number of request messages submitted */ + u32 pdc_replies; /* number of reply messages received */ + u32 last_tx_not_done; /* too few tx descriptors to indicate done */ + u32 tx_ring_full; /* unable to accept msg because tx ring full */ + u32 rx_ring_full; /* unable to accept msg because rx ring full */ + u32 txnobuf; /* unable to create tx descriptor */ + u32 rxnobuf; /* unable to create rx descriptor */ + u32 rx_oflow; /* count of rx overflows */ + + /* hardware type - FA2 or PDC/MDE */ + enum pdc_hw hw_type; +}; + +/* Global variables */ + +struct pdc_globals { + /* Actual number of SPUs in hardware, as reported by device tree */ + u32 num_spu; +}; + +static struct pdc_globals pdcg; + +/* top level debug FS directory for PDC driver */ +static struct dentry *debugfs_dir; + +static ssize_t pdc_debugfs_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct pdc_state *pdcs; + char *buf; + ssize_t ret, out_offset, out_count; + + out_count = 512; + + buf = kmalloc(out_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + pdcs = filp->private_data; + out_offset = 0; + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "SPU %u stats:\n", pdcs->pdc_idx); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "PDC requests....................%u\n", + pdcs->pdc_requests); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "PDC responses...................%u\n", + pdcs->pdc_replies); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Tx not done.....................%u\n", + pdcs->last_tx_not_done); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Tx ring full....................%u\n", + pdcs->tx_ring_full); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Rx ring full....................%u\n", + pdcs->rx_ring_full); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Tx desc write fail. Ring full...%u\n", + pdcs->txnobuf); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Rx desc write fail. Ring full...%u\n", + pdcs->rxnobuf); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Receive overflow................%u\n", + pdcs->rx_oflow); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "Num frags in rx ring............%u\n", + NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr, + pdcs->nrxpost)); + + if (out_offset > out_count) + out_offset = out_count; + + ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); + kfree(buf); + return ret; +} + +static const struct file_operations pdc_debugfs_stats = { + .owner = THIS_MODULE, + .open = simple_open, + .read = pdc_debugfs_read, +}; + +/** + * pdc_setup_debugfs() - Create the debug FS directories. If the top-level + * directory has not yet been created, create it now. Create a stats file in + * this directory for a SPU. + * @pdcs: PDC state structure + */ +static void pdc_setup_debugfs(struct pdc_state *pdcs) +{ + char spu_stats_name[16]; + + if (!debugfs_initialized()) + return; + + snprintf(spu_stats_name, 16, "pdc%d_stats", pdcs->pdc_idx); + if (!debugfs_dir) + debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); + + /* S_IRUSR == 0400 */ + pdcs->debugfs_stats = debugfs_create_file(spu_stats_name, 0400, + debugfs_dir, pdcs, + &pdc_debugfs_stats); +} + +static void pdc_free_debugfs(void) +{ + debugfs_remove_recursive(debugfs_dir); + debugfs_dir = NULL; +} + +/** + * pdc_build_rxd() - Build DMA descriptor to receive SPU result. + * @pdcs: PDC state for SPU that will generate result + * @dma_addr: DMA address of buffer that descriptor is being built for + * @buf_len: Length of the receive buffer, in bytes + * @flags: Flags to be stored in descriptor + */ +static inline void +pdc_build_rxd(struct pdc_state *pdcs, dma_addr_t dma_addr, + u32 buf_len, u32 flags) +{ + struct device *dev = &pdcs->pdev->dev; + struct dma64dd *rxd = &pdcs->rxd_64[pdcs->rxout]; + + dev_dbg(dev, + "Writing rx descriptor for PDC %u at index %u with length %u. flags %#x\n", + pdcs->pdc_idx, pdcs->rxout, buf_len, flags); + + rxd->addrlow = cpu_to_le32(lower_32_bits(dma_addr)); + rxd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr)); + rxd->ctrl1 = cpu_to_le32(flags); + rxd->ctrl2 = cpu_to_le32(buf_len); + + /* bump ring index and return */ + pdcs->rxout = NEXTRXD(pdcs->rxout, pdcs->nrxpost); +} + +/** + * pdc_build_txd() - Build a DMA descriptor to transmit a SPU request to + * hardware. + * @pdcs: PDC state for the SPU that will process this request + * @dma_addr: DMA address of packet to be transmitted + * @buf_len: Length of tx buffer, in bytes + * @flags: Flags to be stored in descriptor + */ +static inline void +pdc_build_txd(struct pdc_state *pdcs, dma_addr_t dma_addr, u32 buf_len, + u32 flags) +{ + struct device *dev = &pdcs->pdev->dev; + struct dma64dd *txd = &pdcs->txd_64[pdcs->txout]; + + dev_dbg(dev, + "Writing tx descriptor for PDC %u at index %u with length %u, flags %#x\n", + pdcs->pdc_idx, pdcs->txout, buf_len, flags); + + txd->addrlow = cpu_to_le32(lower_32_bits(dma_addr)); + txd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr)); + txd->ctrl1 = cpu_to_le32(flags); + txd->ctrl2 = cpu_to_le32(buf_len); + + /* bump ring index and return */ + pdcs->txout = NEXTTXD(pdcs->txout, pdcs->ntxpost); +} + +/** + * pdc_receive_one() - Receive a response message from a given SPU. + * @pdcs: PDC state for the SPU to receive from + * + * When the return code indicates success, the response message is available in + * the receive buffers provided prior to submission of the request. + * + * Return: PDC_SUCCESS if one or more receive descriptors was processed + * -EAGAIN indicates that no response message is available + * -EIO an error occurred + */ +static int +pdc_receive_one(struct pdc_state *pdcs) +{ + struct device *dev = &pdcs->pdev->dev; + struct mbox_controller *mbc; + struct mbox_chan *chan; + struct brcm_message mssg; + u32 len, rx_status; + u32 num_frags; + u8 *resp_hdr; /* virtual addr of start of resp message DMA header */ + u32 frags_rdy; /* number of fragments ready to read */ + u32 rx_idx; /* ring index of start of receive frame */ + dma_addr_t resp_hdr_daddr; + struct pdc_rx_ctx *rx_ctx; + + mbc = &pdcs->mbc; + chan = &mbc->chans[0]; + mssg.type = BRCM_MESSAGE_SPU; + + /* + * return if a complete response message is not yet ready. + * rxin_numd[rxin] is the number of fragments in the next msg + * to read. + */ + frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr, pdcs->nrxpost); + if ((frags_rdy == 0) || + (frags_rdy < pdcs->rx_ctx[pdcs->rxin].rxin_numd)) + /* No response ready */ + return -EAGAIN; + + num_frags = pdcs->txin_numd[pdcs->txin]; + WARN_ON(num_frags == 0); + + dma_unmap_sg(dev, pdcs->src_sg[pdcs->txin], + sg_nents(pdcs->src_sg[pdcs->txin]), DMA_TO_DEVICE); + + pdcs->txin = (pdcs->txin + num_frags) & pdcs->ntxpost; + + dev_dbg(dev, "PDC %u reclaimed %d tx descriptors", + pdcs->pdc_idx, num_frags); + + rx_idx = pdcs->rxin; + rx_ctx = &pdcs->rx_ctx[rx_idx]; + num_frags = rx_ctx->rxin_numd; + /* Return opaque context with result */ + mssg.ctx = rx_ctx->rxp_ctx; + rx_ctx->rxp_ctx = NULL; + resp_hdr = rx_ctx->resp_hdr; + resp_hdr_daddr = rx_ctx->resp_hdr_daddr; + dma_unmap_sg(dev, rx_ctx->dst_sg, sg_nents(rx_ctx->dst_sg), + DMA_FROM_DEVICE); + + pdcs->rxin = (pdcs->rxin + num_frags) & pdcs->nrxpost; + + dev_dbg(dev, "PDC %u reclaimed %d rx descriptors", + pdcs->pdc_idx, num_frags); + + dev_dbg(dev, + "PDC %u txin %u, txout %u, rxin %u, rxout %u, last_rx_curr %u\n", + pdcs->pdc_idx, pdcs->txin, pdcs->txout, pdcs->rxin, + pdcs->rxout, pdcs->last_rx_curr); + + if (pdcs->pdc_resp_hdr_len == PDC_SPUM_RESP_HDR_LEN) { + /* + * For SPU-M, get length of response msg and rx overflow status. + */ + rx_status = *((u32 *)resp_hdr); + len = rx_status & RX_STATUS_LEN; + dev_dbg(dev, + "SPU response length %u bytes", len); + if (unlikely(((rx_status & RX_STATUS_OVERFLOW) || (!len)))) { + if (rx_status & RX_STATUS_OVERFLOW) { + dev_err_ratelimited(dev, + "crypto receive overflow"); + pdcs->rx_oflow++; + } else { + dev_info_ratelimited(dev, "crypto rx len = 0"); + } + return -EIO; + } + } + + dma_pool_free(pdcs->rx_buf_pool, resp_hdr, resp_hdr_daddr); + + mbox_chan_received_data(chan, &mssg); + + pdcs->pdc_replies++; + return PDC_SUCCESS; +} + +/** + * pdc_receive() - Process as many responses as are available in the rx ring. + * @pdcs: PDC state + * + * Called within the hard IRQ. + * Return: + */ +static int +pdc_receive(struct pdc_state *pdcs) +{ + int rx_status; + + /* read last_rx_curr from register once */ + pdcs->last_rx_curr = + (ioread32(&pdcs->rxregs_64->status0) & + CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE; + + do { + /* Could be many frames ready */ + rx_status = pdc_receive_one(pdcs); + } while (rx_status == PDC_SUCCESS); + + return 0; +} + +/** + * pdc_tx_list_sg_add() - Add the buffers in a scatterlist to the transmit + * descriptors for a given SPU. The scatterlist buffers contain the data for a + * SPU request message. + * @spu_idx: The index of the SPU to submit the request to, [0, max_spu) + * @sg: