diff options
Diffstat (limited to 'drivers/cpufreq/longhaul.c')
| -rw-r--r-- | drivers/cpufreq/longhaul.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c new file mode 100644 index 000000000..182a4dbca --- /dev/null +++ b/drivers/cpufreq/longhaul.c @@ -0,0 +1,1002 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * (C) 2001-2004 Dave Jones. + * (C) 2002 Padraig Brady. <padraig@antefacto.com> + * + * Based upon datasheets & sample CPUs kindly provided by VIA. + * + * VIA have currently 3 different versions of Longhaul. + * Version 1 (Longhaul) uses the BCR2 MSR at 0x1147. + * It is present only in Samuel 1 (C5A), Samuel 2 (C5B) stepping 0. + * Version 2 of longhaul is backward compatible with v1, but adds + * LONGHAUL MSR for purpose of both frequency and voltage scaling. + * Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C). + * Version 3 of longhaul got renamed to Powersaver and redesigned + * to use only the POWERSAVER MSR at 0x110a. + * It is present in Ezra-T (C5M), Nehemiah (C5X) and above. + * It's pretty much the same feature wise to longhaul v2, though + * there is provision for scaling FSB too, but this doesn't work + * too well in practice so we don't even try to use this. + * + * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/timex.h> +#include <linux/io.h> +#include <linux/acpi.h> + +#include <asm/msr.h> +#include <asm/cpu_device_id.h> +#include <acpi/processor.h> + +#include "longhaul.h" + +#define TYPE_LONGHAUL_V1 1 +#define TYPE_LONGHAUL_V2 2 +#define TYPE_POWERSAVER 3 + +#define CPU_SAMUEL 1 +#define CPU_SAMUEL2 2 +#define CPU_EZRA 3 +#define CPU_EZRA_T 4 +#define CPU_NEHEMIAH 5 +#define CPU_NEHEMIAH_C 6 + +/* Flags */ +#define USE_ACPI_C3 (1 << 1) +#define USE_NORTHBRIDGE (1 << 2) + +static int cpu_model; +static unsigned int numscales = 16; +static unsigned int fsb; + +static const struct mV_pos *vrm_mV_table; +static const unsigned char *mV_vrm_table; + +static unsigned int highest_speed, lowest_speed; /* kHz */ +static unsigned int minmult, maxmult; +static int can_scale_voltage; +static struct acpi_processor *pr; +static struct acpi_processor_cx *cx; +static u32 acpi_regs_addr; +static u8 longhaul_flags; +static unsigned int longhaul_index; + +/* Module parameters */ +static int scale_voltage; +static int disable_acpi_c3; +static int revid_errata; +static int enable; + +/* Clock ratios multiplied by 10 */ +static int mults[32]; +static int eblcr[32]; +static int longhaul_version; +static struct cpufreq_frequency_table *longhaul_table; + +static char speedbuffer[8]; + +static char *print_speed(int speed) +{ + if (speed < 1000) { + snprintf(speedbuffer, sizeof(speedbuffer), "%dMHz", speed); + return speedbuffer; + } + + if (speed%1000 == 0) + snprintf(speedbuffer, sizeof(speedbuffer), + "%dGHz", speed/1000); + else + snprintf(speedbuffer, sizeof(speedbuffer), + "%d.