From 0e071ee6815692a3b241bbe9a9a29f7cdec023ed Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 31 Jan 2020 13:45:39 +0100 Subject: m68k: mm: Extend table allocator for multiple sizes In addition to the PGD/PMD table size (128*4) add a PTE table size (64*4) to the table allocator. This completely removes the pte-table overhead compared to the old code, even for dense tables. Notes: - the allocator gained a list_empty() check to deal with there not being any pages at all. - the free mask is extended to cover more than the 8 bits required for the (512 byte) PGD/PMD tables. - NR_PAGETABLE accounting is restored. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Will Deacon Acked-by: Greg Ungerer Tested-by: Michael Schmitz Tested-by: Greg Ungerer Link: https://lore.kernel.org/r/20200131125403.882175409@infradead.org Signed-off-by: Geert Uytterhoeven --- arch/m68k/include/asm/motorola_pgalloc.h | 31 +++++++++------ arch/m68k/mm/init.c | 16 ++++---- arch/m68k/mm/motorola.c | 65 +++++++++++++++++++++----------- 3 files changed, 70 insertions(+), 42 deletions(-) (limited to 'arch/m68k') diff --git a/arch/m68k/include/asm/motorola_pgalloc.h b/arch/m68k/include/asm/motorola_pgalloc.h index c15e04277be7..c66e42917912 100644 --- a/arch/m68k/include/asm/motorola_pgalloc.h +++ b/arch/m68k/include/asm/motorola_pgalloc.h @@ -8,61 +8,68 @@ extern void mmu_page_ctor(void *page); extern void mmu_page_dtor(void *page); -extern pmd_t *get_pointer_table(void); -extern int free_pointer_table(pmd_t *); +enum m68k_table_types { + TABLE_PGD = 0, + TABLE_PMD = 0, /* same size as PGD */ + TABLE_PTE = 1, +}; + +extern void init_pointer_table(void *table, int type); +extern void *get_pointer_table(int type); +extern int free_pointer_table(void *table, int type); static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) { - return (pte_t *)get_pointer_table(); + return get_pointer_table(TABLE_PTE); } static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) { - free_pointer_table((void *)pte); + free_pointer_table(pte, TABLE_PTE); } static inline pgtable_t pte_alloc_one(struct mm_struct *mm) { - return (pte_t *)get_pointer_table(); + return get_pointer_table(TABLE_PTE); } static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable) { - free_pointer_table((void *)pgtable); + free_pointer_table(pgtable, TABLE_PTE); } static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable, unsigned long address) { - free_pointer_table((void *)pgtable); + free_pointer_table(pgtable, TABLE_PTE); } static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) { - return get_pointer_table(); + return get_pointer_table(TABLE_PMD); } static inline int pmd_free(struct mm_struct *mm, pmd_t *pmd) { - return free_pointer_table(pmd); + return free_pointer_table(pmd, TABLE_PMD); } static inline int __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, unsigned long address) { - return free_pointer_table(pmd); + return free_pointer_table(pmd, TABLE_PMD); } static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) { - pmd_free(mm, (pmd_t *)pgd); + free_pointer_table(pgd, TABLE_PGD); } static inline pgd_t *pgd_alloc(struct mm_struct *mm) { - return (pgd_t *)get_pointer_table(); + return get_pointer_table(TABLE_PGD); } diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c index a9b6d26cff8a..3e3a74a5b215 100644 --- a/arch/m68k/mm/init.c +++ b/arch/m68k/mm/init.c @@ -40,10 +40,6 @@ void *empty_zero_page; EXPORT_SYMBOL(empty_zero_page); -#if !