diff options
Diffstat (limited to 'arch/powerpc/include/asm/pgtable-ppc32.h')
| -rw-r--r-- | arch/powerpc/include/asm/pgtable-ppc32.h | 319 |
1 files changed, 21 insertions, 298 deletions
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h index 98bd7c5fcd0e..a9c6ecef3656 100644 --- a/arch/powerpc/include/asm/pgtable-ppc32.h +++ b/arch/powerpc/include/asm/pgtable-ppc32.h @@ -19,55 +19,6 @@ extern int icache_44x_need_flush; #endif /* __ASSEMBLY__ */ /* - * The PowerPC MMU uses a hash table containing PTEs, together with - * a set of 16 segment registers (on 32-bit implementations), to define - * the virtual to physical address mapping. - * - * We use the hash table as an extended TLB, i.e. a cache of currently - * active mappings. We maintain a two-level page table tree, much - * like that used by the i386, for the sake of the Linux memory - * management code. Low-level assembler code in hashtable.S - * (procedure hash_page) is responsible for extracting ptes from the - * tree and putting them into the hash table when necessary, and - * updating the accessed and modified bits in the page table tree. - */ - -/* - * The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk. - * We also use the two level tables, but we can put the real bits in them - * needed for the TLB and tablewalk. These definitions require Mx_CTR.PPM = 0, - * Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1. The level 2 descriptor has - * additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit - * based upon user/super access. The TLB does not have accessed nor write - * protect. We assume that if the TLB get loaded with an entry it is - * accessed, and overload the changed bit for write protect. We use - * two bits in the software pte that are supposed to be set to zero in - * the TLB entry (24 and 25) for these indicators. Although the level 1 - * descriptor contains the guarded and writethrough/copyback bits, we can - * set these at the page level since they get copied from the Mx_TWC - * register when the TLB entry is loaded. We will use bit 27 for guard, since - * that is where it exists in the MD_TWC, and bit 26 for writethrough. - * These will get masked from the level 2 descriptor at TLB load time, and - * copied to the MD_TWC before it gets loaded. - * Large page sizes added. We currently support two sizes, 4K and 8M. - * This also allows a TLB hander optimization because we can directly - * load the PMD into MD_TWC. The 8M pages are only used for kernel - * mapping of well known areas. The PMD (PGD) entries contain control - * flags in addition to the address, so care must be taken that the - * software no longer assumes these are only pointers. - */ - -/* - * At present, all PowerPC 400-class processors share a similar TLB - * architecture. The instruction and data sides share a unified, - * 64-entry, fully-associative TLB which is maintained totally under - * software control. In addition, the instruction side has a - * hardware-managed, 4-entry, fully-associative TLB which serves as a - * first level to the shared TLB. These two TLBs are known as the UTLB - * and ITLB, respectively (see "mmu.h" for definitions). - */ - -/* * The normal case is that PTEs are 32-bits and we have a 1-page * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages. -- paulus * @@ -135,261 +86,25 @@ extern int icache_44x_need_flush; */ #if defined(CONFIG_40x) - -/* There are several potential gotchas here. The 40x hardware TLBLO - field looks like this: - - 0 1 2 3 4 ... 