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authorCatalin Marinas <catalin.marinas@arm.com>2011-09-05 17:41:02 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-10-06 15:40:05 +0100
commit17f57211969bddca2e922299a2530b1c65ccabfa (patch)
treef48835b326774f0a7a695d288a86fcfca5f55edf /arch/arm/include/asm/pgtable.h
parente73fc88e19d74fd4dd664cff45b88caab8cde45c (diff)
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ARM: 7075/1: LPAE: Factor out 2-level page table definitions into separate files
This patch moves page table definitions from asm/page.h, asm/pgtable.h and asm/ptgable-hwdef.h into corresponding *-2level* files. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/pgtable.h')
-rw-r--r--arch/arm/include/asm/pgtable.h135
1 files changed, 2 insertions, 133 deletions
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 5750704e0271..d6436dacb17b 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -24,6 +24,8 @@
#include <mach/vmalloc.h>
#include <asm/pgtable-hwdef.h>
+#include <asm/pgtable-2level.h>
+
/*
* Just any arbitrary offset to the start of the vmalloc VM area: the
* current 8MB value just means that there will be a 8MB "hole" after the
@@ -41,79 +43,6 @@
#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#endif
-/*
- * Hardware-wise, we have a two level page table structure, where the first
- * level has 4096 entries, and the second level has 256 entries. Each entry
- * is one 32-bit word. Most of the bits in the second level entry are used
- * by hardware, and there aren't any "accessed" and "dirty" bits.
- *
- * Linux on the other hand has a three level page table structure, which can
- * be wrapped to fit a two level page table structure easily - using the PGD
- * and PTE only. However, Linux also expects one "PTE" table per page, and
- * at least a "dirty" bit.
- *
- * Therefore, we tweak the implementation slightly - we tell Linux that we
- * have 2048 entries in the first level, each of which is 8 bytes (iow, two
- * hardware pointers to the second level.) The second level contains two
- * hardware PTE tables arranged contiguously, preceded by Linux versions
- * which contain the state information Linux needs. We, therefore, end up
- * with 512 entries in the "PTE" level.
- *
- * This leads to the page tables having the following layout:
- *
- * pgd pte
- * | |
- * +--------+
- * | | +------------+ +0
- * +- - - - + | Linux pt 0 |
- * | | +------------+ +1024
- * +--------+ +0 | Linux pt 1 |
- * | |-----> +------------+ +2048
- * +- - - - + +4 | h/w pt 0 |
- * | |-----> +------------+ +3072
- * +--------+ +8 | h/w pt 1 |
- * | | +------------+ +4096
- *
- * See L_PTE_xxx below for definitions of bits in the "Linux pt", and
- * PTE_xxx for definitions of bits appearing in the "h/w pt".
- *
- * PMD_xxx definitions refer to bits in the first level page table.
- *
- * The "dirty" bit is emulated by only granting hardware write permission
- * iff the page is marked "writable" and "dirty" in the Linux PTE. This
- * means that a write to a clean page will cause a permission fault, and
- * the Linux MM layer will mark the page dirty via handle_pte_fault().
- * For the hardware to notice the permission change, the TLB entry must
- * be flushed, and ptep_set_access_flags() does that for us.
- *
- * The "accessed" or "young" bit is emulated by a similar method; we only
- * allow accesses to the page if the "young" bit is set. Accesses to the
- * page will cause a fault, and handle_pte_fault() will set the young bit
- * for us as long as the page is marked present in the corresponding Linux
- * PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is
- * up to date.
- *
- * However, when the "young" bit is cleared, we deny access to the page
- * by clearing the hardware PTE. Currently Linux does not flush the TLB
- * for us in this case, which means the TLB will retain the transation
- * until either the TLB entry is evicted under pressure, or a context
- * switch which changes the user space mapping occurs.
- */
-#define PTRS_PER_PTE 512
-#define PTRS_PER_PMD 1
-#define PTRS_PER_PGD 2048
-
-#define PTE_HWTABLE_PTRS (PTRS_PER_PTE)
-#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t))
-#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32))
-
-/*
- * PMD_SHIFT determines the size of the area a second-level page table can map
- * PGDIR_SHIFT determines what a third-level page table entry can map
- */
-#define PMD_SHIFT 21
-#define PGDIR_SHIFT 21
-
#define LIBRARY_TEXT_START 0x0c000000
#ifndef __ASSEMBLY__
@@ -124,12 +53,6 @@ extern void __pgd_error(const char *file, int line, pgd_t);
#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
-#endif /* !__ASSEMBLY__ */
-
-#define PMD_SIZE (1UL << PMD_SHIFT)
-#define PMD_MASK (~(PMD_SIZE-1))
-#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
-#define PGDIR_MASK (~(PGDIR_SIZE-1))
/*
* This is the lowest virtual address we can permit any user space
@@ -138,60 +61,6 @@ extern void __pgd_error(const char *file, int line, pgd_t);
*/
#define FIRST_USER_ADDRESS PAGE_SIZE
-#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
-
-/*
- * section address mask and size definitions.
- */
-#define SECTION_SHIFT 20
-#define SECTION_SIZE (1UL << SECTION_SHIFT)
-#define SECTION_MASK (~(SECTION_SIZE-1))
-
-/*
- * ARMv6 supersection address mask and size definitions.
- */
-#define SUPERSECTION_SHIFT 24
-#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
-#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))
-
-/*
- * "Linux" PTE definitions.
- *
- * We keep two sets of PTEs - the hardware and the linux version.
- * This allows greater flexibility in the way we map the Linux bits
- * onto the hardware tables, and allows us to have YOUNG and DIRTY
- * bits.
- *
- * The PTE table pointer refers to the hardware entries; the "Linux"
- * entries are stored 1024 bytes below.
- */
-#define L_PTE_PRESENT (_AT(pteval_t, 1) << 0)
-#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
-#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
-#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
-#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
-#define L_PTE_USER (_AT(pteval_t, 1) << 8)
-#define L_PTE_XN (_AT(pteval_t, 1) << 9)
-#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */
-
-/*
- * These are the memory types, defined to be compatible with
- * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
- */
-#define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */
-#define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */
-#define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */
-#define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */
-#define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */
-#define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */
-#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */
-#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */
-#define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */
-#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */
-#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2)
-
-#ifndef __ASSEMBLY__
-
/*
* The pgprot_* and protection_map entries will be fixed up in runtime
* to include the cachable and bufferable bits based on memory policy,
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