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-rw-r--r--arch/cris/arch-v32/mm/tlb.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/mm/tlb.c b/arch/cris/arch-v32/mm/tlb.c
new file mode 100644
index 0000000..8233406
--- /dev/null
+++ b/arch/cris/arch-v32/mm/tlb.c
@@ -0,0 +1,208 @@
+/*
+ * Low level TLB handling.
+ *
+ * Copyright (C) 2000-2003, Axis Communications AB.
+ *
+ * Authors: Bjorn Wesen <bjornw@axis.com>
+ * Tobias Anderberg <tobiasa@axis.com>, CRISv32 port.
+ */
+
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+#include <asm/arch/hwregs/asm/mmu_defs_asm.h>
+#include <asm/arch/hwregs/supp_reg.h>
+
+#define UPDATE_TLB_SEL_IDX(val) \
+do { \
+ unsigned long tlb_sel; \
+ \
+ tlb_sel = REG_FIELD(mmu, rw_mm_tlb_sel, idx, val); \
+ SUPP_REG_WR(RW_MM_TLB_SEL, tlb_sel); \
+} while(0)
+
+#define UPDATE_TLB_HILO(tlb_hi, tlb_lo) \
+do { \
+ SUPP_REG_WR(RW_MM_TLB_HI, tlb_hi); \
+ SUPP_REG_WR(RW_MM_TLB_LO, tlb_lo); \
+} while(0)
+
+/*
+ * The TLB can host up to 256 different mm contexts at the same time. The running
+ * context is found in the PID register. Each TLB entry contains a page_id that
+ * has to match the PID register to give a hit. page_id_map keeps track of which
+ * mm's is assigned to which page_id's, making sure it's known when to
+ * invalidate TLB entries.
+ *
+ * The last page_id is never running, it is used as an invalid page_id so that
+ * it's possible to make TLB entries that will nerver match.
+ *
+ * Note; the flushes needs to be atomic otherwise an interrupt hander that uses
+ * vmalloc'ed memory might cause a TLB load in the middle of a flush.
+ */
+
+/* Flush all TLB entries. */
+void
+__flush_tlb_all(void)
+{
+ int i;
+ int mmu;
+ unsigned long flags;
+ unsigned long mmu_tlb_hi;
+ unsigned long mmu_tlb_sel;
+
+ /*
+ * Mask with 0xf so similar TLB entries aren't written in the same 4-way
+ * entry group.
+ */
+ local_save_flags(flags);
+ local_irq_disable();
+
+ for (mmu = 1; mmu <= 2; mmu++) {
+ SUPP_BANK_SEL(mmu); /* Select the MMU */
+ for (i = 0; i < NUM_TLB_ENTRIES; i++) {
+ /* Store invalid entry */
+ mmu_tlb_sel = REG_FIELD(mmu, rw_mm_tlb_sel, idx, i);
+
+ mmu_tlb_hi = (REG_FIELD(mmu, rw_mm_tlb_hi, pid, INVALID_PAGEID)
+ | REG_FIELD(mmu, rw_mm_tlb_hi, vpn, i & 0xf));
+
+ SUPP_REG_WR(RW_MM_TLB_SEL, mmu_tlb_sel);
+ SUPP_REG_WR(RW_MM_TLB_HI, mmu_tlb_hi);
+ SUPP_REG_WR(RW_MM_TLB_LO, 0);
+ }
+ }
+
+ local_irq_restore(flags);
+}
+
+/* Flush an entire user address space. */
+void
+__flush_tlb_mm(struct mm_struct *mm)
+{
+ int i;
+ int mmu;
+ unsigned long flags;
+ unsigned long page_id;
+ unsigned long tlb_hi;
+ unsigned long mmu_tlb_hi;
+
+ page_id = mm->context.page_id;
+
+ if (page_id == NO_CONTEXT)
+ return;
+
+ /* Mark the TLB entries that match the page_id as invalid. */
+ local_save_flags(flags);
+ local_irq_disable();
+
+ for (mmu = 1; mmu <= 2; mmu++) {
+ SUPP_BANK_SEL(mmu);
+ for (i = 0; i < NUM_TLB_ENTRIES; i++) {
+ UPDATE_TLB_SEL_IDX(i);
+
+ /* Get the page_id */
+ SUPP_REG_RD(RW_MM_TLB_HI, tlb_hi);
+
+ /* Check if the page_id match. */
+ if ((tlb_hi & 0xff) == page_id) {
+ mmu_tlb_hi = (REG_FIELD(mmu, rw_mm_tlb_hi, pid,
+ INVALID_PAGEID)
+ | REG_FIELD(mmu, rw_mm_tlb_hi, vpn,
+ i & 0xf));
+
+ UPDATE_TLB_HILO(mmu_tlb_hi, 0);
+ }
+ }
+ }
+
+ local_irq_restore(flags);
+}
+
+/* Invalidate a single page. */
+void
+__flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
+{
+ int i;
+ int mmu;
+ unsigned long page_id;
+ unsigned long flags;
+ unsigned long tlb_hi;
+ unsigned long mmu_tlb_hi;
+
+ page_id = vma->vm_mm->context.page_id;
+
+ if (page_id == NO_CONTEXT)
+ return;
+
+ addr &= PAGE_MASK;
+
+ /*
+ * Invalidate those TLB entries that match both the mm context and the
+ * requested virtual address.
+ */
+ local_save_flags(flags);
+ local_irq_disable();
+
+ for (mmu = 1; mmu <= 2; mmu++) {
+ SUPP_BANK_SEL(mmu);
+ for (i = 0; i < NUM_TLB_ENTRIES; i++) {
+ UPDATE_TLB_SEL_IDX(i);
+ SUPP_REG_RD(RW_MM_TLB_HI, tlb_hi);
+
+ /* Check if page_id and address matches */
+ if (((tlb_hi & 0xff) == page_id) &&
+ ((tlb_hi & PAGE_MASK) == addr)) {
+ mmu_tlb_hi = REG_FIELD(mmu, rw_mm_tlb_hi, pid,
+ INVALID_PAGEID) | addr;
+
+ UPDATE_TLB_HILO(mmu_tlb_hi, 0);
+ }
+ }
+ }
+
+ local_irq_restore(flags);
+}
+
+/*
+ * 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)
+{
+ int cpu = smp_processor_id();
+
+ /* Make sure there is a MMU context. */
+ spin_lock(&next->page_table_lock);
+ get_mmu_context(next);
+ cpu_set(cpu, next->cpu_vm_mask);
+ spin_unlock(&next->page_table_lock);
+
+ /*
+ * Remember the pgd for the fault handlers. Keep a seperate copy of it
+ * because current and active_mm might be invalid at points where
+ * there's still a need to derefer the pgd.
+ */
+ per_cpu(current_pgd, cpu) = next->pgd;
+
+ /* Switch context in the MMU. */
+ if (tsk && tsk->thread_info)
+ {
+ SPEC_REG_WR(SPEC_REG_PID, next->context.page_id | tsk->thread_info->tls);
+ }
+ else
+ {
+ SPEC_REG_WR(SPEC_REG_PID, next->context.page_id);
+ }
+}
+
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