x86: make x86_32 use tlb_64.c
authorTejun Heo <tj@kernel.org>
Wed, 21 Jan 2009 08:26:06 +0000 (17:26 +0900)
committerTejun Heo <tj@kernel.org>
Wed, 21 Jan 2009 08:26:06 +0000 (17:26 +0900)
Impact: less contention when issuing invalidate IPI, cleanup

Make x86_32 use the same tlb code as 64bit.  The 64bit code uses
multiple IPI vectors for tlb shootdown to reduce contention.  This
patch makes x86_32 allocate the same 8 IPIs as x86_64 and share the
code paths.

Note that the usage of asmlinkage is inconsistent for x86_32 and 64
and calls for further cleanup.  This has been noted with a FIXME
comment in tlb_64.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
arch/x86/include/asm/irq_vectors.h
arch/x86/include/asm/mach-default/entry_arch.h
arch/x86/kernel/Makefile
arch/x86/kernel/entry_32.S
arch/x86/kernel/irqinit_32.c
arch/x86/kernel/tlb_32.c [deleted file]
arch/x86/kernel/tlb_64.c

index 4ee8f80..9a83a10 100644 (file)
 # define CALL_FUNCTION_VECTOR          0xfc
 # define CALL_FUNCTION_SINGLE_VECTOR   0xfb
 # define THERMAL_APIC_VECTOR           0xfa
-/* 0xf1 - 0xf9 : free */
-# define INVALIDATE_TLB_VECTOR         0xf0
+/* 0xf8 - 0xf9 : free */
+# define INVALIDATE_TLB_VECTOR_END     0xf7
+# define INVALIDATE_TLB_VECTOR_START   0xf0    /* f0-f7 used for TLB flush */
+
+# define NUM_INVALIDATE_TLB_VECTORS    8
 
 #else
 
index 6b1add8..6fa399a 100644 (file)
  */
 #ifdef CONFIG_X86_SMP
 BUILD_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR)
-BUILD_INTERRUPT(invalidate_interrupt,INVALIDATE_TLB_VECTOR)
 BUILD_INTERRUPT(call_function_interrupt,CALL_FUNCTION_VECTOR)
 BUILD_INTERRUPT(call_function_single_interrupt,CALL_FUNCTION_SINGLE_VECTOR)
 BUILD_INTERRUPT(irq_move_cleanup_interrupt,IRQ_MOVE_CLEANUP_VECTOR)
+
+BUILD_INTERRUPT3(invalidate_interrupt0,INVALIDATE_TLB_VECTOR_START+0,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt1,INVALIDATE_TLB_VECTOR_START+1,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt2,INVALIDATE_TLB_VECTOR_START+2,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt3,INVALIDATE_TLB_VECTOR_START+3,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt4,INVALIDATE_TLB_VECTOR_START+4,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt5,INVALIDATE_TLB_VECTOR_START+5,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt6,INVALIDATE_TLB_VECTOR_START+6,
+                smp_invalidate_interrupt)
+BUILD_INTERRUPT3(invalidate_interrupt7,INVALIDATE_TLB_VECTOR_START+7,
+                smp_invalidate_interrupt)
 #endif
 
 /*
index eb07453..a62a15c 100644 (file)
@@ -58,7 +58,7 @@ obj-$(CONFIG_PCI)             += early-quirks.o
 apm-y                          := apm_32.o
 obj-$(CONFIG_APM)              += apm.o
 obj-$(CONFIG_X86_SMP)          += smp.o
-obj-$(CONFIG_X86_SMP)          += smpboot.o tsc_sync.o ipi.o tlb_$(BITS).o
+obj-$(CONFIG_X86_SMP)          += smpboot.o tsc_sync.o ipi.o tlb_64.o
 obj-$(CONFIG_X86_32_SMP)       += smpcommon.o
 obj-$(CONFIG_X86_64_SMP)       += tsc_sync.o smpcommon.o
 obj-$(CONFIG_X86_TRAMPOLINE)   += trampoline_$(BITS).o
index 4646902..a0b91aa 100644 (file)
@@ -672,7 +672,7 @@ common_interrupt:
 ENDPROC(common_interrupt)
        CFI_ENDPROC
 
-#define BUILD_INTERRUPT(name, nr)      \
+#define BUILD_INTERRUPT3(name, nr, fn) \
 ENTRY(name)                            \
        RING0_INT_FRAME;                \
        pushl $~(nr);                   \
@@ -680,11 +680,13 @@ ENTRY(name)                               \
        SAVE_ALL;                       \
        TRACE_IRQS_OFF                  \
        movl %esp,%eax;                 \
-       call smp_##name;                \
+       call fn;                        \
        jmp ret_from_intr;              \
        CFI_ENDPROC;                    \
 ENDPROC(name)
 
