1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_POWERPC_NOHASH_32_PTE_8xx_H 3 #define _ASM_POWERPC_NOHASH_32_PTE_8xx_H 4 #ifdef __KERNEL__ 5 6 /* 7 * The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk. 8 * We also use the two level tables, but we can put the real bits in them 9 * needed for the TLB and tablewalk. These definitions require Mx_CTR.PPM = 0, 10 * Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1. The level 2 descriptor has 11 * additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit 12 * based upon user/super access. The TLB does not have accessed nor write 13 * protect. We assume that if the TLB get loaded with an entry it is 14 * accessed, and overload the changed bit for write protect. We use 15 * two bits in the software pte that are supposed to be set to zero in 16 * the TLB entry (24 and 25) for these indicators. Although the level 1 17 * descriptor contains the guarded and writethrough/copyback bits, we can 18 * set these at the page level since they get copied from the Mx_TWC 19 * register when the TLB entry is loaded. We will use bit 27 for guard, since 20 * that is where it exists in the MD_TWC, and bit 26 for writethrough. 21 * These will get masked from the level 2 descriptor at TLB load time, and 22 * copied to the MD_TWC before it gets loaded. 23 * Large page sizes added. We currently support two sizes, 4K and 8M. 24 * This also allows a TLB hander optimization because we can directly 25 * load the PMD into MD_TWC. The 8M pages are only used for kernel 26 * mapping of well known areas. The PMD (PGD) entries contain control 27 * flags in addition to the address, so care must be taken that the 28 * software no longer assumes these are only pointers. 29 */ 30 31 /* Definitions for 8xx embedded chips. */ 32 #define _PAGE_PRESENT 0x0001 /* V: Page is valid */ 33 #define _PAGE_NO_CACHE 0x0002 /* CI: cache inhibit */ 34 #define _PAGE_SH 0x0004 /* SH: No ASID (context) compare */ 35 #define _PAGE_SPS 0x0008 /* SPS: Small Page Size (1 if 16k, 512k or 8M)*/ 36 #define _PAGE_DIRTY 0x0100 /* C: page changed */ 37 38 /* These 4 software bits must be masked out when the L2 entry is loaded 39 * into the TLB. 40 */ 41 #define _PAGE_GUARDED 0x0010 /* Copied to L1 G entry in DTLB */ 42 #define _PAGE_SPECIAL 0x0020 /* SW entry */ 43 #define _PAGE_EXEC 0x0040 /* Copied to PP (bit 21) in ITLB */ 44 #define _PAGE_ACCESSED 0x0080 /* software: page referenced */ 45 46 #define _PAGE_NA 0x0200 /* Supervisor NA, User no access */ 47 #define _PAGE_RO 0x0600 /* Supervisor RO, User no access */ 48 49 /* cache related flags non existing on 8xx */ 50 #define _PAGE_COHERENT 0 51 #define _PAGE_WRITETHRU 0 52 53 #define _PAGE_KERNEL_RO (_PAGE_SH | _PAGE_RO) 54 #define _PAGE_KERNEL_ROX (_PAGE_SH | _PAGE_RO | _PAGE_EXEC) 55 #define _PAGE_KERNEL_RW (_PAGE_SH | _PAGE_DIRTY) 56 #define _PAGE_KERNEL_RWX (_PAGE_SH | _PAGE_DIRTY | _PAGE_EXEC) 57 58 #define _PMD_PRESENT 0x0001 59 #define _PMD_PRESENT_MASK _PMD_PRESENT 60 #define _PMD_BAD 0x0fd0 61 #define _PMD_PAGE_MASK 0x000c 62 #define _PMD_PAGE_8M 0x000c 63 #define _PMD_PAGE_512K 0x0004 64 #define _PMD_USER 0x0020 /* APG 1 */ 65 66 #define _PTE_NONE_MASK 0 67 68 #ifdef CONFIG_PPC_16K_PAGES 69 #define _PAGE_PSIZE _PAGE_SPS 70 #else 71 #define _PAGE_PSIZE 0 72 #endif 73 74 #define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE) 75 #define _PAGE_BASE (_PAGE_BASE_NC) 76 77 /* Permission masks used to generate the __P and __S table */ 78 #define PAGE_NONE __pgprot(_PAGE_BASE | _PAGE_NA) 79 #define PAGE_SHARED __pgprot(_PAGE_BASE) 80 #define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_EXEC) 81 #define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_RO) 82 #define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_RO | _PAGE_EXEC) 83 #define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_RO) 84 #define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_RO | _PAGE_EXEC) 85 86 #ifndef __ASSEMBLY__ 87 static inline pte_t pte_wrprotect(pte_t pte) 88 { 89 return __pte(pte_val(pte) | _PAGE_RO); 90 } 91 92 #define pte_wrprotect pte_wrprotect 93 94 static inline int pte_write(pte_t pte) 95 { 96 return !(pte_val(pte) & _PAGE_RO); 97 } 98 99 #define pte_write pte_write 100 101 static inline pte_t pte_mkwrite(pte_t pte) 102 { 103 return __pte(pte_val(pte) & ~_PAGE_RO); 104 } 105 106 #define pte_mkwrite pte_mkwrite 107 108 static inline bool pte_user(pte_t pte) 109 { 110 return !(pte_val(pte) & _PAGE_SH); 111 } 112 113 #define pte_user pte_user 114 115 static inline pte_t pte_mkprivileged(pte_t pte) 116 { 117 return __pte(pte_val(pte) | _PAGE_SH); 118 } 119 120 #define pte_mkprivileged pte_mkprivileged 121 122 static inline pte_t pte_mkuser(pte_t pte) 123 { 124 return __pte(pte_val(pte) & ~_PAGE_SH); 125 } 126 127 #define pte_mkuser pte_mkuser 128 129 static inline pte_t pte_mkhuge(pte_t pte) 130 { 131 return __pte(pte_val(pte) | _PAGE_SPS); 132 } 133 134 #define pte_mkhuge pte_mkhuge 135 #endif 136 137 #endif /* __KERNEL__ */ 138 #endif /* _ASM_POWERPC_NOHASH_32_PTE_8xx_H */ 139