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Subject[PATCH -v2 09/13] x86: Fixup code testing if a pfn is direct mapped
Date
From: Jacob Shin <jacob.shin@amd.com>

Update code that previously assumed pfns [ 0 - max_low_pfn_mapped ) and
[ 4GB - max_pfn_mapped ) were always direct mapped, to now look up
pfn_mapped ranges instead.


-v2: change applying sequence to keep git bisecting working.
so add dummy pfn_range_is_mapped(). - Yinghai Lu

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
---
arch/x86/include/asm/page_types.h | 8 ++++++++
arch/x86/kernel/cpu/amd.c | 8 +++-----
arch/x86/platform/efi/efi.c | 8 ++++----
3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index e21fdd1..45aae6e 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -51,6 +51,14 @@ static inline phys_addr_t get_max_mapped(void)
return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
}

+static inline bool pfn_range_is_mapped(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ return end_pfn <= max_low_pfn_mapped ||
+ (end_pfn > (1UL << (32 - PAGE_SHIFT)) &&
+ end_pfn <= max_pfn_mapped);
+}
+
extern unsigned long init_memory_mapping(unsigned long start,
unsigned long end);

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9d92e19..4235553 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -676,12 +676,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
* benefit in doing so.
*/
if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+ unsigned long pfn = tseg >> PAGE_SHIFT;
+
printk(KERN_DEBUG "tseg: %010llx\n", tseg);
- if ((tseg>>PMD_SHIFT) <
- (max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
- ((tseg>>PMD_SHIFT) <
- (max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
- (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
+ if (pfn_range_is_mapped(pfn, pfn + 1))
set_memory_4k((unsigned long)__va(tseg), 1);
}
}
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 92660eda..f1facde 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -776,7 +776,7 @@ void __init efi_enter_virtual_mode(void)
efi_memory_desc_t *md, *prev_md = NULL;
efi_status_t status;
unsigned long size;
- u64 end, systab, addr, npages, end_pfn;
+ u64 end, systab, addr, npages, start_pfn, end_pfn;
void *p, *va, *new_memmap = NULL;
int count = 0;

@@ -827,10 +827,10 @@ void __init efi_enter_virtual_mode(void)
size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;

+ start_pfn = PFN_DOWN(md->phys_addr);
end_pfn = PFN_UP(end);
- if (end_pfn <= max_low_pfn_mapped
- || (end_pfn > (1UL << (32 - PAGE_SHIFT))
- && end_pfn <= max_pfn_mapped))
+
+ if (pfn_range_is_mapped(start_pfn, end_pfn))
va = __va(md->phys_addr);
else
va = efi_ioremap(md->phys_addr, size, md->type);
--
1.7.7


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