diff options
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 119 |
1 files changed, 63 insertions, 56 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 160c42d3eb8..9127e31c726 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -30,7 +30,7 @@ #ifdef CONFIG_X86_PAT int __read_mostly pat_enabled = 1; -void __cpuinit pat_disable(char *reason) +void __cpuinit pat_disable(const char *reason) { pat_enabled = 0; printk(KERN_INFO "%s\n", reason); @@ -42,6 +42,11 @@ static int __init nopat(char *str) return 0; } early_param("nopat", nopat); +#else +static inline void pat_disable(const char *reason) +{ + (void)reason; +} #endif @@ -78,16 +83,20 @@ void pat_init(void) if (!pat_enabled) return; - /* Paranoia check. */ - if (!cpu_has_pat && boot_pat_state) { - /* - * If this happens we are on a secondary CPU, but - * switched to PAT on the boot CPU. We have no way to - * undo PAT. - */ - printk(KERN_ERR "PAT enabled, " - "but not supported by secondary CPU\n"); - BUG(); + if (!cpu_has_pat) { + if (!boot_pat_state) { + pat_disable("PAT not supported by CPU."); + return; + } else { + /* + * If this happens we are on a secondary CPU, but + * switched to PAT on the boot CPU. We have no way to + * undo PAT. + */ + printk(KERN_ERR "PAT enabled, " + "but not supported by secondary CPU\n"); + BUG(); + } } /* Set PWT to Write-Combining. All other bits stay the same */ @@ -333,11 +342,23 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, req_type & _PAGE_CACHE_MASK); } - is_range_ram = pagerange_is_ram(start, end); - if (is_range_ram == 1) - return reserve_ram_pages_type(start, end, req_type, new_type); - else if (is_range_ram < 0) - return -EINVAL; + if (new_type) + *new_type = actual_type; + + /* + * For legacy reasons, some parts of the physical address range in the + * legacy 1MB region is treated as non-RAM (even when listed as RAM in + * the e820 tables). So we will track the memory attributes of this + * legacy 1MB region using the linear memtype_list always. + */ + if (end >= ISA_END_ADDRESS) { + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return reserve_ram_pages_type(start, end, req_type, + new_type); + else if (is_range_ram < 0) + return -EINVAL; + } new = kmalloc(sizeof(struct memtype), GFP_KERNEL); if (!new) @@ -347,9 +368,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, new->end = end; new->type = actual_type; - if (new_type) - *new_type = actual_type; - spin_lock(&memtype_lock); if (cached_entry && start >= cached_start) @@ -437,11 +455,19 @@ int free_memtype(u64 start, u64 end) if (is_ISA_range(start, end - 1)) return 0; - is_range_ram = pagerange_is_ram(start, end); - if (is_range_ram == 1) - return free_ram_pages_type(start, end); - else if (is_range_ram < 0) - return -EINVAL; + /* + * For legacy reasons, some parts of the physical address range in the + * legacy 1MB region is treated as non-RAM (even when listed as RAM in + * the e820 tables). So we will track the memory attributes of this + * legacy 1MB region using the linear memtype_list always. + */ + if (end >= ISA_END_ADDRESS) { + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return free_ram_pages_type(start, end); + else if (is_range_ram < 0) + return -EINVAL; + } spin_lock(&memtype_lock); list_for_each_entry(entry, &memtype_list, nd) { @@ -505,35 +531,6 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size) } #endif /* CONFIG_STRICT_DEVMEM */ -/* - * Change the memory type for the physial address range in kernel identity - * mapping space if that range is a part of identity map. - */ -static int kernel_map_sync_memtype(u64 base, unsigned long size, - unsigned long flags) -{ - unsigned long id_sz; - int ret; - - if (!pat_enabled || base >= __pa(high_memory)) - return 0; - - id_sz = (__pa(high_memory) < base + size) ? - __pa(high_memory) - base : - size; - - ret = ioremap_change_attr((unsigned long)__va(base), id_sz, flags); - /* - * -EFAULT return means that the addr was not valid and did not have - * any identity mapping. That case is a success for - * kernel_map_sync_memtype. - */ - if (ret == -EFAULT) - ret = 0; - - return ret; -} - int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, unsigned long size, pgprot_t *vma_prot) { @@ -584,7 +581,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, if (retval < 0) return 0; - if (kernel_map_sync_memtype(offset, size, flags)) { + if (((pfn < max_low_pfn_mapped) || + (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) && + ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { free_memtype(offset, offset + size); printk(KERN_INFO "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n", @@ -632,7 +631,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, int strict_prot) { int is_ram = 0; - int ret; + int id_sz, ret; unsigned long flags; unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK); @@ -673,7 +672,15 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, flags); } - if (kernel_map_sync_memtype(paddr, size, flags)) { + /* Need to keep identity mapping in sync */ + if (paddr >= __pa(high_memory)) + return 0; + + id_sz = (__pa(high_memory) < paddr + size) ? + __pa(high_memory) - paddr : + size; + + if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) { free_memtype(paddr, paddr + size); printk(KERN_ERR "%s:%d reserve_pfn_range ioremap_change_attr failed %s " |