* [PATCH] mm:page.h: Calculate virt_to_page and page_to_virt via predefined macro.
@ 2011-08-23 6:58 ` Sonic Zhang
0 siblings, 0 replies; 2+ messages in thread
From: Sonic Zhang @ 2011-08-23 6:58 UTC (permalink / raw)
To: linux-mm, LKML; +Cc: uclinux-dist-devel, Sonic Zhang
From: Sonic Zhang <sonic.zhang@analog.com>
In NOMMU architecture, if physical memory doesn't start from 0, ARCH_PFN_OFFSET is defined
to generate page index in mem_map array. Because virtual address is equal to physical
address, PAGE_OFFSET is always 0. virt_to_page and page_to_virt should not index page by
PAGE_OFFSET directly.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
---
include/asm-generic/page.h | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/include/asm-generic/page.h b/include/asm-generic/page.h
index 75fec18..96a1dc3 100644
--- a/include/asm-generic/page.h
+++ b/include/asm-generic/page.h
@@ -79,8 +79,13 @@ extern unsigned long memory_end;
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
+#if 0
#define virt_to_page(addr) (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))
#define page_to_virt(page) ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
+#endif
+#define virt_to_page(addr) pfn_to_page(virt_to_pfn(addr))
+#define page_to_virt(page) pfn_to_virt(page_to_pfn(page))
+
#ifndef page_to_phys
#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
--
1.7.0.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] mm:page.h: Calculate virt_to_page and page_to_virt via predefined macro.
@ 2011-08-23 6:58 ` Sonic Zhang
0 siblings, 0 replies; 2+ messages in thread
From: Sonic Zhang @ 2011-08-23 6:58 UTC (permalink / raw)
To: linux-mm, LKML; +Cc: uclinux-dist-devel, Sonic Zhang
From: Sonic Zhang <sonic.zhang@analog.com>
In NOMMU architecture, if physical memory doesn't start from 0, ARCH_PFN_OFFSET is defined
to generate page index in mem_map array. Because virtual address is equal to physical
address, PAGE_OFFSET is always 0. virt_to_page and page_to_virt should not index page by
PAGE_OFFSET directly.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
---
include/asm-generic/page.h | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/include/asm-generic/page.h b/include/asm-generic/page.h
index 75fec18..96a1dc3 100644
--- a/include/asm-generic/page.h
+++ b/include/asm-generic/page.h
@@ -79,8 +79,13 @@ extern unsigned long memory_end;
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
+#if 0
#define virt_to_page(addr) (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))
#define page_to_virt(page) ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
+#endif
+#define virt_to_page(addr) pfn_to_page(virt_to_pfn(addr))
+#define page_to_virt(page) pfn_to_virt(page_to_pfn(page))
+
#ifndef page_to_phys
#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
--
1.7.0.4
--
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^ permalink raw reply related [flat|nested] 2+ messages in thread
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2011-08-23 6:58 [PATCH] mm:page.h: Calculate virt_to_page and page_to_virt via predefined macro Sonic Zhang
2011-08-23 6:58 ` Sonic Zhang
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