diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/main.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/main.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c new file mode 100644 index 000000000000..c48b6fea5ab4 --- /dev/null +++ b/arch/x86/kernel/cpu/mtrr/main.c @@ -0,0 +1,768 @@ +/* Generic MTRR (Memory Type Range Register) driver. + + Copyright (C) 1997-2000 Richard Gooch + Copyright (c) 2002 Patrick Mochel + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + + Richard Gooch may be reached by email at rgooch@atnf.csiro.au + The postal address is: + Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia. + + Source: "Pentium Pro Family Developer's Manual, Volume 3: + Operating System Writer's Guide" (Intel document number 242692), + section 11.11.7 + + This was cleaned and made readable by Patrick Mochel <mochel@osdl.org> + on 6-7 March 2002. + Source: Intel Architecture Software Developers Manual, Volume 3: + System Programming Guide; Section 9.11. (1997 edition - PPro). +*/ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/smp.h> +#include <linux/cpu.h> +#include <linux/mutex.h> + +#include <asm/mtrr.h> + +#include <asm/uaccess.h> +#include <asm/processor.h> +#include <asm/msr.h> +#include "mtrr.h" + +u32 num_var_ranges = 0; + +unsigned int *usage_table; +static DEFINE_MUTEX(mtrr_mutex); + +u64 size_or_mask, size_and_mask; + +static struct mtrr_ops * mtrr_ops[X86_VENDOR_NUM] = {}; + +struct mtrr_ops * mtrr_if = NULL; + +static void set_mtrr(unsigned int reg, unsigned long base, + unsigned long size, mtrr_type type); + +#ifndef CONFIG_X86_64 +extern int arr3_protected; +#else +#define arr3_protected 0 +#endif + +void set_mtrr_ops(struct mtrr_ops * ops) +{ + if (ops->vendor && ops->vendor < X86_VENDOR_NUM) + mtrr_ops[ops->vendor] = ops; +} + +/* Returns non-zero if we have the write-combining memory type */ +static int have_wrcomb(void) +{ + struct pci_dev *dev; + u8 rev; + + if ((dev = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, NULL)) != NULL) { + /* ServerWorks LE chipsets < rev 6 have problems with write-combining + Don't allow it and leave room for other chipsets to be tagged */ + if (dev->vendor == PCI_VENDOR_ID_SERVERWORKS && + dev->device == PCI_DEVICE_ID_SERVERWORKS_LE) { + pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev); + if (rev <= 5) { + printk(KERN_INFO "mtrr: Serverworks LE rev < 6 detected. Write-combining disabled.\n"); + pci_dev_put(dev); + return 0; + } + } + /* Intel 450NX errata # 23. Non ascending cacheline evictions to + write combining memory may resulting in data corruption */ + if (dev->vendor == PCI_VENDOR_ID_INTEL && + dev->device == PCI_DEVICE_ID_INTEL_82451NX) { + printk(KERN_INFO "mtrr: Intel 450NX MMC detected. Write-combining disabled.\n"); + pci_dev_put(dev); + return 0; + } + pci_dev_put(dev); + } + return (mtrr_if->have_wrcomb ? mtrr_if->have_wrcomb() : 0); +} + +/* This function returns the number of variable MTRRs */ +static void __init set_num_var_ranges(void) +{ + unsigned long config = 0, dummy; + + if (use_intel()) { + rdmsr(MTRRcap_MSR, config, dummy); + } else if (is_cpu(AMD)) + config = 2; + else if (is_cpu(CYRIX) || is_cpu(CENTAUR)) + config = 8; + num_var_ranges = config & 0xff; +} + +static void __init init_table(void) +{ + int i, max; + + max = num_var_ranges; + if ((usage_table = kmalloc(max * sizeof *usage_table, GFP_KERNEL)) + == NULL) { + printk(KERN_ERR "mtrr: could not allocate\n"); + return; + } + for (i = 0; i < max; i++) + usage_table[i] = 1; +} + +struct set_mtrr_data { + atomic_t count; + atomic_t gate; + unsigned long smp_base; + unsigned long smp_size; + unsigned int smp_reg; + mtrr_type smp_type; +}; + +#ifdef CONFIG_SMP + +static void ipi_handler(void *info) +/* [SUMMARY] Synchronisation handler. Executed by "other" CPUs. + [RETURNS] Nothing. +*/ +{ + struct set_mtrr_data *data = info; + unsigned long flags; + + local_irq_save(flags); + + atomic_dec(&data->count); + while(!atomic_read(&data->gate)) + cpu_relax(); + + /* The master has cleared me to execute */ + if (data->smp_reg != ~0U) + mtrr_if->set(data->smp_reg, data->smp_base, + data->smp_size, data->smp_type); + else + mtrr_if->set_all(); + + atomic_dec(&data->count); + while(atomic_read(&data->gate)) + cpu_relax(); + + atomic_dec(&data->count); + local_irq_restore(flags); +} + +#endif + +static inline int types_compatible(mtrr_type type1, mtrr_type type2) { + return type1 == MTRR_TYPE_UNCACHABLE || + type2 == MTRR_TYPE_UNCACHABLE || + (type1 == MTRR_TYPE_WRTHROUGH && type2 == MTRR_TYPE_WRBACK) || + (type1 == MTRR_TYPE_WRBACK && type2 == MTRR_TYPE_WRTHROUGH); +} + +/** + * set_mtrr - update mtrrs on all processors + * @reg: mtrr in question + * @base: mtrr base + * @size: mtrr size + * @type: mtrr type + * + * This is kinda tricky, but fortunately, Intel spelled it out for us cleanly: + * + * 1. Send IPI to do the following: + * 2. Disable Interrupts + * 3. Wait for all procs to do so + * 4. Enter no-fill cache mode + * 5. Flush caches + * 6. Clear PGE bit + * 7. Flush all TLBs + * 8. Disable all range registers + * 9. Update the MTRRs + * 10. Enable all range registers + * 11. Flush all TLBs and caches again + * 12. Enter normal cache mode and reenable caching + * 13. Set PGE + * 14. Wait for buddies to catch up + * 15. Enable interrupts. + * + * What does that mean for us? Well, first we set data.count to the number + * of CPUs. As each CPU disables interrupts, it'll decrement it once. We wait + * until it hits 0 and proceed. We set the data.gate flag and reset data.count. + * Meanwhile, they are waiting for that flag to be set. Once it's set, each + * CPU goes through the transition of updating MTRRs. The CPU vendors may each do it + * differently, so we call mtrr_if->set() callback and let them take care of it. + * When they're done, they again decrement data->count and wait for data.gate to + * be reset. + * When we finish, we wait for data.count to hit 0 and toggle the data.gate flag. + * Everyone then enables interrupts and we all continue on. + * + * Note that the mechanism is the same for UP systems, too; all the SMP stuff + * becomes nops. + */ +static void set_mtrr(unsigned int reg, unsigned long base, + unsigned long size, mtrr_type type) +{ + struct set_mtrr_data data; + unsigned long flags; + + data.smp_reg = reg; + data.smp_base = base; + data.smp_size = size; + data.smp_type = type; + atomic_set(&data.count, num_booting_cpus() - 1); + /* make sure data.count is visible before unleashing other CPUs */ + smp_wmb(); + atomic_set(&data.gate,0); + + /* Start the ball rolling on other CPUs */ + if (smp_call_function(ipi_handler, &data, 1, 0) != 0) + panic("mtrr: timed out waiting for other CPUs\n"); + + local_irq_save(flags); + + while(atomic_read(&data.count)) + cpu_relax(); + + /* ok, reset count and toggle gate */ + atomic_set(&data.count, num_booting_cpus() - 1); + smp_wmb(); + atomic_set(&data.gate,1); + + /* do our MTRR business */ + + /* HACK! + * We use this same function to initialize the mtrrs on boot. + * The state of the boot cpu's mtrrs has been saved, and we want + * to replicate across all the APs. + * If we're doing that @reg is set to something special... + */ + if (reg != ~0U) + mtrr_if->set(reg,base,size,type); + + /* wait for the others */ + while(atomic_read(&data.count)) + cpu_relax(); + + atomic_set(&data.count, num_booting_cpus() - 1); + smp_wmb(); + atomic_set(&data.gate,0); + + /* + * Wait here for everyone to have seen the gate change + * So we're the last ones to touch 'data' + */ + while(atomic_read(&data.count)) + cpu_relax(); + + local_irq_restore(flags); +} + +/** + * mtrr_add_page - Add a memory type region + * @base: Physical base address of region in pages (in units of 4 kB!) + * @size: Physical size of region in pages (4 kB) + * @type: Type of MTRR desired + * @increment: If this is true do usage counting on the region + * + * Memory type region registers control the caching on newer Intel and + * non Intel processors. This function allows drivers to request an + * MTRR is added. The details and hardware specifics of each processor's + * implementation are hidden from the caller, but nevertheless the + * caller should expect to need to provide a power of two size on an + * equivalent power of