%dGHz", speed/1000, (speed%1000)/100); + + return speedbuffer; +} + + +static unsigned int calc_speed(int mult) +{ + int khz; + khz = (mult/10)*fsb; + if (mult%10) + khz += fsb/2; + khz *= 1000; + return khz; +} + + +static int longhaul_get_cpu_mult(void) +{ + unsigned long invalue = 0, lo, hi; + + rdmsr(MSR_IA32_EBL_CR_POWERON, lo, hi); + invalue = (lo & (1<<22|1<<23|1<<24|1<<25))>>22; + if (longhaul_version == TYPE_LONGHAUL_V2 || + longhaul_version == TYPE_POWERSAVER) { + if (lo & (1<<27)) + invalue += 16; + } + return eblcr[invalue]; +} + +/* For processor with BCR2 MSR */ + +static void do_longhaul1(unsigned int mults_index) +{ + union msr_bcr2 bcr2; + + rdmsrl(MSR_VIA_BCR2, bcr2.val); + /* Enable software clock multiplier */ + bcr2.bits.ESOFTBF = 1; + bcr2.bits.CLOCKMUL = mults_index & 0xff; + + /* Sync to timer tick */ + safe_halt(); + /* Change frequency on next halt or sleep */ + wrmsrl(MSR_VIA_BCR2, bcr2.val); + /* Invoke transition */ + ACPI_FLUSH_CPU_CACHE(); + halt(); + + /* Disable software clock multiplier */ + local_irq_disable(); + rdmsrl(MSR_VIA_BCR2, bcr2.val); + bcr2.bits.ESOFTBF = 0; + wrmsrl(MSR_VIA_BCR2, bcr2.val); +} + +/* For processor with Longhaul MSR */ + +static void do_powersaver(int cx_address, unsigned int mults_index, + unsigned int dir) +{ + union msr_longhaul longhaul; + u32 t; + + rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Setup new frequency */ + if (!revid_errata) + longhaul.bits.RevisionKey = longhaul.bits.RevisionID; + else + longhaul.bits.RevisionKey = 0; + longhaul.bits.SoftBusRatio = mults_index & 0xf; + longhaul.bits.SoftBusRatio4 = (mults_index & 0x10) >> 4; + /* Setup new voltage */ + if (can_scale_voltage) + longhaul.bits.SoftVID = (mults_index >> 8) & 0x1f; + /* Sync to timer tick */ + safe_halt(); + /* Raise voltage if necessary */ + if (can_scale_voltage && dir) { + longhaul.bits.EnableSoftVID = 1; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Change voltage */ + if (!cx_address) { + ACPI_FLUSH_CPU_CACHE(); + halt(); + } else { + ACPI_FLUSH_CPU_CACHE(); + /* Invoke C3 */ + inb(cx_address); + /* Dummy op - must do something useless after P_LVL3 + * read */ + t = inl(acpi_gbl_FADT.xpm_timer_block.address); + } + longhaul.bits.EnableSoftVID = 0; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + } + + /* Change frequency on next halt or sleep */ + longhaul.bits.EnableSoftBusRatio = 1; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + if (!cx_address) { + ACPI_FLUSH_CPU_CACHE(); + halt(); + } else { + ACPI_FLUSH_CPU_CACHE(); + /* Invoke C3 */ + inb(cx_address); + /* Dummy op - must do something useless after P_LVL3 read */ + t = inl(acpi_gbl_FADT.xpm_timer_block.address); + } + /* Disable bus ratio bit */ + longhaul.bits.EnableSoftBusRatio = 0; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + + /* Reduce voltage if necessary */ + if (can_scale_voltage && !dir) { + longhaul.bits.EnableSoftVID = 1; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Change voltage */ + if (!cx_address) { + ACPI_FLUSH_CPU_CACHE(); + halt(); + } else { + ACPI_FLUSH_CPU_CACHE(); + /* Invoke C3 */ + inb(cx_address); + /* Dummy op - must do something useless after P_LVL3 + * read */ + t = inl(acpi_gbl_FADT.xpm_timer_block.address); + } + longhaul.bits.EnableSoftVID = 0; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + } +} + +/** + * longhaul_set_cpu_frequency() + * @mults_index : bitpattern of the new multiplier. + * + * Sets a new clock ratio. + */ + +static int longhaul_setstate(struct cpufreq_policy *policy, + unsigned int table_index) +{ + unsigned int mults_index; + int speed, mult; + struct cpufreq_freqs freqs; + unsigned long flags; + unsigned int pic1_mask, pic2_mask; + u16 