Scatterlist whose buffers contain part of the SPU request + * + * If a scatterlist buffer is larger than PDC_DMA_BUF_MAX, multiple descriptors + * are written for that buffer, each <= PDC_DMA_BUF_MAX byte in length. + * + * Return: PDC_SUCCESS if successful + * < 0 otherwise + */ +static int pdc_tx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg) +{ + u32 flags = 0; + u32 eot; + u32 tx_avail; + + /* + * Num descriptors needed. Conservatively assume we need a descriptor + * for every entry in sg. + */ + u32 num_desc; + u32 desc_w = 0; /* Number of tx descriptors written */ + u32 bufcnt; /* Number of bytes of buffer pointed to by descriptor */ + dma_addr_t databufptr; /* DMA address to put in descriptor */ + + num_desc = (u32)sg_nents(sg); + + /* check whether enough tx descriptors are available */ + tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout, + pdcs->ntxpost); + if (unlikely(num_desc > tx_avail)) { + pdcs->txnobuf++; + return -ENOSPC; + } + + /* build tx descriptors */ + if (pdcs->tx_msg_start == pdcs->txout) { + /* Start of frame */ + pdcs->txin_numd[pdcs->tx_msg_start] = 0; + pdcs->src_sg[pdcs->txout] = sg; + flags = D64_CTRL1_SOF; + } + + while (sg) { + if (unlikely(pdcs->txout == (pdcs->ntxd - 1))) + eot = D64_CTRL1_EOT; + else + eot = 0; + + /* + * If sg buffer larger than PDC limit, split across + * multiple descriptors + */ + bufcnt = sg_dma_len(sg); + databufptr = sg_dma_address(sg); + while (bufcnt > PDC_DMA_BUF_MAX) { + pdc_build_txd(pdcs, databufptr, PDC_DMA_BUF_MAX, + flags | eot); + desc_w++; + bufcnt -= PDC_DMA_BUF_MAX; + databufptr += PDC_DMA_BUF_MAX; + if (unlikely(pdcs->txout == (pdcs->ntxd - 1))) + eot = D64_CTRL1_EOT; + else + eot = 0; + } + sg = sg_next(sg); + if (!sg) + /* Writing last descriptor for frame */ + flags |= (D64_CTRL1_EOF | D64_CTRL1_IOC); + pdc_build_txd(pdcs, databufptr, bufcnt, flags | eot); + desc_w++; + /* Clear start of frame after first descriptor */ + flags &= ~D64_CTRL1_SOF; + } + pdcs->txin_numd[pdcs->tx_msg_start] += desc_w; + + return PDC_SUCCESS; +} + +/** + * pdc_tx_list_final() - Initiate DMA transfer of last frame written to tx + * ring. + * @pdcs: PDC state for SPU to process the request + * + * Sets the index of the last descriptor written in both the rx and tx ring. + * + * Return: PDC_SUCCESS + */ +static int pdc_tx_list_final(struct pdc_state *pdcs) +{ + /* + * write barrier to ensure all register writes are complete + * before chip starts to process new request + */ + wmb(); + iowrite32(pdcs->rxout << 4, &pdcs->rxregs_64->ptr); + iowrite32(pdcs->txout << 4, &pdcs->txregs_64->ptr); + pdcs->pdc_requests++; + + return PDC_SUCCESS; +} + +/** + * pdc_rx_list_init() - Start a new receive descriptor list for a given PDC. + * @pdcs: PDC state for SPU handling request + * @dst_sg: scatterlist providing rx buffers for response to be returned to + * mailbox client + * @ctx: Opaque context for this request + * + * Posts a single receive descriptor to hold the metadata that precedes a + * response. For example, with SPU-M, the metadata is a 32-byte DMA header and + * an 8-byte BCM header. Moves the msg_start descriptor indexes for both tx and + * rx to indicate the start of a new message. + * + * Return: PDC_SUCCESS if successful + * < 0 if an error (e.g., rx ring is full) + */ +static int pdc_rx_list_init(struct pdc_state *pdcs, struct scatterlist *dst_sg, + void *ctx) +{ + u32 flags = 0; + u32 rx_avail; + u32 rx_pkt_cnt = 1; /* Adding a single rx buffer */ + dma_addr_t daddr; + void *vaddr; + struct pdc_rx_ctx *rx_ctx; + + rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout, + pdcs->nrxpost); + if (unlikely(rx_pkt_cnt > rx_avail)) { + pdcs->rxnobuf++; + return -ENOSPC; + } + + /* allocate a buffer for the dma rx status */ + vaddr = dma_pool_zalloc(pdcs->rx_buf_pool, GFP_ATOMIC, &daddr); + if (unlikely(!vaddr)) + return -ENOMEM; + + /* + * Update msg_start indexes for both tx and rx to indicate the start + * of a new sequence of descriptor indexes that contain the fragments + * of the same message. + */ + pdcs->rx_msg_start = pdcs->rxout; + pdcs->tx_msg_start = pdcs->txout; + + /* This is always the first descriptor in the receive sequence */ + flags = D64_CTRL1_SOF; + pdcs->rx_ctx[pdcs->rx_msg_start].rxin_numd = 1; + + if (unlikely(pdcs->rxout == (pdcs->nrxd - 1))) + flags |= D64_CTRL1_EOT; + + rx_ctx = &pdcs->rx_ctx[pdcs->rxout]; + rx_ctx->rxp_ctx = ctx; + rx_ctx->dst_sg = dst_sg; + rx_ctx->resp_hdr = vaddr; + rx_ctx->resp_hdr_daddr = daddr; + pdc_build_rxd(pdcs, daddr, pdcs->pdc_resp_hdr_len, flags); + return PDC_SUCCESS; +} + +/** + * pdc_rx_list_sg_add() - Add the buffers in a scatterlist to the receive + * descriptors for a given SPU. The caller must have already DMA mapped the + * scatterlist. + * @spu_idx: Indicates which SPU the buffers are for + * @sg: Scatterlist whose buffers are added to the receive ring + * + * If a receive buffer in the scatterlist is larger than PDC_DMA_BUF_MAX, + * multiple receive descriptors are written, each with a buffer <= + * PDC_DMA_BUF_MAX. + * + * Return: PDC_SUCCESS if successful + * < 0 otherwise (e.g., receive ring is full) + */ +static int pdc_rx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg) +{ + u32 flags = 0; + u32 rx_avail; + + /* + * Num descriptors needed. Conservatively assume we need a descriptor + * for every entry from our starting point in the scatterlist. + */ + u32 num_desc; + u32 desc_w = 0; /* Number of tx descriptors written */ + u32 bufcnt; /* Number of bytes of buffer pointed to by descriptor */ + dma_addr_t databufptr; /* DMA address to put in descriptor */ + + num_desc = (u32)sg_nents(sg); + + rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout, + pdcs->nrxpost); + if (unlikely(num_desc > rx_avail)) { + pdcs->rxnobuf++; + return -ENOSPC; + } + + while (sg) { + if (unlikely(pdcs->rxout == (pdcs->nrxd - 1))) + flags = D64_CTRL1_EOT; + else + flags = 0; + + /* + * If sg buffer larger than PDC limit, split across + * multiple descriptors + */ + bufcnt = sg_dma_len(sg); + databufptr = sg_dma_address(sg); + while (bufcnt > PDC_DMA_BUF_MAX) { + pdc_build_rxd(pdcs, databufptr, PDC_DMA_BUF_MAX, flags); + desc_w++; + bufcnt -= PDC_DMA_BUF_MAX; + databufptr += PDC_DMA_BUF_MAX; + if (unlikely(pdcs->rxout == (pdcs->nrxd - 1))) + flags = D64_CTRL1_EOT; + else + flags = 0; + } + pdc_build_rxd(pdcs, databufptr, bufcnt, flags); + desc_w++; + sg = sg_next(sg); + } + pdcs->rx_ctx[pdcs->rx_msg_start].rxin_numd += desc_w; + + return PDC_SUCCESS; +} + +/** + * pdc_irq_handler() - Interrupt handler called in interrupt context. + * @irq: Interrupt number that has fired + * @data: device struct for DMA engine that generated the interrupt + * + * We have to clear the device interrupt status flags here. So cache the + * status for later use in the thread function. Other than that, just return + * WAKE_THREAD to invoke the thread function. + * + * Return: IRQ_WAKE_THREAD if interrupt is ours + * IRQ_NONE otherwise + */ +static irqreturn_t pdc_irq_handler(int irq, void *data) +{ + struct device *dev = (struct device *)data; + struct pdc_state *pdcs = dev_get_drvdata(dev); + u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET); + + if (unlikely(intstatus == 0)) + return IRQ_NONE; + + /* Disable interrupts until soft handler runs */ + iowrite32(0, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET); + + /* Clear interrupt flags in device */ + iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET); + + /* Wakeup IRQ thread */ + tasklet_schedule(&pdcs->rx_tasklet); + return IRQ_HANDLED; +} + +/** + * pdc_tasklet_cb() - Tasklet callback that runs the deferred processing after + * a DMA receive interrupt. Reenables the receive interrupt. + * @data: PDC state structure + */ +static void pdc_tasklet_cb(unsigned long data) +{ + struct pdc_state *pdcs = (struct pdc_state *)data; + + pdc_receive(pdcs); + + /* reenable interrupts */ + iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET); +} + +/** + * pdc_ring_init() - Allocate DMA rings and initialize constant fields of + * descriptors in one ringset. + * @pdcs: PDC instance state + * @ringset: index of ringset being used + * + * Return: PDC_SUCCESS if ring initialized + * < 0 otherwise + */ +static int pdc_ring_init(struct pdc_state *pdcs, int ringset) +{ + int i; + int err = PDC_SUCCESS; + struct dma64 *dma_reg; + struct device *dev = &pdcs->pdev->dev; + struct pdc_ring_alloc tx; + struct pdc_ring_alloc rx; + + /* Allocate tx ring */ + tx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &tx.dmabase); + if (unlikely(!tx.vbase)) { + err = -ENOMEM; + goto done; + } + + /* Allocate rx ring */ + rx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &rx.dmabase); + if (unlikely(!rx.vbase)) { + err = -ENOMEM; + goto fail_dealloc; + } + + dev_dbg(dev, " - base DMA addr of tx ring %pad", &tx.dmabase); + dev_dbg(dev, " - base virtual addr of tx ring %p", tx.vbase); + dev_dbg(dev, " - base