two boundary. + * + * If the region cannot be added either because all regions are in use + * or the CPU cannot support it a negative value is returned. On success + * the register number for this entry is returned, but should be treated + * as a cookie only. + * + * On a multiprocessor machine the changes are made to all processors. + * This is required on x86 by the Intel processors. + * + * The available types are + * + * %MTRR_TYPE_UNCACHABLE - No caching + * + * %MTRR_TYPE_WRBACK - Write data back in bursts whenever + * + * %MTRR_TYPE_WRCOMB - Write data back soon but allow bursts + * + * %MTRR_TYPE_WRTHROUGH - Cache reads but not writes + * + * BUGS: Needs a quiet flag for the cases where drivers do not mind + * failures and do not wish system log messages to be sent. + */ + +int mtrr_add_page(unsigned long base, unsigned long size, + unsigned int type, char increment) +{ + int i, replace, error; + mtrr_type ltype; + unsigned long lbase, lsize; + + if (!mtrr_if) + return -ENXIO; + + if ((error = mtrr_if->validate_add_page(base,size,type))) + return error; + + if (type >= MTRR_NUM_TYPES) { + printk(KERN_WARNING "mtrr: type: %u invalid\n", type); + return -EINVAL; + } + + /* If the type is WC, check that this processor supports it */ + if ((type == MTRR_TYPE_WRCOMB) && !have_wrcomb()) { + printk(KERN_WARNING + "mtrr: your processor doesn't support write-combining\n"); + return -ENOSYS; + } + + if (!size) { + printk(KERN_WARNING "mtrr: zero sized request\n"); + return -EINVAL; + } + + if (base & size_or_mask || size & size_or_mask) { + printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n"); + return -EINVAL; + } + + error = -EINVAL; + replace = -1; + + /* No CPU hotplug when we change MTRR entries */ + lock_cpu_hotplug(); + /* Search for existing MTRR */ + mutex_lock(&mtrr_mutex); + for (i = 0; i < num_var_ranges; ++i) { + mtrr_if->get(i, &lbase, &lsize, <ype); + if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase) + continue; + /* At this point we know there is some kind of overlap/enclosure */ + if (base < lbase || base + size - 1 > lbase + lsize - 1) { + if (base <= lbase && base + size - 1 >= lbase + lsize - 1) { + /* New region encloses an existing region */ + if (type == ltype) { + replace = replace == -1 ? i : -2; + continue; + } + else if (types_compatible(type, ltype)) + continue; + } + printk(KERN_WARNING + "mtrr: 0x%lx000,0x%lx000 overlaps existing" + " 0x%lx000,0x%lx000\n", base, size, lbase, + lsize); + goto out; + } + /* New region is enclosed by an existing region */ + if (ltype != type) { + if (types_compatible(type, ltype)) + continue; + printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n", + base, size, mtrr_attrib_to_str(ltype), + mtrr_attrib_to_str(type)); + goto out; + } + if (increment) + ++usage_table[i]; + error = i; + goto out; + } + /* Search for an empty MTRR */ + i = mtrr_if->get_free_region(base, size, replace); + if (i >= 0) { + set_mtrr(i, base, size, type); + if (likely(replace < 0)) + usage_table[i] = 1; + else { + usage_table[i] = usage_table[replace] + !!increment; + if (unlikely(replace != i)) { + set_mtrr(replace, 0, 0, 0); + usage_table[replace] = 0; + } + } + } else + printk(KERN_INFO "mtrr: no more MTRRs available\n"); + error = i; + out: + mutex_unlock(&mtrr_mutex); + unlock_cpu_hotplug(); + return error; +} + +static int mtrr_check(unsigned long base, unsigned long size) +{ + if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1))) { + printk(KERN_WARNING + "mtrr: size and base must be multiples of 4 kiB\n"); + printk(KERN_DEBUG + "mtrr: size: 0x%lx base: 0x%lx\n", size, base); + dump_stack(); + return -1; + } + return 0; +} + +/** + * mtrr_add - Add a memory type region + * @base: Physical base address of region + * @size: Physical size of region + * @type: Type of MTRR desired + * @increment: If this is true do usage counting on the region + * + * Memory type region registers control the caching on newer Intel and + * non Intel processors. This function allows drivers to request an + * MTRR is added. The details and hardware specifics of each processor's + * implementation are