summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/powernow-k7.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/cpufreq/powernow-k7.c696
1 files changed, 696 insertions, 0 deletions
diff --git a/drivers/cpufreq/powernow-k7.c b/drivers/cpufreq/powernow-k7.c
new file mode 100644
index 000000000..5d515fc34
--- /dev/null
+++ b/drivers/cpufreq/powernow-k7.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD K7 Powernow driver.
+ * (C) 2003 Dave Jones on behalf of SuSE Labs.
+ *
+ * Based upon datasheets & sample CPUs kindly provided by AMD.
+ *
+ * Errata 5:
+ * CPU may fail to execute a FID/VID change in presence of interrupt.
+ * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
+ * Errata 15:
+ * CPU with half frequency multipliers may hang upon wakeup from disconnect.
+ * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
+ */
+
+#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/slab.h>
+#include <linux/string.h>
+#include <linux/dmi.h>
+#include <linux/timex.h>
+#include <linux/io.h>
+
+#include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
+#include <asm/msr.h>
+#include <asm/cpu_device_id.h>
+
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+#endif
+
+#include "powernow-k7.h"
+
+struct psb_s {
+ u8 signature[10];
+ u8 tableversion;
+ u8 flags;
+ u16 settlingtime;
+ u8 reserved1;
+ u8 numpst;
+};
+
+struct pst_s {
+ u32 cpuid;
+ u8 fsbspeed;
+ u8 maxfid;
+ u8 startvid;
+ u8 numpstates;
+};
+
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+union powernow_acpi_control_t {
+ struct {
+ unsigned long fid:5,
+ vid:5,
+ sgtc:20,
+ res1:2;
+ } bits;
+ unsigned long val;
+};
+#endif
+
+/* divide by 1000 to get VCore voltage in V. */
+static const int mobile_vid_table[32] = {
+ 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
+ 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
+ 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
+ 1075, 1050, 1025, 1000, 975, 950, 925, 0,
+};
+
+/* divide by 10 to get FID. */
+static const int fid_codes[32] = {
+ 110, 115, 120, 125, 50, 55, 60, 65,
+ 70, 75, 80, 85, 90, 95, 100, 105,
+ 30, 190, 40, 200, 130, 135, 140, 210,
+ 150, 225, 160, 165, 170, 180, -1, -1,
+};
+
+/* This parameter is used in order to force ACPI instead of legacy method for
+ * configuration purpose.
+ */
+
+static int acpi_force;
+
+static struct cpufreq_frequency_table *powernow_table;
+
+static unsigned int can_scale_bus;
+static unsigned int can_scale_vid;
+static unsigned int minimum_speed = -1;
+static unsigned int maximum_speed;
+static unsigned int number_scales;
+static unsigned int fsb;
+static unsigned int latency;
+static char have_a0;
+
+static int check_fsb(unsigned int fsbspeed)
+{
+ int delta;
+ unsigned int f = fsb / 1000;
+
+ delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
+ return delta < 5;
+}
+
+static const struct x86_cpu_id powernow_k7_cpuids[] = {
+ X86_MATCH_VENDOR_FAM(AMD, 6, NULL),
+ {}
+};
+MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
+
+static int check_powernow(void)
+{
+ struct cpuinfo_x86 *c = &cpu_data(0);
+ unsigned int maxei, eax, ebx, ecx, edx;
+
+ if (!x86_match_cpu(powernow_k7_cpuids))
+ return 0;
+
