The following commit has been merged into the locking/kcsan branch of tip: Commit-ID: 3408974d0533e1e9bd6345610b335c7c52195a49 Gitweb: https://git.kernel.org/tip/3408974d0533e1e9bd6345610b335c7c52195a49 Author: Will Deacon <will@xxxxxxxxxx> AuthorDate: Mon, 11 May 2020 21:41:34 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Tue, 12 May 2020 11:04:09 +02:00 sparc32: mm: Restructure sparc32 MMU page-table layout The "SRMMU" supports 4k pages using a fixed three-level walk with a 256-entry PGD and 64-entry PMD/PTE levels. In order to fill a page with a 'pgtable_t', the SRMMU code allocates four native PTE tables into a single PTE allocation and similarly for the PMD level, leading to an array of 16 physical pointers in a 'pmd_t' This breaks the generic code which assumes READ_ONCE(*pmd) will be word sized. In a manner similar to ef22d8abd876 ("m68k: mm: Restructure Motorola MMU page-table layout"), implement the native page-table setup directly. This significantly increases the page-table memory overhead, but will be addressed in a subsequent patch. Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200511204150.27858-3-will@xxxxxxxxxx --- arch/sparc/include/asm/page_32.h | 10 ++--- arch/sparc/include/asm/pgalloc_32.h | 5 +- arch/sparc/include/asm/pgtable_32.h | 29 +++++++------- arch/sparc/include/asm/pgtsrmmu.h | 36 +---------------- arch/sparc/include/asm/viking.h | 5 +- arch/sparc/kernel/head_32.S | 8 ++-- arch/sparc/mm/hypersparc.S | 3 +- arch/sparc/mm/srmmu.c | 60 +++++++++------------------- arch/sparc/mm/viking.S | 5 +- 9 files changed, 58 insertions(+), 103 deletions(-) diff --git a/arch/sparc/include/asm/page_32.h b/arch/sparc/include/asm/page_32.h index 4782600..da01c8c 100644 --- a/arch/sparc/include/asm/page_32.h +++ b/arch/sparc/include/asm/page_32.h @@ -54,7 +54,7 @@ extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1]; */ typedef struct { unsigned long pte; } pte_t; typedef struct { unsigned long iopte; } iopte_t; -typedef struct { unsigned long pmdv[16]; } pmd_t; +typedef struct { unsigned long pmd; } pmd_t; typedef struct { unsigned long pgd; } pgd_t; typedef struct { unsigned long ctxd; } ctxd_t; typedef struct { unsigned long pgprot; } pgprot_t; @@ -62,7 +62,7 @@ typedef struct { unsigned long iopgprot; } iopgprot_t; #define pte_val(x) ((x).pte) #define iopte_val(x) ((x).iopte) -#define pmd_val(x) ((x).pmdv[0]) +#define pmd_val(x) ((x).pmd) #define pgd_val(x) ((x).pgd) #define ctxd_val(x) ((x).ctxd) #define pgprot_val(x) ((x).pgprot) @@ -82,7 +82,7 @@ typedef struct { unsigned long iopgprot; } iopgprot_t; */ typedef unsigned long pte_t; typedef unsigned long iopte_t; -typedef struct { unsigned long pmdv[16]; } pmd_t; +typedef unsigned long pmd_t; typedef unsigned long pgd_t; typedef unsigned long ctxd_t; typedef unsigned long pgprot_t; @@ -90,14 +90,14 @@ typedef unsigned long iopgprot_t; #define pte_val(x) (x) #define iopte_val(x) (x) -#define pmd_val(x) ((x).pmdv[0]) +#define pmd_val(x) (x) #define pgd_val(x) (x) #define ctxd_val(x) (x) #define pgprot_val(x) (x) #define iopgprot_val(x) (x) #define __pte(x) (x) -#define __pmd(x) ((pmd_t) { { (x) }, }) +#define __pmd(x) (x) #define __iopte(x) (x) #define __pgd(x) (x) #define __ctxd(x) (x) diff --git