DMA addr of rx ring %pad", &rx.dmabase); + dev_dbg(dev, " - base virtual addr of rx ring %p", rx.vbase); + + memcpy(&pdcs->tx_ring_alloc, &tx, sizeof(tx)); + memcpy(&pdcs->rx_ring_alloc, &rx, sizeof(rx)); + + pdcs->rxin = 0; + pdcs->rx_msg_start = 0; + pdcs->last_rx_curr = 0; + pdcs->rxout = 0; + pdcs->txin = 0; + pdcs->tx_msg_start = 0; + pdcs->txout = 0; + + /* Set descriptor array base addresses */ + pdcs->txd_64 = (struct dma64dd *)pdcs->tx_ring_alloc.vbase; + pdcs->rxd_64 = (struct dma64dd *)pdcs->rx_ring_alloc.vbase; + + /* Tell device the base DMA address of each ring */ + dma_reg = &pdcs->regs->dmaregs[ringset]; + + /* But first disable DMA and set curptr to 0 for both TX & RX */ + iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control); + iowrite32((PDC_RX_CTL + (pdcs->rx_status_len << 1)), + &dma_reg->dmarcv.control); + iowrite32(0, &dma_reg->dmaxmt.ptr); + iowrite32(0, &dma_reg->dmarcv.ptr); + + /* Set base DMA addresses */ + iowrite32(lower_32_bits(pdcs->tx_ring_alloc.dmabase), + &dma_reg->dmaxmt.addrlow); + iowrite32(upper_32_bits(pdcs->tx_ring_alloc.dmabase), + &dma_reg->dmaxmt.addrhigh); + + iowrite32(lower_32_bits(pdcs->rx_ring_alloc.dmabase), + &dma_reg->dmarcv.addrlow); + iowrite32(upper_32_bits(pdcs->rx_ring_alloc.dmabase), + &dma_reg->dmarcv.addrhigh); + + /* Re-enable DMA */ + iowrite32(PDC_TX_CTL | PDC_TX_ENABLE, &dma_reg->dmaxmt.control); + iowrite32((PDC_RX_CTL | PDC_RX_ENABLE | (pdcs->rx_status_len << 1)), + &dma_reg->dmarcv.control); + + /* Initialize descriptors */ + for (i = 0; i < PDC_RING_ENTRIES; i++) { + /* Every tx descriptor can be used for start of frame. */ + if (i != pdcs->ntxpost) { + iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF, + &pdcs->txd_64[i].ctrl1); + } else { + /* Last descriptor in ringset. Set End of Table. */ + iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF | + D64_CTRL1_EOT, &pdcs->txd_64[i].ctrl1); + } + + /* Every rx descriptor can be used for start of frame */ + if (i != pdcs->nrxpost) { + iowrite32(D64_CTRL1_SOF, + &pdcs->rxd_64[i].ctrl1); + } else { + /* Last descriptor in ringset. Set End of Table. */ + iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOT, + &pdcs->rxd_64[i].ctrl1); + } + } + return PDC_SUCCESS; + +fail_dealloc: + dma_pool_free(pdcs->ring_pool, tx.vbase, tx.dmabase); +done: + return err; +} + +static void pdc_ring_free(struct pdc_state *pdcs) +{ + if (pdcs->tx_ring_alloc.vbase) { + dma_pool_free(pdcs->ring_pool, pdcs->tx_ring_alloc.vbase, + pdcs->tx_ring_alloc.dmabase); + pdcs->tx_ring_alloc.vbase = NULL; + } + + if (pdcs->rx_ring_alloc.vbase) { + dma_pool_free(pdcs->ring_pool, pdcs->rx_ring_alloc.vbase, + pdcs->rx_ring_alloc.dmabase); + pdcs->rx_ring_alloc.vbase = NULL; + } +} + +/** + * pdc_desc_count() - Count the number of DMA descriptors that will be required + * for a given scatterlist. Account for the max length of a DMA buffer. + * @sg: Scatterlist to be DMA'd + * Return: Number of descriptors required + */ +static u32 pdc_desc_count(struct scatterlist *sg) +{ + u32 cnt = 0; + + while (sg) { + cnt += ((sg->length / PDC_DMA_BUF_MAX) + 1); + sg = sg_next(sg); + } + return cnt; +} + +/** + * pdc_rings_full() - Check whether the tx ring has room for tx_cnt descriptors + * and the rx ring has room for rx_cnt descriptors. + * @pdcs: PDC state + * @tx_cnt: The number of descriptors required in the tx ring + * @rx_cnt: The number of descriptors required i the rx ring + * + * Return: true if one of the rings does not have enough space + * false if sufficient space is available in both rings + */ +static bool pdc_rings_full(struct pdc_state *pdcs, int tx_cnt, int rx_cnt) +{ + u32 rx_avail; + u32 tx_avail; + bool full = false; + + /* Check if the tx and rx rings are likely to have enough space */ + rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout, + pdcs->nrxpost); + if (unlikely(rx_cnt > rx_avail)) { + pdcs->rx_ring_full++; + full = true; + } + + if (likely(!full)) { + tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout, + pdcs->ntxpost); + if (unlikely(tx_cnt > tx_avail)) { + pdcs->tx_ring_full++; + full = true; + } + } + return full; +} + +/** + * pdc_last_tx_done() - If both the tx and rx rings have at least + * PDC_RING_SPACE_MIN descriptors available, then indicate that the mailbox + * framework can submit another message. + * @chan: mailbox channel to check + * Return: true if PDC can accept another message on this channel + */ +static bool pdc_last_tx_done(struct