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Subject[PATCH 2/4] x86-64: use smp_call_function_mask for SMP TLB invalidations
Now that smp_call_function_mask exists and is scalable, there's no
reason to have a special TLB flush IPI. This saves a mass of code.

In the process, I removed a copy of a cpumask_t. The UV tlb flush
code relies on that copy, so I propagated it down.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Cliff Wickman <cpw@sgi.com>
---
arch/x86/kernel/entry_64.S | 15 ----
arch/x86/kernel/irqinit_64.c | 10 ---
arch/x86/kernel/tlb_64.c | 125 ++++++-----------------------------------
arch/x86/kernel/tlb_uv.c | 5 -
include/asm-x86/irq_vectors.h | 4 -
include/asm-x86/uv/uv_bau.h | 2
6 files changed, 23 insertions(+), 138 deletions(-)

===================================================================
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -869,21 +869,6 @@
apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt
END(reschedule_interrupt)

- .macro INVALIDATE_ENTRY num
-ENTRY(invalidate_interrupt\num)
- apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt
-END(invalidate_interrupt\num)
- .endm
-
- INVALIDATE_ENTRY 0
- INVALIDATE_ENTRY 1
- INVALIDATE_ENTRY 2
- INVALIDATE_ENTRY 3
- INVALIDATE_ENTRY 4
- INVALIDATE_ENTRY 5
- INVALIDATE_ENTRY 6
- INVALIDATE_ENTRY 7
-
ENTRY(call_function_interrupt)
apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt
END(call_function_interrupt)
===================================================================
--- a/arch/x86/kernel/irqinit_64.c
+++ b/arch/x86/kernel/irqinit_64.c
@@ -187,16 +187,6 @@
*/
alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_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);

===================================================================
--- a/arch/x86/kernel/tlb_64.c
+++ b/arch/x86/kernel/tlb_64.c
@@ -1,24 +1,16 @@
-#include <linux/init.h>
-
#include <linux/mm.h>
-#include <linux/delay.h>
-#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
-#include <linux/mc146818rtc.h>
-#include <linux/interrupt.h>
+#include <linux/module.h>

-#include <asm/mtrr.h>
-#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
-#include <asm/proto.h>
-#include <asm/apicdef.h>
-#include <asm/idle.h>
+
+/* For UV tlb flush */
#include <asm/uv/uv_hub.h>
#include <asm/uv/uv_bau.h>
+#include <asm/genapic.h> /* for is_uv_system */

-#include <mach_ipi.h>
/*
* Smarter SMP flushing macros.
* c/o Linus Torvalds.
@@ -27,34 +19,12 @@
* writing to user space from interrupts. (Its not allowed anyway).
*
* Optimizations Manfred Spraul <manfred@colorfullife.com>
- *
- * More scalable flush, from Andi Kleen
- *
- * To avoid global state use 8 different call vectors.
- * Each CPU uses a specific vector to trigger flushes on other
- * CPUs. Depending on the received vector the target CPUs look into
- * the right per cpu variable for the flush data.
- *
- * With more than 8 CPUs they are hashed to the 8 available
- * vectors. The limited global vector space forces us to this right now.
- * In future when interrupts are split into per CPU domains this could be
- * fixed, at the cost of triggering multiple IPIs in some cases.
*/

-union smp_flush_state {
- struct {
- cpumask_t flush_cpumask;
- struct mm_struct *flush_mm;
- unsigned long flush_va;
- spinlock_t tlbstate_lock;
- };
- char pad[SMP_CACHE_BYTES];
-} ____cacheline_aligned;
-
-/* State is put into the per CPU data section, but padded
- to a full cache line because other CPUs can access it and we don't
- want false sharing in the per cpu data segment. */
-static DEFINE_PER_CPU(union smp_flush_state, flush_state);
+struct tlb_flush {
+ struct mm_struct *mm;
+ unsigned long va;
+};

/*
* We cannot call mmdrop() because we are in interrupt context,
@@ -117,95 +87,38 @@
* Interrupts are disabled.
*/

-asmlinkage void smp_invalidate_interrupt(struct pt_regs *regs)
+static void tlb_invalidate(void *arg)
{
+ struct tlb_flush *f = arg;
int cpu;
- int sender;
- union smp_flush_state *f;

cpu = smp_processor_id();
- /*
- * orig_rax contains the negated interrupt vector.
- * Use that to determine where the sender put the data.
- */
- sender = ~regs->orig_ax - INVALIDATE_TLB_VECTOR_START;
- f = &per_cpu(flush_state, sender);

