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authorRalf Baechle <ralf@linux-mips.org>2006-04-05 09:45:45 +0100
committerRalf Baechle <ralf@linux-mips.org>2006-04-19 04:14:28 +0200
commit41c594ab65fc89573af296d192aa5235d09717ab (patch)
tree562462512a320f386bdf49eabfbb26bb3ee761fa /include/asm-mips/mmu_context.h
parent2600990e640e3bef29ed89d565864cf16ee83833 (diff)
[MIPS] MT: Improved multithreading support.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/mmu_context.h')
-rw-r--r--include/asm-mips/mmu_context.h112
1 files changed, 109 insertions, 3 deletions
diff --git a/include/asm-mips/mmu_context.h b/include/asm-mips/mmu_context.h
index 61cf22588137..6e09f4c87211 100644
--- a/include/asm-mips/mmu_context.h
+++ b/include/asm-mips/mmu_context.h
@@ -17,6 +17,10 @@
#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 */
/*
* For the fast tlb miss handlers, we keep a per cpu array of pointers
@@ -54,6 +58,14 @@ extern unsigned long pgd_current[];
#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
@@ -76,6 +88,8 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
#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)
{
@@ -91,6 +105,12 @@ get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
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.
@@ -111,14 +131,46 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
{
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);
/*
@@ -151,12 +203,34 @@ 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 */
@@ -174,17 +248,49 @@ 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 (i = 0; i < num_online_cpus(); 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);
}