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-rw-r--r--arch/mips/mm/tlb-r4k.c419
1 files changed, 419 insertions, 0 deletions
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
new file mode 100644
index 00000000000..59d38bc05b6
--- /dev/null
+++ b/arch/mips/mm/tlb-r4k.c
@@ -0,0 +1,419 @@
+/*
+ * 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) 1996 David S. Miller (dm@engr.sgi.com)
+ * Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2002 MIPS Technologies, Inc. All rights reserved.
+ */
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+
+#include <asm/cpu.h>
+#include <asm/bootinfo.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+
+extern void build_tlb_refill_handler(void);
+
+/* CP0 hazard avoidance. */
+#define BARRIER __asm__ __volatile__(".set noreorder\n\t" \
+ "nop; nop; nop; nop; nop; nop;\n\t" \
+ ".set reorder\n\t")
+
+void local_flush_tlb_all(void)
+{
+ unsigned long flags;
+ unsigned long old_ctx;
+ int entry;
+
+ local_irq_save(flags);
+ /* Save old context and create impossible VPN2 value */
+ old_ctx = read_c0_entryhi();
+ write_c0_entrylo0(0);
+ write_c0_entrylo1(0);
+
+ entry = read_c0_wired();
+
+ /* Blast 'em all away. */
+ while (entry < current_cpu_data.tlbsize) {
+ /*
+ * Make sure all entries differ. If they're not different
+ * MIPS32 will take revenge ...
+ */
+ write_c0_entryhi(CKSEG0 + (entry << (PAGE_SHIFT + 1)));
+ write_c0_index(entry);
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ entry++;
+ }
+ tlbw_use_hazard();
+ write_c0_entryhi(old_ctx);
+ local_irq_restore(flags);
+}
+
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+ int cpu = smp_processor_id();
+
+ if (cpu_context(cpu, mm) != 0)
+ drop_mmu_context(mm,cpu);
+}
+
+void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int cpu = smp_processor_id();
+
+ if (cpu_context(cpu, mm) != 0) {
+ unsigned long flags;
+ int size;
+
+ local_irq_save(flags);
+ size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+ size = (size + 1) >> 1;
+ if (size <= current_cpu_data.tlbsize/2) {
+ int oldpid = read_c0_entryhi();
+ int newpid = cpu_asid(cpu, mm);
+
+ start &= (PAGE_MASK << 1);
+ end += ((PAGE_SIZE << 1) - 1);
+ end &= (PAGE_MASK << 1);
+ while (start < end) {
+ int idx;
+
+ write_c0_entryhi(start | newpid);
+ start += (PAGE_SIZE << 1);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ idx = read_c0_index();
+ write_c0_entrylo0(0);
+ write_c0_entrylo1(0);
+ if (idx < 0)
+ continue;
+ /* Make sure all entries differ. */
+ write_c0_entryhi(CKSEG0 +
+ (idx << (PAGE_SHIFT + 1)));
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ }
+ tlbw_use_hazard();
+ write_c0_entryhi(oldpid);
+ } else {
+ drop_mmu_context(mm, cpu);
+ }
+ local_irq_restore(flags);
+ }
+}
+
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+ unsigned long flags;
+ int size;
+
+ local_irq_save(flags);
+ size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+ size = (size + 1) >> 1;
+ if (size <= current_cpu_data.tlbsize / 2) {
+ int pid = read_c0_entryhi();
+
+ start &= (PAGE_MASK << 1);
+ end += ((PAGE_SIZE << 1) - 1);
+ end &= (PAGE_MASK << 1);
+
+ while (start < end) {
+ int idx;
+
+ write_c0_entryhi(start);
+ start += (PAGE_SIZE << 1);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ idx = read_c0_index();
+ write_c0_entrylo0(0);
+ write_c0_entrylo1(0);
+ if (idx < 0)
+ continue;
+ /* Make sure all entries differ. */
+ write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ }
+ tlbw_use_hazard();
+ write_c0_entryhi(pid);
+ } else {
+ local_flush_tlb_all();
+ }
+ local_irq_restore(flags);
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+ int cpu = smp_processor_id();
+
+ if (cpu_context(cpu, vma->vm_mm) != 0) {
+ unsigned long flags;
+ int oldpid, newpid, idx;
+
+ newpid = cpu_asid(cpu, vma->vm_mm);
+ page &= (PAGE_MASK << 1);
+ local_irq_save(flags);
+ oldpid = read_c0_entryhi();
+ write_c0_entryhi(page | newpid);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ idx = read_c0_index();
+ write_c0_entrylo0(0);
+ write_c0_entrylo1(0);
+ if (idx < 0)
+ goto finish;
+ /* Make sure all entries differ. */
+ write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ tlbw_use_hazard();
+
+ finish:
+ write_c0_entryhi(oldpid);
+ local_irq_restore(flags);
+ }
+}
+
+/*
+ * This one is only used for pages with the global bit set so we don't care
+ * much about the ASID.