+ /* Get maximum capabilities */
+ maxei = cpuid_eax(0x80000000);
+ if (maxei < 0x80000007) { /* Any powernow info ? */
+#ifdef MODULE
+ pr_info("No powernow capabilities detected\n");
+#endif
+ return 0;
+ }
+
+ if ((c->x86_model == 6) && (c->x86_stepping == 0)) {
+ pr_info("K7 660[A0] core detected, enabling errata workarounds\n");
+ have_a0 = 1;
+ }
+
+ cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
+
+ /* Check we can actually do something before we say anything.*/
+ if (!(edx & (1 << 1 | 1 << 2)))
+ return 0;
+
+ pr_info("PowerNOW! Technology present. Can scale: ");
+
+ if (edx & 1 << 1) {
+ pr_cont("frequency");
+ can_scale_bus = 1;
+ }
+
+ if ((edx & (1 << 1 | 1 << 2)) == 0x6)
+ pr_cont(" and ");
+
+ if (edx & 1 << 2) {
+ pr_cont("voltage");
+ can_scale_vid = 1;
+ }
+
+ pr_cont("\n");
+ return 1;
+}
+
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+static void invalidate_entry(unsigned int entry)
+{
+ powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
+}
+#endif
+
+static int get_ranges(unsigned char *pst)
+{
+ unsigned int j;
+ unsigned int speed;
+ u8 fid, vid;
+
+ powernow_table = kzalloc((sizeof(*powernow_table) *
+ (number_scales + 1)), GFP_KERNEL);
+ if (!powernow_table)
+ return -ENOMEM;
+
+ for (j = 0 ; j < number_scales; j++) {
+ fid = *pst++;
+
+ powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
+ powernow_table[j].driver_data = fid; /* lower 8 bits */
+
+ speed = powernow_table[j].frequency;
+
+ if ((fid_codes[fid] % 10) == 5) {
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+ if (have_a0 == 1)
+ invalidate_entry(j);
+#endif
+ }
+
+ if (speed < minimum_speed)
+ minimum_speed = speed;
+ if (speed > maximum_speed)
+ maximum_speed = speed;
+
+ vid = *pst++;
+ powernow_table[j].driver_data |= (vid << 8); /* upper 8 bits */
+
+ pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
+ "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
+ fid_codes[fid] % 10, speed/1000, vid,
+ mobile_vid_table[vid]/1000,
+ mobile_vid_table[vid]%1000);
+ }
+ powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
+ powernow_table[number_scales].driver_data = 0;
+
+ return 0;
+}
+
+
+static void change_FID(int fid)
+{
+ union msr_fidvidctl fidvidctl;
+
+ rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
+ if (fidvidctl.bits.FID != fid) {
+ fidvidctl.bits.SGTC = latency;
+ fidvidctl.bits.FID = fid;
+ fidvidctl.bits.VIDC = 0;
+ fidvidctl.bits.FIDC = 1;
+ wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
+ }
+}
+
+
+static void change_VID(int vid)
+{
+ union msr_fidvidctl fidvidctl;
+
+ rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
+ if (fidvidctl.bits.VID != vid) {
+ fidvidctl.bits.SGTC = latency;
+ fidvidctl.bits.VID = vid;
+ fidvidctl.bits.FIDC = 0;
+ fidvidctl.bits.VIDC = 1;
+ wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
+ }
+}
+
+
+static int powernow_target(struct cpufreq_policy *policy, unsigned int index)
+{
+ u8 fid, vid;
+ struct cpufreq_freqs freqs;
+ union msr_fidvidstatus fidvidstatus;
+ int cfid;
+
+ /* fid are the lower 8 bits of the index we stored into
+ * the cpufreq frequency table in powernow_decode_bios,
+ * vid are the upper 8 bits.
