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-rw-r--r--arch/mips/include/asm/mmu_context.h297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
new file mode 100644
index 0000000..d7f3eb0
--- /dev/null
+++ b/arch/mips/include/asm/mmu_context.h
@@ -0,0 +1,297 @@
+/*
+ * Switch a MMU context.
+ *
+ * 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, 1997, 1998, 1999 by Ralf Baechle
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_MMU_CONTEXT_H
+#define _ASM_MMU_CONTEXT_H
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#ifdef CONFIG_MIPS_MT_SMTC
+#include <asm/mipsmtregs.h>
+#include <asm/smtc.h>
+#endif /* SMTC */
+#include <asm-generic/mm_hooks.h>
+
+/*
+ * For the fast tlb miss handlers, we keep a per cpu array of pointers
+ * to the current pgd for each processor. Also, the proc. id is stuffed
+ * into the context register.
+ */
+extern unsigned long pgd_current[];
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
+ pgd_current[smp_processor_id()] = (unsigned long)(pgd)
+
+#ifdef CONFIG_32BIT
+#define TLBMISS_HANDLER_SETUP() \
+ write_c0_context((unsigned long) smp_processor_id() << 25); \
+ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
+#endif
+#ifdef CONFIG_64BIT
+#define TLBMISS_HANDLER_SETUP() \
+ write_c0_context((unsigned long) smp_processor_id() << 26); \
+ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
+#endif
+
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+
+#define ASID_INC 0x40
+#define ASID_MASK 0xfc0
+
+#elif defined(CONFIG_CPU_R8000)
+
+#define ASID_INC 0x10
+#define ASID_MASK 0xff0
+
+#elif defined(CONFIG_CPU_RM9000)
+
+#define ASID_INC 0x1
+#define ASID_MASK 0xfff
+
+/* SMTC/34K debug hack - but maybe we'll keep it */
+#elif defined(CONFIG_MIPS_MT_SMTC)
+
+#define ASID_INC 0x1
+extern unsigned long smtc_asid_mask;
+#define ASID_MASK (smtc_asid_mask)
+#define HW_ASID_MASK 0xff
+/* End SMTC/34K debug hack */
+#else /* FIXME: not correct for R6000 */
+
+#define ASID_INC 0x1
+#define ASID_MASK 0xff
+
+#endif
+
+#define cpu_context(cpu, mm) ((mm)->context[cpu])
+#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
+#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+/*
+ * All unused by hardware upper bits will be considered
+ * as a software asid extension.
+ */
+#define ASID_VERSION_MASK ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
+#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
+
+#ifndef CONFIG_MIPS_MT_SMTC
+/* Normal, classic MIPS get_new_mmu_context */
+static inline void
+get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
+{
+ unsigned long asid = asid_cache(cpu);
+
+ if (! ((asid += ASID_INC) & ASID_MASK) ) {
+ if (cpu_has_vtag_icache)
+ flush_icache_all();
+ local_flush_tlb_all(); /* start new asid cycle */
+ if (!asid) /* fix version if needed */
+ asid = ASID_FIRST_VERSION;
+ }
+ cpu_context(cpu, mm) = asid_cache(cpu) = asid;
+}
+
+#else /* CONFIG_MIPS_MT_SMTC */
+
+#define get_new_mmu_context(mm, cpu) smtc_get_new_mmu_context((mm), (cpu))
+
+#endif /* CONFIG_MIPS_MT_SMTC */
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+static inline int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+ int i;
+
+ for_each_online_cpu(i)
+ cpu_context(i, mm) = 0;
+
+ return 0;
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned long flags;
+#ifdef CONFIG_MIPS_MT_SMTC
+ unsigned long oldasid;
+ unsigned long mtflags;
+ int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
+ local_irq_save(flags);
+ mtflags = dvpe();
+#else /* Not SMTC */
+ local_irq_save(flags);
+#endif /* CONFIG_MIPS_MT_SMTC */
+
+ /* Check if our ASID is of an older version and thus invalid */
+ if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
+ get_new_mmu_context(next, cpu);
+#ifdef CONFIG_MIPS_MT_SMTC
+ /*
+ * If the EntryHi ASID being replaced happens to be
+ * the value flagged at ASID recycling time as having
+ * an extended life, clear the bit showing it being
+ * in use by this "CPU", and if that's the last bit,
+ * free up the ASID value for use and flush any old
+ * instances of it from the TLB.
+ */
+ oldasid = (read_c0_entryhi() & ASID_MASK);
+ if(smtc_live_asid[mytlb][oldasid]) {
+ smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
+ if(smtc_live_asid[mytlb][oldasid] == 0)
+ smtc_flush_tlb_asid(oldasid);
+ }
+ /*
+ * Tread softly on EntryHi, and so long as we support
+ * having ASID_MASK smaller than the hardware maximum,
+ * make sure no "soft" bits become "hard"...