18 19 20 21 22 23 24 25 26 27 28 29 30 31 - RPN..................... 0 0 EX WR ZSEL....... W I M G - - Where possible we make the Linux PTE bits match up with this - - - bits 20 and 21 must be cleared, because we use 4k pages (40x can - support down to 1k pages), this is done in the TLBMiss exception - handler. - - We use only zones 0 (for kernel pages) and 1 (for user pages) - of the 16 available. Bit 24-26 of the TLB are cleared in the TLB - miss handler. Bit 27 is PAGE_USER, thus selecting the correct - zone. - - PRESENT *must* be in the bottom two bits because swap cache - entries use the top 30 bits. Because 40x doesn't support SMP - anyway, M is irrelevant so we borrow it for PAGE_PRESENT. Bit 30 - is cleared in the TLB miss handler before the TLB entry is loaded. - - All other bits of the PTE are loaded into TLBLO without - modification, leaving us only the bits 20, 21, 24, 25, 26, 30 for - software PTE bits. We actually use use bits 21, 24, 25, and - 30 respectively for the software bits: ACCESSED, DIRTY, RW, and - PRESENT. -*/ - -/* Definitions for 40x embedded chips. */ -#define _PAGE_GUARDED 0x001 /* G: page is guarded from prefetch */ -#define _PAGE_FILE 0x001 /* when !present: nonlinear file mapping */ -#define _PAGE_PRESENT 0x002 /* software: PTE contains a translation */ -#define _PAGE_NO_CACHE 0x004 /* I: caching is inhibited */ -#define _PAGE_WRITETHRU 0x008 /* W: caching is write-through */ -#define _PAGE_USER 0x010 /* matches one of the zone permission bits */ -#define _PAGE_RW 0x040 /* software: Writes permitted */ -#define _PAGE_DIRTY 0x080 /* software: dirty page */ -#define _PAGE_HWWRITE 0x100 /* hardware: Dirty & RW, set in exception */ -#define _PAGE_HWEXEC 0x200 /* hardware: EX permission */ -#define _PAGE_ACCESSED 0x400 /* software: R: page referenced */ - -#define _PMD_PRESENT 0x400 /* PMD points to page of PTEs */ -#define _PMD_BAD 0x802 -#define _PMD_SIZE 0x0e0 /* size field, != 0 for large-page PMD entry */ -#define _PMD_SIZE_4M 0x0c0 -#define _PMD_SIZE_16M 0x0e0 -#define PMD_PAGE_SIZE(pmdval) (1024 << (((pmdval) & _PMD_SIZE) >> 4)) - -/* Until my rework is finished, 40x still needs atomic PTE updates */ -#define PTE_ATOMIC_UPDATES 1 - +#include <asm/pte-40x.h> #elif defined(CONFIG_44x) -/* - * Definitions for PPC440 - * - * Because of the 3 word TLB entries to support 36-bit addressing, - * the attribute are difficult to map in such a fashion that they - * are easily loaded during exception processing. I decided to - * organize the entry so the ERPN is the only portion in the - * upper word of the PTE and the attribute bits below are packed - * in as sensibly as they can be in the area below a 4KB page size - * oriented RPN. This at least makes it easy to load the RPN and - * ERPN fields in the TLB. -Matt - * - * Note that these bits preclude future use of a page size - * less than 4KB. - * - * - * PPC 440 core has following TLB attribute fields; - * - * TLB1: - * 0 1 2 3 4 ... 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 - * RPN................................. - - - - - - ERPN....... - * - * TLB2: - * 0 1 2 3 4 ... 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 - * - - - - - - U0 U1 U2 U3 W I M G E - UX UW UR SX SW SR - * - * Newer 440 cores (440x6 as used on AMCC 460EX/460GT) have additional - * TLB2 storage attibute fields. Those are: - * - * TLB2: - * 0...10 11 12 13 14 15 16...31 - * no change WL1 IL1I IL1D IL2I IL2D no change - * - * There are some constrains and options, to decide mapping software bits - * into TLB entry. - * - * - PRESENT *must* be in the bottom three bits because swap cache - * entries use the top 29 bits for TLB2. - * - * - FILE *must* be in the bottom three bits because swap cache - * entries use the top 29 bits for TLB2. - * - * - CACHE COHERENT bit (M) has no effect on original PPC440 cores, - * because it doesn't support SMP. However, some later 460 variants - * have -some- form