v4.19.13 snapshot.
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
new file mode 100644
index 0000000..5846962
--- /dev/null
+++ b/arch/arm/mm/flush.c
@@ -0,0 +1,423 @@
+/*
+ * linux/arch/arm/mm/flush.c
+ *
+ * Copyright (C) 1995-2002 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cachetype.h>
+#include <asm/highmem.h>
+#include <asm/smp_plat.h>
+#include <asm/tlbflush.h>
+#include <linux/hugetlb.h>
+
+#include "mm.h"
+
+#ifdef CONFIG_ARM_HEAVY_MB
+void (*soc_mb)(void);
+
+void arm_heavy_mb(void)
+{
+#ifdef CONFIG_OUTER_CACHE_SYNC
+ if (outer_cache.sync)
+ outer_cache.sync();
+#endif
+ if (soc_mb)
+ soc_mb();
+}
+EXPORT_SYMBOL(arm_heavy_mb);
+#endif
+
+#ifdef CONFIG_CPU_CACHE_VIPT
+
+static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
+{
+ unsigned long to = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
+ const int zero = 0;
+
+ set_top_pte(to, pfn_pte(pfn, PAGE_KERNEL));
+
+ asm( "mcrr p15, 0, %1, %0, c14\n"
+ " mcr p15, 0, %2, c7, c10, 4"
+ :
+ : "r" (to), "r" (to + PAGE_SIZE - 1), "r" (zero)
+ : "cc");
+}
+
+static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned long len)
+{
+ unsigned long va = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
+ unsigned long offset = vaddr & (PAGE_SIZE - 1);
+ unsigned long to;
+
+ set_top_pte(va, pfn_pte(pfn, PAGE_KERNEL));
+ to = va + offset;
+ flush_icache_range(to, to + len);
+}
+
+void flush_cache_mm(struct mm_struct *mm)
+{
+ if (cache_is_vivt()) {
+ vivt_flush_cache_mm(mm);
+ return;
+ }
+
+ if (cache_is_vipt_aliasing()) {
+ asm( "mcr p15, 0, %0, c7, c14, 0\n"
+ " mcr p15, 0, %0, c7, c10, 4"
+ :
+ : "r" (0)
+ : "cc");
+ }
+}
+
+void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+ if (cache_is_vivt()) {
+ vivt_flush_cache_range(vma, start, end);
+ return;
+ }
+
+ if (cache_is_vipt_aliasing()) {
+ asm( "mcr p15, 0, %0, c7, c14, 0\n"
+ " mcr p15, 0, %0, c7, c10, 4"
+ :
+ : "r" (0)
+ : "cc");
+ }
+
+ if (vma->vm_flags & VM_EXEC)
+ __flush_icache_all();
+}
+
+void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
+{
+ if (cache_is_vivt()) {
+ vivt_flush_cache_page(vma, user_addr, pfn);
+ return;
+ }
+
+ if (cache_is_vipt_aliasing()) {
+ flush_pfn_alias(pfn, user_addr);
+ __flush_icache_all();
+ }
+
+ if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged())
+ __flush_icache_all();
+}
+
+#else
+#define flush_pfn_alias(pfn,vaddr) do { } while (0)
+#define flush_icache_alias(pfn,vaddr,len) do { } while (0)
+#endif
+
+#define FLAG_PA_IS_EXEC 1
+#define FLAG_PA_CORE_IN_MM 2
+
+static void flush_ptrace_access_other(void *args)
+{
+ __flush_icache_all();
+}
+
+static inline
+void __flush_ptrace_access(struct page *page, unsigned long uaddr, void *kaddr,
+ unsigned long len, unsigned int flags)
+{
+ if (cache_is_vivt()) {
+ if (flags & FLAG_PA_CORE_IN_MM) {
+ unsigned long addr = (unsigned long)kaddr;
+ __cpuc_coherent_kern_range(addr, addr + len);
+ }
+ return;
+ }
+
+ if (cache_is_vipt_aliasing()) {
+ flush_pfn_alias(page_to_pfn(page), uaddr);
+ __flush_icache_all();
+ return;
+ }
+
+ /* VIPT non-aliasing D-cache */
+ if (flags & FLAG_PA_IS_EXEC) {
+ unsigned long addr = (unsigned long)kaddr;
+ if (icache_is_vipt_aliasing())
+ flush_icache_alias(page_to_pfn(page), uaddr, len);
+ else
+ __cpuc_coherent_kern_range(addr, addr + len);
+ if (cache_ops_need_broadcast())
+ smp_call_function(flush_ptrace_access_other,
+ NULL, 1);
+ }
+}
+
+static
+void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
+ unsigned long uaddr, void *kaddr, unsigned long len)
+{
+ unsigned int flags = 0;
+ if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm)))
+ flags |= FLAG_PA_CORE_IN_MM;
+ if (vma->vm_flags & VM_EXEC)
+ flags |= FLAG_PA_IS_EXEC;
+ __flush_ptrace_access(page, uaddr, kaddr, len, flags);
+}
+
+void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
+ void *kaddr, unsigned long len)
+{
+ unsigned int flags = FLAG_PA_CORE_IN_MM|FLAG_PA_IS_EXEC;
+
+ __flush_ptrace_access(page, uaddr, kaddr, len, flags);
+}
+
+/*
+ * Copy user data from/to a page which is mapped into a different
+ * processes address space. Really, we want to allow our "user
+ * space" model to handle this.