bm_status = 0; + u32 bm_timeout = 1000; + unsigned int dir = 0; + + mults_index = longhaul_table[table_index].driver_data; + /* Safety precautions */ + mult = mults[mults_index & 0x1f]; + if (mult == -1) + return -EINVAL; + + speed = calc_speed(mult); + if ((speed > highest_speed) || (speed < lowest_speed)) + return -EINVAL; + + /* Voltage transition before frequency transition? */ + if (can_scale_voltage && longhaul_index < table_index) + dir = 1; + + freqs.old = calc_speed(longhaul_get_cpu_mult()); + freqs.new = speed; + + pr_debug("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n", + fsb, mult/10, mult%10, print_speed(speed/1000)); +retry_loop: + preempt_disable(); + local_irq_save(flags); + + pic2_mask = inb(0xA1); + pic1_mask = inb(0x21); /* works on C3. save mask. */ + outb(0xFF, 0xA1); /* Overkill */ + outb(0xFE, 0x21); /* TMR0 only */ + + /* Wait while PCI bus is busy. */ + if (acpi_regs_addr && (longhaul_flags & USE_NORTHBRIDGE + || ((pr != NULL) && pr->flags.bm_control))) { + bm_status = inw(acpi_regs_addr); + bm_status &= 1 << 4; + while (bm_status && bm_timeout) { + outw(1 << 4, acpi_regs_addr); + bm_timeout--; + bm_status = inw(acpi_regs_addr); + bm_status &= 1 << 4; + } + } + + if (longhaul_flags & USE_NORTHBRIDGE) { + /* Disable AGP and PCI arbiters */ + outb(3, 0x22); + } else if ((pr != NULL) && pr->flags.bm_control) { + /* Disable bus master arbitration */ + acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); + } + switch (longhaul_version) { + + /* + * Longhaul v1. (Samuel[C5A] and Samuel2 stepping 0[C5B]) + * Software controlled multipliers only. + */ + case TYPE_LONGHAUL_V1: + do_longhaul1(mults_index); + break; + + /* + * Longhaul v2 appears in Samuel2 Steppings 1->7 [C5B] and Ezra [C5C] + * + * Longhaul v3 (aka Powersaver). (Ezra-T [C5M] & Nehemiah [C5N]) + * Nehemiah can do FSB scaling too, but this has never been proven + * to work in practice. + */ + case TYPE_LONGHAUL_V2: + case TYPE_POWERSAVER: + if (longhaul_flags & USE_ACPI_C3) { + /* Don't allow wakeup */ + acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 0); + do_powersaver(cx->address, mults_index, dir); + } else { + do_powersaver(0, mults_index, dir); + } + break; + } + + if (longhaul_flags & USE_NORTHBRIDGE) { + /* Enable arbiters */ + outb(0, 0x22); + } else if ((pr != NULL) && pr->flags.bm_control) { + /* Enable bus master arbitration */ + acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); + } + outb(pic2_mask, 0xA1); /* restore mask */ + outb(pic1_mask, 0x21); + + local_irq_restore(flags); + preempt_enable(); + + freqs.new = calc_speed(longhaul_get_cpu_mult()); + /* Check if requested frequency is set. */ + if (unlikely(freqs.new != speed)) { + pr_info("Failed to set requested frequency!\n"); + /* Revision ID = 1 but processor is expecting revision key + * equal to 0. Jumpers at the bottom of processor will change + * multiplier and FSB, but will not change bits in Longhaul + * MSR nor enable voltage scaling. */ + if (!revid_errata) { + pr_info("Enabling \"Ignore Revision ID\" option\n"); + revid_errata = 1; + msleep(200); + goto retry_loop; + } + /* Why ACPI C3 sometimes doesn't work is a mystery for me. + * But it does happen. Processor is entering ACPI C3 state, + * but it doesn't change frequency. I