text: /*
   *   (c) 2003-2012 Advanced Micro Devices, Inc.
   *  Your use of this code is subject to the terms and conditions of the
   *  GNU general public license version 2. See "COPYING" or
   *  http://www.gnu.org/licenses/gpl.html
   *
   *  Maintainer:
   *  Andreas Herrmann <herrmann.der.user@googlemail.com>
   *
   *  Based on the powernow-k7.c module written by Dave Jones.
   *  (C) 2003 Dave Jones on behalf of SuSE Labs
   *  (C) 2004 Dominik Brodowski <linux@brodo.de>
   *  (C) 2004 Pavel Machek <pavel@ucw.cz>
   *  Licensed under the terms of the GNU GPL License version 2.
   *  Based upon datasheets & sample CPUs kindly provided by AMD.
   *
   *  Valuable input gratefully received from Dave Jones, Pavel Machek,
   *  Dominik Brodowski, Jacob Shin, and others.
   *  Originally developed by Paul Devriendt.
   *
   *  Processor information obtained from Chapter 9 (Power and Thermal
   *  Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
   *  the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
   *  Power Management" in BKDGs for newer AMD CPU families.
   *
   *  Tables for specific CPUs can be inferred from AMD's processor
   *  power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/kernel.h>
  #include <linux/smp.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/cpufreq.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/cpumask.h>
  #include <linux/io.h>
  #include <linux/delay.h>
  
  #include <asm/msr.h>
  #include <asm/cpu_device_id.h>
  
  #include <linux/acpi.h>
  #include <linux/mutex.h>
  #include <acpi/processor.h>
  
  #define VERSION "version 2.20.00"
  #include "powernow-k8.h"
  
  /* serialize freq changes  */
  static DEFINE_MUTEX(fidvid_mutex);
  
  static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
  
  static struct cpufreq_driver cpufreq_amd64_driver;
  
  /* Return a frequency in MHz, given an input fid */
  static u32 find_freq_from_fid(u32 fid)
  {
  	return 800 + (fid * 100);
  }
  
  /* Return a frequency in KHz, given an input fid */
  static u32 find_khz_freq_from_fid(u32 fid)
  {
  	return 1000 * find_freq_from_fid(fid);
  }
  
  /* Return the vco fid for an input fid
   *
   * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
   * only from corresponding high fids. This returns "high" fid corresponding to
   * "low" one.
   */
  static u32 convert_fid_to_vco_fid(u32 fid)
  {
  	if (fid < HI_FID_TABLE_BOTTOM)
  		return 8 + (2 * fid);
  	else
  		return fid;
  }
  
  /*
   * Return 1 if the pending bit is set. Unless we just instructed the processor
   * to transition to a new state, seeing this bit set is really bad news.
   */
  static int pending_bit_stuck(void)
  {
  	u32 lo, hi;
  
  	rdmsr(MSR_FIDVID_STATUS, lo, hi);
  	return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
  }
  
  /*
   * Update the global current fid / vid values from the status msr.
   * Returns 1 on error.
   */
  static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
  {
  	u32 lo, hi;
  	u32 i = 0;
  
  	do {
  		if (i++ > 10000) {
  			pr_debug("detected change pending stuck\n");
  			return 1;
  		}
  		rdmsr(MSR_FIDVID_STATUS, lo, hi);
  	} while (lo & MSR_S_LO_CHANGE_PENDING);
  
  	data->currvid = hi & MSR_S_HI_CURRENT_VID;
  	data->currfid = lo & MSR_S_LO_CURRENT_FID;
  
  	return 0;
  }
  
  /* the isochronous relief time */
  static void count_off_irt(struct powernow_k8_data *data)
  {
  	udelay((1 << data->irt) * 10);
  	return;
  }
  
  /* the voltage stabilization time */
  static void count_off_vst(struct powernow_k8_data *data)
  {
  	udelay(data->vstable * VST_UNITS_20US);
  	return;
  }
  
  /* need to init the control msr to a safe value (for each cpu) */
  static void fidvid_msr_init(void)
  {
  	u32 lo, hi;
  	u8 fid, vid;
  
  	rdmsr(MSR_FIDVID_STATUS, lo, hi);
  	vid = hi & MSR_S_HI_CURRENT_VID;
  	fid = lo & MSR_S_LO_CURRENT_FID;
  	lo = fid | (vid << MSR_C_LO_VID_SHIFT);
  	hi = MSR_C_HI_STP_GNT_BENIGN;
  	pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
  	wrmsr(MSR_FIDVID_CTL, lo, hi);
  }
  