hidden from the caller, but nevertheless the + * caller should expect to need to provide a power of two size on an + * equivalent power of two boundary. + * + * If the region cannot be added either because all regions are in use + * or the CPU cannot support it a negative value is returned. On success + * the register number for this entry is returned, but should be treated + * as a cookie only. + * + * On a multiprocessor machine the changes are made to all processors. + * This is required on x86 by the Intel processors. + * + * The available types are + * + * %MTRR_TYPE_UNCACHABLE - No caching + * + * %MTRR_TYPE_WRBACK - Write data back in bursts whenever + * + * %MTRR_TYPE_WRCOMB - Write data back soon but allow bursts + * + * %MTRR_TYPE_WRTHROUGH - Cache reads but not writes + * + * BUGS: Needs a quiet flag for the cases where drivers do not mind + * failures and do not wish system log messages to be sent. + */ + +int +mtrr_add(unsigned long base, unsigned long size, unsigned int type, + char increment) +{ + if (mtrr_check(base, size)) + return -EINVAL; + return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type, + increment); +} + +/** + * mtrr_del_page - delete a memory type region + * @reg: Register returned by mtrr_add + * @base: Physical base address + * @size: Size of region + * + * If register is supplied then base and size are ignored. This is + * how drivers should call it. + * + * Releases an MTRR region. If the usage count drops to zero the + * register is freed and the region returns to default state. + * On success the register is returned, on failure a negative error + * code. + */ + +int mtrr_del_page(int reg, unsigned long base, unsigned long size) +{ + int i, max; + mtrr_type ltype; + unsigned long lbase, lsize; + int error = -EINVAL; + + if (!mtrr_if) + return -ENXIO; + + max = num_var_ranges; + /* No CPU hotplug when we change MTRR entries */ + lock_cpu_hotplug(); + mutex_lock(&mtrr_mutex); + if (reg < 0) { + /* Search for existing MTRR */ + for (i = 0; i < max; ++i) { + mtrr_if->get(i, &lbase, &lsize, <ype); + if (lbase == base && lsize == size) { + reg = i; + break; + } + } + if (reg < 0) { + printk(KERN_DEBUG "mtrr: no MTRR for %lx000,%lx000 found\n", base, + size); + goto out; + } + } + if (reg >= max) { + printk(KERN_WARNING "mtrr: register: %d too big\n", reg); + goto out; + } + if (is_cpu(CYRIX) && !use_intel()) { + if ((reg == 3) && arr3_protected) { + printk(KERN_WARNING "mtrr: ARR3 cannot be changed\n"); + goto out; + } + } + mtrr_if->get(reg, &lbase, &lsize, <ype); + if (lsize < 1) { + printk(KERN_WARNING "mtrr: MTRR %d not used\n", reg); + goto out; + } + if (usage_table[reg] < 1) { + printk(KERN_WARNING "mtrr: reg: %d has count=0\n", reg); + goto out; + } + if (--usage_table[reg] < 1) + set_mtrr(reg, 0, 0, 0); + error = reg; + out: + mutex_unlock(&mtrr_mutex); + unlock_cpu_hotplug(); + return error; +} +/** + * mtrr_del - delete a memory type region + * @reg: Register returned by mtrr_add + * @base: Physical base address + * @size: Size of region + * + * If register is supplied then base and size are ignored. This is + * how drivers should call it. + * + * Releases an MTRR region. If the usage count drops to zero the + * register is freed and the region returns to default state. + * On success the register is returned, on failure a negative error + * code. + */ + +int +mtrr_del(int reg, unsigned long base, unsigned long size) +{ + if (mtrr_check(base, size)) + return -EINVAL; + return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT); +} + +EXPORT_SYMBOL(mtrr_add); +EXPORT_SYMBOL(mtrr_del); + +/* HACK ALERT! + * These should be called implicitly, but we can't yet until all the initcall + * stuff is done... + */ +extern void amd_init_mtrr(void); +extern void cyrix_init_mtrr(void); +extern void centaur_init_mtrr(void); + +static void __init init_ifs(void) +{ +#ifndef CONFIG_X86_64 + amd_init_mtrr(); + cyrix_init_mtrr(); + centaur_init_mtrr(); +#endif +} + +/* The suspend/resume methods are only for CPU without MTRR. CPU using generic + * MTRR driver doesn't require this + */ +struct mtrr_value { + mtrr_type