+ */
+ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
+ | (cpu_context(cpu, next) & ASID_MASK));
+ ehb(); /* Make sure it propagates to TCStatus */
+ evpe(mtflags);
+#else
+ write_c0_entryhi(cpu_context(cpu, next));
+#endif /* CONFIG_MIPS_MT_SMTC */
+ TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+
+ /*
+ * Mark current->active_mm as not "active" anymore.
+ * We don't want to mislead possible IPI tlb flush routines.
+ */
+ cpu_clear(cpu, prev->cpu_vm_mask);
+ cpu_set(cpu, next->cpu_vm_mask);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * Destroy context related info for an mm_struct that is about
+ * to be put to rest.
+ */
+static inline void destroy_context(struct mm_struct *mm)
+{
+}
+
+#define deactivate_mm(tsk, mm) do { } while (0)
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+static inline void
+activate_mm(struct mm_struct *prev, struct mm_struct *next)
+{
+ unsigned long flags;
+ unsigned int cpu = smp_processor_id();
+
+#ifdef CONFIG_MIPS_MT_SMTC
+ unsigned long oldasid;
+ unsigned long mtflags;
+ int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
+#endif /* CONFIG_MIPS_MT_SMTC */
+
+ local_irq_save(flags);
+
+ /* Unconditionally get a new ASID. */
+ get_new_mmu_context(next, cpu);
+
+#ifdef CONFIG_MIPS_MT_SMTC
+ /* See comments for similar code above */
+ mtflags = dvpe();
+ oldasid = read_c0_entryhi() & ASID_MASK;
+ if(smtc_live_asid[mytlb][oldasid]) {
+ smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
+ if(smtc_live_asid[mytlb][oldasid] == 0)
+ smtc_flush_tlb_asid(oldasid);
+ }
+ /* See comments for similar code above */
+ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
+ (cpu_context(cpu, next) & ASID_MASK));
+ ehb(); /* Make sure it propagates to TCStatus */
+ evpe(mtflags);
+#else
+ write_c0_entryhi(cpu_context(cpu, next));
+#endif /* CONFIG_MIPS_MT_SMTC */
+ TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+
+ /* mark mmu ownership change */
+ cpu_clear(cpu, prev->cpu_vm_mask);
+ cpu_set(cpu, next->cpu_vm_mask);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * If mm is currently active_mm, we can't really drop it. Instead,
+ * we will get a new one for it.
+ */
+static inline void
+drop_mmu_context(struct mm_struct *mm, unsigned cpu)
+{
+ unsigned long flags;
+#ifdef CONFIG_MIPS_MT_SMTC
+ unsigned long oldasid;
+ /* Can't use spinlock because called from TLB flush within DVPE */
+ unsigned int prevvpe;
+ int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
+#endif /* CONFIG_MIPS_MT_SMTC */
+
+ local_irq_save(flags);
+
+ if (cpu_isset(cpu, mm->cpu_vm_mask)) {
+ get_new_mmu_context(mm, cpu);
+#ifdef CONFIG_MIPS_MT_SMTC
+ /* See comments for similar code above */
+ prevvpe = dvpe();
+ oldasid = (read_c0_entryhi() & ASID_MASK);
+ if (smtc_live_asid[mytlb][oldasid]) {
+ smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
+ if(smtc_live_asid[mytlb][oldasid] == 0)
+ smtc_flush_tlb_asid(oldasid);
+ }
+ /* See comments for similar code above */
+ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
+ | cpu_asid(cpu, mm));
+ ehb(); /* Make sure it propagates to TCStatus */
+ evpe(prevvpe);
+#else /* not CONFIG_MIPS_MT_SMTC */
+ write_c0_entryhi(cpu_asid(cpu, mm));
+#endif /* CONFIG_MIPS_MT_SMTC */
+ } else {
+ /* will get a new context next time */
+#ifndef CONFIG_MIPS_MT_SMTC
+ cpu_context(cpu, mm) = 0;
+#else /* SMTC */
+ int i;
+
+ /* SMTC shares the TLB (and ASIDs) across VPEs */
+ for_each_online_cpu(i) {
+ if((smtc_status & SMTC_TLB_SHARED)
+ || (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id))
+ cpu_context(i, mm) = 0;
+ }
+#endif /* CONFIG_MIPS_MT_SMTC */
+ }
+ local_irq_restore(flags);
+}
+
+#endif /* _ASM_MMU_CONTEXT_H */
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