ARM: LPAE: Page table maintenance for the 3-level format
This patch modifies the pgd/pmd/pte manipulation functions to support
the 3-level page table format. Since there is no need for an 'ext'
argument to cpu_set_pte_ext(), this patch conditionally defines a
different prototype for this function when CONFIG_ARM_LPAE.
The patch also introduces the L_PGD_SWAPPER flag to mark pgd entries
pointing to pmd tables pre-allocated in the swapper_pg_dir and avoid
trying to free them at run-time. This flag is 0 with the classic page
table format.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h
index 7418894..943504f 100644
--- a/arch/arm/include/asm/pgalloc.h
+++ b/arch/arm/include/asm/pgalloc.h
@@ -25,6 +25,26 @@
#define _PAGE_USER_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
#define _PAGE_KERNEL_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
+#ifdef CONFIG_ARM_LPAE
+
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+ return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
+}
+
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+ BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+ free_page((unsigned long)pmd);
+}
+
+static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
+{
+ set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
+}
+
+#else /* !CONFIG_ARM_LPAE */
+
/*
* Since we have only two-level page tables, these are trivial
*/
@@ -32,6 +52,8 @@
#define pmd_free(mm, pmd) do { } while (0)
#define pud_populate(mm,pmd,pte) BUG()
+#endif /* CONFIG_ARM_LPAE */
+
extern pgd_t *pgd_alloc(struct mm_struct *mm);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
@@ -109,7 +131,9 @@
{
pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
pmdp[0] = __pmd(pmdval);
+#ifndef CONFIG_ARM_LPAE
pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
+#endif
flush_pmd_entry(pmdp);
}
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 79bf0ac..759af70 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -99,4 +99,57 @@
#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 3) << 2) /* normal inner write-back */
#define L_PTE_MT_MASK (_AT(pteval_t, 7) << 2)
+/*
+ * Software PGD flags.
+ */
+#define L_PGD_SWAPPER (_AT(pgdval_t, 1) << 55) /* swapper_pg_dir entry */
+
+#ifndef __ASSEMBLY__
+
+#define pud_none(pud) (!pud_val(pud))
+#define pud_bad(pud) (!(pud_val(pud) & 2))
+#define pud_present(pud) (pud_val(pud))
+
+#define pud_clear(pudp) \
+ do { \
+ *pudp = __pud(0); \
+ clean_pmd_entry(pudp); \
+ } while (0)
+
+#define set_pud(pudp, pud) \
+ do { \
+ *pudp = pud; \
+ flush_pmd_entry(pudp); \
+ } while (0)
+
+static inline pmd_t *pud_page_vaddr(pud_t pud)
+{
+ return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
+}
+
+/* Find an entry in the second-level page table.. */
+#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
+static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
+{
+ return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
+}
+
+#define pmd_bad(pmd) (!(pmd_val(pmd) & 2))
+
+#define copy_pmd(pmdpd,pmdps) \
+ do { \
+ *pmdpd = *pmdps; \
+ flush_pmd_entry(pmdpd); \
+ } while (0)
+
+#define pmd_clear(pmdp) \
+ do { \
+ *pmdp = __pmd(0); \
+ clean_pmd_entry(pmdp); \
+ } while (0)
+
+#define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
+
+#endif /* __ASSEMBLY__ */
+
#endif /* _ASM_PGTABLE_3LEVEL_H */
diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index 9e92cb20..f3628fb 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -65,7 +65,11 @@
* Set a possibly extended PTE. Non-extended PTEs should
* ignore 'ext'.
*/
+#ifdef CONFIG_ARM_LPAE
+ void (*set_pte_ext)(pte_t *ptep, pte_t pte);
+#else
void (*set_pte_ext)(pte_t *ptep, pte_t pte, unsigned int ext);
+#endif
/* Suspend/resume */
unsigned int suspend_size;
@@ -79,7 +83,11 @@
extern int cpu_do_idle(void);
extern void cpu_dcache_clean_area(void *, int);
extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm);
+#ifdef CONFIG_ARM_LPAE
+extern void cpu_set_pte_ext(pte_t *ptep, pte_t pte);
+#else
extern void cpu_set_pte_ext(pte_t *ptep, pte_t pte, unsigned int ext);
+#endif
extern void cpu_reset(unsigned long addr) __attribute__((noreturn));
/* These three are private to arch/arm/kernel/suspend.c */
@@ -107,6 +115,18 @@
#define cpu_switch_mm(pgd,mm) cpu_do_switch_mm(virt_to_phys(pgd),mm)
+#ifdef CONFIG_ARM_LPAE
+#define cpu_get_pgd() \
+ ({ \
+ unsigned long pg, pg2; \
+ __asm__("mrrc p15, 0, %0, %1, c2" \
+ : "=r" (pg), "=r" (pg2) \
+ : \
+ : "cc"); \
+ pg &= ~(PTRS_PER_PGD*sizeof(pgd_t)-1); \
+ (pgd_t *)phys_to_virt(pg); \
+ })
+#else
#define cpu_get_pgd() \
({ \
unsigned long pg; \
@@ -115,6 +135,7 @@
pg &= ~0x3fff; \
(pgd_t *)phys_to_virt(pg); \
})
+#endif
#endif