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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/m68k/mm/memory.c
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/m68k/mm/memory.c')
-rw-r--r--arch/m68k/mm/memory.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/arch/m68k/mm/memory.c b/arch/m68k/mm/memory.c
new file mode 100644
index 00000000000..a5dbb74fe1d
--- /dev/null
+++ b/arch/m68k/mm/memory.c
@@ -0,0 +1,299 @@
+/*
+ * linux/arch/m68k/mm/memory.c
+ *
+ * Copyright (C) 1995 Hamish Macdonald
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/gfp.h>
+
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/machdep.h>
+
+
+/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from
+ struct page instead of separately kmalloced struct. Stolen from
+ arch/sparc/mm/srmmu.c ... */
+
+typedef struct list_head ptable_desc;
+static LIST_HEAD(ptable_list);
+
+#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru))
+#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru))
+#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index)
+
+#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t))
+
+void __init init_pointer_table(unsigned long ptable)
+{
+ ptable_desc *dp;
+ unsigned long page = ptable & PAGE_MASK;
+ unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE);
+
+ dp = PD_PTABLE(page);
+ if (!(PD_MARKBITS(dp) & mask)) {
+ PD_MARKBITS(dp) = 0xff;
+ list_add(dp, &ptable_list);
+ }
+
+ PD_MARKBITS(dp) &= ~mask;
+#ifdef DEBUG
+ printk("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
+#endif
+
+ /* unreserve the page so it's possible to free that page */
+ PD_PAGE(dp)->flags &= ~(1 << PG_reserved);
+ init_page_count(PD_PAGE(dp));
+
+ return;
+}
+
+pmd_t *get_pointer_table (void)
+{
+ ptable_desc *dp = ptable_list.next;
+ unsigned char mask = PD_MARKBITS (dp);
+ unsigned char tmp;
+ unsigned int off;
+
+ /*
+ * For a pointer table for a user process address space, a
+ * table is taken from a page allocated for the purpose. Each
+ * page can hold 8 pointer tables. The page is remapped in
+ * virtual address space to be noncacheable.
+ */
+ if (mask == 0) {
+ void *page;
+ ptable_desc *new;
+
+ if (!(page = (void *)get_zeroed_page(GFP_KERNEL)))
+ return NULL;
+
+ flush_tlb_kernel_page(page);
+ nocache_page(page);
+
+ new = PD_PTABLE(page);
+ PD_MARKBITS(new) = 0xfe;
+ list_add_tail(new, dp);
+
+ return (pmd_t *)page;
+ }
+
+ for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE)
+ ;
+ PD_MARKBITS(dp) = mask & ~tmp;
+ if (!PD_MARKBITS(dp)) {
+ /* move to end of list */
+ list_move_tail(dp, &ptable_list);
+ }
+ return (pmd_t *) (page_address(PD_PAGE(dp)) + off);
+}
+
+int free_pointer_table (pmd_t *ptable)
+{
+ ptable_desc *dp;
+ unsigned long page = (unsigned long)ptable & PAGE_MASK;
+ unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE);
+
+ dp = PD_PTABLE(page);
+ if (PD_MARKBITS (dp) & mask)
+ panic ("table already free!");
+
+ PD_MARKBITS (dp) |= mask;
+
+ if (PD_MARKBITS(dp) == 0xff) {
+ /* all tables in page are free, free page */
+ list_del(dp);
+ cache_page((void *)page);
+ free_page (page);
+ return 1;
+ } else if (ptable_list.next != dp) {
+ /*
+ * move this descriptor to the front of the list, since
+ * it has one or more free tables.
+ */
+ list_move(dp, &ptable_list);
+ }
+ return 0;
+}
+
+/* invalidate page in both caches */
+static inline void clear040(unsigned long paddr)
+{
+ asm volatile (
+ "nop\n\t"
+ ".chip 68040\n\t"
+ "cinvp %%bc,(%0)\n\t"
+ ".chip 68k"
+ : : "a" (paddr));
+}
+
+/* invalidate page in i-cache */
+static inline void cleari040(unsigned long paddr)
+{
+ asm volatile (
+ "nop\n\t"
+ ".chip 68040\n\t"
+ "cinvp %%ic,(%0)\n\t"
+ ".chip 68k"
+ : : "a" (paddr));
+}
+
+/* push page in both caches */
+/* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */
+static inline void push040(unsigned long paddr)
+{
+ asm volatile (
+ "nop\n\t"
+ ".chip 68040\n\t"
+ "cpushp %%bc,(%0)\n\t"
+ ".chip 68k"
+ : : "a" (paddr));
+}
+
+/* push and invalidate page in both caches, must disable ints
+ * to avoid invalidating valid data */
+static inline void pushcl040(unsigned long paddr)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ push040(paddr);
+ if (CPU_IS_060)
+ clear040(paddr);
+ local_irq_restore(flags);
+}
+
+/*
+ * 040: Hit every page containing an address in the range paddr..paddr+len-1.
+ * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s).
+ * Hit every page until there is a page or less to go. Hit the next page,
+ * and the one after that if the range hits it.
+ */
+/* ++roman: A little bit more care is required here: The CINVP instruction
+ * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning
+ * and the end of the region must be treated differently if they are not
+ * exactly at the beginning or end of a page boundary. Else, maybe too much
+ * data becomes invalidated and thus lost forever. CPUSHP does what we need:
+ * it invalidates the page after pushing dirty data to memory. (Thanks to Jes
+ * for discovering the problem!)
+ */
+/* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set
+ * the DPI bit in the CACR; would it cause problems with temporarily changing
+ * this?). So we have to push first and then additionally to invalidate.
+ */
+
+
+/*
+ * cache_clear() semantics: Clear any cache entries for the area in question,
+ * without writing back dirty entries first. This is useful if the data will
+ * be overwritten anyway, e.g. by DMA to memory. The range is defined by a
+ * _physical_ address.
+ */
+
+void cache_clear (unsigned long paddr, int len)
+{
+ if (CPU_IS_COLDFIRE) {
+ flush_cf_bcache(0, DCACHE_MAX_ADDR);
+ } else if (CPU_IS_040_OR_060) {
+ int tmp;
+
+ /*
+ * We need special treatment for the first page, in case it
+ * is not page-aligned. Page align the addresses to work
+ * around bug I17 in the 68060.
+ */
+ if ((tmp = -paddr & (PAGE_SIZE - 1))) {
+ pushcl040(paddr & PAGE_MASK);
+ if ((len -= tmp) <= 0)
+ return;
+ paddr += tmp;
+ }
+ tmp = PAGE_SIZE;
+ paddr &= PAGE_MASK;
+ while ((len -= tmp) >= 0) {
+ clear040(paddr);
+ paddr += tmp;
+ }
+ if ((len += tmp))
+ /* a page boundary gets crossed at the end */
+ pushcl040(paddr);
+ }
+ else /* 68030 or 68020 */
+ asm volatile ("movec %/cacr,%/d0\n\t"
+ "oriw %0,%/d0\n\t"
+ "movec %/d0,%/cacr"
+ : : "i" (FLUSH_I_AND_D)
+ : "d0");
+#ifdef CONFIG_M68K_L2_CACHE
+ if(mach_l2_flush)
+ mach_l2_flush(0);
+#endif
+}
+EXPORT_SYMBOL(cache_clear);
+
+
+/*
+ * cache_push() semantics: Write back any dirty cache data in the given area,
+ * and invalidate the range in the instruction cache. It needs not (but may)
+ * invalidate those entries also in the data cache. The range is defined by a
+ * _physical_ address.
+ */
+
+void cache_push (unsigned long paddr, int len)
+{
+ if (CPU_IS_COLDFIRE) {
+ flush_cf_bcache(0, DCACHE_MAX_ADDR);
+ } else if (CPU_IS_040_OR_060) {
+ int tmp = PAGE_SIZE;
+
+ /*
+ * on 68040 or 68060, push cache lines for pages in the range;
+ * on the '040 this also invalidates the pushed lines, but not on
+ * the '060!
+ */
+ len += paddr & (PAGE_SIZE - 1);
+
+ /*
+ * Work around bug I17 in the 68060 affecting some instruction
+ * lines not being invalidated properly.
+ */
+ paddr &= PAGE_MASK;
+
+ do {
+ push040(paddr);
+ paddr += tmp;
+ } while ((len -= tmp) > 0);
+ }
+ /*
+ * 68030/68020 have no writeback cache. On the other hand,
+ * cache_push is actually a superset of cache_clear (the lines
+ * get written back and invalidated), so we should make sure
+ * to perform the corresponding actions. After all, this is getting
+ * called in places where we've just loaded code, or whatever, so
+ * flushing the icache is appropriate; flushing the dcache shouldn't
+ * be required.
+ */
+ else /* 68030 or 68020 */
+ asm volatile ("movec %/cacr,%/d0\n\t"
+ "oriw %0,%/d0\n\t"
+ "movec %/d0,%/cacr"
+ : : "i" (FLUSH_I)
+ : "d0");
+#ifdef CONFIG_M68K_L2_CACHE
+ if(mach_l2_flush)
+ mach_l2_flush(1);
+#endif
+}
+EXPORT_SYMBOL(cache_push);
+