mbox_chan *chan) +{ + struct pdc_state *pdcs = chan->con_priv; + bool ret; + + if (unlikely(pdc_rings_full(pdcs, PDC_RING_SPACE_MIN, + PDC_RING_SPACE_MIN))) { + pdcs->last_tx_not_done++; + ret = false; + } else { + ret = true; + } + return ret; +} + +/** + * pdc_send_data() - mailbox send_data function + * @chan: The mailbox channel on which the data is sent. The channel + * corresponds to a DMA ringset. + * @data: The mailbox message to be sent. The message must be a + * brcm_message structure. + * + * This function is registered as the send_data function for the mailbox + * controller. From the destination scatterlist in the mailbox message, it + * creates a sequence of receive descriptors in the rx ring. From the source + * scatterlist, it creates a sequence of transmit descriptors in the tx ring. + * After creating the descriptors, it writes the rx ptr and tx ptr registers to + * initiate the DMA transfer. + * + * This function does the DMA map and unmap of the src and dst scatterlists in + * the mailbox message. + * + * Return: 0 if successful + * -ENOTSUPP if the mailbox message is a type this driver does not + * support + * < 0 if an error + */ +static int pdc_send_data(struct mbox_chan *chan, void *data) +{ + struct pdc_state *pdcs = chan->con_priv; + struct device *dev = &pdcs->pdev->dev; + struct brcm_message *mssg = data; + int err = PDC_SUCCESS; + int src_nent; + int dst_nent; + int nent; + u32 tx_desc_req; + u32 rx_desc_req; + + if (unlikely(mssg->type != BRCM_MESSAGE_SPU)) + return -ENOTSUPP; + + src_nent = sg_nents(mssg->spu.src); + if (likely(src_nent)) { + nent = dma_map_sg(dev, mssg->spu.src, src_nent, DMA_TO_DEVICE); + if (unlikely(nent == 0)) + return -EIO; + } + + dst_nent = sg_nents(mssg->spu.dst); + if (likely(dst_nent)) { + nent = dma_map_sg(dev, mssg->spu.dst, dst_nent, + DMA_FROM_DEVICE); + if (unlikely(nent == 0)) { + dma_unmap_sg(dev, mssg->spu.src, src_nent, + DMA_TO_DEVICE); + return -EIO; + } + } + + /* + * Check if the tx and rx rings have enough space. Do this prior to + * writing any tx or rx descriptors. Need to ensure that we do not write + * a partial set of descriptors, or write just rx descriptors but + * corresponding tx descriptors don't fit. Note that we want this check + * and the entire sequence of descriptor to happen without another + * thread getting in. The channel spin lock in the mailbox framework + * ensures this. + */ + tx_desc_req = pdc_desc_count(mssg->spu.src); + rx_desc_req = pdc_desc_count(mssg->spu.dst); + if (unlikely(pdc_rings_full(pdcs, tx_desc_req, rx_desc_req + 1))) + return -ENOSPC; + + /* Create rx descriptors to SPU catch response */ + err = pdc_rx_list_init(pdcs, mssg->spu.dst, mssg->ctx); + err |= pdc_rx_list_sg_add(pdcs, mssg->spu.dst); + + /* Create tx descriptors to submit SPU request */ + err |= pdc_tx_list_sg_add(pdcs, mssg->spu.src); + err |= pdc_tx_list_final(pdcs); /* initiate transfer */ + + if (unlikely(err)) + dev_err(&pdcs->pdev->dev, + "%s failed with error %d", __func__, err); + + return err; +} + +static int pdc_startup(struct mbox_chan *chan) +{ + return pdc_ring_init(chan->con_priv, PDC_RINGSET); +} + +static void pdc_shutdown(struct mbox_chan *chan) +{ + struct pdc_state *pdcs = chan->con_priv; + + if (!pdcs) + return; + + dev_dbg(&pdcs->pdev->dev, + "Shutdown mailbox channel for PDC %u", pdcs->pdc_idx); + pdc_ring_free(pdcs); +} + +/** + * pdc_hw_init() - Use the given initialization parameters to initialize the + * state for one of the PDCs. + * @pdcs: state of the PDC + */ +static +void pdc_hw_init(struct pdc_state *pdcs) +{ + struct platform_device *pdev; + struct device *dev; + struct dma64 *dma_reg; + int ringset = PDC_RINGSET; + + pdev = pdcs->pdev; + dev = &pdev->dev; + + dev_dbg(dev, "PDC %u initial values:", pdcs->pdc_idx); + dev_dbg(dev, "state structure: %p", + pdcs); + dev_dbg(dev, " - base virtual addr of hw regs %p", + pdcs->pdc_reg_vbase); + + /* initialize data structures */ + pdcs->regs = (struct pdc_regs *)pdcs->pdc_reg_vbase; + pdcs->txregs_64 = (struct dma64_regs *) + (((u8 *)pdcs->pdc_reg_vbase) + + PDC_TXREGS_OFFSET + (sizeof(struct dma64) * ringset)); + pdcs->rxregs_64 = (struct dma64_regs *) + (((u8 *)pdcs->pdc_reg_vbase) + + PDC_RXREGS_OFFSET + (sizeof(struct dma64) * ringset)); + + pdcs->ntxd = PDC_RING_ENTRIES; + pdcs->nrxd = PDC_RING_ENTRIES; + pdcs->ntxpost = PDC_RING_ENTRIES - 1; + pdcs->nrxpost = PDC_RING_ENTRIES - 1; + iowrite32(0, &pdcs->regs->intmask); + + dma_reg = &pdcs->regs->dmaregs[ringset]; + + /* Configure DMA but will enable later in pdc_ring_init() */ + iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control); + + iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1), + &dma_reg->dmarcv.control); + + /* Reset current index pointers after making sure DMA is disabled */ + iowrite32(0, &dma_reg->dmaxmt.ptr); + iowrite32(0, &dma_reg->dmarcv.ptr); + + if (pdcs->pdc_resp_hdr_len == PDC_SPU2_RESP_HDR_LEN) + iowrite32(PDC_CKSUM_CTRL, + pdcs->pdc_reg_vbase + PDC_CKSUM_CTRL_OFFSET); +} + +/** + * pdc_hw_disable() - Disable the tx and rx control in the hw. + * @pdcs: PDC state structure + * + */ +static void pdc_hw_disable(struct pdc_state *pdcs) +{ + struct dma64 *dma_reg; + + dma_reg = &pdcs->regs->dmaregs[PDC_RINGSET]; + iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control); + iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1), + &dma_reg->dmarcv.control); +} + +/** + * pdc_rx_buf_pool_create() - Pool of receive buffers used to catch the metadata + * header returned with each response message. + * @pdcs: PDC state structure + * + * The metadata is not returned to the mailbox client. So the PDC driver + * manages these buffers. + * + * Return: PDC_SUCCESS + * -ENOMEM if pool creation fails + */ +static int pdc_rx_buf_pool_create(struct pdc_state *pdcs) +{ + struct platform_device *pdev; + struct device *dev; + + pdev = pdcs->pdev; + dev = &pdev->dev; + + pdcs->pdc_resp_hdr_len = pdcs->rx_status_len; + if (pdcs->use_bcm_hdr) + pdcs->pdc_resp_hdr_len += BCM_HDR_LEN; + + pdcs->rx_buf_pool = dma_pool_create("pdc rx bufs", dev, + pdcs->pdc_resp_hdr_len, + RX_BUF_ALIGN, 0); + if (!pdcs->rx_buf_pool) + return -ENOMEM; + + return PDC_SUCCESS; +} + +/** + * pdc_interrupts_init() - Initialize the interrupt configuration for a PDC and + * specify a threaded IRQ handler for deferred handling of interrupts outside of + * interrupt context. + * @pdcs: PDC state + * + * Set the interrupt mask for transmit and receive done. + * Set the lazy interrupt frame count to generate an interrupt for just one pkt. + * + * Return: PDC_SUCCESS + * <0 if threaded irq request fails + */ +static int pdc_interrupts_init(struct pdc_state *pdcs) +{ + struct platform_device *pdev = pdcs->pdev; + struct device *dev = &pdev->dev; + struct device_node *dn = pdev->dev.of_node; + int err; + + /* interrupt configuration */ + iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET); + + if (pdcs->hw_type == FA_HW) + iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase + + FA_RCVLAZY0_OFFSET); + else + iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase + + PDC_RCVLAZY0_OFFSET); + + /* read irq from device tree */ + pdcs->pdc_irq = irq_of_parse_and_map(dn, 0); + dev_dbg(dev, "pdc device %s irq %u for pdcs %p", + dev_name(dev), pdcs->pdc_irq, pdcs); + + err = devm_request_irq(dev, pdcs->pdc_irq, pdc_irq_handler, 0, + dev_name(dev), dev); + if (err) { + dev_err(dev, "IRQ %u request failed with err %d\n", + pdcs->pdc_irq, err); + return err; + } + return PDC_SUCCESS; +} + +static const struct mbox_chan_ops pdc_mbox_chan_ops = { + .send_data = pdc_send_data, + .last_tx_done = pdc_last_tx_done, + .startup = pdc_startup, + .shutdown = pdc_shutdown +}; + +/** + * pdc_mb_init() - Initialize the mailbox controller. + * @pdcs: PDC state + * + * Each PDC is a mailbox controller. Each ringset is a mailbox channel. Kernel + * driver only uses one ringset and thus one mb channel. PDC uses the transmit + * complete interrupt to determine when a mailbox message has successfully been + * transmitted. + * + * Return: 0 on success + * < 0 if there is an allocation or registration failure + */ +static int pdc_mb_init(struct pdc_state *pdcs) +{ + struct device *dev = &pdcs->pdev->dev; + struct mbox_controller *mbc; + int chan_index; + int err; + + mbc = &pdcs->mbc; + mbc->dev = dev; + mbc->ops = &pdc_mbox_chan_ops; + mbc->num_chans = 1; + mbc->chans = devm_kcalloc(dev, mbc->num_chans, sizeof(*mbc->chans), + GFP_KERNEL); + if (!mbc->chans) + return -ENOMEM; + + mbc->txdone_irq = false; + mbc->txdone_poll = true; + mbc->txpoll_period = 1; + for (chan_index = 0; chan_index < mbc->num_chans; chan_index++) + mbc->chans[chan_index].con_priv = pdcs; + + /* Register mailbox controller */ + err = mbox_controller_register(mbc); + if (err) { + dev_crit(dev, + "Failed to register PDC mailbox controller. Error %d.", + err); + return err; + } + return 0; +} + +/* Device tree API */ +static const