+#define BUILD_INTERRUPT(name, nr)      BUILD_INTERRUPT3(name, nr, smp_##name)
+
 /* The include is where all of the SMP etc. interrupts come from */
 #include "entry_arch.h"
 
index 1507ad4..bf629ca 100644 (file)
@@ -149,8 +149,15 @@ void __init native_init_IRQ(void)
         */
        alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
 
-       /* IPI for invalidation */
-       alloc_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
+       /* IPIs for invalidation */
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+0, invalidate_interrupt0);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+1, invalidate_interrupt1);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+2, invalidate_interrupt2);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+3, invalidate_interrupt3);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+4, invalidate_interrupt4);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+5, invalidate_interrupt5);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+6, invalidate_interrupt6);
+       alloc_intr_gate(INVALIDATE_TLB_VECTOR_START+7, invalidate_interrupt7);
 
        /* IPI for generic function call */
        alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c
deleted file mode 100644 (file)
index 93fcb05..0000000
+++ /dev/null
@@ -1,239 +0,0 @@
-#include <linux/spinlock.h>
-#include <linux/cpu.h>
-#include <linux/interrupt.h>
-
-#include <asm/tlbflush.h>
-
-DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate)
-                       = { &init_mm, 0, };
-
-/* must come after the send_IPI functions above for inlining */
-#include <mach_ipi.h>
-
-/*
- *     Smarter SMP flushing macros.
- *             c/o Linus Torvalds.
- *
- *     These mean you can really definitely utterly forget about
- *     writing to user space from interrupts. (Its not allowed anyway).
- *
- *     Optimizations Manfred Spraul <manfred@colorfullife.com>
- */
-
-static cpumask_var_t flush_cpumask;
-static struct mm_struct *flush_mm;
-static unsigned long flush_va;
-static DEFINE_SPINLOCK(tlbstate_lock);
-
-/*
- * We cannot call mmdrop() because we are in interrupt context,
- * instead update mm->cpu_vm_mask.
- *
- * We need to reload %cr3 since the page tables may be going
- * away from under us..
- */
-void leave_mm(int cpu)
-{
-       BUG_ON(percpu_read(cpu_tlbstate.state) == TLBSTATE_OK);
-       cpu_clear(cpu, percpu_read(cpu_tlbstate.active_mm)->cpu_vm_mask);
-       load_cr3(swapper_pg_dir);
-}
-EXPORT_SYMBOL_GPL(leave_mm);
-
-/*
- *
- * The flush IPI assumes that a thread switch happens in this order:
- * [cpu0: the cpu that switches]
- * 1) switch_mm() either 1a) or 1b)
- * 1a) thread switch to a different mm
- * 1a1) cpu_clear(cpu, old_mm->cpu_vm_mask);
- *     Stop ipi delivery for the old mm. This is not synchronized with
- *     the other cpus, but smp_invalidate_interrupt ignore flush ipis
- *     for the wrong mm, and in the worst case we perform a superfluous
- *     tlb flush.
- * 1a2) set cpu_tlbstate to TLBSTATE_OK
- *     Now the smp_invalidate_interrupt won't call leave_mm if cpu0
- *     was in lazy tlb mode.
- * 1a3) update cpu_tlbstate[].active_mm
- *     Now cpu0 accepts tlb flushes for the new mm.
- * 1a4) cpu_set(cpu, new_mm->cpu_vm_mask);
- *     Now the other cpus will send tlb flush ipis.
- * 1a4) change cr3.
- * 1b) thread switch without mm change
- *     cpu_tlbstate[].active_mm is correct, cpu0 already handles
- *     flush ipis.
- * 1b1) set cpu_tlbstate to TLBSTATE_OK
- * 1b2) test_and_set the cpu bit in cpu_vm_mask.
- *     Atomically set the bit [other cpus will start sending flush ipis],
- *     and test the bit.
- * 1b3) if the bit was 0: leave_mm was called, flush the tlb.
- * 2) switch %%esp, ie current
- *
- * The interrupt must handle 2 special cases:
- * - cr3 is changed before %%esp, ie. it cannot use current->{active_,}mm.
- * - the cpu performs speculative tlb reads, i.e. even if the cpu only
- *   runs in kernel space, the cpu could load tlb entries for user space
- *   pages.
- *
- * The good news is that cpu_tlbstate is local to each cpu, no
- * write/read ordering problems.
- */
-
-/*
- * TLB flush IPI:
- *
- * 1) Flush the tlb entries if the cpu uses the mm that's being flushed.
- * 2) Leave the mm if we are in the lazy tlb mode.
- *
- * Interrupts are disabled.
- */
-
-void smp_invalidate_interrupt(struct pt_regs *regs)
-{
-       unsigned int cpu;
-
-       cpu = smp_processor_id();
-
-       if (!cpumask_test_cpu(cpu, flush_cpumask))
-               goto out;
-               /*
-                * This was a BUG() but until someone can quote me the
