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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/ia64/include/asm/tlb.h |
Initial import
Diffstat (limited to 'arch/ia64/include/asm/tlb.h')
-rw-r--r-- | arch/ia64/include/asm/tlb.h | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h new file mode 100644 index 000000000..39d64e0df --- /dev/null +++ b/arch/ia64/include/asm/tlb.h @@ -0,0 +1,283 @@ +#ifndef _ASM_IA64_TLB_H +#define _ASM_IA64_TLB_H +/* + * Based on <asm-generic/tlb.h>. + * + * Copyright (C) 2002-2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + */ +/* + * Removing a translation from a page table (including TLB-shootdown) is a four-step + * procedure: + * + * (1) Flush (virtual) caches --- ensures virtual memory is coherent with kernel memory + * (this is a no-op on ia64). + * (2) Clear the relevant portions of the page-table + * (3) Flush the TLBs --- ensures that stale content is gone from CPU TLBs + * (4) Release the pages that were freed up in step (2). + * + * Note that the ordering of these steps is crucial to avoid races on MP machines. + * + * The Linux kernel defines several platform-specific hooks for TLB-shootdown. When + * unmapping a portion of the virtual address space, these hooks are called according to + * the following template: + * + * tlb <- tlb_gather_mmu(mm, start, end); // start unmap for address space MM + * { + * for each vma that needs a shootdown do { + * tlb_start_vma(tlb, vma); + * for each page-table-entry PTE that needs to be removed do { + * tlb_remove_tlb_entry(tlb, pte, address); + * if (pte refers to a normal page) { + * tlb_remove_page(tlb, page); + * } + * } + * tlb_end_vma(tlb, vma); + * } + * } + * tlb_finish_mmu(tlb, start, end); // finish unmap for address space MM + */ +#include <linux/mm.h> +#include <linux/pagemap.h> +#include <linux/swap.h> + +#include <asm/pgalloc.h> +#include <asm/processor.h> +#include <asm/tlbflush.h> +#include <asm/machvec.h> + +/* + * If we can't allocate a page to make a big batch of page pointers + * to work on, then just handle a few from the on-stack structure. + */ +#define IA64_GATHER_BUNDLE 8 + +struct mmu_gather { + struct mm_struct *mm; + unsigned int nr; + unsigned int max; + unsigned char fullmm; /* non-zero means full mm flush */ + unsigned char need_flush; /* really unmapped some PTEs? */ + unsigned long start, end; + unsigned long start_addr; + unsigned long end_addr; + struct page **pages; + struct page *local[IA64_GATHER_BUNDLE]; +}; + +struct ia64_tr_entry { + u64 ifa; + u64 itir; + u64 pte; + u64 rr; +}; /*Record for tr entry!*/ + +extern int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size); +extern void ia64_ptr_entry(u64 target_mask, int slot); + +extern struct ia64_tr_entry *ia64_idtrs[NR_CPUS]; + +/* + region register macros +*/ +#define RR_TO_VE(val) (((val) >> 0) & 0x0000000000000001) +#define RR_VE(val) (((val) & 0x0000000000000001) << 0) +#define RR_VE_MASK 0x0000000000000001L +#define RR_VE_SHIFT 0 +#define RR_TO_PS(val) (((val) >> 2) & 0x000000000000003f) +#define RR_PS(val) (((val) & 0x000000000000003f) << 2) +#define RR_PS_MASK 0x00000000000000fcL +#define RR_PS_SHIFT 2 +#define RR_RID_MASK 0x00000000ffffff00L +#define RR_TO_RID(val) ((val >> 8) & 0xffffff) + +static inline void +ia64_tlb_flush_mmu_tlbonly(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + tlb->need_flush = 0; + + if (tlb->fullmm) { + /* + * Tearing down the entire address space. This happens both as a result + * of exit() and execve(). The latter case necessitates the call to + * flush_tlb_mm() here. + */ + flush_tlb_mm(tlb->mm); + } else if (unlikely (end - start >= 1024*1024*1024*1024UL + || REGION_NUMBER(start) != REGION_NUMBER(end - 1))) + { + /* + * If we flush more than a tera-byte or across regions, we're probably + * better off just flushing the entire TLB(s). This should be very rare + * and is not worth optimizing for. + */ + flush_tlb_all(); + } else { + /* + * XXX fix me: flush_tlb_range() should take an