diff options
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/Kconfig | 1 | ||||
-rw-r--r-- | arch/s390/include/asm/pgtable.h | 79 | ||||
-rw-r--r-- | arch/s390/mm/Makefile | 2 | ||||
-rw-r--r-- | arch/s390/mm/gup.c | 300 |
4 files changed, 57 insertions, 325 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index ed554b09eb3f..6023021c9b23 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -148,6 +148,7 @@ config S390 select HAVE_FUNCTION_TRACER select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_GCC_PLUGINS + select HAVE_GENERIC_GUP select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZ4 diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 063732414dfb..861f2b63f290 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1203,42 +1203,79 @@ static inline pte_t mk_pte(struct page *page, pgprot_t pgprot) #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1)) -#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) -#define pgd_offset_k(address) pgd_offset(&init_mm, address) -#define pgd_offset_raw(pgd, addr) ((pgd) + pgd_index(addr)) - #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN) #define p4d_deref(pud) (p4d_val(pud) & _REGION_ENTRY_ORIGIN) #define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) -static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address) +/* + * The pgd_offset function *always* adds the index for the top-level + * region/segment table. This is done to get a sequence like the + * following to work: + * pgdp = pgd_offset(current->mm, addr); + * pgd = READ_ONCE(*pgdp); + * p4dp = p4d_offset(&pgd, addr); + * ... + * The subsequent p4d_offset, pud_offset and pmd_offset functions + * only add an index if they dereferenced the pointer. + */ +static inline pgd_t *pgd_offset_raw(pgd_t *pgd, unsigned long address) { - p4d_t *p4d = (p4d_t *) pgd; + unsigned long rste; + unsigned int shift; - if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1) - p4d = (p4d_t *) pgd_deref(*pgd); - return p4d + p4d_index(address); + /* Get the first entry of the top level table */ + rste = pgd_val(*pgd); + /* Pick up the shift from the table type of the first entry */ + shift = ((rste & _REGION_ENTRY_TYPE_MASK) >> 2) * 11 + 20; + return pgd + ((address >> shift) & (PTRS_PER_PGD - 1)); } -static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address) +#define pgd_offset(mm, address) pgd_offset_raw(READ_ONCE((mm)->pgd), address) +#define pgd_offset_k(address) pgd_offset(&init_mm, address) + +static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address) { - pud_t *pud = (pud_t *) p4d; + if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R1) + return (p4d_t *) pgd_deref(*pgd) + p4d_index(address); + return (p4d_t *) pgd; +} - if ((p4d_val(*p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) - pud = (pud_t *) p4d_deref(*p4d); - return pud + pud_index(address); +static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address) +{ + if ((p4d_val(*p4d) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R2) + return (pud_t *) p4d_deref(*p4d) + pud_index(address); + return (pud_t *) p4d; } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { - pmd_t *pmd = (pmd_t *) pud; + if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R3) + return (pmd_t *) pud_deref(*pud) + pmd_index(address); + return (pmd_t *) pud; +} - if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) - pmd = (pmd_t *) pud_deref(*pud); - return pmd + pmd_index(address); +static inline pte_t *pte_offset(pmd_t *pmd, unsigned long address) +{ + return (pte_t *) pmd_deref(*pmd) + pte_index(address); } +#define pte_offset_kernel(pmd, address) pte_offset(pmd, address) +#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address) +#define pte_unmap(pte) do { } while (0) + +static inline bool gup_fast_permitted(unsigned long start, int nr_pages) +{ + unsigned long len, end; + + len = (unsigned long) nr_pages << PAGE_SHIFT; + end = start + len; + if (end < start) + return false; + return end <= current->mm->context.asce_limit; +} +#define gup_fast_permitted gup_fast_permitted + #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot)) #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT) #define