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE) -extern void init_pointer_table(unsigned long ptable); -#endif - #ifdef CONFIG_MMU pg_data_t pg_data_map[MAX_NUMNODES]; @@ -127,12 +123,16 @@ static inline void init_pointer_tables(void) int i; /* insert pointer tables allocated so far into the tablelist */ - init_pointer_table((unsigned long)kernel_pg_dir); + init_pointer_table(kernel_pg_dir, TABLE_PGD); for (i = 0; i < PTRS_PER_PGD; i++) { - pud_t *pud = (pud_t *)(&kernel_pg_dir[i]); + pud_t *pud = (pud_t *)&kernel_pg_dir[i]; + pmd_t *pmd_dir; + + if (!pud_present(*pud)) + continue; - if (pud_present(*pud)) - init_pointer_table(pgd_page_vaddr(kernel_pg_dir[i])); + pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]); + init_pointer_table(pmd_dir, TABLE_PMD); } #endif } diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c index 600f9c1d96f8..fc16190ec2d6 100644 --- a/arch/m68k/mm/motorola.c +++ b/arch/m68k/mm/motorola.c @@ -72,24 +72,35 @@ void mmu_page_dtor(void *page) arch/sparc/mm/srmmu.c ... */ typedef struct list_head ptable_desc; -static LIST_HEAD(ptable_list); + +static struct list_head ptable_list[2] = { + LIST_HEAD_INIT(ptable_list[0]), + LIST_HEAD_INIT(ptable_list[1]), +}; #define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru)) #define PD_PAGE(ptable) (list_entry(ptable, struct page, lru)) -#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index) +#define PD_MARKBITS(dp) (*(unsigned int *)&PD_PAGE(dp)->index) + +static const int ptable_shift[2] = { + 7+2, /* PGD, PMD */ + 6+2, /* PTE */ +}; -#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t)) +#define ptable_size(type) (1U << ptable_shift[type]) +#define ptable_mask(type) ((1U << (PAGE_SIZE / ptable_size(type))) - 1) -void __init init_pointer_table(unsigned long ptable) +void __init init_pointer_table(void *table, int type) { ptable_desc *dp; + unsigned long ptable = (unsigned long)table; unsigned long page = ptable & PAGE_MASK; - unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE); + unsigned int mask = 1U << ((ptable - page)/ptable_size(type)); dp = PD_PTABLE(page); if (!(PD_MARKBITS(dp) & mask)) { - PD_MARKBITS(dp) = 0xff; - list_add(dp, &ptable_list); + PD_MARKBITS(dp) = ptable_mask(type); + list_add(dp, &ptable_list[type]); } PD_MARKBITS(dp) &= ~mask; @@ -102,12 +113,11 @@ void __init init_pointer_table(unsigned long ptable) return; } -pmd_t *get_pointer_table (void) +void *get_pointer_table(int type) { - ptable_desc *dp = ptable_list.next; - unsigned char mask = PD_MARKBITS (dp); - unsigned char tmp; - unsigned int off; + ptable_desc *dp = ptable_list[type].next; + unsigned int mask = list_empty(&ptable_list[type]) ? 0 : PD_MARKBITS(dp); + unsigned int tmp, off; /* * For a pointer table for a user process address space, a @@ -122,30 +132,39 @@ pmd_t *get_pointer_table (void) if (!(page = (void *)get_zeroed_page(GFP_KERNEL))) return NULL; + if (type == TABLE_PTE) { + /* + * m68k doesn't have SPLIT_PTE_PTLOCKS for not having + * SMP. + */ + pgtable_pte_page_ctor(virt_to_page(page)); + } + mmu_page_ctor(page); new = PD_PTABLE(page); - PD_MARKBITS(new) = 0xfe; + PD_MARKBITS(new) = ptable_mask(type) - 1; list_add_tail(new, dp); return (pmd_t *)page; } - for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE) + for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += ptable_size(type)) ; PD_MARKBITS(dp) = mask & ~tmp; if (!PD_MARKBITS(dp)) { /* move to end of list */ - list_move_tail(dp, &ptable_list); + list_move_tail(dp, &ptable_list[type]); } - return (pmd_t *) (page_address(PD_PAGE(dp)) + off); + return page_address(PD_PAGE(dp)) + off; } -int free_pointer_table (pmd_t *ptable) +int free_pointer_table(void *table, int type) { ptable_desc *dp; - unsigned long page = (unsigned long)ptable & PAGE_MASK; - unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE); + unsigned long ptable = (unsigned long)table; + unsigned long page = ptable & PAGE_MASK; + unsigned int mask = 1U << ((ptable - page)/ptable_size(type)); dp = PD_PTABLE(page); if (PD_MARKBITS (dp) & mask) @@ -153,18 +172,20 @@ int free_pointer_table (pmd_t *ptable) PD_MARKBITS (dp) |= mask; - if (PD_MARKBITS(dp) == 0xff) { + if (PD_MARKBITS(dp) == ptable_mask(type)) { /* all tables in page are free, free page */ list_del(dp); mmu_page_dtor((void *)page); + if (type == TABLE_PTE) + pgtable_pte_page_dtor(virt_to_page(page)); free_page (page); return 1; - } else if (ptable_list.next != dp) { + } else if (ptable_list[type].next != dp) { /* * move this descriptor to the front of the list, since * it has one or more free tables. */ - list_move(dp, &ptable_list); + list_move(dp, &ptable_list[type]); } return 0; } -- cgit v1.2.3