-                * line from the intel manual that guarantees an IPI to
-                * multiple CPUs is retried _only_ on the erroring CPUs
-                * its staying as a return
-                *
-                * BUG();
-                */
-
-       if (flush_mm == percpu_read(cpu_tlbstate.active_mm)) {
-               if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
-                       if (flush_va == TLB_FLUSH_ALL)
-                               local_flush_tlb();
-                       else
-                               __flush_tlb_one(flush_va);
-               } else
-                       leave_mm(cpu);
-       }
-out:
-       ack_APIC_irq();
-       smp_mb__before_clear_bit();
-       cpumask_clear_cpu(cpu, flush_cpumask);
-       smp_mb__after_clear_bit();
-       inc_irq_stat(irq_tlb_count);
-}
-
-void native_flush_tlb_others(const struct cpumask *cpumask,
-                            struct mm_struct *mm, unsigned long va)
-{
-       /*
-        * - mask must exist :)
-        */
-       BUG_ON(cpumask_empty(cpumask));
-       BUG_ON(!mm);
-
-       /*
-        * i'm not happy about this global shared spinlock in the
-        * MM hot path, but we'll see how contended it is.
-        * AK: x86-64 has a faster method that could be ported.
-        */
-       spin_lock(&tlbstate_lock);
-
-       cpumask_andnot(flush_cpumask, cpumask, cpumask_of(smp_processor_id()));
-#ifdef CONFIG_HOTPLUG_CPU
-       /* If a CPU which we ran on has gone down, OK. */
-       cpumask_and(flush_cpumask, flush_cpumask, cpu_online_mask);
-       if (unlikely(cpumask_empty(flush_cpumask))) {
-               spin_unlock(&tlbstate_lock);
-               return;
-       }
-#endif
-       flush_mm = mm;
-       flush_va = va;
-
-       /*
-        * Make the above memory operations globally visible before
-        * sending the IPI.
-        */
-       smp_mb();
-       /*
-        * We have to send the IPI only to
-        * CPUs affected.
-        */
-       send_IPI_mask(flush_cpumask, INVALIDATE_TLB_VECTOR);
-
-       while (!cpumask_empty(flush_cpumask))
-               /* nothing. lockup detection does not belong here */
-               cpu_relax();
-
-       flush_mm = NULL;
-       flush_va = 0;
-       spin_unlock(&tlbstate_lock);
-}
-
-void flush_tlb_current_task(void)
-{
-       struct mm_struct *mm = current->mm;
-
-       preempt_disable();
-
-       local_flush_tlb();
-       if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
-               flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
-       preempt_enable();
-}
-
-void flush_tlb_mm(struct mm_struct *mm)
-{
-
-       preempt_disable();
-
-       if (current->active_mm == mm) {
-               if (current->mm)
-                       local_flush_tlb();
-               else
-                       leave_mm(smp_processor_id());
-       }
-       if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
-               flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
-
-       preempt_enable();
-}
-
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
-{
-       struct mm_struct *mm = vma->vm_mm;
-
-       preempt_disable();
-
-       if (current->active_mm == mm) {
-               if (current->mm)
-                       __flush_tlb_one(va);
-                else
-                       leave_mm(smp_processor_id());
-       }
-
-       if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
-               flush_tlb_others(&mm->cpu_vm_mask, mm, va);
-       preempt_enable();
-}
-
-static void do_flush_tlb_all(void *info)
-{
-       unsigned long cpu = smp_processor_id();
-
-       __flush_tlb_all();
-       if (percpu_read(cpu_tlbstate.state) == TLBSTATE_LAZY)
-               leave_mm(cpu);
-}
-
-void flush_tlb_all(void)
-{
-       on_each_cpu(do_flush_tlb_all, NULL, 1);
-}
-
-static int init_flush_cpumask(void)
-{
-       alloc_cpumask_var(&flush_cpumask, GFP_KERNEL);
-       return 0;
-}
-early_initcall(init_flush_cpumask);
index 19ac661..b3ca1b9 100644 (file)
@@ -113,7 +113,17 @@ EXPORT_SYMBOL_GPL(leave_mm);
  * Interrupts are disabled.
  */
 
-asmlinkage void smp_invalidate_interrupt(struct pt_regs *regs)
+/*
+ * FIXME: use of asmlinkage is not consistent.  On x86_64 it's noop
+ * but still used for documentation purpose but the usage is slightly
+ * inconsistent.  On x86_32, asmlinkage is regparm(0) but interrupt
+ * entry calls in with the first parameter in %eax.  Maybe define
+ * intrlinkage?
+ */
+#ifdef CONFIG_X86_64
+asmlinkage
+#endif
+void smp_invalidate_interrupt(struct pt_regs *regs)
 {
        unsigned int cpu;
        unsigned int sender;