  /* write the new fid value along with the other control fields to the msr */
  static int write_new_fid(struct powernow_k8_data *data, u32 fid)
  {
  	u32 lo;
  	u32 savevid = data->currvid;
  	u32 i = 0;
  
  	if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
  		pr_err("internal error - overflow on fid write\n");
  		return 1;
  	}
  
  	lo = fid;
  	lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
  	lo |= MSR_C_LO_INIT_FID_VID;
  
  	pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
  		fid, lo, data->plllock * PLL_LOCK_CONVERSION);
  
  	do {
  		wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
  		if (i++ > 100) {
  			pr_err("Hardware error - pending bit very stuck - no further pstate changes possible\n");
  			return 1;
  		}
  	} while (query_current_values_with_pending_wait(data));
  
  	count_off_irt(data);
  
  	if (savevid != data->currvid) {
  		pr_err("vid change on fid trans, old 0x%x, new 0x%x\n",
  		       savevid, data->currvid);
  		return 1;
  	}
  
  	if (fid != data->currfid) {
  		pr_err("fid trans failed, fid 0x%x, curr 0x%x\n", fid,
  			data->currfid);
  		return 1;
  	}
  
  	return 0;
  }
  
  /* Write a new vid to the hardware */
  static int write_new_vid(struct powernow_k8_data *data, u32 vid)
  {
  	u32 lo;
  	u32 savefid = data->currfid;
  	int i = 0;
  
  	if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
  		pr_err("internal error - overflow on vid write\n");
  		return 1;
  	}
  
  	lo = data->currfid;
  	lo |= (vid << MSR_C_LO_VID_SHIFT);
  	lo |= MSR_C_LO_INIT_FID_VID;
  
  	pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
  		vid, lo, STOP_GRANT_5NS);
  
  	do {
  		wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
  		if (i++ > 100) {
  			pr_err("internal error - pending bit very stuck - no further pstate changes possible\n");
  			return 1;
  		}
  	} while (query_current_values_with_pending_wait(data));
  
  	if (savefid != data->currfid) {
  		pr_err("fid changed on vid trans, old 0x%x new 0x%x\n",
  			savefid, data->currfid);
  		return 1;
  	}
  
  	if (vid != data->currvid) {
  		pr_err("vid trans failed, vid 0x%x, curr 0x%x\n",
  				vid, data->currvid);
  		return 1;
  	}
  
  	return 0;
  }
  
  /*
   * Reduce the vid by the max of step or reqvid.
   * Decreasing vid codes represent increasing voltages:
   * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
   */
  static int decrease_vid_code_by_step(struct powernow_k8_data *data,
  		u32 reqvid, u32 step)
  {
  	if ((data->currvid - reqvid) > step)
  		reqvid = data->currvid - step;
  
  	if (write_new_vid(data, reqvid))
  		return 1;
  
  	count_off_vst(data);
  
  	return 0;
  }
  
  /* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
  static int transition_fid_vid(struct powernow_k8_data *data,
  		u32 reqfid, u32 reqvid)
  {
  	if (core_voltage_pre_transition(data, reqvid, reqfid))
  		return 1;
  
  	if (core_frequency_transition(data, reqfid))
  		return 1;
  
  	if (core_voltage_post_transition(data, reqvid))
  		return 1;
  
  	if (query_current_values_with_pending_wait(data))
  		return 1;
  
  	if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
  		pr_err("failed (cpu%d): req 0x%x 0x%x, curr 0x%x 0x%x\n",
  				smp_processor_id(),
  				reqfid, reqvid, data->currfid, data->currvid);
  		return 1;
  	}
  
  	pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
  		smp_processor_id(), data->currfid, data->currvid);
  
  	return 0;
  }
  
  /* Phase 1 - core voltage transition ... setup voltage */
  static int core_voltage_pre_transition(struct powernow_k8_data *data,
  		u32 reqvid, u32 reqfid)
  {
  	u32 rvosteps = data->rvo;
  	u32 savefid = data->currfid;
  	u32 maxvid, lo, rvomult = 1;
  
  	pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, reqvid 0x%x, rvo 0x%x\n",
  		smp_processor_id(),
  		data->currfid, data->currvid, reqvid, data->rvo);
  
  	if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
  		rvomult = 2;
  	rvosteps *= rvomult;
  	rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
  	maxvid = 0x1f & (maxvid >> 16);
  	pr_debug("ph1 maxvid=0x%x\n", maxvid);
  	if (reqvid < maxvid) /* lower numbers are higher voltages */
  		reqvid = maxvid;
  
  	while (data->currvid > reqvid) {
  		pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
  			data->currvid, reqvid);
  		if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
  			return 1;
  	}
  
  	while ((rvosteps > 0) &&
  			((rvomult * data->rvo + data->currvid) > reqvid)) {
  		if (data->currvid == maxvid) {
  			rvosteps = 0;
  		} else {
  			pr_debug("ph1: changing vid for rvo, req 0x%x\n",
  				data->currvid - 1);
  			if (decrease_vid_code_by_step(data, data->currvid-1, 1))
  				return 1;
  			rvosteps--;
  		}
  	}
  