+ */
+
+ fid = powernow_table[index].driver_data & 0xFF;
+ vid = (powernow_table[index].driver_data & 0xFF00) >> 8;
+
+ rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
+ cfid = fidvidstatus.bits.CFID;
+ freqs.old = fsb * fid_codes[cfid] / 10;
+
+ freqs.new = powernow_table[index].frequency;
+
+ /* Now do the magic poking into the MSRs. */
+
+ if (have_a0 == 1) /* A0 errata 5 */
+ local_irq_disable();
+
+ if (freqs.old > freqs.new) {
+ /* Going down, so change FID first */
+ change_FID(fid);
+ change_VID(vid);
+ } else {
+ /* Going up, so change VID first */
+ change_VID(vid);
+ change_FID(fid);
+ }
+
+
+ if (have_a0 == 1)
+ local_irq_enable();
+
+ return 0;
+}
+
+
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+
+static struct acpi_processor_performance *acpi_processor_perf;
+
+static int powernow_acpi_init(void)
+{
+ int i;
+ int retval = 0;
+ union powernow_acpi_control_t pc;
+
+ if (acpi_processor_perf != NULL && powernow_table != NULL) {
+ retval = -EINVAL;
+ goto err0;
+ }
+
+ acpi_processor_perf = kzalloc(sizeof(*acpi_processor_perf), GFP_KERNEL);
+ if (!acpi_processor_perf) {
+ retval = -ENOMEM;
+ goto err0;
+ }
+
+ if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
+ GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto err05;
+ }
+
+ if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
+ retval = -EIO;
+ goto err1;
+ }
+
+ if (acpi_processor_perf->control_register.space_id !=
+ ACPI_ADR_SPACE_FIXED_HARDWARE) {
+ retval = -ENODEV;
+ goto err2;
+ }
+
+ if (acpi_processor_perf->status_register.space_id !=
+ ACPI_ADR_SPACE_FIXED_HARDWARE) {
+ retval = -ENODEV;
+ goto err2;
+ }
+
+ number_scales = acpi_processor_perf->state_count;
+
+ if (number_scales < 2) {
+ retval = -ENODEV;
+ goto err2;
+ }
+
+ powernow_table = kzalloc((sizeof(*powernow_table) *
+ (number_scales + 1)), GFP_KERNEL);
+ if (!powernow_table) {
+ retval = -ENOMEM;
+ goto err2;
+ }
+
+ pc.val = (unsigned long) acpi_processor_perf->states[0].control;
+ for (i = 0; i < number_scales; i++) {
+ u8 fid, vid;
+ struct acpi_processor_px *state =
+ &acpi_processor_perf->states[i];
+ unsigned int speed, speed_mhz;
+
+ pc.val = (unsigned long) state->control;
+ pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
+ i,
+ (u32) state->core_frequency,
+ (u32) state->power,
+ (u32) state->transition_latency,
+ (u32) state->control,
+ pc.bits.sgtc);
+
+ vid = pc.bits.vid;
+ fid = pc.bits.fid;
+
+ powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
+ powernow_table[i].driver_data = fid; /* lower 8 bits */
+ powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */
+
+ speed = powernow_table[i].frequency;
+ speed_mhz = speed / 1000;
+
+ /* processor_perflib will multiply the MHz value by 1000 to
+ * get a KHz value (e.g. 1266000). However, powernow-k7 works
+ * with true KHz values (e.g. 1266768). To ensure that all
+ * powernow frequencies are available, we must ensure that
+ * ACPI doesn't restrict them, so we round up the MHz value
+ * to ensure that perflib's computed KHz value is greater than
+ * or equal to powernow's KHz value.