tried poking various + * bits in northbridge registers, but without success. */ + if (longhaul_flags & USE_ACPI_C3) { + pr_info("Disabling ACPI C3 support\n"); + longhaul_flags &= ~USE_ACPI_C3; + if (revid_errata) { + pr_info("Disabling \"Ignore Revision ID\" option\n"); + revid_errata = 0; + } + msleep(200); + goto retry_loop; + } + /* This shouldn't happen. Longhaul ver. 2 was reported not + * working on processors without voltage scaling, but with + * RevID = 1. RevID errata will make things right. Just + * to be 100% sure. */ + if (longhaul_version == TYPE_LONGHAUL_V2) { + pr_info("Switching to Longhaul ver. 1\n"); + longhaul_version = TYPE_LONGHAUL_V1; + msleep(200); + goto retry_loop; + } + } + + if (!bm_timeout) { + pr_info("Warning: Timeout while waiting for idle PCI bus\n"); + return -EBUSY; + } + + return 0; +} + +/* + * Centaur decided to make life a little more tricky. + * Only longhaul v1 is allowed to read EBLCR BSEL[0:1]. + * Samuel2 and above have to try and guess what the FSB is. + * We do this by assuming we booted at maximum multiplier, and interpolate + * between that value multiplied by possible FSBs and cpu_mhz which + * was calculated at boot time. Really ugly, but no other way to do this. + */ + +#define ROUNDING 0xf + +static int guess_fsb(int mult) +{ + int speed = cpu_khz / 1000; + int i; + int speeds[] = { 666, 1000, 1333, 2000 }; + int f_max, f_min; + + for (i = 0; i < 4; i++) { + f_max = ((speeds[i] * mult) + 50) / 100; + f_max += (ROUNDING / 2); + f_min = f_max - ROUNDING; + if ((speed <= f_max) && (speed >= f_min)) + return speeds[i] / 10; + } + return 0; +} + + +static int longhaul_get_ranges(void) +{ + unsigned int i, j, k = 0; + unsigned int ratio; + int mult; + + /* Get current frequency */ + mult = longhaul_get_cpu_mult(); + if (mult == -1) { + pr_info("Invalid (reserved) multiplier!\n"); + return -EINVAL; + } + fsb = guess_fsb(mult); + if (fsb == 0) { + pr_info("Invalid (reserved) FSB!\n"); + return -EINVAL; + } + /* Get max multiplier - as we always did. + * Longhaul MSR is useful only when voltage scaling is enabled. + * C3 is booting at max anyway. */ + maxmult = mult; + /* Get min multiplier */ + switch (cpu_model) { + case CPU_NEHEMIAH: + minmult = 50; + break; + case CPU_NEHEMIAH_C: + minmult = 40; + break; + default: + minmult = 30; + break; + } + + pr_debug("MinMult:%d.%dx MaxMult:%d.%dx\n", + minmult/10, minmult%10, maxmult/10, maxmult%10); + + highest_speed = calc_speed(maxmult); + lowest_speed = calc_speed(minmult); + pr_debug("FSB:%dMHz Lowest speed: %s Highest speed:%s\n", fsb, + print_speed(lowest_speed/1000), + print_speed(highest_speed/1000)); + + if (lowest_speed == highest_speed) { + pr_info("highestspeed == lowest, aborting\n"); + return -EINVAL; + } + if (lowest_speed > highest_speed) { + pr_info("nonsense! lowest (%d > %d) !