- if (!cpu_isset(cpu, f->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 (f->flush_mm == read_pda(active_mm)) {
+ if (f->mm == read_pda(active_mm)) {
if (read_pda(mmu_state) == TLBSTATE_OK) {
- if (f->flush_va == TLB_FLUSH_ALL)
+ if (f->va == TLB_FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(f->flush_va);
+ __flush_tlb_one(f->va);
} else
leave_mm(cpu);
}
-out:
- ack_APIC_irq();
- cpu_clear(cpu, f->flush_cpumask);
add_pda(irq_tlb_count, 1);
}

void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
unsigned long va)
{
- int sender;
- union smp_flush_state *f;
- cpumask_t cpumask = *cpumaskp;
+ struct tlb_flush flush = {
+ .mm = mm,
+ .va = va,
+ };

- if (is_uv_system() && uv_flush_tlb_others(&cpumask, mm, va))
+ if (is_uv_system() && uv_flush_tlb_others(cpumaskp, mm, va))
return;

- /* Caller has disabled preemption */
- sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
- f = &per_cpu(flush_state, sender);
-
- /*
- * Could avoid this lock when
- * num_online_cpus() <= NUM_INVALIDATE_TLB_VECTORS, but it is
- * probably not worth checking this for a cache-hot lock.
- */
- spin_lock(&f->tlbstate_lock);
-
- f->flush_mm = mm;
- f->flush_va = va;
- cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask);
-
- /*
- * We have to send the IPI only to
- * CPUs affected.
- */
- send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR_START + sender);
-
- while (!cpus_empty(f->flush_cpumask))
- cpu_relax();
-
- f->flush_mm = NULL;
- f->flush_va = 0;
- spin_unlock(&f->tlbstate_lock);
+ smp_call_function_mask(*cpumaskp, tlb_invalidate, &flush, 1);
}
-
-static int __cpuinit init_smp_flush(void)
-{
- int i;
-
- for_each_possible_cpu(i)
- spin_lock_init(&per_cpu(flush_state, i).tlbstate_lock);
-
- return 0;
-}
-core_initcall(init_smp_flush);

void flush_tlb_current_task(void)
{
===================================================================
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -295,7 +295,7 @@
* Returns 1 if all remote flushing was done.
* Returns 0 if some remote flushing remains to be done.
*/
-int uv_flush_tlb_others(cpumask_t *cpumaskp, struct mm_struct *mm,
+int uv_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
unsigned long va)
{
int i;
@@ -305,6 +305,7 @@
int this_blade;
int locals = 0;
struct bau_desc *bau_desc;
+ cpumask_t cpumask = *cpumaskp;

cpu = uv_blade_processor_id();
this_blade = uv_numa_blade_id();
@@ -339,7 +340,7 @@
bau_desc->payload.address = va;
bau_desc->payload.sending_cpu = smp_processor_id();

- return uv_flush_send_and_wait(cpu, this_blade, bau_desc, cpumaskp);
+ return uv_flush_send_and_wait(cpu, this_blade, bau_desc, &cpumask);
}

/*
===================================================================
--- a/include/asm-x86/irq_vectors.h
+++ b/include/asm-x86/irq_vectors.h
@@ -75,10 +75,6 @@
#define CALL_FUNCTION_SINGLE_VECTOR 0xfb
#define THERMAL_APIC_VECTOR 0xfa
#define THRESHOLD_APIC_VECTOR 0xf9
-#define INVALIDATE_TLB_VECTOR_END 0xf7
-#define INVALIDATE_TLB_VECTOR_START 0xf0 /* f0-f7 used for TLB flush */
-
-#define NUM_INVALIDATE_TLB_VECTORS 8

#endif

===================================================================
--- a/include/asm-x86/uv/uv_bau.h
+++ b/include/asm-x86/uv/uv_bau.h
@@ -330,7 +330,7 @@
#define cpubit_isset(cpu, bau_local_cpumask) \
test_bit((cpu), (bau_local_cpumask).bits)

-extern int uv_flush_tlb_others(cpumask_t *, struct mm_struct *, unsigned long);
+extern int uv_flush_tlb_others(const cpumask_t *, struct mm_struct *, unsigned long);
extern void uv_bau_message_intr1(void);
extern void uv_bau_timeout_intr1(void);




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