int pdc_hw = PDC_HW; +static const int fa_hw = FA_HW; + +static const struct of_device_id pdc_mbox_of_match[] = { + {.compatible = "brcm,iproc-pdc-mbox", .data = &pdc_hw}, + {.compatible = "brcm,iproc-fa2-mbox", .data = &fa_hw}, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, pdc_mbox_of_match); + +/** + * pdc_dt_read() - Read application-specific data from device tree. + * @pdev: Platform device + * @pdcs: PDC state + * + * Reads the number of bytes of receive status that precede each received frame. + * Reads whether transmit and received frames should be preceded by an 8-byte + * BCM header. + * + * Return: 0 if successful + * -ENODEV if device not available + */ +static int pdc_dt_read(struct platform_device *pdev, struct pdc_state *pdcs) +{ + struct device *dev = &pdev->dev; + struct device_node *dn = pdev->dev.of_node; + const struct of_device_id *match; + const int *hw_type; + int err; + + err = of_property_read_u32(dn, "brcm,rx-status-len", + &pdcs->rx_status_len); + if (err < 0) + dev_err(dev, + "%s failed to get DMA receive status length from device tree", + __func__); + + pdcs->use_bcm_hdr = of_property_read_bool(dn, "brcm,use-bcm-hdr"); + + pdcs->hw_type = PDC_HW; + + match = of_match_device(of_match_ptr(pdc_mbox_of_match), dev); + if (match != NULL) { + hw_type = match->data; + pdcs->hw_type = *hw_type; + } + + return 0; +} + +/** + * pdc_probe() - Probe function for PDC driver. + * @pdev: PDC platform device + * + * Reserve and map register regions defined in device tree. + * Allocate and initialize tx and rx DMA rings. + * Initialize a mailbox controller for each PDC. + * + * Return: 0 if successful + * < 0 if an error + */ +static int pdc_probe(struct platform_device *pdev) +{ + int err = 0; + struct device *dev = &pdev->dev; + struct resource *pdc_regs; + struct pdc_state *pdcs; + + /* PDC state for one SPU */ + pdcs = devm_kzalloc(dev, sizeof(*pdcs), GFP_KERNEL); + if (!pdcs) { + err = -ENOMEM; + goto cleanup; + } + + pdcs->pdev = pdev; + platform_set_drvdata(pdev, pdcs); + pdcs->pdc_idx = pdcg.num_spu; + pdcg.num_spu++; + + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(39)); + if (err) { + dev_warn(dev, "PDC device cannot perform DMA. Error %d.", err); + goto cleanup; + } + + /* Create DMA pool for tx ring */ + pdcs->ring_pool = dma_pool_create("pdc rings", dev, PDC_RING_SIZE, + RING_ALIGN, 0); + if (!pdcs->ring_pool) { + err = -ENOMEM; + goto cleanup; + } + + err = pdc_dt_read(pdev, pdcs); + if (err) + goto cleanup_ring_pool; + + pdc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!pdc_regs) { + err = -ENODEV; + goto cleanup_ring_pool; + } + dev_dbg(dev, "PDC register region res.start = %pa, res.end = %pa", + &pdc_regs->start, &pdc_regs->end); + + pdcs->pdc_reg_vbase = devm_ioremap_resource(&pdev->dev, pdc_regs); + if (IS_ERR(pdcs->pdc_reg_vbase)) { + err = PTR_ERR(pdcs->pdc_reg_vbase); + dev_err(&pdev->dev, "Failed to map registers: %d\n", err); + goto cleanup_ring_pool; + } + + /* create rx buffer pool after dt read to know how big buffers are */ + err = pdc_rx_buf_pool_create(pdcs); + if (err) + goto cleanup_ring_pool; + + pdc_hw_init(pdcs); + + /* Init tasklet for deferred DMA rx processing */ + tasklet_init(&pdcs->rx_tasklet, pdc_tasklet_cb, (unsigned long)pdcs); + + err = pdc_interrupts_init(pdcs); + if (err) + goto cleanup_buf_pool; + + /* Initialize mailbox controller */ + err = pdc_mb_init(pdcs); + if (err) + goto cleanup_buf_pool; + + pdcs->debugfs_stats = NULL; + pdc_setup_debugfs(pdcs); + + dev_dbg(dev, "pdc_probe() successful"); + return PDC_SUCCESS; + +cleanup_buf_pool: + tasklet_kill(&pdcs->rx_tasklet); + dma_pool_destroy(pdcs->rx_buf_pool); + +cleanup_ring_pool: + dma_pool_destroy(pdcs->ring_pool); + +cleanup: + return err; +} + +static int pdc_remove(struct platform_device *pdev) +{ + struct pdc_state *pdcs = platform_get_drvdata(pdev); + + pdc_free_debugfs(); + + tasklet_kill(&pdcs->rx_tasklet); + + pdc_hw_disable(pdcs); + + mbox_controller_unregister(&pdcs->mbc); + + dma_pool_destroy(pdcs->rx_buf_pool); + dma_pool_destroy(pdcs->ring_pool); + return 0; +} + +static struct platform_driver pdc_mbox_driver = { + .probe = pdc_probe, + .remove = pdc_remove, + .driver = { + .name = "brcm-iproc-pdc-mbox", + .of_match_table = of_match_ptr(pdc_mbox_of_match), + }, +}; +module_platform_driver(pdc_mbox_driver); + +MODULE_AUTHOR("Rob Rice <rob.rice@broadcom.com>"); +MODULE_DESCRIPTION("Broadcom PDC mailbox driver"); +MODULE_LICENSE("GPL v2"); |