  	if (query_current_values_with_pending_wait(data))
  		return 1;
  
  	if (savefid != data->currfid) {
  		pr_err("ph1 err, currfid changed 0x%x\n", data->currfid);
  		return 1;
  	}
  
  	pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
  		data->currfid, data->currvid);
  
  	return 0;
  }
  
  /* Phase 2 - core frequency transition */
  static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
  {
  	u32 vcoreqfid, vcocurrfid, vcofiddiff;
  	u32 fid_interval, savevid = data->currvid;
  
  	if (data->currfid == reqfid) {
  		pr_err("ph2 null fid transition 0x%x\n", data->currfid);
  		return 0;
  	}
  
  	pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, reqfid 0x%x\n",
  		smp_processor_id(),
  		data->currfid, data->currvid, reqfid);
  
  	vcoreqfid = convert_fid_to_vco_fid(reqfid);
  	vcocurrfid = convert_fid_to_vco_fid(data->currfid);
  	vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
  	    : vcoreqfid - vcocurrfid;
  
  	if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
  		vcofiddiff = 0;
  
  	while (vcofiddiff > 2) {
  		(data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
  
  		if (reqfid > data->currfid) {
  			if (data->currfid > LO_FID_TABLE_TOP) {
  				if (write_new_fid(data,
  						data->currfid + fid_interval))
  					return 1;
  			} else {
  				if (write_new_fid
  				    (data,
  				     2 + convert_fid_to_vco_fid(data->currfid)))
  					return 1;
  			}
  		} else {
  			if (write_new_fid(data, data->currfid - fid_interval))
  				return 1;
  		}
  
  		vcocurrfid = convert_fid_to_vco_fid(data->currfid);
  		vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
  		    : vcoreqfid - vcocurrfid;
  	}
  
  	if (write_new_fid(data, reqfid))
  		return 1;
  
  	if (query_current_values_with_pending_wait(data))
  		return 1;
  
  	if (data->currfid != reqfid) {
  		pr_err("ph2: mismatch, failed fid transition, curr 0x%x, req 0x%x\n",
  			data->currfid, reqfid);
  		return 1;
  	}
  
  	if (savevid != data->currvid) {
  		pr_err("ph2: vid changed, save 0x%x, curr 0x%x\n",
  			savevid, data->currvid);
  		return 1;
  	}
  
  	pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
  		data->currfid, data->currvid);
  
  	return 0;
  }
  
  /* Phase 3 - core voltage transition flow ... jump to the final vid. */
  static int core_voltage_post_transition(struct powernow_k8_data *data,
  		u32 reqvid)
  {
  	u32 savefid = data->currfid;
  	u32 savereqvid = reqvid;
  
  	pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
  		smp_processor_id(),
  		data->currfid, data->currvid);
  
  	if (reqvid != data->currvid) {
  		if (write_new_vid(data, reqvid))
  			return 1;
  
  		if (savefid != data->currfid) {
  			pr_err("ph3: bad fid change, save 0x%x, curr 0x%x\n",
  				savefid, data->currfid);
  			return 1;
  		}
  
  		if (data->currvid != reqvid) {
  			pr_err("ph3: failed vid transition\n, req 0x%x, curr 0x%x",
  				reqvid, data->currvid);
  			return 1;
  		}
  	}
  
  	if (query_current_values_with_pending_wait(data))
  		return 1;
  
  	if (savereqvid != data->currvid) {
  		pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
  		return 1;
  	}
  
  	if (savefid != data->currfid) {
  		pr_debug("ph3 failed, currfid changed 0x%x\n",
  			data->currfid);
  		return 1;
  	}
  
  	pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
  		data->currfid, data->currvid);
  
  	return 0;
  }
  
  static const struct x86_cpu_id powernow_k8_ids[] = {
  	/* IO based frequency switching */
  	{ X86_VENDOR_AMD, 0xf },
  	{}
  };
  MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
  
  static void check_supported_cpu(void *_rc)
  {
  	u32 eax, ebx, ecx, edx;
  	int *rc = _rc;
  