+ */
+void local_flush_tlb_one(unsigned long page)
+{
+ unsigned long flags;
+ int oldpid, idx;
+
+ local_irq_save(flags);
+ page &= (PAGE_MASK << 1);
+ oldpid = read_c0_entryhi();
+ write_c0_entryhi(page);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ idx = read_c0_index();
+ write_c0_entrylo0(0);
+ write_c0_entrylo1(0);
+ if (idx >= 0) {
+ /* Make sure all entries differ. */
+ write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ tlbw_use_hazard();
+ }
+ write_c0_entryhi(oldpid);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * We will need multiple versions of update_mmu_cache(), one that just
+ * updates the TLB with the new pte(s), and another which also checks
+ * for the R4k "end of page" hardware bug and does the needy.
+ */
+void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
+{
+ unsigned long flags;
+ pgd_t *pgdp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ int idx, pid;
+
+ /*
+ * Handle debugger faulting in for debugee.
+ */
+ if (current->active_mm != vma->vm_mm)
+ return;
+
+ pid = read_c0_entryhi() & ASID_MASK;
+
+ local_irq_save(flags);
+ address &= (PAGE_MASK << 1);
+ write_c0_entryhi(address | pid);
+ pgdp = pgd_offset(vma->vm_mm, address);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ pmdp = pmd_offset(pgdp, address);
+ idx = read_c0_index();
+ ptep = pte_offset_map(pmdp, address);
+
+ #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
+ write_c0_entrylo0(ptep->pte_high);
+ ptep++;
+ write_c0_entrylo1(ptep->pte_high);
+#else
+ write_c0_entrylo0(pte_val(*ptep++) >> 6);
+ write_c0_entrylo1(pte_val(*ptep) >> 6);
+#endif
+ write_c0_entryhi(address | pid);
+ mtc0_tlbw_hazard();
+ if (idx < 0)
+ tlb_write_random();
+ else
+ tlb_write_indexed();
+ tlbw_use_hazard();
+ write_c0_entryhi(pid);
+ local_irq_restore(flags);
+}
+
+#if 0
+static void r4k_update_mmu_cache_hwbug(struct vm_area_struct * vma,
+ unsigned long address, pte_t pte)
+{
+ unsigned long flags;
+ unsigned int asid;
+ pgd_t *pgdp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ int idx;
+
+ local_irq_save(flags);
+ address &= (PAGE_MASK << 1);
+ asid = read_c0_entryhi() & ASID_MASK;
+ write_c0_entryhi(address | asid);
+ pgdp = pgd_offset(vma->vm_mm, address);
+ mtc0_tlbw_hazard();
+ tlb_probe();
+ BARRIER;
+ pmdp = pmd_offset(pgdp, address);
+ idx = read_c0_index();
+ ptep = pte_offset_map(pmdp, address);
+ write_c0_entrylo0(pte_val(*ptep++) >> 6);
+ write_c0_entrylo1(pte_val(*ptep) >> 6);
+ mtc0_tlbw_hazard();
+ if (idx < 0)
+ tlb_write_random();
+ else
+ tlb_write_indexed();
+ tlbw_use_hazard();
+ local_irq_restore(flags);
+}
+#endif
+
+void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
+ unsigned long entryhi, unsigned long pagemask)
+{
+ unsigned long flags;
+ unsigned long wired;
+ unsigned long old_pagemask;