pte_page(x) pfn_to_page(pte_pfn(x)) @@ -1248,12 +1285,6 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) #define p4d_page(p4d) pfn_to_page(p4d_pfn(p4d)) #define pgd_page(pgd) pfn_to_page(pgd_pfn(pgd)) -/* Find an entry in the lowest level page table.. */ -#define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr)) -#define pte_offset_kernel(pmd, address) pte_offset(pmd,address) -#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address) -#define pte_unmap(pte) do { } while (0) - static inline pmd_t pmd_wrprotect(pmd_t pmd) { pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE; diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile index f5880bfd1b0c..3175413186b9 100644 --- a/arch/s390/mm/Makefile +++ b/arch/s390/mm/Makefile @@ -4,7 +4,7 @@ # obj-y := init.o fault.o extmem.o mmap.o vmem.o maccess.o -obj-y += page-states.o gup.o pageattr.o pgtable.o pgalloc.o +obj-y += page-states.o pageattr.o pgtable.o pgalloc.o obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c deleted file mode 100644 index 2809d11c7a28..000000000000 --- a/arch/s390/mm/gup.c +++ /dev/null @@ -1,300 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Lockless get_user_pages_fast for s390 - * - * Copyright IBM Corp. 2010 - * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> - */ -#include <linux/sched.h> -#include <linux/mm.h> -#include <linux/hugetlb.h> -#include <linux/vmstat.h> -#include <linux/pagemap.h> -#include <linux/rwsem.h> -#include <asm/pgtable.h> - -/* - * The performance critical leaf functions are made noinline otherwise gcc - * inlines everything into a single function which results in too much - * register pressure. - */ -static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - struct page *head, *page; - unsigned long mask; - pte_t *ptep, pte; - - mask = (write ? _PAGE_PROTECT : 0) | _PAGE_INVALID | _PAGE_SPECIAL; - - ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr); - do { - pte = *ptep; - barrier(); - /* Similar to the PMD case, NUMA hinting must take slow path */ - if (pte_protnone(pte)) - return 0; - if ((pte_val(pte) & mask) != 0) - return 0; - VM_BUG_ON(!pfn_valid(pte_pfn(pte))); - page = pte_page(pte); - head = compound_head(page); - if (!page_cache_get_speculative(head)) - return 0; - if (unlikely(pte_val(pte) != pte_val(*ptep))) { - put_page(head); - return 0; - } - VM_BUG_ON_PAGE(compound_head(page) != head, page); - pages[*nr] = page; - (*nr)++; - - } while (ptep++, addr += PAGE_SIZE, addr != end); - - return 1; -} - -static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - struct page *head, *page; - unsigned long mask; - int refs; - - mask = (write ? _SEGMENT_ENTRY_PROTECT : 0) | _SEGMENT_ENTRY_INVALID; - if ((pmd_val(pmd) & mask) != 0) - return 0; - VM_BUG_ON(!pfn_valid(pmd_val(pmd) >> PAGE_SHIFT)); - - refs = 0; - head = pmd_page(pmd); - page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - do { - VM_BUG_ON(compound_head(page) != head); - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); - - if (!page_cache_add_speculative(head, refs)) { - *nr -= refs; - return 0; - } - - if (unlikely(pmd_val(pmd) != pmd_val(*pmdp))) { - *nr -= refs; - while (refs--) - put_page(head); - return 0; - } - - return 1; -} - - -static inline int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - unsigned long next; - pmd_t *pmdp, pmd; - - pmdp = (pmd_t *) pudp; - if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) - pmdp = (pmd_t *) pud_deref(pud); - pmdp += pmd_index(addr); - do { - pmd = *pmdp; - barrier(); - next = pmd_addr_end(addr, end); - if (pmd_none(pmd)) - return 0; - if (unlikely(pmd_large(pmd))) { - /* - * NUMA hinting faults need to be handled in the GUP - * slowpath for accounting purposes and so that they - * can be serialised against THP migration. - */ - if (pmd_protnone(pmd)) - return 0; - if (!gup_huge_pmd(pmdp, pmd, addr, next, - write, pages, nr)) - return 0; - } else if (!gup_pte_range(pmdp, pmd, addr, next, - write, pages, nr)) - return 0; - } while (pmdp++, addr = next, addr != end); - - return 1; -} - -static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - struct page *head, *page; - unsigned long mask; - int refs; - - mask = (write ? _REGION_ENTRY_PROTECT : 0) | _REGION_ENTRY_INVALID; - if ((pud_val(pud) & mask) != 0) - return 0; - VM_BUG_ON(!pfn_valid(pud_pfn(pud))); - - refs = 0; - head = pud_page(pud); - page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - do { - VM_BUG_ON_PAGE(compound_head(page) != head, page); - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); - - if (!page_cache_add_speculative(head, refs)) { - *nr -= refs; - return 0; - } - - if (unlikely(pud_val(pud) != pud_val(*pudp))) { - *nr -= refs; - while (refs--) - put_page(head); - return 0; - } - - return 1; -} - -static inline int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - unsigned long next; - pud_t *pudp, pud; - - pudp = (pud_t *) p4dp; - if ((p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) - pudp = (pud_t *) p4d_deref(p4d); - pudp += pud_index(addr); - do { - pud = *pudp; - barrier(); - next = pud_addr_end(addr, end); - if (pud_none(pud)) - return 0; - if (unlikely(pud_large(pud))) { - if (!gup_huge_pud(pudp, pud, addr, next, write, pages, - nr)) - return 0; - } else if (!gup_pmd_range(pudp, pud, addr, next, write, pages, - nr)) - return 0; - } while (pudp++, addr = next, addr != end); - - return 1; -} - -static inline int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, - unsigned long end, int write, struct page **pages, int *nr) -{ - unsigned long next; - p4d_t *p4dp, p4d; - - p4dp = (p4d_t *) pgdp; - if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1) - p4dp = (p4d_t *) pgd_deref(pgd); - p4dp += p4d_index(addr); - do { - p4d = *p4dp; - barrier(); - next = p4d_addr_end(addr, end); - if (p4d_none(p4d)) - return 0; - if (!gup_pud_range(p4dp, p4d, addr, next, write, pages, nr)) - return 0; - } while (p4dp++, addr = next, addr != end); - - return 1; -} - -/* - * Like get_user_pages_fast() except its IRQ-safe in that it won't fall - * back to the regular GUP. - * Note a difference with get_user_pages_fast: this always returns the - * number of pages pinned, 0 if no pages were pinned. - */ -int __get_user_pages_fast(unsigned long start, int nr_pages, int write, - struct page **pages) -{ - struct mm_struct *mm = current->mm; - unsigned long addr, len, end; - unsigned long next, flags; - pgd_t *pgdp, pgd; - int nr = 0; - - start &= PAGE_MASK; - addr = start; - len = (unsigned long) nr_pages << PAGE_SHIFT; - end = start + len; - if ((end <= start) || (end > mm->context.asce_limit)) - return 0; - /* - * local_irq_save() doesn't prevent pagetable teardown, but does - * prevent the pagetables from being freed on s390. - * - * So long as we atomically load page table pointers versus teardown, - * we can follow the address down to the the page and take a ref on it. - */ - local_irq_save(flags); - pgdp = pgd_offset(mm, addr); - do { - pgd = *pgdp; - barrier(); - next = pgd_addr_end(addr, end); - if (pgd_none(pgd)) - break; - if (!gup_p4d_range(pgdp, pgd, addr, next, write, pages, &nr)) - break; - } while (pgdp++, addr = next, addr != end); - local_irq_restore(flags); - - return nr; -} - -/** - * get_user_pages_fast() - pin user pages in memory - * @start: starting user address - * @nr_pages: number of pages from start to pin - * @write: whether pages will be written to - * @pages: array that receives pointers to the pages pinned. - * Should be at least nr_pages long. - * - * Attempt to pin user pages in memory without taking mm->mmap_sem. - * If not successful, it will fall back to taking the lock and - * calling get_user_pages(). - * - * Returns number of pages pinned. This may be fewer than the number - * requested. If nr_pages is 0 or negative, returns 0. If no pages - * were pinned, returns -errno. - */ -int get_user_pages_fast(unsigned long start, int nr_pages, int write, - struct page **pages) -{ - int nr, ret; - - might_sleep(); - start &= PAGE_MASK; - nr = __get_user_pages_fast(start, nr_pages, write, pages); - if (nr == nr_pages) - return nr; - - /* Try to get the remaining pages with get_user_pages */ - start += nr << PAGE_SHIFT; - pages += nr; - ret = get_user_pages_unlocked(start, nr_pages - nr, pages, - write ? FOLL_WRITE : 0); - /* Have to be a bit careful with return values */ - if (nr > 0) - ret = (ret < 0) ? nr : ret + nr; - return ret; -} |