of SMP support and so I keep the bit there for - * future use - * - * With the PPC 44x Linux implementation, the 0-11th LSBs of the PTE are used - * for memory protection related functions (see PTE structure in - * include/asm-ppc/mmu.h). The _PAGE_XXX definitions in this file map to the - * above bits. Note that the bit values are CPU specific, not architecture - * specific. - * - * The kernel PTE entry holds an arch-dependent swp_entry structure under - * certain situations. In other words, in such situations some portion of - * the PTE bits are used as a swp_entry. In the PPC implementation, the - * 3-24th LSB are shared with swp_entry, however the 0-2nd three LSB still - * hold protection values. That means the three protection bits are - * reserved for both PTE and SWAP entry at the most significant three - * LSBs. - * - * There are three protection bits available for SWAP entry: - * _PAGE_PRESENT - * _PAGE_FILE - * _PAGE_HASHPTE (if HW has) - * - * So those three bits have to be inside of 0-2nd LSB of PTE. - * - */ - -#define _PAGE_PRESENT 0x00000001 /* S: PTE valid */ -#define _PAGE_RW 0x00000002 /* S: Write permission */ -#define _PAGE_FILE 0x00000004 /* S: nonlinear file mapping */ -#define _PAGE_HWEXEC 0x00000004 /* H: Execute permission */ -#define _PAGE_ACCESSED 0x00000008 /* S: Page referenced */ -#define _PAGE_DIRTY 0x00000010 /* S: Page dirty */ -#define _PAGE_SPECIAL 0x00000020 /* S: Special page */ -#define _PAGE_USER 0x00000040 /* S: User page */ -#define _PAGE_ENDIAN 0x00000080 /* H: E bit */ -#define _PAGE_GUARDED 0x00000100 /* H: G bit */ -#define _PAGE_COHERENT 0x00000200 /* H: M bit */ -#define _PAGE_NO_CACHE 0x00000400 /* H: I bit */ -#define _PAGE_WRITETHRU 0x00000800 /* H: W bit */ - -/* TODO: Add large page lowmem mapping support */ -#define _PMD_PRESENT 0 -#define _PMD_PRESENT_MASK (PAGE_MASK) -#define _PMD_BAD (~PAGE_MASK) - -/* ERPN in a PTE never gets cleared, ignore it */ -#define _PTE_NONE_MASK 0xffffffff00000000ULL - -#define __HAVE_ARCH_PTE_SPECIAL - +#include <asm/pte-44x.h> #elif defined(CONFIG_FSL_BOOKE) -/* - MMU Assist Register 3: - - 32 33 34 35 36 ... 50 51 52 53 54 55 56 57 58 59 60 61 62 63 - RPN...................... 0 0 U0 U1 U2 U3 UX SX UW SW UR SR - - - PRESENT *must* be in the bottom three bits because swap cache - entries use the top 29 bits. - - - FILE *must* be in the bottom three bits because swap cache - entries use the top 29 bits. -*/ - -/* Definitions for FSL Book-E Cores */ -#define _PAGE_PRESENT 0x00001 /* S: PTE contains a translation */ -#define _PAGE_USER 0x00002 /* S: User page (maps to UR) */ -#define _PAGE_FILE 0x00002 /* S: when !present: nonlinear file mapping */ -#define _PAGE_RW 0x00004 /* S: Write permission (SW) */ -#define _PAGE_DIRTY 0x00008 /* S: Page dirty */ -#define _PAGE_HWEXEC 0x00010 /* H: SX permission */ -#define _PAGE_ACCESSED 0x00020 /* S: Page referenced */ - -#define _PAGE_ENDIAN 0x00040 /* H: E bit */ -#define _PAGE_GUARDED 0x00080 /* H: G bit */ -#define _PAGE_COHERENT 0x00100 /* H: M bit */ -#define _PAGE_NO_CACHE 0x00200 /* H: I bit */ -#define _PAGE_WRITETHRU 0x00400 /* H: W bit */ -#define _PAGE_SPECIAL 0x00800 /* S: Special page */ - -#ifdef CONFIG_PTE_64BIT -/* ERPN in a PTE never gets cleared, ignore it */ -#define _PTE_NONE_MASK 0xffffffffffff0000ULL -#endif - -#define _PMD_PRESENT 0 -#define _PMD_PRESENT_MASK (PAGE_MASK) -#define _PMD_BAD (~PAGE_MASK) - -#define __HAVE_ARCH_PTE_SPECIAL - +#include <asm/pte-fsl-booke.h> #elif defined(CONFIG_8xx) -/* Definitions for 8xx embedded chips. */ -#define _PAGE_PRESENT 0x0001 /* Page is valid */ -#define _PAGE_FILE 0x0002 /* when !present: nonlinear file mapping */ -#define _PAGE_NO_CACHE 0x0002 /* I: cache