ltype; + unsigned long lbase; + unsigned long lsize; +}; + +static struct mtrr_value * mtrr_state; + +static int mtrr_save(struct sys_device * sysdev, pm_message_t state) +{ + int i; + int size = num_var_ranges * sizeof(struct mtrr_value); + + mtrr_state = kzalloc(size,GFP_ATOMIC); + if (!mtrr_state) + return -ENOMEM; + + for (i = 0; i < num_var_ranges; i++) { + mtrr_if->get(i, + &mtrr_state[i].lbase, + &mtrr_state[i].lsize, + &mtrr_state[i].ltype); + } + return 0; +} + +static int mtrr_restore(struct sys_device * sysdev) +{ + int i; + + for (i = 0; i < num_var_ranges; i++) { + if (mtrr_state[i].lsize) + set_mtrr(i, + mtrr_state[i].lbase, + mtrr_state[i].lsize, + mtrr_state[i].ltype); + } + kfree(mtrr_state); + return 0; +} + + + +static struct sysdev_driver mtrr_sysdev_driver = { + .suspend = mtrr_save, + .resume = mtrr_restore, +}; + + +/** + * mtrr_bp_init - initialize mtrrs on the boot CPU + * + * This needs to be called early; before any of the other CPUs are + * initialized (i.e. before smp_init()). + * + */ +void __init mtrr_bp_init(void) +{ + init_ifs(); + + if (cpu_has_mtrr) { + mtrr_if = &generic_mtrr_ops; + size_or_mask = 0xff000000; /* 36 bits */ + size_and_mask = 0x00f00000; + + /* This is an AMD specific MSR, but we assume(hope?) that + Intel will implement it to when they extend the address + bus of the Xeon. */ + if (cpuid_eax(0x80000000) >= 0x80000008) { + u32 phys_addr; + phys_addr = cpuid_eax(0x80000008) & 0xff; + /* CPUID workaround for Intel 0F33/0F34 CPU */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 0xF && + boot_cpu_data.x86_model == 0x3 && + (boot_cpu_data.x86_mask == 0x3 || + boot_cpu_data.x86_mask == 0x4)) + phys_addr = 36; + + size_or_mask = ~((1ULL << (phys_addr - PAGE_SHIFT)) - 1); + size_and_mask = ~size_or_mask & 0xfffff00000ULL; + } else if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR && + boot_cpu_data.x86 == 6) { + /* VIA C* family have Intel style MTRRs, but + don't support PAE */ + size_or_mask = 0xfff00000; /* 32 bits */ + size_and_mask = 0; + } + } else { + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + if (cpu_has_k6_mtrr) { + /* Pre-Athlon (K6) AMD CPU MTRRs */ + mtrr_if = mtrr_ops[X86_VENDOR_AMD]; + size_or_mask = 0xfff00000; /* 32 bits */ + size_and_mask = 0; + } + break; + case X86_VENDOR_CENTAUR: + if (cpu_has_centaur_mcr) { + mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR]; + size_or_mask = 0xfff00000; /* 32 bits */ + size_and_mask = 0; + } + break; + case X86_VENDOR_CYRIX: + if (cpu_has_cyrix_arr) { + mtrr_if = mtrr_ops[X86_VENDOR_CYRIX]; + size_or_mask = 0xfff00000; /* 32 bits */ + size_and_mask = 0; + } + break; + default: + break; + } + } + + if (mtrr_if) { + set_num_var_ranges(); + init_table(); + if (use_intel()) + get_mtrr_state(); + } +} + +void mtrr_ap_init(void) +{ + unsigned long flags; + + if (!mtrr_if || !use_intel()) + return; + /* + * Ideally we should hold mtrr_mutex here to avoid mtrr entries changed, + * but this routine will be called in cpu boot time, holding the lock + * breaks it. This routine is called in two cases: 1.very earily time + * of software resume, when there absolutely isn't mtrr entry changes; + * 2.cpu hotadd time. We let mtrr_add/del_page hold cpuhotplug lock to + * prevent mtrr entry changes + */ + local_irq_save(flags); + + mtrr_if->set_all(); + + local_irq_restore(flags); +} + +/** + * Save current fixed-range MTRR state of the BSP + */ +void mtrr_save_state(void) +{ + int cpu = get_cpu(); + + if (cpu == 0) + mtrr_save_fixed_ranges(NULL); + else + smp_call_function_single(0, mtrr_save_fixed_ranges, NULL, 1, 1); + put_cpu(); +} + +static int __init mtrr_init_finialize(void) +{ + if (!mtrr_if) + return 0; + if (use_intel()) + mtrr_state_warn(); + else { + /* The CPUs haven't MTRR and seemes not support SMP. They have + * specific drivers, we use a tricky method to support + * suspend/resume for them. + * TBD: is there any system with such CPU which supports + * suspend/resume? if no, we should remove the code. + */ + sysdev_driver_register(&cpu_sysdev_class, + &mtrr_sysdev_driver); + } + return 0; +} +subsys_initcall(mtrr_init_finialize); |