a/arch/sparc/include/asm/pgalloc_32.h b/arch/sparc/include/asm/pgalloc_32.h index eae0c92..99c0324 100644 --- a/arch/sparc/include/asm/pgalloc_32.h +++ b/arch/sparc/include/asm/pgalloc_32.h @@ -60,13 +60,14 @@ pgtable_t pte_alloc_one(struct mm_struct *mm); static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) { - return srmmu_get_nocache(PTE_SIZE, PTE_SIZE); + return srmmu_get_nocache(SRMMU_PTE_TABLE_SIZE, + SRMMU_PTE_TABLE_SIZE); } static inline void free_pte_fast(pte_t *pte) { - srmmu_free_nocache(pte, PTE_SIZE); + srmmu_free_nocache(pte, SRMMU_PTE_TABLE_SIZE); } #define pte_free_kernel(mm, pte) free_pte_fast(pte) diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h index 0de659a..3367e2b 100644 --- a/arch/sparc/include/asm/pgtable_32.h +++ b/arch/sparc/include/asm/pgtable_32.h @@ -11,6 +11,16 @@ #include <linux/const.h> +#define PMD_SHIFT 18 +#define PMD_SIZE (1UL << PMD_SHIFT) +#define PMD_MASK (~(PMD_SIZE-1)) +#define PMD_ALIGN(__addr) (((__addr) + ~PMD_MASK) & PMD_MASK) + +#define PGDIR_SHIFT 24 +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) +#define PGDIR_ALIGN(__addr) (((__addr) + ~PGDIR_MASK) & PGDIR_MASK) + #ifndef __ASSEMBLY__ #include <asm-generic/pgtable-nopud.h> @@ -34,17 +44,10 @@ unsigned long __init bootmem_init(unsigned long *pages_avail); #define pmd_ERROR(e) __builtin_trap() #define pgd_ERROR(e) __builtin_trap() -#define PMD_SHIFT 22 -#define PMD_SIZE (1UL << PMD_SHIFT) -#define PMD_MASK (~(PMD_SIZE-1)) -#define PMD_ALIGN(__addr) (((__addr) + ~PMD_MASK) & PMD_MASK) -#define PGDIR_SHIFT SRMMU_PGDIR_SHIFT -#define PGDIR_SIZE SRMMU_PGDIR_SIZE -#define PGDIR_MASK SRMMU_PGDIR_MASK -#define PTRS_PER_PTE 1024 -#define PTRS_PER_PMD SRMMU_PTRS_PER_PMD -#define PTRS_PER_PGD SRMMU_PTRS_PER_PGD -#define USER_PTRS_PER_PGD PAGE_OFFSET / SRMMU_PGDIR_SIZE +#define PTRS_PER_PTE 64 +#define PTRS_PER_PMD 64 +#define PTRS_PER_PGD 256 +#define USER_PTRS_PER_PGD PAGE_OFFSET / PGDIR_SIZE #define FIRST_USER_ADDRESS 0UL #define PTE_SIZE (PTRS_PER_PTE*4) @@ -179,9 +182,7 @@ static inline int pmd_none(pmd_t pmd) static inline void pmd_clear(pmd_t *pmdp) { - int i; - for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) - set_pte((pte_t *)&pmdp->pmdv[i], __pte(0)); + set_pte((pte_t *)&pmd_val(*pmdp), __pte(0)); } static inline int pud_none(pud_t pud) diff --git a/arch/sparc/include/asm/pgtsrmmu.h b/arch/sparc/include/asm/pgtsrmmu.h index 32a5088..58ea8e8 100644 --- a/arch/sparc/include/asm/pgtsrmmu.h +++ b/arch/sparc/include/asm/pgtsrmmu.h @@ -17,39 +17,9 @@ /* Number of contexts is implementation-dependent; 64k is the most we support */ #define SRMMU_MAX_CONTEXTS 65536 -/* PMD_SHIFT determines the size of the area a second-level page table entry can map */ -#define SRMMU_REAL_PMD_SHIFT 18 -#define SRMMU_REAL_PMD_SIZE (1UL << SRMMU_REAL_PMD_SHIFT) -#define SRMMU_REAL_PMD_MASK (~(SRMMU_REAL_PMD_SIZE-1)) -#define SRMMU_REAL_PMD_ALIGN(__addr) (((__addr)+SRMMU_REAL_PMD_SIZE-1)&SRMMU_REAL_PMD_MASK) - -/* PGDIR_SHIFT determines what a third-level page table entry can map */ -#define SRMMU_PGDIR_SHIFT 24 -#define SRMMU_PGDIR_SIZE (1UL << SRMMU_PGDIR_SHIFT) -#define SRMMU_PGDIR_MASK (~(SRMMU_PGDIR_SIZE-1)) -#define SRMMU_PGDIR_ALIGN(addr) (((addr)+SRMMU_PGDIR_SIZE-1)&SRMMU_PGDIR_MASK) - -#define