\n", + lowest_speed, highest_speed); + return -EINVAL; + } + + longhaul_table = kcalloc(numscales + 1, sizeof(*longhaul_table), + GFP_KERNEL); + if (!longhaul_table) + return -ENOMEM; + + for (j = 0; j < numscales; j++) { + ratio = mults[j]; + if (ratio == -1) + continue; + if (ratio > maxmult || ratio < minmult) + continue; + longhaul_table[k].frequency = calc_speed(ratio); + longhaul_table[k].driver_data = j; + k++; + } + if (k <= 1) { + kfree(longhaul_table); + return -ENODEV; + } + /* Sort */ + for (j = 0; j < k - 1; j++) { + unsigned int min_f, min_i; + min_f = longhaul_table[j].frequency; + min_i = j; + for (i = j + 1; i < k; i++) { + if (longhaul_table[i].frequency < min_f) { + min_f = longhaul_table[i].frequency; + min_i = i; + } + } + if (min_i != j) { + swap(longhaul_table[j].frequency, + longhaul_table[min_i].frequency); + swap(longhaul_table[j].driver_data, + longhaul_table[min_i].driver_data); + } + } + + longhaul_table[k].frequency = CPUFREQ_TABLE_END; + + /* Find index we are running on */ + for (j = 0; j < k; j++) { + if (mults[longhaul_table[j].driver_data & 0x1f] == mult) { + longhaul_index = j; + break; + } + } + return 0; +} + + +static void longhaul_setup_voltagescaling(void) +{ + struct cpufreq_frequency_table *freq_pos; + union msr_longhaul longhaul; + struct mV_pos minvid, maxvid, vid; + unsigned int j, speed, pos, kHz_step, numvscales; + int min_vid_speed; + + rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); + if (!(longhaul.bits.RevisionID & 1)) { + pr_info("Voltage scaling not supported by CPU\n"); + return; + } + + if (!longhaul.bits.VRMRev) { + pr_info("VRM 8.5\n"); + vrm_mV_table = &vrm85_mV[0]; + mV_vrm_table = &mV_vrm85[0]; + } else { + pr_info("Mobile VRM\n"); + if (cpu_model < CPU_NEHEMIAH) + return; + vrm_mV_table = &mobilevrm_mV[0]; + mV_vrm_table = &mV_mobilevrm[0]; + } + + minvid = vrm_mV_table[longhaul.bits.MinimumVID]; + maxvid = vrm_mV_table[longhaul.bits.MaximumVID]; + + if (minvid.mV == 0 || maxvid.mV == 0 || minvid.mV > maxvid.mV) { + pr_info("Bogus values Min:%d.%03d Max:%d.%03d - Voltage scaling disabled\n", + minvid.mV/1000, minvid.mV%1000, + maxvid.mV/1000, maxvid.mV%1000); + return; + } + + if (minvid.mV == maxvid.mV) { + pr_info("Claims to support voltage scaling but min & max are both %d.%03d - Voltage scaling disabled\n", + maxvid.mV/1000, maxvid.mV%1000); + return; + } + + /* How many voltage steps*/ + numvscales = maxvid.pos - minvid.pos + 1; + pr_info("Max VID=%d.%03d Min VID=%d.%03d, %d possible voltage scales\n", + maxvid.mV/1000, maxvid.mV%1000, + minvid.mV/1000, minvid.mV%1000, + numvscales); + + /* Calculate max frequency at min voltage */ + j = longhaul.bits.MinMHzBR; + if (longhaul.bits.MinMHzBR4) + j += 16; + min_vid_speed = eblcr[j]; + if (min_vid_speed == -1) + return; + switch (longhaul.bits.MinMHzFSB) { + case 0: + min_vid_speed *= 13333; + break; + case 1: + min_vid_speed *= 10000; + break; + case 3: + min_vid_speed *= 6666; + break; + default: + return; + } + if (min_vid_speed >= highest_speed) + return; + /* Calculate kHz for one voltage step */ + kHz_step = (highest_speed - min_vid_speed) / numvscales; + + cpufreq_for_each_entry_idx(freq_pos, longhaul_table, j) { + speed = freq_pos->frequency; + if (speed > min_vid_speed) + pos = (speed - min_vid_speed) / kHz_step + minvid.pos; + else + pos = minvid.pos; + freq_pos->driver_data |= mV_vrm_table[pos] << 8; + vid = vrm_mV_table[mV_vrm_table[pos]]; + pr_info("f: %d kHz, index: %d, vid: %d mV\n", + speed, j, vid.mV); + } + + can_scale_voltage = 1; + pr_info("Voltage scaling enabled\n"); +} + + +static int longhaul_target(struct cpufreq_policy *policy, + unsigned int table_index) +{ + unsigned int i; + unsigned int dir = 0; + u8 