Why are you initializing psize/pmask? Dave Hansen <[email protected]> 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 <[email protected]> >Acked-by: Rik van Riel <[email protected]> >--- > > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