+ */
+ if (speed % 1000 > 0)
+ speed_mhz++;
+
+ if ((fid_codes[fid] % 10) == 5) {
+ if (have_a0 == 1)
+ invalidate_entry(i);
+ }
+
+ pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
+ "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
+ fid_codes[fid] % 10, speed_mhz, vid,
+ mobile_vid_table[vid]/1000,
+ mobile_vid_table[vid]%1000);
+
+ if (state->core_frequency != speed_mhz) {
+ state->core_frequency = speed_mhz;
+ pr_debug(" Corrected ACPI frequency to %d\n",
+ speed_mhz);
+ }
+
+ if (latency < pc.bits.sgtc)
+ latency = pc.bits.sgtc;
+
+ if (speed < minimum_speed)
+ minimum_speed = speed;
+ if (speed > maximum_speed)
+ maximum_speed = speed;
+ }
+
+ powernow_table[i].frequency = CPUFREQ_TABLE_END;
+ powernow_table[i].driver_data = 0;
+
+ /* notify BIOS that we exist */
+ acpi_processor_notify_smm(THIS_MODULE);
+
+ return 0;
+
+err2:
+ acpi_processor_unregister_performance(0);
+err1:
+ free_cpumask_var(acpi_processor_perf->shared_cpu_map);
+err05:
+ kfree(acpi_processor_perf);
+err0:
+ pr_warn("ACPI perflib can not be used on this platform\n");
+ acpi_processor_perf = NULL;
+ return retval;
+}
+#else
+static int powernow_acpi_init(void)
+{
+ pr_info("no support for ACPI processor found - please recompile your kernel with ACPI processor\n");
+ return -EINVAL;
+}
+#endif
+
+static void print_pst_entry(struct pst_s *pst, unsigned int j)
+{
+ pr_debug("PST:%d (@%p)\n", j, pst);
+ pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
+ pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
+}
+
+static int powernow_decode_bios(int maxfid, int startvid)
+{
+ struct psb_s *psb;
+ struct pst_s *pst;
+ unsigned int i, j;
+ unsigned char *p;
+ unsigned int etuple;
+ unsigned int ret;
+
+ etuple = cpuid_eax(0x80000001);
+
+ for (i = 0xC0000; i < 0xffff0 ; i += 16) {
+
+ p = phys_to_virt(i);
+
+ if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
+ pr_debug("Found PSB header at %p\n", p);
+ psb = (struct psb_s *) p;
+ pr_debug("Table version: 0x%x\n", psb->tableversion);
+ if (psb->tableversion != 0x12) {
+ pr_info("Sorry, only v1.2 tables supported right now\n");
+ return -ENODEV;
+ }
+
+ pr_debug("Flags: 0x%x\n", psb->flags);
+ if ((psb->flags & 1) == 0)
+ pr_debug("Mobile voltage regulator\n");
+ else
+ pr_debug("Desktop voltage regulator\n");
+
+ latency = psb->settlingtime;
+ if (latency < 100) {
+ pr_info("BIOS set settling time to %d microseconds. Should be at least 100. Correcting.\n",
+ latency);
+ latency = 100;
+ }
+ pr_debug("Settling Time: %d microseconds.\n",
+ psb->settlingtime);
+ pr_debug("Has %d PST tables. (Only dumping ones "
+ "relevant to this CPU).\n",
+ psb->numpst);
+
+ p += sizeof(*psb);
+
+ pst = (struct pst_s *) p;
+
+ for (j = 0; j < psb->numpst; j++) {
+ pst = (struct pst_s *) p;
+ number_scales = pst->numpstates;
+
+ if ((etuple == pst->cpuid) &&
+ check_fsb(pst->fsbspeed) &&
+ (maxfid == pst->maxfid) &&
+ (startvid == pst->startvid)) {
+ print_pst_entry(pst, j);
+ p = (char *)pst + sizeof(*pst);
+ ret = get_ranges(p);
+ return ret;
+ } else {
+ unsigned int k;
+ p = (char *)pst + sizeof(*pst);
+ for (k = 0; k < number_scales; k++)
+ p += 2;
+ }
+ }
+ pr_info("No PST tables match this cpuid (0x%x)\n",
+ etuple);
+ pr_info("This is indicative of a broken BIOS\n");
+
+ return -EINVAL;
+ }
+ p++;
+ }
+
+ return -ENODEV;
+}
+
+
+/*
+ * We use the fact that the bus frequency is somehow
+ * a multiple of 100000/3 khz, then we compute sgtc according
+ * to this multiple.
+ * That way, we match more how AMD thinks all of that work.
+ * We will then get the same kind of behaviour already tested under
+ * the "well-known" other OS.
