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 000000000000..d7f3eb03ad12
--- /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 */