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Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c119
1 files changed, 63 insertions, 56 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 160c42d3eb8f..9127e31c7268 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 "
generated by cgit v1.2.3 (git 2.0.4) at 2024-07-09 08:38:25 +0000