  	*rc = -ENODEV;
  
  	eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
  
  	if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
  		if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
  		    ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
  			pr_info("Processor cpuid %x not supported\n", eax);
  			return;
  		}
  
  		eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
  		if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
  			pr_info("No frequency change capabilities detected\n");
  			return;
  		}
  
  		cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
  		if ((edx & P_STATE_TRANSITION_CAPABLE)
  			!= P_STATE_TRANSITION_CAPABLE) {
  			pr_info("Power state transitions not supported\n");
  			return;
  		}
  		*rc = 0;
  	}
  }
  
  static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
  		u8 maxvid)
  {
  	unsigned int j;
  	u8 lastfid = 0xff;
  
  	for (j = 0; j < data->numps; j++) {
  		if (pst[j].vid > LEAST_VID) {
  			pr_err(FW_BUG "vid %d invalid : 0x%x\n", j,
  				pst[j].vid);
  			return -EINVAL;
  		}
  		if (pst[j].vid < data->rvo) {
  			/* vid + rvo >= 0 */
  			pr_err(FW_BUG "0 vid exceeded with pstate %d\n", j);
  			return -ENODEV;
  		}
  		if (pst[j].vid < maxvid + data->rvo) {
  			/* vid + rvo >= maxvid */
  			pr_err(FW_BUG "maxvid exceeded with pstate %d\n", j);
  			return -ENODEV;
  		}
  		if (pst[j].fid > MAX_FID) {
  			pr_err(FW_BUG "maxfid exceeded with pstate %d\n", j);
  			return -ENODEV;
  		}
  		if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
  			/* Only first fid is allowed to be in "low" range */
  			pr_err(FW_BUG "two low fids - %d : 0x%x\n", j,
  				pst[j].fid);
  			return -EINVAL;
  		}
  		if (pst[j].fid < lastfid)
  			lastfid = pst[j].fid;
  	}
  	if (lastfid & 1) {
  		pr_err(FW_BUG "lastfid invalid\n");
  		return -EINVAL;
  	}
  	if (lastfid > LO_FID_TABLE_TOP)
  		pr_info(FW_BUG "first fid not from lo freq table\n");
  
  	return 0;
  }
  
  static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
  		unsigned int entry)
  {
  	powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
  }
  
  static void print_basics(struct powernow_k8_data *data)
  {
  	int j;
  	for (j = 0; j < data->numps; j++) {
  		if (data->powernow_table[j].frequency !=
  				CPUFREQ_ENTRY_INVALID) {
  			pr_info("fid 0x%x (%d MHz), vid 0x%x\n",
  				data->powernow_table[j].driver_data & 0xff,
  				data->powernow_table[j].frequency/1000,
  				data->powernow_table[j].driver_data >> 8);
  		}
  	}
  	if (data->batps)
  		pr_info("Only %d pstates on battery\n", data->batps);
  }
  
  static int fill_powernow_table(struct powernow_k8_data *data,
  		struct pst_s *pst, u8 maxvid)
  {
  	struct cpufreq_frequency_table *powernow_table;
  	unsigned int j;
  
  	if (data->batps) {
  		/* use ACPI support to get full speed on mains power */
  		pr_warn("Only %d pstates usable (use ACPI driver for full range\n",
  			data->batps);
  		data->numps = data->batps;
  	}
  
  	for (j = 1; j < data->numps; j++) {
  		if (pst[j-1].fid >= pst[j].fid) {
  			pr_err("PST out of sequence\n");
  			return -EINVAL;
  		}
  	}
  
  	if (data->numps < 2) {
  		pr_err("no p states to transition\n");
  		return -ENODEV;
  	}
  
  	if (check_pst_table(data, pst, maxvid))
  		return -EINVAL;
  
  	powernow_table = kzalloc((sizeof(*powernow_table)
  		* (data->numps + 1)), GFP_KERNEL);
  	if (!powernow_table) {
  		pr_err("powernow_table memory alloc failure\n");
  		return -ENOMEM;
  	}
  
  	for (j = 0; j < data->numps; j++) {
  		int freq;
  		powernow_table[j].driver_data = pst[j].fid; /* lower 8 bits */
  		powernow_table[j].driver_data |= (pst[j].vid << 8); /* upper 8 bits */
  		freq = find_khz_freq_from_fid(pst[j].fid);
  		powernow_table[j].frequency = freq;
  	}
  	powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
  	powernow_table[data->numps].driver_data = 0;
  
  	if (query_current_values_with_pending_wait(data)) {
  		kfree(powernow_table);
  		return -EIO;
  	}
  
  	pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
  	data->powernow_table = powernow_table;
  	if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
  		print_basics(data);
  
  	for (j = 0; j < data->numps; j++)
  		if ((pst[j].fid == data->currfid) &&
  		    (pst[j].vid == data->currvid))
  			return 0;
  
  	pr_debug("currfid/vid do not match PST, ignoring\n");
  	return 0;
  }
  
  /* Find and validate the PSB/PST table in BIOS. */
  static int find_psb_table(struct powernow_k8_data *data)
  {
  	struct psb_s *psb;
  	unsigned int i;
  	u32 mvs;
  	u8 maxvid;
  	u32 cpst = 0;
  	u32 thiscpuid;
  