vid, current_vid; + int retval = 0; + + if (!can_scale_voltage) + retval = longhaul_setstate(policy, table_index); + else { + /* On test system voltage transitions exceeding single + * step up or down were turning motherboard off. Both + * "ondemand" and "userspace" are unsafe. C7 is doing + * this in hardware, C3 is old and we need to do this + * in software. */ + i = longhaul_index; + current_vid = (longhaul_table[longhaul_index].driver_data >> 8); + current_vid &= 0x1f; + if (table_index > longhaul_index) + dir = 1; + while (i != table_index) { + vid = (longhaul_table[i].driver_data >> 8) & 0x1f; + if (vid != current_vid) { + retval = longhaul_setstate(policy, i); + current_vid = vid; + msleep(200); + } + if (dir) + i++; + else + i--; + } + retval = longhaul_setstate(policy, table_index); + } + + longhaul_index = table_index; + return retval; +} + + +static unsigned int longhaul_get(unsigned int cpu) +{ + if (cpu) + return 0; + return calc_speed(longhaul_get_cpu_mult()); +} + +static acpi_status longhaul_walk_callback(acpi_handle obj_handle, + u32 nesting_level, + void *context, void **return_value) +{ + struct acpi_device *d; + + if (acpi_bus_get_device(obj_handle, &d)) + return 0; + + *return_value = acpi_driver_data(d); + return 1; +} + +/* VIA don't support PM2 reg, but have something similar */ +static int enable_arbiter_disable(void) +{ + struct pci_dev *dev; + int status = 1; + int reg; + u8 pci_cmd; + + /* Find PLE133 host bridge */ + reg = 0x78; + dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8601_0, + NULL); + /* Find PM133/VT8605 host bridge */ + if (dev == NULL) + dev = pci_get_device(PCI_VENDOR_ID_VIA, + PCI_DEVICE_ID_VIA_8605_0, NULL); + /* Find CLE266 host bridge */ + if (dev == NULL) { + reg = 0x76; + dev = pci_get_device(PCI_VENDOR_ID_VIA, + PCI_DEVICE_ID_VIA_862X_0, NULL); + /* Find CN400 V-Link host bridge */ + if (dev == NULL) + dev = pci_get_device(PCI_VENDOR_ID_VIA, 0x7259, NULL); + } + if (dev != NULL) { + /* Enable access to port 0x22 */ + pci_read_config_byte(dev, reg, &pci_cmd); + if (!(pci_cmd & 1<<7)) { + pci_cmd |= 1<<7; + pci_write_config_byte(dev, reg, pci_cmd); + pci_read_config_byte(dev, reg, &pci_cmd); + if (!(pci_cmd & 1<<7)) { + pr_err("Can't enable access to port 0x22\n"); + status = 0; + } + } + pci_dev_put(dev); + return status; + } + return 0; +} + +static int longhaul_setup_southbridge(void) +{ + struct pci_dev *dev; + u8 pci_cmd; + + /* Find VT8235 southbridge */ + dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, NULL); + if (dev == NULL) + /* Find VT8237 southbridge */ + dev = pci_get_device(PCI_VENDOR_ID_VIA, + PCI_DEVICE_ID_VIA_8237, NULL); + if (dev != NULL) { + /* Set transition time to max */ + pci_read_config_byte(dev, 0xec, &pci_cmd); + pci_cmd &= ~(1 << 2); + pci_write_config_byte(dev, 0xec, pci_cmd); + pci_read_config_byte(dev, 0xe4, &pci_cmd); + pci_cmd &= ~(1 << 7); + pci_write_config_byte(dev, 0xe4, pci_cmd); + pci_read_config_byte(dev, 0xe5, &pci_cmd); + pci_cmd |= 1 << 7; + pci_write_config_byte(dev, 0xe5, pci_cmd); + /* Get address of ACPI registers block*/ + pci_read_config_byte(dev, 0x81, &pci_cmd); + if (pci_cmd & 1 << 7) { + pci_read_config_dword(dev, 0x88, &acpi_regs_addr); + acpi_regs_addr &= 0xff00; + pr_info("ACPI I/O at 