SRMMU_REAL_PTRS_PER_PTE 64 -#define SRMMU_REAL_PTRS_PER_PMD 64 -#define SRMMU_PTRS_PER_PGD 256 - -#define SRMMU_REAL_PTE_TABLE_SIZE (SRMMU_REAL_PTRS_PER_PTE*4) -#define SRMMU_PMD_TABLE_SIZE (SRMMU_REAL_PTRS_PER_PMD*4) -#define SRMMU_PGD_TABLE_SIZE (SRMMU_PTRS_PER_PGD*4) - -/* - * To support pagetables in highmem, Linux introduces APIs which - * return struct page* and generally manipulate page tables when - * they are not mapped into kernel space. Our hardware page tables - * are smaller than pages. We lump hardware tabes into big, page sized - * software tables. - * - * PMD_SHIFT determines the size of the area a second-level page table entry - * can map, and our pmd_t is 16 times larger than normal. The values which - * were once defined here are now generic for 4c and srmmu, so they're - * found in pgtable.h. - */ -#define SRMMU_PTRS_PER_PMD 4 +#define SRMMU_PTE_TABLE_SIZE (PAGE_SIZE) +#define SRMMU_PMD_TABLE_SIZE (PAGE_SIZE) +#define SRMMU_PGD_TABLE_SIZE (PTRS_PER_PGD*4) /* Definition of the values in the ET field of PTD's and PTE's */ #define SRMMU_ET_MASK 0x3 diff --git a/arch/sparc/include/asm/viking.h b/arch/sparc/include/asm/viking.h index 0bbefd1..08ffc60 100644 --- a/arch/sparc/include/asm/viking.h +++ b/arch/sparc/include/asm/viking.h @@ -10,6 +10,7 @@ #include <asm/asi.h> #include <asm/mxcc.h> +#include <asm/pgtable.h> #include <asm/pgtsrmmu.h> /* Bits in the SRMMU control register for GNU/Viking modules. @@ -227,7 +228,7 @@ static inline unsigned long viking_hwprobe(unsigned long vaddr) : "=r" (val) : "r" (vaddr | 0x200), "i" (ASI_M_FLUSH_PROBE)); if ((val & SRMMU_ET_MASK) == SRMMU_ET_PTE) { - vaddr &= ~SRMMU_PGDIR_MASK; + vaddr &= ~PGDIR_MASK; vaddr >>= PAGE_SHIFT; return val | (vaddr << 8); } @@ -237,7 +238,7 @@ static inline unsigned long viking_hwprobe(unsigned long vaddr) : "=r" (val) : "r" (vaddr | 0x100), "i" (ASI_M_FLUSH_PROBE)); if ((val & SRMMU_ET_MASK) == SRMMU_ET_PTE) { - vaddr &= ~SRMMU_REAL_PMD_MASK; + vaddr &= ~PMD_MASK; vaddr >>= PAGE_SHIFT; return val | (vaddr << 8); } diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S index e55f2c0..be30c8d 100644 --- a/arch/sparc/kernel/head_32.S +++ b/arch/sparc/kernel/head_32.S @@ -24,7 +24,7 @@ #include <asm/winmacro.h> #include <asm/thread_info.h> /* TI_UWINMASK */ #include <asm/errno.h> -#include <asm/pgtsrmmu.h> /* SRMMU_PGDIR_SHIFT */ +#include <asm/pgtable.h> /* PGDIR_SHIFT */ #include <asm/export.h> .data @@ -273,7 +273,7 @@ not_a_sun4: lda [%o1] ASI_M_BYPASS, %o2 ! This is the 0x0 16MB pgd /* Calculate to KERNBASE entry. */ - add %o1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %o3 + add %o1, KERNBASE >> (PGDIR_SHIFT - 2), %o3 /* Poke the entry into the calculated address. */ sta %o2, [%o3] ASI_M_BYPASS @@ -317,7 +317,7 @@ srmmu_not_viking: sll %g1, 0x8, %g1 ! make phys addr for l1 tbl lda [%g1] ASI_M_BYPASS, %g2 ! get level1 entry for 0x0 - add %g1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %g3 + add %g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3 sta %g2, [%g3] ASI_M_BYPASS ! place at KERNBASE entry b go_to_highmem nop ! wheee.... @@ -341,7 +341,7 @@ leon_remap: sll %g1, 0x8, %g1 ! make phys addr for l1 tbl lda [%g1] ASI_M_BYPASS, %g2 ! get level1 entry for 0x0 - add %g1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %g3 + add %g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3 sta %g2, [%g3] ASI_M_BYPASS ! place at KERNBASE entry b go_to_highmem nop ! wheee.... diff --git a/arch/sparc/mm/hypersparc.S b/arch/sparc/mm/hypersparc.S index 66885a8..6c2521e 100644 --- a/arch/sparc/mm/hypersparc.S +++ b/arch/sparc/mm/hypersparc.S @@ -10,6 +10,7 @@ #include <asm/asm-offsets.h> #include <asm/asi.h> #include <asm/page.h> +#include <asm/pgtable.h> #include <asm/pgtsrmmu.h> #include <linux/init.h> @@ -293,7 +294,7 @@ hypersparc_flush_tlb_range: cmp %o3, -1 be hypersparc_flush_tlb_range_out #endif - sethi %hi(~((1 << SRMMU_PGDIR_SHIFT) - 1)), %o4 + sethi %hi(~((1 << PGDIR_SHIFT) - 1)), %o4 sta %o3, [%g1] ASI_M_MMUREGS and %o1, %o4, %o1 add %o1, 0x200, %o1 diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c index cb9ded8..50da4bc 100644 --- a/arch/sparc/mm/srmmu.c +++ b/arch/sparc/mm/srmmu.c @@ -136,26 +136,14 @@ static void msi_set_sync(void) void pmd_set(pmd_t *pmdp, pte_t *ptep) { - unsigned long ptp; /* Physical address, shifted right by 4 */ - int i; - - ptp = __nocache_pa(ptep) >> 4; - for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) { - set_pte((pte_t *)&pmdp->pmdv[i], __pte(SRMMU_ET_PTD | ptp)); - ptp += (SRMMU_REAL_PTRS_PER_PTE * sizeof(pte_t) >> 4); - } + unsigned long ptp = __nocache_pa(ptep) >> 4; + set_pte((pte_t *)&pmd_val(*pmdp), __pte(SRMMU_ET_PTD | ptp)); } void pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *ptep) { - unsigned long ptp; /* Physical address, shifted right by 4 */ - int i; - - ptp = page_to_pfn(ptep) << (PAGE_SHIFT-4); /* watch for overflow */ - for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) { - set_pte((pte_t *)&pmdp->pmdv[i], __pte(SRMMU_ET_PTD | ptp)); - ptp += (SRMMU_REAL_PTRS_PER_PTE * sizeof(pte_t) >> 4); - } + unsigned long ptp = page_to_pfn(ptep) << (PAGE_SHIFT-4); /* watch for overflow */ + set_pte((pte_t *)&pmd_val(*pmdp), __pte(SRMMU_ET_PTD | ptp)); } /* Find an entry in the third-level page table.. */ @@ -163,7 +151,7 @@ pte_t *pte_offset_kernel(pmd_t *dir, unsigned long address) { void *pte; - pte = __nocache_va((dir->pmdv[0] & SRMMU_PTD_PMASK) << 4); + pte = __nocache_va((pmd_val(*dir) & SRMMU_PTD_PMASK) << 4); return (pte_t *) pte + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)); } @@ -400,7 +388,7 @@ void pte_free(struct mm_struct *mm, pgtable_t pte) p = page_to_pfn(pte) << PAGE_SHIFT; /* Physical address */ /* free non cached virtual address*/ - srmmu_free_nocache(__nocache_va(p), PTE_SIZE); + srmmu_free_nocache(__nocache_va(p), SRMMU_PTE_TABLE_SIZE); } /* context handling - a dynamically sized pool is used */ @@ -822,13 +810,13 @@ static void __init srmmu_inherit_prom_mappings(unsigned long start, what = 0; addr = start - PAGE_SIZE; - if (!(start & ~(SRMMU_REAL_PMD_MASK))) { - if (srmmu_probe(addr + SRMMU_REAL_PMD_SIZE) == probed) + if (!(start & ~(PMD_MASK))) { + if (srmmu_probe(addr + PMD_SIZE) == probed) what = 1; } - if (!(start & ~(SRMMU_PGDIR_MASK))) { - if (srmmu_probe(addr + SRMMU_PGDIR_SIZE) == probed) + if (!