  	for (i = 0xc0000; i < 0xffff0; i += 0x10) {
  		/* Scan BIOS looking for the signature. */
  		/* It can not be at ffff0 - it is too big. */
  
  		psb = phys_to_virt(i);
  		if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
  			continue;
  
  		pr_debug("found PSB header at 0x%p\n", psb);
  
  		pr_debug("table vers: 0x%x\n", psb->tableversion);
  		if (psb->tableversion != PSB_VERSION_1_4) {
  			pr_err(FW_BUG "PSB table is not v1.4\n");
  			return -ENODEV;
  		}
  
  		pr_debug("flags: 0x%x\n", psb->flags1);
  		if (psb->flags1) {
  			pr_err(FW_BUG "unknown flags\n");
  			return -ENODEV;
  		}
  
  		data->vstable = psb->vstable;
  		pr_debug("voltage stabilization time: %d(*20us)\n",
  				data->vstable);
  
  		pr_debug("flags2: 0x%x\n", psb->flags2);
  		data->rvo = psb->flags2 & 3;
  		data->irt = ((psb->flags2) >> 2) & 3;
  		mvs = ((psb->flags2) >> 4) & 3;
  		data->vidmvs = 1 << mvs;
  		data->batps = ((psb->flags2) >> 6) & 3;
  
  		pr_debug("ramp voltage offset: %d\n", data->rvo);
  		pr_debug("isochronous relief time: %d\n", data->irt);
  		pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
  
  		pr_debug("numpst: 0x%x\n", psb->num_tables);
  		cpst = psb->num_tables;
  		if ((psb->cpuid == 0x00000fc0) ||
  		    (psb->cpuid == 0x00000fe0)) {
  			thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
  			if ((thiscpuid == 0x00000fc0) ||
  			    (thiscpuid == 0x00000fe0))
  				cpst = 1;
  		}
  		if (cpst != 1) {
  			pr_err(FW_BUG "numpst must be 1\n");
  			return -ENODEV;
  		}
  
  		data->plllock = psb->plllocktime;
  		pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
  		pr_debug("maxfid: 0x%x\n", psb->maxfid);
  		pr_debug("maxvid: 0x%x\n", psb->maxvid);
  		maxvid = psb->maxvid;
  
  		data->numps = psb->numps;
  		pr_debug("numpstates: 0x%x\n", data->numps);
  		return fill_powernow_table(data,
  				(struct pst_s *)(psb+1), maxvid);
  	}
  	/*
  	 * If you see this message, complain to BIOS manufacturer. If
  	 * he tells you "we do not support Linux" or some similar
  	 * nonsense, remember that Windows 2000 uses the same legacy
  	 * mechanism that the old Linux PSB driver uses. Tell them it
  	 * is broken with Windows 2000.
  	 *
  	 * The reference to the AMD documentation is chapter 9 in the
  	 * BIOS and Kernel Developer's Guide, which is available on
  	 * www.amd.com
  	 */
  	pr_err(FW_BUG "No PSB or ACPI _PSS objects\n");
  	pr_err("Make sure that your BIOS is up to date and Cool'N'Quiet support is enabled in BIOS setup\n");
  	return -ENODEV;
  }
  
  static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
  		unsigned int index)
  {
  	u64 control;
  
  	if (!data->acpi_data.state_count)
  		return;
  
  	control = data->acpi_data.states[index].control;
  	data->irt = (control >> IRT_SHIFT) & IRT_MASK;
  	data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
  	data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
  	data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
  	data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
  	data->vstable = (control >> VST_SHIFT) & VST_MASK;
  }
  
  static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
  {
  	struct cpufreq_frequency_table *powernow_table;
  	int ret_val = -ENODEV;
  	u64 control, status;
  
  	if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
  		pr_debug("register performance failed: bad ACPI data\n");
  		return -EIO;
  	}
  
  	/* verify the data contained in the ACPI structures */
  	if (data->acpi_data.state_count <= 1) {
  		pr_debug("No ACPI P-States\n");
  		goto err_out;
  	}
  
  	control = data->acpi_data.control_register.space_id;
  	status = data->acpi_data.status_register.space_id;
  
  	if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
  	    (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
  		pr_debug("Invalid control/status registers (%llx - %llx)\n",
  			control, status);
  		goto err_out;
  	}
  
  	/* fill in data->powernow_table */
  	powernow_table = kzalloc((sizeof(*powernow_table)
  		* (data->acpi_data.state_count + 1)), GFP_KERNEL);
  	if (!powernow_table) {
  		pr_debug("powernow_table memory alloc failure\n");
  		goto err_out;
  	}
  