0x%x\n", acpi_regs_addr); + } + + pci_dev_put(dev); + return 1; + } + return 0; +} + +static int longhaul_cpu_init(struct cpufreq_policy *policy) +{ + struct cpuinfo_x86 *c = &cpu_data(0); + char *cpuname = NULL; + int ret; + u32 lo, hi; + + /* Check what we have on this motherboard */ + switch (c->x86_model) { + case 6: + cpu_model = CPU_SAMUEL; + cpuname = "C3 'Samuel' [C5A]"; + longhaul_version = TYPE_LONGHAUL_V1; + memcpy(mults, samuel1_mults, sizeof(samuel1_mults)); + memcpy(eblcr, samuel1_eblcr, sizeof(samuel1_eblcr)); + break; + + case 7: + switch (c->x86_stepping) { + case 0: + longhaul_version = TYPE_LONGHAUL_V1; + cpu_model = CPU_SAMUEL2; + cpuname = "C3 'Samuel 2' [C5B]"; + /* Note, this is not a typo, early Samuel2's had + * Samuel1 ratios. */ + memcpy(mults, samuel1_mults, sizeof(samuel1_mults)); + memcpy(eblcr, samuel2_eblcr, sizeof(samuel2_eblcr)); + break; + case 1 ... 15: + longhaul_version = TYPE_LONGHAUL_V2; + if (c->x86_stepping < 8) { + cpu_model = CPU_SAMUEL2; + cpuname = "C3 'Samuel 2' [C5B]"; + } else { + cpu_model = CPU_EZRA; + cpuname = "C3 'Ezra' [C5C]"; + } + memcpy(mults, ezra_mults, sizeof(ezra_mults)); + memcpy(eblcr, ezra_eblcr, sizeof(ezra_eblcr)); + break; + } + break; + + case 8: + cpu_model = CPU_EZRA_T; + cpuname = "C3 'Ezra-T' [C5M]"; + longhaul_version = TYPE_POWERSAVER; + numscales = 32; + memcpy(mults, ezrat_mults, sizeof(ezrat_mults)); + memcpy(eblcr, ezrat_eblcr, sizeof(ezrat_eblcr)); + break; + + case 9: + longhaul_version = TYPE_POWERSAVER; + numscales = 32; + memcpy(mults, nehemiah_mults, sizeof(nehemiah_mults)); + memcpy(eblcr, nehemiah_eblcr, sizeof(nehemiah_eblcr)); + switch (c->x86_stepping) { + case 0 ... 1: + cpu_model = CPU_NEHEMIAH; + cpuname = "C3 'Nehemiah A' [C5XLOE]"; + break; + case 2 ... 4: + cpu_model = CPU_NEHEMIAH; + cpuname = "C3 'Nehemiah B' [C5XLOH]"; + break; + case 5 ... 15: + cpu_model = CPU_NEHEMIAH_C; + cpuname = "C3 'Nehemiah C' [C5P]"; + break; + } + break; + + default: + cpuname = "Unknown"; + break; + } + /* Check Longhaul ver. 2 */ + if (longhaul_version == TYPE_LONGHAUL_V2) { + rdmsr(MSR_VIA_LONGHAUL, lo, hi); + if (lo == 0 && hi == 0) + /* Looks like MSR isn't present */ + longhaul_version = TYPE_LONGHAUL_V1; + } + + pr_info("VIA %s CPU detected. ", cpuname); + switch (longhaul_version) { + case TYPE_LONGHAUL_V1: + case TYPE_LONGHAUL_V2: + pr_cont("Longhaul v%d supported\n", longhaul_version); + break; + case TYPE_POWERSAVER: + pr_cont("Powersaver supported\n"); + break; + } + + /* Doesn't hurt */ + longhaul_setup_southbridge(); + + /* Find ACPI data for processor */ + acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, &longhaul_walk_callback, NULL, + NULL, (void *)&pr); + + /* Check ACPI support for C3 state */ + if (pr != NULL && longhaul_version == TYPE_POWERSAVER) { + cx = &pr->power.states[ACPI_STATE_C3]; + if (cx->address > 0 && cx->latency <= 1000) + longhaul_flags |= USE_ACPI_C3; + } + /* Disable if it isn't working */ + if (disable_acpi_c3) + longhaul_flags &= ~USE_ACPI_C3; + /* Check if northbridge is friendly */ + if (enable_arbiter_disable()) + longhaul_flags |= USE_NORTHBRIDGE; + + /* Check ACPI support for bus master arbiter disable */ + if (!(longhaul_flags & USE_ACPI_C3 + || longhaul_flags & USE_NORTHBRIDGE) + && ((pr == NULL) || !