+ unsigned long old_ctx;
+
+ local_irq_save(flags);
+ /* Save old context and create impossible VPN2 value */
+ old_ctx = read_c0_entryhi();
+ old_pagemask = read_c0_pagemask();
+ wired = read_c0_wired();
+ write_c0_wired(wired + 1);
+ write_c0_index(wired);
+ BARRIER;
+ write_c0_pagemask(pagemask);
+ write_c0_entryhi(entryhi);
+ write_c0_entrylo0(entrylo0);
+ write_c0_entrylo1(entrylo1);
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ tlbw_use_hazard();
+
+ write_c0_entryhi(old_ctx);
+ BARRIER;
+ write_c0_pagemask(old_pagemask);
+ local_flush_tlb_all();
+ local_irq_restore(flags);
+}
+
+/*
+ * Used for loading TLB entries before trap_init() has started, when we
+ * don't actually want to add a wired entry which remains throughout the
+ * lifetime of the system
+ */
+
+static int temp_tlb_entry __initdata;
+
+__init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
+ unsigned long entryhi, unsigned long pagemask)
+{
+ int ret = 0;
+ unsigned long flags;
+ unsigned long wired;
+ unsigned long old_pagemask;
+ unsigned long old_ctx;
+
+ local_irq_save(flags);
+ /* Save old context and create impossible VPN2 value */
+ old_ctx = read_c0_entryhi();
+ old_pagemask = read_c0_pagemask();
+ wired = read_c0_wired();
+ if (--temp_tlb_entry < wired) {
+ printk(KERN_WARNING "No TLB space left for add_temporary_entry\n");
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ write_c0_index(temp_tlb_entry);
+ write_c0_pagemask(pagemask);
+ write_c0_entryhi(entryhi);
+ write_c0_entrylo0(entrylo0);
+ write_c0_entrylo1(entrylo1);
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+ tlbw_use_hazard();
+
+ write_c0_entryhi(old_ctx);
+ write_c0_pagemask(old_pagemask);
+out:
+ local_irq_restore(flags);
+ return ret;
+}
+
+static void __init probe_tlb(unsigned long config)
+{
+ struct cpuinfo_mips *c = &current_cpu_data;
+ unsigned int reg;
+
+ /*
+ * If this isn't a MIPS32 / MIPS64 compliant CPU. Config 1 register
+ * is not supported, we assume R4k style. Cpu probing already figured
+ * out the number of tlb entries.
+ */
+ if ((c->processor_id & 0xff0000) == PRID_COMP_LEGACY)
+ return;
+
+ reg = read_c0_config1();
+ if (!((config >> 7) & 3))
+ panic("No TLB present");
+
+ c->tlbsize = ((reg >> 25) & 0x3f) + 1;
+}
+
+void __init tlb_init(void)
+{
+ unsigned int config = read_c0_config();
+
+ /*
+ * You should never change this register:
+ * - On R4600 1.7 the tlbp never hits for pages smaller than
+ * the value in the c0_pagemask register.
+ * - The entire mm handling assumes the c0_pagemask register to
+ * be set for 4kb pages.
+ */
+ probe_tlb(config);
+ write_c0_pagemask(PM_DEFAULT_MASK);
+ write_c0_wired(0);
+ temp_tlb_entry = current_cpu_data.tlbsize - 1;
+ local_flush_tlb_all();
+
+ build_tlb_refill_handler();
+}
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