  	/* fill in data */
  	data->numps = data->acpi_data.state_count;
  	powernow_k8_acpi_pst_values(data, 0);
  
  	ret_val = fill_powernow_table_fidvid(data, powernow_table);
  	if (ret_val)
  		goto err_out_mem;
  
  	powernow_table[data->acpi_data.state_count].frequency =
  		CPUFREQ_TABLE_END;
  	data->powernow_table = powernow_table;
  
  	if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
  		print_basics(data);
  
  	/* notify BIOS that we exist */
  	acpi_processor_notify_smm(THIS_MODULE);
  
  	if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
  		pr_err("unable to alloc powernow_k8_data cpumask\n");
  		ret_val = -ENOMEM;
  		goto err_out_mem;
  	}
  
  	return 0;
  
  err_out_mem:
  	kfree(powernow_table);
  
  err_out:
  	acpi_processor_unregister_performance(data->cpu);
  
  	/* data->acpi_data.state_count informs us at ->exit()
  	 * whether ACPI was used */
  	data->acpi_data.state_count = 0;
  
  	return ret_val;
  }
  
  static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
  		struct cpufreq_frequency_table *powernow_table)
  {
  	int i;
  
  	for (i = 0; i < data->acpi_data.state_count; i++) {
  		u32 fid;
  		u32 vid;
  		u32 freq, index;
  		u64 status, control;
  
  		if (data->exttype) {
  			status =  data->acpi_data.states[i].status;
  			fid = status & EXT_FID_MASK;
  			vid = (status >> VID_SHIFT) & EXT_VID_MASK;
  		} else {
  			control =  data->acpi_data.states[i].control;
  			fid = control & FID_MASK;
  			vid = (control >> VID_SHIFT) & VID_MASK;
  		}
  
  		pr_debug("   %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
  
  		index = fid | (vid<<8);
  		powernow_table[i].driver_data = index;
  
  		freq = find_khz_freq_from_fid(fid);
  		powernow_table[i].frequency = freq;
  
  		/* verify frequency is OK */
  		if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
  			pr_debug("invalid freq %u kHz, ignoring\n", freq);
  			invalidate_entry(powernow_table, i);
  			continue;
  		}
  
  		/* verify voltage is OK -
  		 * BIOSs are using "off" to indicate invalid */
  		if (vid == VID_OFF) {
  			pr_debug("invalid vid %u, ignoring\n", vid);
  			invalidate_entry(powernow_table, i);
  			continue;
  		}
  
  		if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
  			pr_info("invalid freq entries %u kHz vs. %u kHz\n",
  				freq, (unsigned int)
  				(data->acpi_data.states[i].core_frequency
  				 * 1000));
  			invalidate_entry(powernow_table, i);
  			continue;
  		}
  	}
  	return 0;
  }
  
  static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
  {
  	if (data->acpi_data.state_count)
  		acpi_processor_unregister_performance(data->cpu);
  	free_cpumask_var(data->acpi_data.shared_cpu_map);
  }
  
  static int get_transition_latency(struct powernow_k8_data *data)
  {
  	int max_latency = 0;
  	int i;
  	for (i = 0; i < data->acpi_data.state_count; i++) {
  		int cur_latency = data->acpi_data.states[i].transition_latency
  			+ data->acpi_data.states[i].bus_master_latency;
  		if (cur_latency > max_latency)
  			max_latency = cur_latency;
  	}
  	if (max_latency == 0) {
  		pr_err(FW_WARN "Invalid zero transition latency\n");
  		max_latency = 1;
  	}
  	/* value in usecs, needs to be in nanoseconds */
  	return 1000 * max_latency;
  }
  
  /* Take a frequency, and issue the fid/vid transition command */
  static int transition_frequency_fidvid(struct powernow_k8_data *data,
  		unsigned int index)
  {
  	struct cpufreq_policy *policy;
  	u32 fid = 0;
  	u32 vid = 0;
  	int res;
  	struct cpufreq_freqs freqs;
  
  	pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
  
  	/* fid/vid correctness check for k8 */
  	/* fid are the lower 8 bits of the index we stored into
  	 * the cpufreq frequency table in find_psb_table, vid
  	 * are the upper 8 bits.
  	 */
  	fid = data->powernow_table[index].driver_data & 0xFF;
  	vid = (data->powernow_table[index].driver_data & 0xFF00) >> 8;
  
  	pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
  
  	if (query_current_values_with_pending_wait(data))
  		return 1;
  
  	if ((data->currvid == vid) && (data->currfid == fid)) {
  		pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
  			fid, vid);
  		return 0;
  	}
  
  	pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
  		smp_processor_id(), fid, vid);
  	freqs.old = find_khz_freq_from_fid(data->currfid);
  	freqs.new = find_khz_freq_from_fid(fid);
  
