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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/ia64/include/asm/tlb.h
Initial import
Diffstat (limited to 'arch/ia64/include/asm/tlb.h')
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diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h
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+#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 */