linux-kernel - [PATCH 4/5] x86: Fixup code testing if a pfn is direct mapped

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Date:	Fri, 24 Aug 2012 18:55:15 -0500
From:	Jacob Shin <jacob.shin@....com>
To:	X86-ML <x86@...nel.org>
CC:	LKML <linux-kernel@...r.kernel.org>,
	"H. Peter Anvin" <hpa@...or.com>, Yinghai Lu <yinghai@...nel.org>,
	Tejun Heo <tj@...nel.org>, Dave Young <dyoung@...hat.com>,
	Chao Wang <chaowang@...hat.com>,
	Vivek Goyal <vgoyal@...hat.com>,
	Andreas Herrmann <andreas.herrmann3@....com>,
	Borislav Petkov <borislav.petkov@....com>,
	Jacob Shin <jacob.shin@....com>
Subject: [PATCH 4/5] x86: Fixup code testing if a pfn is direct mapped

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.

Signed-off-by: Jacob Shin <jacob.shin@....com>
---
 arch/x86/kernel/cpu/amd.c   |    6 +-----
 arch/x86/platform/efi/efi.c |    8 ++++----
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9d92e19..554ccfc 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -677,11 +677,7 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 		 */
 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
 			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_is_mapped(tseg))
 				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);
-- 
1.7.9.5


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