+ *
+ * Note that this code needs to run on the current CPU.
+ */
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+ unsigned long uaddr, void *dst, const void *src,
+ unsigned long len)
+{
+#ifdef CONFIG_SMP
+ preempt_disable();
+#endif
+ memcpy(dst, src, len);
+ flush_ptrace_access(vma, page, uaddr, dst, len);
+#ifdef CONFIG_SMP
+ preempt_enable();
+#endif
+}
+
+void __flush_dcache_page(struct address_space *mapping, struct page *page)
+{
+ /*
+ * Writeback any data associated with the kernel mapping of this
+ * page. This ensures that data in the physical page is mutually
+ * coherent with the kernels mapping.
+ */
+ if (!PageHighMem(page)) {
+ size_t page_size = PAGE_SIZE << compound_order(page);
+ __cpuc_flush_dcache_area(page_address(page), page_size);
+ } else {
+ unsigned long i;
+ if (cache_is_vipt_nonaliasing()) {
+ for (i = 0; i < (1 << compound_order(page)); i++) {
+ void *addr = kmap_atomic(page + i);
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ }
+ } else {
+ for (i = 0; i < (1 << compound_order(page)); i++) {
+ void *addr = kmap_high_get(page + i);
+ if (addr) {
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ kunmap_high(page + i);
+ }
+ }
+ }
+ }
+
+ /*
+ * If this is a page cache page, and we have an aliasing VIPT cache,
+ * we only need to do one flush - which would be at the relevant
+ * userspace colour, which is congruent with page->index.
+ */
+ if (mapping && cache_is_vipt_aliasing())
+ flush_pfn_alias(page_to_pfn(page),
+ page->index << PAGE_SHIFT);
+}
+
+static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
+{
+ struct mm_struct *mm = current->active_mm;
+ struct vm_area_struct *mpnt;
+ pgoff_t pgoff;
+
+ /*
+ * There are possible user space mappings of this page:
+ * - VIVT cache: we need to also write back and invalidate all user
+ * data in the current VM view associated with this page.
+ * - aliasing VIPT: we only need to find one mapping of this page.
+ */
+ pgoff = page->index;
+
+ flush_dcache_mmap_lock(mapping);
+ vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long offset;
+
+ /*
+ * If this VMA is not in our MM, we can ignore it.
+ */
+ if (mpnt->vm_mm != mm)
+ continue;
+ if (!(mpnt->vm_flags & VM_MAYSHARE))
+ continue;
+ offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
+ flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
+ }
+ flush_dcache_mmap_unlock(mapping);
+}
+
+#if __LINUX_ARM_ARCH__ >= 6
+void __sync_icache_dcache(pte_t pteval)
+{
+ unsigned long pfn;
+ struct page *page;
+ struct address_space *mapping;
+
+ if (cache_is_vipt_nonaliasing() && !pte_exec(pteval))
+ /* only flush non-aliasing VIPT caches for exec mappings */
+ return;
+ pfn = pte_pfn(pteval);
+ if (!pfn_valid(pfn))
+ return;
+
+ page = pfn_to_page(pfn);
+ if (cache_is_vipt_aliasing())
+ mapping = page_mapping_file(page);
+ else
+ mapping = NULL;
+
+ if (!test_and_set_bit(PG_dcache_clean, &page->flags))
+ __flush_dcache_page(mapping, page);
+
+ if (pte_exec(pteval))
+ __flush_icache_all();
+}
+#endif
+
+/*
+ * Ensure cache coherency between kernel mapping and userspace mapping
+ * of this page.
