@@ -62,6 +62,16 @@ enum fixed_addresses {
FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+
+ /*
+ * Used for kernel page table creation, so unmapped memory may be used
+ * for tables.
+ */
+ FIX_PTE,
+ FIX_PMD,
+ FIX_PUD,
+ FIX_PGD,
+
__end_of_fixed_addresses
};
@@ -57,6 +57,7 @@
#ifndef __ASSEMBLY__
+#include <asm/fixmap.h>
#include <linux/mmdebug.h>
extern void __pte_error(const char *file, int line, unsigned long val);
@@ -426,6 +427,10 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
#define pte_unmap(pte) do { } while (0)
#define pte_unmap_nested(pte) do { } while (0)
+#define pte_fixmap(addr) ((pte_t *)set_fixmap_offset(FIX_PTE, addr))
+#define pte_fixmap_offset(pmd, addr) pte_fixmap(pte_offset_phys(pmd, addr))
+#define pte_fixmap_unmap() clear_fixmap(FIX_PTE)
+
#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
/*
@@ -465,12 +470,21 @@ static inline phys_addr_t pud_page_paddr(pud_t pud)
#define pmd_offset_phys(dir, addr) (pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
#define pmd_offset(dir, addr) ((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
+#define pmd_fixmap(addr) ((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
+#define pmd_fixmap_offset(pud, addr) pmd_fixmap(pmd_offset_phys(pud, addr))
+#define pmd_fixmap_unmap() clear_fixmap(FIX_PMD)
+
#define pud_page(pud) pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
#else
#define pud_page_paddr(pud) ({ BUILD_BUG(); 0; })
+/* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
+#define pmd_fixmap(addr) NULL
+#define pmd_fixmap_offset(pudp, addr) ((pmd_t *)pudp)
+#define pmd_fixmap_unmap()
+
#endif /* CONFIG_PGTABLE_LEVELS > 2 */
#if CONFIG_PGTABLE_LEVELS > 3
@@ -503,12 +517,21 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
#define pud_offset_phys(dir, addr) (pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
#define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr))))
+#define pud_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr))
+#define pud_fixmap_offset(pgd, addr) pud_fixmap(pmd_offset_phys(pgd, addr))
+#define pud_fixmap_unmap() clear_fixmap(FIX_PUD)
+
#define pgd_page(pgd) pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
#else
#define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0;})
+/* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
+#define pud_fixmap(addr) NULL
+#define pud_fixmap_offset(pgdp, addr) ((pud_t *)pgdp)
+#define pud_fixmap_unmap()
+
#endif /* CONFIG_PGTABLE_LEVELS > 3 */
#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
@@ -523,6 +546,9 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
+#define pgd_fixmap(addr) ((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
+#define pgd_fixmap_unmap() clear_fixmap(FIX_PGD)
+
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
As a prepratory step to allow us to allocate early page tables from unmapped memory using memblock_alloc, add new p??_fixmap* functions that can be used to walk page tables outside of the linear mapping by using fixmap slots. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/fixmap.h | 10 ++++++++++ arch/arm64/include/asm/pgtable.h | 26 ++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel