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Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c127
1 files changed, 88 insertions, 39 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 85cbd3cd372..3be399013de 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -333,11 +333,20 @@ 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;
+ /*
+ * 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)
@@ -437,11 +446,19 @@ 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) {
@@ -505,6 +522,35 @@ 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)
{
@@ -555,9 +601,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
if (retval < 0)
return 0;
- 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) {
+ if (kernel_map_sync_memtype(offset, size, flags)) {
free_memtype(offset, offset + size);
printk(KERN_INFO
"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
@@ -601,12 +645,13 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
* Reserved non RAM regions only and after successful reserve_memtype,
* this func also keeps identity mapping (if any) in sync with this new prot.
*/
-static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t vma_prot)
+static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
+ int strict_prot)
{
int is_ram = 0;
- int id_sz, ret;
+ int ret;
unsigned long flags;
- unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
+ unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
is_ram = pagerange_is_ram(paddr, paddr + size);
@@ -625,26 +670,27 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t vma_prot)
return ret;
if (flags != want_flags) {
- free_memtype(paddr, paddr + size);
- printk(KERN_ERR
- "%s:%d map pfn expected mapping type %s for %Lx-%Lx, got %s\n",
- current->comm, current->pid,
- cattr_name(want_flags),
- (unsigned long long)paddr,
- (unsigned long long)(paddr + size),
- cattr_name(flags));
- return -EINVAL;
+ if (strict_prot || !is_new_memtype_allowed(want_flags, flags)) {
+ free_memtype(paddr, paddr + size);
+ printk(KERN_ERR "%s:%d map pfn expected mapping type %s"
+ " for %Lx-%Lx, got %s\n",
+ current->comm, current->pid,
+ cattr_name(want_flags),
+ (unsigned long long)paddr,
+ (unsigned long long)(paddr + size),
+ cattr_name(flags));
+ return -EINVAL;
+ }
+ /*
+ * We allow returning different type than the one requested in
+ * non strict case.
+ */
+ *vma_prot = __pgprot((pgprot_val(*vma_prot) &
+ (~_PAGE_CACHE_MASK)) |
+ 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) {
+ if (kernel_map_sync_memtype(paddr, size, flags)) {
free_memtype(paddr, paddr + size);
printk(KERN_ERR
"%s:%d reserve_pfn_range ioremap_change_attr failed %s "
@@ -689,6 +735,7 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
unsigned long vma_start = vma->vm_start;
unsigned long vma_end = vma->vm_end;
unsigned long vma_size = vma_end - vma_start;
+ pgprot_t pgprot;
if (!pat_enabled)
return 0;
@@ -702,7 +749,8 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
WARN_ON_ONCE(1);
return -EINVAL;
}
- return reserve_pfn_range(paddr, vma_size, __pgprot(prot));
+ pgprot = __pgprot(prot);
+ return reserve_pfn_range(paddr, vma_size, &pgprot, 1);
}
/* reserve entire vma page by page, using pfn and prot from pte */
@@ -710,7 +758,8 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
continue;
- retval = reserve_pfn_range(paddr, PAGE_SIZE, __pgprot(prot));
+ pgprot = __pgprot(prot);
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, &pgprot, 1);
if (retval)
goto cleanup_ret;
}
@@ -741,7 +790,7 @@ cleanup_ret:
* Note that this function can be called with caller trying to map only a
* subrange/page inside the vma.
*/
-int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long size)
{
int retval = 0;
@@ -758,14 +807,14 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
if (is_linear_pfn_mapping(vma)) {
/* reserve the whole chunk starting from vm_pgoff */
paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
- return reserve_pfn_range(paddr, vma_size, prot);
+ return reserve_pfn_range(paddr, vma_size, prot, 0);
}
/* reserve page by page using pfn and size */
base_paddr = (resource_size_t)pfn << PAGE_SHIFT;
for (i = 0; i < size; i += PAGE_SIZE) {
paddr = base_paddr + i;
- retval = reserve_pfn_range(paddr, PAGE_SIZE, prot);
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, prot, 0);
if (retval)
goto cleanup_ret;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-13 17:41:03 +0000