  	policy = cpufreq_cpu_get(smp_processor_id());
  	cpufreq_cpu_put(policy);
  
  	cpufreq_freq_transition_begin(policy, &freqs);
  	res = transition_fid_vid(data, fid, vid);
  	cpufreq_freq_transition_end(policy, &freqs, res);
  
  	return res;
  }
  
  struct powernowk8_target_arg {
  	struct cpufreq_policy		*pol;
  	unsigned			newstate;
  };
  
  static long powernowk8_target_fn(void *arg)
  {
  	struct powernowk8_target_arg *pta = arg;
  	struct cpufreq_policy *pol = pta->pol;
  	unsigned newstate = pta->newstate;
  	struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
  	u32 checkfid;
  	u32 checkvid;
  	int ret;
  
  	if (!data)
  		return -EINVAL;
  
  	checkfid = data->currfid;
  	checkvid = data->currvid;
  
  	if (pending_bit_stuck()) {
  		pr_err("failing targ, change pending bit set\n");
  		return -EIO;
  	}
  
  	pr_debug("targ: cpu %d, %d kHz, min %d, max %d\n",
  		pol->cpu, data->powernow_table[newstate].frequency, pol->min,
  		pol->max);
  
  	if (query_current_values_with_pending_wait(data))
  		return -EIO;
  
  	pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
  		data->currfid, data->currvid);
  
  	if ((checkvid != data->currvid) ||
  	    (checkfid != data->currfid)) {
  		pr_info("error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
  		       checkfid, data->currfid,
  		       checkvid, data->currvid);
  	}
  
  	mutex_lock(&fidvid_mutex);
  
  	powernow_k8_acpi_pst_values(data, newstate);
  
  	ret = transition_frequency_fidvid(data, newstate);
  
  	if (ret) {
  		pr_err("transition frequency failed\n");
  		mutex_unlock(&fidvid_mutex);
  		return 1;
  	}
  	mutex_unlock(&fidvid_mutex);
  
  	pol->cur = find_khz_freq_from_fid(data->currfid);
  
  	return 0;
  }
  
  /* Driver entry point to switch to the target frequency */
  static int powernowk8_target(struct cpufreq_policy *pol, unsigned index)
  {
  	struct powernowk8_target_arg pta = { .pol = pol, .newstate = index };
  
  	return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
  }
  
  struct init_on_cpu {
  	struct powernow_k8_data *data;
  	int rc;
  };
  
  static void powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
  {
  	struct init_on_cpu *init_on_cpu = _init_on_cpu;
  
  	if (pending_bit_stuck()) {
  		pr_err("failing init, change pending bit set\n");
  		init_on_cpu->rc = -ENODEV;
  		return;
  	}
  
  	if (query_current_values_with_pending_wait(init_on_cpu->data)) {
  		init_on_cpu->rc = -ENODEV;
  		return;
  	}
  
  	fidvid_msr_init();
  
  	init_on_cpu->rc = 0;
  }
  
  #define MISSING_PSS_MSG \
  	FW_BUG "No compatible ACPI _PSS objects found.\n" \
  	FW_BUG "First, make sure Cool'N'Quiet is enabled in the BIOS.\n" \
  	FW_BUG "If that doesn't help, try upgrading your BIOS.\n"
  
  /* per CPU init entry point to the driver */
  static int powernowk8_cpu_init(struct cpufreq_policy *pol)
  {
  	struct powernow_k8_data *data;
  	struct init_on_cpu init_on_cpu;
  	int rc, cpu;
  
  	smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
  	if (rc)
  		return -ENODEV;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data) {
  		pr_err("unable to alloc powernow_k8_data");
  		return -ENOMEM;
  	}
  
  	data->cpu = pol->cpu;
  
  	if (powernow_k8_cpu_init_acpi(data)) {
  		/*
  		 * Use the PSB BIOS structure. This is only available on
  		 * an UP version, and is deprecated by AMD.
  		 */
  		if (num_online_cpus() != 1) {
  			pr_err_once(MISSING_PSS_MSG);
  			goto err_out;
  		}
  		if (pol->cpu != 0) {
  			pr_err(FW_BUG "No ACPI _PSS objects for CPU other than CPU0. Complain to your BIOS vendor.\n");
  			goto err_out;
  		}
  		rc = find_psb_table(data);
  		if (rc)
  			goto err_out;
  
  		/* Take a crude guess here.
  		 * That guess was in microseconds, so multiply with 1000 */
  		pol->cpuinfo.transition_latency = (
  			 ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
  			 ((1 << data->irt) * 30)) * 1000;
  	} else /* ACPI _PSS objects available */
  		pol->cpuinfo.transition_latency = get_transition_latency(data);
  
  	/* only run on specific CPU from here on */
  	init_on_cpu.data = data;
  	smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
  				 &init_on_cpu, 1);
  	rc = init_on_cpu.rc;
  	if (rc != 0)
  		goto err_out_exit_acpi;
  
  	cpumask_copy(pol->cpus, topology_core_cpumask(pol->cpu));
  	data->available_cores = pol->cpus;
  
  	/* min/max the cpu is capable of */
  	if (cpufreq_table_validate_and_show(pol, data->powernow_table)) {
  		pr_err(FW_BUG "invalid powernow_table\n");
  		powernow_k8_cpu_exit_acpi(data);
  		kfree(data->powernow_table);
  		kfree(data);
  		return -EINVAL;
  	}
  
  	pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
  		data->currfid, data->currvid);
  
  	/* Point all the CPUs in this policy to the same data */
  	for_each_cpu(cpu, pol->cpus)
  		per_cpu(powernow_data, cpu) = data;
  
  	return 0;
  
  err_out_exit_acpi:
  	powernow_k8_cpu_exit_acpi(data);
  
  err_out:
  	kfree(data);
  	return -ENODEV;
  }
  
  static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
  {
  	struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
  	int cpu;
  
  	if (!data)
  		return -EINVAL;
  
  	powernow_k8_cpu_exit_acpi(data);
  
  	kfree(data->powernow_table);
  	kfree(data);
  	for_each_cpu(cpu, pol->cpus)
  		per_cpu(powernow_data, cpu) = NULL;
  
  	return 0;
  }
  
  static void query_values_on_cpu(void *_err)
  {
  	int *err = _err;
  	struct powernow_k8_data *data = __this_cpu_read(powernow_data);
  
  	*err = query_current_values_with_pending_wait(data);
  }
  
  static unsigned int powernowk8_get(unsigned int cpu)
  {
  	struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
  	unsigned int khz = 0;
  	int err;
  
  	if (!data)
  		return 0;
  
  	smp_call_function_single(cpu, query_values_on_cpu, &err, true);
  	if (err)
  		goto out;
  
  	khz = find_khz_freq_from_fid(data->currfid);
  
  
  out:
  	return khz;
  }
  
  static struct cpufreq_driver cpufreq_amd64_driver = {
  	.flags		= CPUFREQ_ASYNC_NOTIFICATION,
  	.verify		= cpufreq_generic_frequency_table_verify,
  	.target_index	= powernowk8_target,
  	.bios_limit	= acpi_processor_get_bios_limit,
  	.init		= powernowk8_cpu_init,
  	.exit		= powernowk8_cpu_exit,
  	.get		= powernowk8_get,
  	.name		= "powernow-k8",
  	.attr		= cpufreq_generic_attr,
  };
  
  static void __request_acpi_cpufreq(void)
  {
  	const char drv[] = "acpi-cpufreq";
  	const char *cur_drv;
  
  	cur_drv = cpufreq_get_current_driver();
  	if (!cur_drv)
  		goto request;
  
  	if (strncmp(cur_drv, drv, min_t(size_t, strlen(cur_drv), strlen(drv))))
  		pr_warn("WTF driver: %s\n", cur_drv);
  
  	return;
  
   request:
  	pr_warn("This CPU is not supported anymore, using acpi-cpufreq instead.\n");
  	request_module(drv);
  }
  
  /* driver entry point for init */
  static int powernowk8_init(void)
  {
  	unsigned int i, supported_cpus = 0;
  	int ret;
  
  	if (static_cpu_has(X86_FEATURE_HW_PSTATE)) {
  		__request_acpi_cpufreq();
  		return -ENODEV;
  	}
  
  	if (!x86_match_cpu(powernow_k8_ids))
  		return -ENODEV;
  
  	get_online_cpus();
  	for_each_online_cpu(i) {
  		smp_call_function_single(i, check_supported_cpu, &ret, 1);
  		if (!ret)
  			supported_cpus++;
  	}
  
  	if (supported_cpus != num_online_cpus()) {
  		put_online_cpus();
  		return -ENODEV;
  	}
  	put_online_cpus();
  
  	ret = cpufreq_register_driver(&cpufreq_amd64_driver);
  	if (ret)
  		return ret;
  
  	pr_info("Found %d %s (%d cpu cores) (" VERSION ")\n",
  		num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
  
  	return ret;
  }
  
  /* driver entry point for term */
  static void __exit powernowk8_exit(void)
  {
  	pr_debug("exit\n");
  
  	cpufreq_unregister_driver(&cpufreq_amd64_driver);
  }
  
  MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com>");
  MODULE_AUTHOR("Mark Langsdorf <mark.langsdorf@amd.com>");
  MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
  MODULE_LICENSE("GPL");
  
  late_initcall(powernowk8_init);
  module_exit(powernowk8_exit);
  