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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/mcfmmu.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/mcfmmu.c')
-rw-r--r--arch/m68k/mm/mcfmmu.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
new file mode 100644
index 00000000000..875b800ef0d
--- /dev/null
+++ b/arch/m68k/mm/mcfmmu.c
@@ -0,0 +1,199 @@
+/*
+ * Based upon linux/arch/m68k/mm/sun3mmu.c
+ * Based upon linux/arch/ppc/mm/mmu_context.c
+ *
+ * Implementations of mm routines specific to the Coldfire MMU.
+ *
+ * Copyright (c) 2008 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/bootmem.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+#include <asm/mcf_pgalloc.h>
+#include <asm/tlbflush.h>
+
+#define KMAPAREA(x) ((x >= VMALLOC_START) && (x < KMAP_END))
+
+mm_context_t next_mmu_context;
+unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
+atomic_t nr_free_contexts;
+struct mm_struct *context_mm[LAST_CONTEXT+1];
+extern unsigned long num_pages;
+
+void free_initmem(void)
+{
+}
+
+/*
+ * ColdFire paging_init derived from sun3.
+ */
+void __init paging_init(void)
+{
+ pgd_t *pg_dir;
+ pte_t *pg_table;
+ unsigned long address, size;
+ unsigned long next_pgtable, bootmem_end;
+ unsigned long zones_size[MAX_NR_ZONES];
+ enum zone_type zone;
+ int i;
+
+ empty_zero_page = (void *) alloc_bootmem_pages(PAGE_SIZE);
+ memset((void *) empty_zero_page, 0, PAGE_SIZE);
+
+ pg_dir = swapper_pg_dir;
+ memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
+
+ size = num_pages * sizeof(pte_t);
+ size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
+ next_pgtable = (unsigned long) alloc_bootmem_pages(size);
+
+ bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
+ pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
+
+ address = PAGE_OFFSET;
+ while (address < (unsigned long)high_memory) {
+ pg_table = (pte_t *) next_pgtable;
+ next_pgtable += PTRS_PER_PTE * sizeof(pte_t);
+ pgd_val(*pg_dir) = (unsigned long) pg_table;
+ pg_dir++;
+
+ /* now change pg_table to kernel virtual addresses */
+ for (i = 0; i < PTRS_PER_PTE; ++i, ++pg_table) {
+ pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
+ if (address >= (unsigned long) high_memory)
+ pte_val(pte) = 0;
+
+ set_pte(pg_table, pte);
+ address += PAGE_SIZE;
+ }
+ }
+
+ current->mm = NULL;
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++)
+ zones_size[zone] = 0x0;
+ zones_size[ZONE_DMA] = num_pages;
+ free_area_init(zones_size);
+}
+
+int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word)
+{
+ unsigned long flags, mmuar, mmutr;
+ struct mm_struct *mm;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ int asid;
+
+ local_irq_save(flags);
+
+ mmuar = (dtlb) ? mmu_read(MMUAR) :
+ regs->pc + (extension_word * sizeof(long));
+
+ mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm;
+ if (!mm) {
+ local_irq_restore(flags);
+ return -1;
+ }
+
+ pgd = pgd_offset(mm, mmuar);
+ if (pgd_none(*pgd)) {
+ local_irq_restore(flags);
+ return -1;
+ }
+
+ pmd = pmd_offset(pgd, mmuar);
+ if (pmd_none(*pmd)) {
+ local_irq_restore(flags);
+ return -1;
+ }
+
+ pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar)
+ : pte_offset_map(pmd, mmuar);
+ if (pte_none(*pte) || !pte_present(*pte)) {
+ local_irq_restore(flags);
+ return -1;
+ }
+
+ if (write) {
+ if (!pte_write(*pte)) {
+ local_irq_restore(flags);
+ return -1;
+ }
+ set_pte(pte, pte_mkdirty(*pte));
+ }
+
+ set_pte(pte, pte_mkyoung(*pte));
+ asid = mm->context & 0xff;
+ if (!pte_dirty(*pte) && !KMAPAREA(mmuar))
+ set_pte(pte, pte_wrprotect(*pte));
+
+ mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V;
+ if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE))
+ mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT;
+ mmu_write(MMUTR, mmutr);
+
+ mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
+ ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
+
+ if (dtlb)
+ mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
+ else
+ mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA);
+
+ local_irq_restore(flags);
+ return 0;
+}
+
+/*
+ * Initialize the context management stuff.
+ * The following was taken from arch/ppc/mmu_context.c
+ */
+void __init mmu_context_init(void)
+{
+ /*
+ * Some processors have too few contexts to reserve one for
+ * init_mm, and require using context 0 for a normal task.
+ * Other processors reserve the use of context zero for the kernel.
+ * This code assumes FIRST_CONTEXT < 32.
+ */
+ context_map[0] = (1 << FIRST_CONTEXT) - 1;
+ next_mmu_context = FIRST_CONTEXT;
+ atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
+}
+
+/*
+ * Steal a context from a task that has one at the moment.
+ * This is only used on 8xx and 4xx and we presently assume that
+ * they don't do SMP. If they do then thicfpgalloc.hs will have to check
+ * whether the MM we steal is in use.
+ * We also assume that this is only used on systems that don't
+ * use an MMU hash table - this is true for 8xx and 4xx.
+ * This isn't an LRU system, it just frees up each context in
+ * turn (sort-of pseudo-random replacement :). This would be the
+ * place to implement an LRU scheme if anyone was motivated to do it.
+ * -- paulus
+ */
+void steal_context(void)
+{
+ struct mm_struct *mm;
+ /*
+ * free up context `next_mmu_context'
+ * if we shouldn't free context 0, don't...
+ */
+ if (next_mmu_context < FIRST_CONTEXT)
+ next_mmu_context = FIRST_CONTEXT;
+ mm = context_mm[next_mmu_context];
+ flush_tlb_mm(mm);
+ destroy_context(mm);
+}
+