+ */
+static int fixup_sgtc(void)
+{
+ unsigned int sgtc;
+ unsigned int m;
+
+ m = fsb / 3333;
+ if ((m % 10) >= 5)
+ m += 5;
+
+ m /= 10;
+
+ sgtc = 100 * m * latency;
+ sgtc = sgtc / 3;
+ if (sgtc > 0xfffff) {
+ pr_warn("SGTC too large %d\n", sgtc);
+ sgtc = 0xfffff;
+ }
+ return sgtc;
+}
+
+static unsigned int powernow_get(unsigned int cpu)
+{
+ union msr_fidvidstatus fidvidstatus;
+ unsigned int cfid;
+
+ if (cpu)
+ return 0;
+ rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
+ cfid = fidvidstatus.bits.CFID;
+
+ return fsb * fid_codes[cfid] / 10;
+}
+
+
+static int acer_cpufreq_pst(const struct dmi_system_id *d)
+{
+ pr_warn("%s laptop with broken PST tables in BIOS detected\n",
+ d->ident);
+ pr_warn("You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
+ pr_warn("cpufreq scaling has been disabled as a result of this\n");
+ return 0;
+}
+
+/*
+ * Some Athlon laptops have really fucked PST tables.
+ * A BIOS update is all that can save them.
+ * Mention this, and disable cpufreq.
+ */
+static const struct dmi_system_id powernow_dmi_table[] = {
+ {
+ .callback = acer_cpufreq_pst,
+ .ident = "Acer Aspire",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
+ DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
+ },
+ },
+ { }
+};
+
+static int powernow_cpu_init(struct cpufreq_policy *policy)
+{
+ union msr_fidvidstatus fidvidstatus;
+ int result;
+
+ if (policy->cpu != 0)
+ return -ENODEV;
+
+ rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
+
+ recalibrate_cpu_khz();
+
+ fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
+ if (!fsb) {
+ pr_warn("can not determine bus frequency\n");
+ return -EINVAL;
+ }
+ pr_debug("FSB: %3dMHz\n", fsb/1000);
+
+ if (dmi_check_system(powernow_dmi_table) || acpi_force) {
+ pr_info("PSB/PST known to be broken - trying ACPI instead\n");
+ result = powernow_acpi_init();
+ } else {
+ result = powernow_decode_bios(fidvidstatus.bits.MFID,
+ fidvidstatus.bits.SVID);
+ if (result) {
+ pr_info("Trying ACPI perflib\n");
+ maximum_speed = 0;
+ minimum_speed = -1;
+ latency = 0;
+ result = powernow_acpi_init();
+ if (result) {
+ pr_info("ACPI and legacy methods failed\n");
+ }
+ } else {
+ /* SGTC use the bus clock as timer */
+ latency = fixup_sgtc();
+ pr_info("SGTC: %d\n", latency);
+ }
+ }
+
+ if (result)
+ return result;
+
+ pr_info("Minimum speed %d MHz - Maximum speed %d MHz\n",
+ minimum_speed/1000, maximum_speed/1000);
+
+ policy->cpuinfo.transition_latency =
+ cpufreq_scale(2000000UL, fsb, latency);
+ policy->freq_table = powernow_table;
+
+ return 0;
+}
+
+static int powernow_cpu_exit(struct cpufreq_policy *policy)
+{
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+ if (acpi_processor_perf) {
+ acpi_processor_unregister_performance(0);
+ free_cpumask_var(acpi_processor_perf->shared_cpu_map);
+ kfree(acpi_processor_perf);
+ }
+#endif
+
+ kfree(powernow_table);
+ return 0;
+}
+
+static struct cpufreq_driver powernow_driver = {
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = powernow_target,
+ .get = powernow_get,
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+ .bios_limit = acpi_processor_get_bios_limit,
+#endif
+ .init = powernow_cpu_init,
+ .exit = powernow_cpu_exit,
+ .name = "powernow-k7",
+ .attr = cpufreq_generic_attr,
+};
+
+static int __init powernow_init(void)
+{
+ if (check_powernow() == 0)
+ return -ENODEV;
+ return cpufreq_register_driver(&powernow_driver);
+}
+
+
+static void __exit powernow_exit(void)
+{
+ cpufreq_unregister_driver(&powernow_driver);
+}
+
+module_param(acpi_force, int, 0444);
+MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
+
+MODULE_AUTHOR("Dave Jones");
+MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
+MODULE_LICENSE("GPL");
+
+late_initcall(powernow_init);
+module_exit(powernow_exit);
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 23:56:44 +0000