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-rw-r--r--arch/cris/arch-v10/mm/tlb.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/mm/tlb.c b/arch/cris/arch-v10/mm/tlb.c
new file mode 100644
index 000000000000..9d06125ff5a2
--- /dev/null
+++ b/arch/cris/arch-v10/mm/tlb.c
@@ -0,0 +1,248 @@
+/*
+ * linux/arch/cris/arch-v10/mm/tlb.c
+ *
+ * Low level TLB handling
+ *
+ *
+ * Copyright (C) 2000-2002 Axis Communications AB
+ *
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ *
+ */
+
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+#include <asm/arch/svinto.h>
+
+#define D(x)
+
+/* The TLB can host up to 64 different mm contexts at the same time.
+ * The running context is R_MMU_CONTEXT, and each TLB entry contains a
+ * page_id that has to match to give a hit. In page_id_map, we keep track
+ * of which mm's we have assigned which page_id's, so that we know when
+ * to invalidate TLB entries.
+ *
+ * The last page_id is never running - it is used as an invalid page_id
+ * so we can make TLB entries that will never match.
+ *
+ * Notice that we need to make the flushes atomic, otherwise an interrupt
+ * handler that uses vmalloced memory might cause a TLB load in the middle
+ * of a flush causing.
+ */
+
+/* invalidate all TLB entries */
+
+void
+flush_tlb_all(void)
+{
+ int i;
+ unsigned long flags;
+
+ /* the vpn of i & 0xf is so we dont write similar TLB entries
+ * in the same 4-way entry group. details..
+ */
+
+ local_save_flags(flags);
+ local_irq_disable();
+ for(i = 0; i < NUM_TLB_ENTRIES; i++) {
+ *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
+ *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
+ IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
+
+ *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
+ IO_STATE(R_TLB_LO, valid, no ) |
+ IO_STATE(R_TLB_LO, kernel,no ) |
+ IO_STATE(R_TLB_LO, we, no ) |
+ IO_FIELD(R_TLB_LO, pfn, 0 ) );
+ }
+ local_irq_restore(flags);
+ D(printk("tlb: flushed all\n"));
+}
+
+/* invalidate the selected mm context only */
+
+void
+flush_tlb_mm(struct mm_struct *mm)
+{
+ int i;
+ int page_id = mm->context.page_id;
+ unsigned long flags;
+
+ D(printk("tlb: flush mm context %d (%p)\n", page_id, mm));
+
+ if(page_id == NO_CONTEXT)
+ return;
+
+ /* mark the TLB entries that match the page_id as invalid.
+ * here we could also check the _PAGE_GLOBAL bit and NOT flush
+ * global pages. is it worth the extra I/O ?
+ */
+
+ local_save_flags(flags);
+ local_irq_disable();
+ for(i = 0; i < NUM_TLB_ENTRIES; i++) {
+ *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
+ if (IO_EXTRACT(R_TLB_HI, page_id, *R_TLB_HI) == page_id) {
+ *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
+ IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
+
+ *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
+ IO_STATE(R_TLB_LO, valid, no ) |
+ IO_STATE(R_TLB_LO, kernel,no ) |
+ IO_STATE(R_TLB_LO, we, no ) |
+ IO_FIELD(R_TLB_LO, pfn, 0 ) );
+ }
+ }
+ local_irq_restore(flags);
+}
+
+/* invalidate a single page */
+
+void
+flush_tlb_page(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int page_id = mm->context.page_id;
+ int i;
+ unsigned long flags;
+
+ D(printk("tlb: flush page %p in context %d (%p)\n", addr, page_id, mm));
+
+ if(page_id == NO_CONTEXT)
+ return;
+
+ addr &= PAGE_MASK; /* perhaps not necessary */
+
+ /* invalidate those TLB entries that match both the mm context
+ * and the virtual address requested
+ */
+
+ local_save_flags(flags);
+ local_irq_disable();
+ for(i = 0; i < NUM_TLB_ENTRIES; i++) {
+ unsigned long tlb_hi;
+ *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
+ tlb_hi = *R_TLB_HI;
+ if (IO_EXTRACT(R_TLB_HI, page_id, tlb_hi) == page_id &&
+ (tlb_hi & PAGE_MASK) == addr) {
+ *R_TLB_HI = IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
+ addr; /* same addr as before works. */
+
+ *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
+ IO_STATE(R_TLB_LO, valid, no ) |
+ IO_STATE(R_TLB_LO, kernel,no ) |
+ IO_STATE(R_TLB_LO, we, no ) |
+ IO_FIELD(R_TLB_LO, pfn, 0 ) );
+ }
+ }
+ local_irq_restore(flags);
+}
+
+/* invalidate a page range */
+
+void
+flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int page_id = mm->context.page_id;
+ int i;
+ unsigned long flags;
+
+ D(printk("tlb: flush range %p<->%p in context %d (%p)\n",
+ start, end, page_id, mm));
+
+ if(page_id == NO_CONTEXT)
+ return;
+
+ start &= PAGE_MASK; /* probably not necessary */
+ end &= PAGE_MASK; /* dito */
+
+ /* invalidate those TLB entries that match both the mm context
+ * and the virtual address range
+ */
+
+ local_save_flags(flags);
+ local_irq_disable();
+ for(i = 0; i < NUM_TLB_ENTRIES; i++) {
+ unsigned long tlb_hi, vpn;
+ *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
+ tlb_hi = *R_TLB_HI;
+ vpn = tlb_hi & PAGE_MASK;
+ if (IO_EXTRACT(R_TLB_HI, page_id, tlb_hi) == page_id &&
+ vpn >= start && vpn < end) {
+ *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
+ IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
+
+ *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
+ IO_STATE(R_TLB_LO, valid, no ) |
+ IO_STATE(R_TLB_LO, kernel,no ) |
+ IO_STATE(R_TLB_LO, we, no ) |
+ IO_FIELD(R_TLB_LO, pfn, 0 ) );
+ }
+ }
+ local_irq_restore(flags);
+}
+
+/* dump the entire TLB for debug purposes */
+
+#if 0
+void
+dump_tlb_all(void)
+{
+ int i;
+ unsigned long flags;
+
+ printk("TLB dump. LO is: pfn | reserved | global | valid | kernel | we |\n");
+
+ local_save_flags(flags);
+ local_irq_disable();
+ for(i = 0; i < NUM_TLB_ENTRIES; i++) {
+ *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
+ printk("Entry %d: HI 0x%08lx, LO 0x%08lx\n",
+ i, *R_TLB_HI, *R_TLB_LO);
+ }
+ local_irq_restore(flags);
+}
+#endif
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+
+int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+ mm->context.page_id = NO_CONTEXT;
+ return 0;
+}
+
+/* called in schedule() just before actually doing the switch_to */
+
+void
+switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk)
+{
+ /* make sure we have a context */
+
+ get_mmu_context(next);
+
+ /* remember the pgd for the fault handlers
+ * this is similar to the pgd register in some other CPU's.
+ * we need our own copy of it because current and active_mm
+ * might be invalid at points where we still need to derefer
+ * the pgd.
+ */
+
+ current_pgd = next->pgd;
+
+ /* switch context in the MMU */
+
+ D(printk("switching mmu_context to %d (%p)\n", next->context, next));
+
+ *R_MMU_CONTEXT = IO_FIELD(R_MMU_CONTEXT, page_id, next->context.page_id);
+}
+
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