nios2: Cache handling

This patch adds functionality required for cache maintenance.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 271 insertions, 0 deletions

diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
new file mode 100644
index 000000000000..2ae482b42669
--- /dev/null
+++ b/arch/nios2/mm/cacheflush.c
@@ -0,0 +1,271 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2009, Wind River Systems Inc
+ * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cpuinfo.h>
+
+static void __flush_dcache(unsigned long start, unsigned long end)
+{
+        unsigned long addr;
+
+        start &= ~(cpuinfo.dcache_line_size - 1);
+        end += (cpuinfo.dcache_line_size - 1);
+        end &= ~(cpuinfo.dcache_line_size - 1);
+
+        if (end > start + cpuinfo.dcache_size)
+                end = start + cpuinfo.dcache_size;
+
+        for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
+                __asm__ __volatile__ ("   flushda 0(%0)\n"
+                                        : /* Outputs */
+                                        : /* Inputs  */ "r"(addr)
+                                        /* : No clobber */);
+        }
+}
+
+static void __flush_dcache_all(unsigned long start, unsigned long end)
+{
+        unsigned long addr;
+
+        start &= ~(cpuinfo.dcache_line_size - 1);
+        end += (cpuinfo.dcache_line_size - 1);
+        end &= ~(cpuinfo.dcache_line_size - 1);
+
+        if (end > start + cpuinfo.dcache_size)
+                end = start + cpuinfo.dcache_size;
+
+        for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
+                __asm__ __volatile__ ("   flushd 0(%0)\n"
+                                        : /* Outputs */
+                                        : /* Inputs  */ "r"(addr)
+                                        /* : No clobber */);
+        }
+}
+
+static void __invalidate_dcache(unsigned long start, unsigned long end)
+{
+        unsigned long addr;
+
+        start &= ~(cpuinfo.dcache_line_size - 1);
+        end += (cpuinfo.dcache_line_size - 1);
+        end &= ~(cpuinfo.dcache_line_size - 1);
+
+        if (end > start + cpuinfo.dcache_size)
+                end = start + cpuinfo.dcache_size;
+
+        for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
+                __asm__ __volatile__ ("   initda 0(%0)\n"
+                                        : /* Outputs */
+                                        : /* Inputs  */ "r"(addr)
+                                        /* : No clobber */);
+        }
+}
+
+static void __flush_icache(unsigned long start, unsigned long end)
+{
+        unsigned long addr;
+
+        start &= ~(cpuinfo.icache_line_size - 1);
+        end += (cpuinfo.icache_line_size - 1);
+        end &= ~(cpuinfo.icache_line_size - 1);
+
+        if (end > start + cpuinfo.icache_size)
+                end = start + cpuinfo.icache_size;
+
+        for (addr = start; addr < end; addr += cpuinfo.icache_line_size) {
+                __asm__ __volatile__ ("   flushi %0\n"
+                                        : /* Outputs */
+                                        : /* Inputs  */ "r"(addr)
+                                        /* : No clobber */);
+        }
+        __asm__ __volatile(" flushp\n");
+}
+
+static void flush_aliases(struct address_space *mapping, struct page *page)
+{
+        struct mm_struct *mm = current->active_mm;
+        struct vm_area_struct *mpnt;
+        pgoff_t pgoff;
+
+        pgoff = page->index;
+
+        flush_dcache_mmap_lock(mapping);
+        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
+                unsigned long offset;
+
+                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);
+}
+
+void flush_cache_all(void)
+{
+        __flush_dcache_all(0, cpuinfo.dcache_size);
+        __flush_icache(0, cpuinfo.icache_size);
+}
+
+void flush_cache_mm(struct mm_struct *mm)
+{
+        flush_cache_all();
+}
+
+void flush_cache_dup_mm(struct mm_struct *mm)
+{
+        flush_cache_all();
+}
+
+void flush_icache_range(unsigned long start, unsigned long end)
+{