(start & ~(PGDIR_MASK))) { + if (srmmu_probe(addr + PGDIR_SIZE) == probed) what = 2; } @@ -837,7 +825,7 @@ static void __init srmmu_inherit_prom_mappings(unsigned long start, pudp = pud_offset(p4dp, start); if (what == 2) { *(pgd_t *)__nocache_fix(pgdp) = __pgd(probed); - start += SRMMU_PGDIR_SIZE; + start += PGDIR_SIZE; continue; } if (pud_none(*(pud_t *)__nocache_fix(pudp))) { @@ -849,6 +837,11 @@ static void __init srmmu_inherit_prom_mappings(unsigned long start, pud_set(__nocache_fix(pudp), pmdp); } pmdp = pmd_offset(__nocache_fix(pgdp), start); + if (what == 1) { + *(pmd_t *)__nocache_fix(pmdp) = __pmd(probed); + start += PMD_SIZE; + continue; + } if (srmmu_pmd_none(*(pmd_t *)__nocache_fix(pmdp))) { ptep = __srmmu_get_nocache(PTE_SIZE, PTE_SIZE); if (ptep == NULL) @@ -856,19 +849,6 @@ static void __init srmmu_inherit_prom_mappings(unsigned long start, memset(__nocache_fix(ptep), 0, PTE_SIZE); pmd_set(__nocache_fix(pmdp), ptep); } - if (what == 1) { - /* We bend the rule where all 16 PTPs in a pmd_t point - * inside the same PTE page, and we leak a perfectly - * good hardware PTE piece. Alternatives seem worse. - */ - unsigned int x; /* Index of HW PMD in soft cluster */ - unsigned long *val; - x = (start >> PMD_SHIFT) & 15; - val = &pmdp->pmdv[x]; - *(unsigned long *)__nocache_fix(val) = probed; - start += SRMMU_REAL_PMD_SIZE; - continue; - } ptep = pte_offset_kernel(__nocache_fix(pmdp), start); *(pte_t *)__nocache_fix(ptep) = __pte(probed); start += PAGE_SIZE; @@ -890,9 +870,9 @@ static void __init do_large_mapping(unsigned long vaddr, unsigned long phys_base /* Map sp_bank entry SP_ENTRY, starting at virtual address VBASE. */ static unsigned long __init map_spbank(unsigned long vbase, int sp_entry) { - unsigned long pstart = (sp_banks[sp_entry].base_addr & SRMMU_PGDIR_MASK); - unsigned long vstart = (vbase & SRMMU_PGDIR_MASK); - unsigned long vend = SRMMU_PGDIR_ALIGN(vbase + sp_banks[sp_entry].num_bytes); + unsigned long pstart = (sp_banks[sp_entry].base_addr & PGDIR_MASK); + unsigned long vstart = (vbase & PGDIR_MASK); + unsigned long vend = PGDIR_ALIGN(vbase + sp_banks[sp_entry].num_bytes); /* Map "low" memory only */ const unsigned long min_vaddr = PAGE_OFFSET; const unsigned long max_vaddr = PAGE_OFFSET + SRMMU_MAXMEM; @@ -905,7 +885,7 @@ static unsigned long __init map_spbank(unsigned long vbase, int sp_entry) while (vstart < vend) { do_large_mapping(vstart, pstart); - vstart += SRMMU_PGDIR_SIZE; pstart += SRMMU_PGDIR_SIZE; + vstart += PGDIR_SIZE; pstart += PGDIR_SIZE; } return vstart; } diff --git a/arch/sparc/mm/viking.S b/arch/sparc/mm/viking.S index adaef6e..48f062d 100644 --- a/arch/sparc/mm/viking.S +++ b/arch/sparc/mm/viking.S @@ -13,6 +13,7 @@ #include <asm/asi.h> #include <asm/mxcc.h> #include <asm/page.h> +#include <asm/pgtable.h> #include <asm/pgtsrmmu.h> #include <asm/viking.h> @@ -157,7 +158,7 @@ viking_flush_tlb_range: cmp %o3, -1 be 2f #endif - sethi %hi(~((1 << SRMMU_PGDIR_SHIFT) - 1)), %o4 + sethi %hi(~((1 << PGDIR_SHIFT) - 1)), %o4 sta %o3, [%g1] ASI_M_MMUREGS and %o1, %o4, %o1 add %o1, 0x200, %o1 @@ -243,7 +244,7 @@ sun4dsmp_flush_tlb_range: ld [%o0 + VMA_VM_MM], %o0 ld [%o0 + AOFF_mm_context], %o3 lda [%g1] ASI_M_MMUREGS, %g5 - sethi %hi(~((1 << SRMMU_PGDIR_SHIFT) - 1)), %o4 + sethi %hi(~((1 << PGDIR_SHIFT) - 1)), %o4 sta %o3, [%g1] ASI_M_MMUREGS and %o1, %o4, %o1 add %o1, 0x200, %o1
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