mm pointer instead of a + * vma pointer. + */ + struct vm_area_struct vma; + + vma.vm_mm = tlb->mm; + /* flush the address range from the tlb: */ + flush_tlb_range(&vma, start, end); + /* now flush the virt. page-table area mapping the address range: */ + flush_tlb_range(&vma, ia64_thash(start), ia64_thash(end)); + } + +} + +static inline void +ia64_tlb_flush_mmu_free(struct mmu_gather *tlb) +{ + unsigned long i; + unsigned int nr; + + /* lastly, release the freed pages */ + nr = tlb->nr; + + tlb->nr = 0; + tlb->start_addr = ~0UL; + for (i = 0; i < nr; ++i) + free_page_and_swap_cache(tlb->pages[i]); +} + +/* + * Flush the TLB for address range START to END and, if not in fast mode, release the + * freed pages that where gathered up to this point. + */ +static inline void +ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + if (!tlb->need_flush) + return; + ia64_tlb_flush_mmu_tlbonly(tlb, start, end); + ia64_tlb_flush_mmu_free(tlb); +} + +static inline void __tlb_alloc_page(struct mmu_gather *tlb) +{ + unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + + if (addr) { + tlb->pages = (void *)addr; + tlb->max = PAGE_SIZE / sizeof(void *); + } +} + + +static inline void +tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start, unsigned long end) +{ + tlb->mm = mm; + tlb->max = ARRAY_SIZE(tlb->local); + tlb->pages = tlb->local; + tlb->nr = 0; + tlb->fullmm = !(start | (end+1)); + tlb->start = start; + tlb->end = end; + tlb->start_addr = ~0UL; +} + +/* + * Called at the end of the shootdown operation to free up any resources that were + * collected. + */ +static inline void +tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + /* + * Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and + * tlb->end_addr. + */ + ia64_tlb_flush_mmu(tlb, start, end); + + /* keep the page table cache within bounds */ + check_pgt_cache(); + + if (tlb->pages != tlb->local) + free_pages((unsigned long)tlb->pages, 0); +} + +/* + * Logically, this routine frees PAGE. On MP machines, the actual freeing of the page + * must be delayed until after the TLB has been flushed (see comments at the beginning of + * this file). + */ +static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + tlb->need_flush = 1; + + if (!tlb->nr && tlb->pages == tlb->local) + __tlb_alloc_page(tlb); + + tlb->pages[tlb->nr++] = page; + VM_BUG_ON(tlb->nr > tlb->max); + + return tlb->max - tlb->nr; +} + +static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) +{ + ia64_tlb_flush_mmu_tlbonly(tlb, tlb->start_addr, tlb->end_addr); +} + +static inline void tlb_flush_mmu_free(struct mmu_gather *tlb) +{ + ia64_tlb_flush_mmu_free(tlb); +} + +static inline void tlb_flush_mmu(struct mmu_gather *tlb) +{ + ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr); +} + +static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + if (!__tlb_remove_page(tlb, page)) + tlb_flush_mmu(tlb); +} + +/* + * Remove TLB entry for PTE mapped at virtual address ADDRESS. This is called for any + * PTE, not just those pointing to (normal) physical memory. + */ +static inline void +__tlb_remove_tlb_entry (struct mmu_gather *tlb, pte_t *ptep, unsigned long address) +{ + if (tlb->start_addr == ~0UL) + tlb->start_addr = address; + tlb->end_addr = address + PAGE_SIZE; +} + +#define tlb_migrate_finish(mm) platform_tlb_migrate_finish(mm) + +#define tlb_start_vma(tlb, vma) do { } while (0) +#define tlb_end_vma(tlb, vma) do { } while (0) + +#define tlb_remove_tlb_entry(tlb, ptep, addr) \ +do { \ + tlb->need_flush = 1; \ + __tlb_remove_tlb_entry(tlb, ptep, addr); \ +} while (0) + +#define pte_free_tlb(tlb, ptep, address) \ +do { \ + tlb->need_flush = 1; \ + __pte_free_tlb(tlb, ptep, address); \ +} while (0) + +#define pmd_free_tlb(tlb, ptep, address) \ +do { \ + tlb->need_flush = 1; \ + __pmd_free_tlb(tlb, ptep, address); \ +} while (0) + +#define pud_free_tlb(tlb, pudp, address) \ +do { \ + tlb->need_flush = 1; \ + __pud_free_tlb(tlb, pudp, address); \ +} while (0) + +#endif /* _ASM_IA64_TLB_H */ |