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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:17 -0700
commit1dcf58d6e6e6eb7ec10e9abc56887b040205b06f (patch)
treec03e7a25ef13eea62f1547914a76e5c68f3f4c28 /arch/x86/mm/ioremap.c
parent80dcc31fbe55932ac9204daee5f2ebc0c49b6da3 (diff)
parente4b0db72be2487bae0e3251c22f82c104f7c1cfd (diff)
Merge branch 'akpm' (patches from Andrew)
Merge first patchbomb from Andrew Morton: - arch/sh updates - ocfs2 updates - kernel/watchdog feature - about half of mm/ * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (122 commits) Documentation: update arch list in the 'memtest' entry Kconfig: memtest: update number of test patterns up to 17 arm: add support for memtest arm64: add support for memtest memtest: use phys_addr_t for physical addresses mm: move memtest under mm mm, hugetlb: abort __get_user_pages if current has been oom killed mm, mempool: do not allow atomic resizing memcg: print cgroup information when system panics due to panic_on_oom mm: numa: remove migrate_ratelimited mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE mm: split ET_DYN ASLR from mmap ASLR s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE mm: expose arch_mmap_rnd when available s390: standardize mmap_rnd() usage powerpc: standardize mmap_rnd() usage mips: extract logic for mmap_rnd() arm64: standardize mmap_rnd() usage x86: standardize mmap_rnd() usage arm: factor out mmap ASLR into mmap_rnd ...
Diffstat (limited to 'arch/x86/mm/ioremap.c')
-rw-r--r--arch/x86/mm/ioremap.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index fdf617c00e2f..5ead4d6cf3a7 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -67,8 +67,13 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
/*
* Remap an arbitrary physical address space into the kernel virtual
- * address space. Needed when the kernel wants to access high addresses
- * directly.
+ * address space. It transparently creates kernel huge I/O mapping when
+ * the physical address is aligned by a huge page size (1GB or 2MB) and
+ * the requested size is at least the huge page size.
+ *
+ * NOTE: MTRRs can override PAT memory types with a 4KB granularity.
+ * Therefore, the mapping code falls back to use a smaller page toward 4KB
+ * when a mapping range is covered by non-WB type of MTRRs.
*
* NOTE! We need to allow non-page-aligned mappings too: we will obviously
* have to convert them into an offset in a page-aligned mapping, but the
@@ -326,6 +331,20 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);
+int arch_ioremap_pud_supported(void)
+{
+#ifdef CONFIG_X86_64
+ return cpu_has_gbpages;
+#else
+ return 0;
+#endif
+}
+
+int arch_ioremap_pmd_supported(void)
+{
+ return cpu_has_pse;
+}
+
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access