Why are you initializing psize/pmask?
Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> wrote:
>
>This is necessary because __pa() does not work on some kinds of
>memory, like vmalloc() or the alloc_remap() areas on 32-bit
>NUMA systems. We have some functions to do conversions _like_
>this in the vmalloc() code (like vmalloc_to_page()), but they
>do not work on sizes other than 4k pages. We would potentially
>need to be able to handle all the page sizes that we use for
>the kernel linear mapping (4k, 2M, 1G).
>
>In practice, on 32-bit NUMA systems, the percpu areas get stuck
>in the alloc_remap() area. Any __pa() call on them will break
>and basically return garbage.
>
>This patch introduces a new function slow_virt_to_phys(), which
>walks the kernel page tables on x86 and should do precisely
>the same logical thing as __pa(), but actually work on a wider
>range of memory. It should work on the normal linear mapping,
>vmalloc(), kmap(), etc...
>
>Signed-off-by: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
>Acked-by: Rik van Riel <riel@xxxxxxxxxx>
>---
>
> linux-2.6.git-dave/arch/x86/include/asm/pgtable_types.h | 1
>linux-2.6.git-dave/arch/x86/mm/pageattr.c | 31
>++++++++++++++++
> 2 files changed, 32 insertions(+)
>
>diff -puN arch/x86/include/asm/pgtable_types.h~create-slow_virt_to_phys
>arch/x86/include/asm/pgtable_types.h
>---
>linux-2.6.git/arch/x86/include/asm/pgtable_types.h~create-slow_virt_to_phys 2013-01-17
>10:22:26.590434129 -0800
>+++ linux-2.6.git-dave/arch/x86/include/asm/pgtable_types.h 2013-01-17
>10:22:26.598434199 -0800
>@@ -352,6 +352,7 @@ static inline void update_page_count(int
> * as a pte too.
> */
>extern pte_t *lookup_address(unsigned long address, unsigned int
>*level);
>+extern phys_addr_t slow_virt_to_phys(void *__address);
>
> #endif /* !__ASSEMBLY__ */
>
>diff -puN arch/x86/mm/pageattr.c~create-slow_virt_to_phys
>arch/x86/mm/pageattr.c
>---
>linux-2.6.git/arch/x86/mm/pageattr.c~create-slow_virt_to_phys 2013-01-17
>10:22:26.594434163 -0800
>+++ linux-2.6.git-dave/arch/x86/mm/pageattr.c 2013-01-17
>10:22:26.598434199 -0800
>@@ -364,6 +364,37 @@ pte_t *lookup_address(unsigned long addr
> EXPORT_SYMBOL_GPL(lookup_address);
>
> /*
>+ * This is necessary because __pa() does not work on some
>+ * kinds of memory, like vmalloc() or the alloc_remap()
>+ * areas on 32-bit NUMA systems. The percpu areas can
>+ * end up in this kind of memory, for instance.
>+ *
>+ * This could be optimized, but it is only intended to be
>+ * used at inititalization time, and keeping it
>+ * unoptimized should increase the testing coverage for
>+ * the more obscure platforms.
>+ */
>+phys_addr_t slow_virt_to_phys(void *__virt_addr)
>+{
>+ unsigned long virt_addr = (unsigned long)__virt_addr;
>+ phys_addr_t phys_addr;
>+ unsigned long offset;
>+ unsigned int level = -1;
>+ unsigned long psize = 0;
>+ unsigned long pmask = 0;
>+ pte_t *pte;
>+
>+ pte = lookup_address(virt_addr, &level);
>+ BUG_ON(!pte);
>+ psize = page_level_size(level);
>+ pmask = page_level_mask(level);
>+ offset = virt_addr & ~pmask;
>+ phys_addr = pte_pfn(*pte) << PAGE_SHIFT;
>+ return (phys_addr | offset);
>+}
>+EXPORT_SYMBOL_GPL(slow_virt_to_phys);
>+
>+/*
> * Set the new pmd in all the pgds we know about:
> */
>static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t
>pte)
>_
--
Sent from my mobile phone. Please excuse brevity and lack of formatting.
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