(pr->flags.bm_control))) { + pr_err("No ACPI support: Unsupported northbridge\n"); + return -ENODEV; + } + + if (longhaul_flags & USE_NORTHBRIDGE) + pr_info("Using northbridge support\n"); + if (longhaul_flags & USE_ACPI_C3) + pr_info("Using ACPI support\n"); + + ret = longhaul_get_ranges(); + if (ret != 0) + return ret; + + if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0)) + longhaul_setup_voltagescaling(); + + policy->transition_delay_us = 200000; /* usec */ + policy->freq_table = longhaul_table; + + return 0; +} + +static struct cpufreq_driver longhaul_driver = { + .verify = cpufreq_generic_frequency_table_verify, + .target_index = longhaul_target, + .get = longhaul_get, + .init = longhaul_cpu_init, + .name = "longhaul", + .attr = cpufreq_generic_attr, +}; + +static const struct x86_cpu_id longhaul_id[] = { + X86_MATCH_VENDOR_FAM(CENTAUR, 6, NULL), + {} +}; +MODULE_DEVICE_TABLE(x86cpu, longhaul_id); + +static int __init longhaul_init(void) +{ + struct cpuinfo_x86 *c = &cpu_data(0); + + if (!x86_match_cpu(longhaul_id)) + return -ENODEV; + + if (!enable) { + pr_err("Option \"enable\" not set - Aborting\n"); + return -ENODEV; + } +#ifdef CONFIG_SMP + if (num_online_cpus() > 1) { + pr_err("More than 1 CPU detected, longhaul disabled\n"); + return -ENODEV; + } +#endif +#ifdef CONFIG_X86_IO_APIC + if (boot_cpu_has(X86_FEATURE_APIC)) { + pr_err("APIC detected. Longhaul is currently broken in this configuration.\n"); + return -ENODEV; + } +#endif + switch (c->x86_model) { + case 6 ... 9: + return cpufreq_register_driver(&longhaul_driver); + case 10: + pr_err("Use acpi-cpufreq driver for VIA C7\n"); + default: + ; + } + + return -ENODEV; +} + + +static void __exit longhaul_exit(void) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(0); + int i; + + for (i = 0; i < numscales; i++) { + if (mults[i] == maxmult) { + struct cpufreq_freqs freqs; + + freqs.old = policy->cur; + freqs.new = longhaul_table[i].frequency; + freqs.flags = 0; + + cpufreq_freq_transition_begin(policy, &freqs); + longhaul_setstate(policy, i); + cpufreq_freq_transition_end(policy, &freqs, 0); + break; + } + } + + cpufreq_cpu_put(policy); + cpufreq_unregister_driver(&longhaul_driver); + kfree(longhaul_table); +} + +/* Even if BIOS is exporting ACPI C3 state, and it is used + * with success when CPU is idle, this state doesn't + * trigger frequency transition in some cases. */ +module_param(disable_acpi_c3, int, 0644); +MODULE_PARM_DESC(disable_acpi_c3, "Don't use ACPI C3 support"); +/* Change CPU voltage with frequency. Very useful to save + * power, but most VIA C3 processors aren't supporting it. */ +module_param(scale_voltage, int, 0644); +MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor"); +/* Force revision key to 0 for processors which doesn't + * support voltage scaling, but are introducing itself as + * such. */ +module_param(revid_errata, int, 0644); +MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID"); +/* By default driver is disabled to prevent incompatible + * system freeze. */ +module_param(enable, int, 0644); +MODULE_PARM_DESC(enable, "Enable driver"); + +MODULE_AUTHOR("Dave Jones"); +MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors."); +MODULE_LICENSE("GPL"); + +late_initcall(longhaul_init); +module_exit(longhaul_exit); |