diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-sh/pgtable.h | 76 |
1 files changed, 45 insertions, 31 deletions
diff --git a/include/asm-sh/pgtable.h b/include/asm-sh/pgtable.h index 9728b58f7c13..41c559d8ba87 100644 --- a/include/asm-sh/pgtable.h +++ b/include/asm-sh/pgtable.h @@ -54,20 +54,41 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define VMALLOC_START (P3SEG+0x00100000) #define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE) -#define _PAGE_WT 0x001 /* WT-bit on SH-4, 0 on SH-3 */ -#define _PAGE_HW_SHARED 0x002 /* SH-bit : page is shared among processes */ -#define _PAGE_DIRTY 0x004 /* D-bit : page changed */ -#define _PAGE_CACHABLE 0x008 /* C-bit : cachable */ -#define _PAGE_SZ0 0x010 /* SZ0-bit : Size of page */ -#define _PAGE_RW 0x020 /* PR0-bit : write access allowed */ -#define _PAGE_USER 0x040 /* PR1-bit : user space access allowed */ -#define _PAGE_SZ1 0x080 /* SZ1-bit : Size of page (on SH-4) */ -#define _PAGE_PRESENT 0x100 /* V-bit : page is valid */ -#define _PAGE_PROTNONE 0x200 /* software: if not present */ -#define _PAGE_ACCESSED 0x400 /* software: page referenced */ -#define _PAGE_U0_SHARED 0x800 /* software: page is shared in user space */ - -#define _PAGE_FILE _PAGE_WT /* software: pagecache or swap? */ +/* + * Linux PTEL encoding. + * + * Hardware and software bit definitions for the PTEL value: + * + * - Bits 0 and 7 are reserved on SH-3 (_PAGE_WT and _PAGE_SZ1 on SH-4). + * + * - Bit 1 is the SH-bit, but is unused on SH-3 due to an MMU bug (the + * hardware PTEL value can't have the SH-bit set when MMUCR.IX is set, + * which is the default in cpu-sh3/mmu_context.h:MMU_CONTROL_INIT). + * + * In order to keep this relatively clean, do not use these for defining + * SH-3 specific flags until all of the other unused bits have been + * exhausted. + * + * - Bit 9 is reserved by everyone and used by _PAGE_PROTNONE. + * + * - Bits 10 and 11 are low bits of the PPN that are reserved on >= 4K pages. + * Bit 10 is used for _PAGE_ACCESSED, bit 11 remains unused. + * + * - Bits 31, 30, and 29 remain unused by everyone and can be used for future + * software flags, although care must be taken to update _PAGE_CLEAR_FLAGS. + */ +#define _PAGE_WT 0x001 /* WT-bit on SH-4, 0 on SH-3 */ +#define _PAGE_HW_SHARED 0x002 /* SH-bit : shared among processes */ +#define _PAGE_DIRTY 0x004 /* D-bit : page changed */ +#define _PAGE_CACHABLE 0x008 /* C-bit : cachable */ +#define _PAGE_SZ0 0x010 /* SZ0-bit : Size of page */ +#define _PAGE_RW 0x020 /* PR0-bit : write access allowed */ +#define _PAGE_USER 0x040 /* PR1-bit : user space access allowed */ +#define _PAGE_SZ1 0x080 /* SZ1-bit : Size of page (on SH-4) */ +#define _PAGE_PRESENT 0x100 /* V-bit : page is valid */ +#define _PAGE_PROTNONE 0x200 /* software: if not present */ +#define _PAGE_ACCESSED 0x400 /* software: page referenced */ +#define _PAGE_FILE _PAGE_WT /* software: pagecache or swap? */ /* software: moves to PTEA.TC (Timing Control) */ #define _PAGE_PCC_AREA5 0x00000000 /* use BSC registers for area5 */ @@ -82,22 +103,17 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define _PAGE_PCC_ATR8 0x60000000 /* Attribute Memory space, 8 bit bus */ #define _PAGE_PCC_ATR16 0x60000001 /* Attribute Memory space, 6 bit bus */ -/* Mask which drop software flags - * We also drop WT bit since it is used for _PAGE_FILE - * bit in this implementation. - */ -#define _PAGE_CLEAR_FLAGS (_PAGE_WT | _PAGE_PROTNONE | _PAGE_ACCESSED | _PAGE_U0_SHARED) - -#if defined(CONFIG_CPU_SH3) -/* - * MMU on SH-3 has bug on SH-bit: We can't use it if MMUCR.IX=1. - * Work around: Just drop SH-bit. - */ -#define _PAGE_FLAGS_HARDWARE_MASK (0x1fffffff & ~(_PAGE_CLEAR_FLAGS | _PAGE_HW_SHARED)) +/* Mask which drops unused bits from the PTEL value */ +#ifdef CONFIG_CPU_SH3 +#define _PAGE_CLEAR_FLAGS (_PAGE_PROTNONE | _PAGE_ACCESSED| \ + _PAGE_FILE | _PAGE_SZ1 | \ + _PAGE_HW_SHARED) #else -#define _PAGE_FLAGS_HARDWARE_MASK (0x1fffffff & ~(_PAGE_CLEAR_FLAGS)) +#define _PAGE_CLEAR_FLAGS (_PAGE_PROTNONE | _PAGE_ACCESSED | _PAGE_FILE) #endif +#define _PAGE_FLAGS_HARDWARE_MASK (0x1fffffff & ~(_PAGE_CLEAR_FLAGS)) + /* Hardware flags: SZ0=1 (4k-byte) */ #define _PAGE_FLAGS_HARD _PAGE_SZ0 @@ -107,17 +123,15 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define _PAGE_SZHUGE (_PAGE_SZ0 | _PAGE_SZ1) #endif -#define _PAGE_SHARED _PAGE_U0_SHARED - #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY) #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) -#define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_SHARED) +#define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | _PAGE_DIRTY) #ifndef __ASSEMBLY__ #ifdef CONFIG_MMU #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_FLAGS_HARD) -#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_SHARED | _PAGE_FLAGS_HARD) +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_CACHABLE |_PAGE_ACCESSED | _PAGE_FLAGS_HARD) #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED | _PAGE_FLAGS_HARD) #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | _PAGE_ACCESSED | _PAGE_FLAGS_HARD) #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD) |