+ *
+ * We have three cases to consider:
+ * - VIPT non-aliasing cache: fully coherent so nothing required.
+ * - VIVT: fully aliasing, so we need to handle every alias in our
+ * current VM view.
+ * - VIPT aliasing: need to handle one alias in our current VM view.
+ *
+ * If we need to handle aliasing:
+ * If the page only exists in the page cache and there are no user
+ * space mappings, we can be lazy and remember that we may have dirty
+ * kernel cache lines for later. Otherwise, we assume we have
+ * aliasing mappings.
+ *
+ * Note that we disable the lazy flush for SMP configurations where
+ * the cache maintenance operations are not automatically broadcasted.
+ */
+void flush_dcache_page(struct page *page)
+{
+ struct address_space *mapping;
+
+ /*
+ * The zero page is never written to, so never has any dirty
+ * cache lines, and therefore never needs to be flushed.
+ */
+ if (page == ZERO_PAGE(0))
+ return;
+
+ if (!cache_ops_need_broadcast() && cache_is_vipt_nonaliasing()) {
+ if (test_bit(PG_dcache_clean, &page->flags))
+ clear_bit(PG_dcache_clean, &page->flags);
+ return;
+ }
+
+ mapping = page_mapping_file(page);
+
+ if (!cache_ops_need_broadcast() &&
+ mapping && !page_mapcount(page))
+ clear_bit(PG_dcache_clean, &page->flags);
+ else {
+ __flush_dcache_page(mapping, page);
+ if (mapping && cache_is_vivt())
+ __flush_dcache_aliases(mapping, page);
+ else if (mapping)
+ __flush_icache_all();
+ set_bit(PG_dcache_clean, &page->flags);
+ }
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+/*
+ * Ensure cache coherency for the kernel mapping of this page. We can
+ * assume that the page is pinned via kmap.
+ *
+ * If the page only exists in the page cache and there are no user
+ * space mappings, this is a no-op since the page was already marked
+ * dirty at creation. Otherwise, we need to flush the dirty kernel
+ * cache lines directly.
+ */
+void flush_kernel_dcache_page(struct page *page)
+{
+ if (cache_is_vivt() || cache_is_vipt_aliasing()) {
+ struct address_space *mapping;
+
+ mapping = page_mapping_file(page);
+
+ if (!mapping || mapping_mapped(mapping)) {
+ void *addr;
+
+ addr = page_address(page);
+ /*
+ * kmap_atomic() doesn't set the page virtual
+ * address for highmem pages, and
+ * kunmap_atomic() takes care of cache
+ * flushing already.
+ */
+ if (!IS_ENABLED(CONFIG_HIGHMEM) || addr)
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ }
+ }
+}
+EXPORT_SYMBOL(flush_kernel_dcache_page);
+
+/*
+ * Flush an anonymous page so that users of get_user_pages()
+ * can safely access the data. The expected sequence is:
+ *
+ * get_user_pages()
+ * -> flush_anon_page
+ * memcpy() to/from page
+ * if written to page, flush_dcache_page()
+ */
+void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
+{
+ unsigned long pfn;
+
+ /* VIPT non-aliasing caches need do nothing */
+ if (cache_is_vipt_nonaliasing())
+ return;
+
+ /*
+ * Write back and invalidate userspace mapping.
+ */
+ pfn = page_to_pfn(page);
+ if (cache_is_vivt()) {
+ flush_cache_page(vma, vmaddr, pfn);
+ } else {
+ /*
+ * For aliasing VIPT, we can flush an alias of the
+ * userspace address only.
+ */
+ flush_pfn_alias(pfn, vmaddr);
+ __flush_icache_all();
+ }
+
+ /*
+ * Invalidate kernel mapping. No data should be contained
+ * in this mapping of the page. FIXME: this is overkill
+ * since we actually ask for a write-back and invalidate.
+ */
+ __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
+}