+        __flush_icache(start, end);
+}
+
+void flush_dcache_range(unsigned long start, unsigned long end)
+{
+        __flush_dcache(start, end);
+}
+EXPORT_SYMBOL(flush_dcache_range);
+
+void invalidate_dcache_range(unsigned long start, unsigned long end)
+{
+        __invalidate_dcache(start, end);
+}
+EXPORT_SYMBOL(invalidate_dcache_range);
+
+void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
+                        unsigned long end)
+{
+        __flush_dcache(start, end);
+        if (vma == NULL || (vma->vm_flags & VM_EXEC))
+                __flush_icache(start, end);
+}
+
+void flush_icache_page(struct vm_area_struct *vma, struct page *page)
+{
+        unsigned long start = (unsigned long) page_address(page);
+        unsigned long end = start + PAGE_SIZE;
+
+        __flush_icache(start, end);
+}
+
+void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
+                        unsigned long pfn)
+{
+        unsigned long start = vmaddr;
+        unsigned long end = start + PAGE_SIZE;
+
+        __flush_dcache(start, end);
+        if (vma->vm_flags & VM_EXEC)
+                __flush_icache(start, end);
+}
+
+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;
+
+        mapping = page_mapping(page);
+
+        /* Flush this page if there are aliases. */
+        if (mapping && !mapping_mapped(mapping)) {
+                clear_bit(PG_dcache_clean, &page->flags);
+        } else {
+                unsigned long start = (unsigned long)page_address(page);
+
+                __flush_dcache_all(start, start + PAGE_SIZE);
+                if (mapping)
+                        flush_aliases(mapping,  page);
+                set_bit(PG_dcache_clean, &page->flags);
+        }
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+void update_mmu_cache(struct vm_area_struct *vma,
+                      unsigned long address, pte_t *pte)
+{
+        unsigned long pfn = pte_pfn(*pte);
+        struct page *page;
+
+        if (!pfn_valid(pfn))
+                return;
+
+        /*
+        * The zero page is never written to, so never has any dirty
+        * cache lines, and therefore never needs to be flushed.
+        */
+        page = pfn_to_page(pfn);
+        if (page == ZERO_PAGE(0))
+                return;
+
+        if (!PageReserved(page) &&
+             !test_and_set_bit(PG_dcache_clean, &page->flags)) {
+                unsigned long start = page_to_virt(page);
+                struct address_space *mapping;
+
+                __flush_dcache(start, start + PAGE_SIZE);
+
+                mapping = page_mapping(page);
+                if (mapping)
+                        flush_aliases(mapping, page);
+        }
+}
+
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+                    struct page *to)
+{
+        __flush_dcache(vaddr, vaddr + PAGE_SIZE);
+        copy_page(vto, vfrom);
+        __flush_dcache((unsigned long)vto, (unsigned long)vto + PAGE_SIZE);
+}
+
+void clear_user_page(void *addr, unsigned long vaddr, struct page *page)
+{
+        __flush_dcache(vaddr, vaddr + PAGE_SIZE);
+        clear_page(addr);
+        __flush_dcache((unsigned long)addr, (unsigned long)addr + PAGE_SIZE);
+}
+
+void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
+                        unsigned long user_vaddr,
+                        void *dst, void *src, int len)
+{
+        flush_cache_page(vma, user_vaddr, page_to_pfn(page));
+        memcpy(dst, src, len);
+        __flush_dcache((unsigned long)src, (unsigned long)src + len);
+        if (vma->vm_flags & VM_EXEC)
+                __flush_icache((unsigned long)src, (unsigned long)src + len);
+}
+
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+                        unsigned long user_vaddr,
+                        void *dst, void *src, int len)
+{
+        flush_cache_page(vma, user_vaddr, page_to_pfn(page));
+        memcpy(dst, src, len);
+        __flush_dcache((unsigned long)dst, (unsigned long)dst + len);
+        if (vma->vm_flags & VM_EXEC)
+                __flush_icache((unsigned long)dst, (unsigned long)dst + len);
+}