inhibit */ -#define _PAGE_SHARED 0x0004 /* No ASID (context) compare */ - -/* These five software bits must be masked out when the entry is loaded - * into the TLB. - */ -#define _PAGE_EXEC 0x0008 /* software: i-cache coherency required */ -#define _PAGE_GUARDED 0x0010 /* software: guarded access */ -#define _PAGE_DIRTY 0x0020 /* software: page changed */ -#define _PAGE_RW 0x0040 /* software: user write access allowed */ -#define _PAGE_ACCESSED 0x0080 /* software: page referenced */ - -/* Setting any bits in the nibble with the follow two controls will - * require a TLB exception handler change. It is assumed unused bits - * are always zero. - */ -#define _PAGE_HWWRITE 0x0100 /* h/w write enable: never set in Linux PTE */ -#define _PAGE_USER 0x0800 /* One of the PP bits, the other is USER&~RW */ - -#define _PMD_PRESENT 0x0001 -#define _PMD_BAD 0x0ff0 -#define _PMD_PAGE_MASK 0x000c -#define _PMD_PAGE_8M 0x000c - -#define _PTE_NONE_MASK _PAGE_ACCESSED - -/* Until my rework is finished, 8xx still needs atomic PTE updates */ -#define PTE_ATOMIC_UPDATES 1 - +#include <asm/pte-8xx.h> #else /* CONFIG_6xx */ -/* Definitions for 60x, 740/750, etc. */ -#define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ -#define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ -#define _PAGE_FILE 0x004 /* when !present: nonlinear file mapping */ -#define _PAGE_USER 0x004 /* usermode access allowed */ -#define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ -#define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ -#define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ -#define _PAGE_WRITETHRU 0x040 /* W: cache write-through */ -#define _PAGE_DIRTY 0x080 /* C: page changed */ -#define _PAGE_ACCESSED 0x100 /* R: page referenced */ -#define _PAGE_EXEC 0x200 /* software: i-cache coherency required */ -#define _PAGE_RW 0x400 /* software: user write access allowed */ -#define _PAGE_SPECIAL 0x800 /* software: Special page */ - -#ifdef CONFIG_PTE_64BIT -/* We never clear the high word of the pte */ -#define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE) -#else -#define _PTE_NONE_MASK _PAGE_HASHPTE +#include <asm/pte-hash32.h> #endif -#define _PMD_PRESENT 0 -#define _PMD_PRESENT_MASK (PAGE_MASK) -#define _PMD_BAD (~PAGE_MASK) - -/* Hash table based platforms need atomic updates of the linux PTE */ -#define PTE_ATOMIC_UPDATES 1 - +/* If _PAGE_SPECIAL is defined, then we advertise our support for it */ +#ifdef _PAGE_SPECIAL #define __HAVE_ARCH_PTE_SPECIAL - #endif /* - * Some bits are only used on some cpu families... + * Some bits are only used on some cpu families... Make sure that all + * the undefined gets defined as 0 */ #ifndef _PAGE_HASHPTE #define _PAGE_HASHPTE 0 @@ -600,11 +315,19 @@ extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long address); /* - * Atomic PTE updates. + * PTE updates. This function is called whenever an existing + * valid PTE is updated. This does -not- include set_pte_at() + * which nowadays only sets a new PTE. + * + * Depending on the type of MMU, we may need to use atomic updates + * and the PTE may be either 32 or 64 bit wide. In the later case, + * when using atomic updates, only the low part of the PTE is + * accessed atomically. * - * pte_update clears and sets bit atomically, and returns - * the old pte value. In the 64-bit PTE case we lock around the - * low PTE word since we expect ALL flag bits to be there + * In addition, on 44x, we also maintain a global flag indicating + * that an executable user mapping was modified, which is needed + * to properly flush the virtually tagged instruction cache of + * those implementations. */ #ifndef CONFIG_PTE_64BIT static inline unsigned long pte_update(pte_t *p, |
