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-rw-r--r--arch/x86/mm/tlb.c401
1 files changed, 206 insertions, 195 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 5e57e11..613cd83 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -12,6 +12,7 @@
#include <asm/cache.h>
#include <asm/apic.h>
#include <asm/uv/uv.h>
+#include <linux/debugfs.h>
DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate)
= { &init_mm, 0, };
@@ -27,33 +28,14 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate)
*
* 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 array slot 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.
+ * Implement flush IPI by CALL_FUNCTION_VECTOR, Alex Shi
*/
-union smp_flush_state {
- struct {
- struct mm_struct *flush_mm;
- unsigned long flush_va;
- raw_spinlock_t tlbstate_lock;
- DECLARE_BITMAP(flush_cpumask, NR_CPUS);
- };
- char pad[INTERNODE_CACHE_BYTES];
-} ____cacheline_internodealigned_in_smp;
-
-/* 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 union smp_flush_state flush_state[NUM_INVALIDATE_TLB_VECTORS];
-
-static DEFINE_PER_CPU_READ_MOSTLY(int, tlb_vector_offset);
+struct flush_tlb_info {
+ struct mm_struct *flush_mm;
+ unsigned long flush_start;
+ unsigned long flush_end;
+};
/*
* We cannot call mmdrop() because we are in interrupt context,
@@ -72,28 +54,25 @@ void leave_mm(int cpu)
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 mmu_state to TLBSTATE_OK
- * Now the smp_invalidate_interrupt won't call leave_mm if cpu0
- * was in lazy tlb mode.
- * 1a3) update cpu active_mm
+ * 1a1) set cpu_tlbstate to TLBSTATE_OK
+ * Now the tlb flush NMI handler flush_tlb_func won't call leave_mm
+ * if cpu0 was in lazy tlb mode.
+ * 1a2) update cpu active_mm
* Now cpu0 accepts tlb flushes for the new mm.
- * 1a4) cpu_set(cpu, new_mm->cpu_vm_mask);
+ * 1a3) cpu_set(cpu, new_mm->cpu_vm_mask);
* Now the other cpus will send tlb flush ipis.
* 1a4) change cr3.
+ * 1a5) cpu_clear(cpu, old_mm->cpu_vm_mask);
+ * Stop ipi delivery for the old mm. This is not synchronized with
+ * the other cpus, but flush_tlb_func ignore flush ipis for the wrong
+ * mm, and in the worst case we perform a superfluous tlb flush.
* 1b) thread switch without mm change
- * cpu active_mm is correct, cpu0 already handles
- * flush ipis.
- * 1b1) set cpu mmu_state to TLBSTATE_OK
+ * cpu 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.
@@ -106,174 +85,62 @@ EXPORT_SYMBOL_GPL(leave_mm);
* runs in kernel space, the cpu could load tlb entries for user space
* pages.
*
- * The good news is that cpu mmu_state is local to each cpu, no
+ * The good news is that cpu_tlbstate is local to each cpu, no
* write/read ordering problems.
*/
/*
- * TLB flush IPI:
- *
+ * TLB flush funcation:
* 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.
- */
-
-/*
- * 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)
+static void flush_tlb_func(void *info)
{
- unsigned int cpu;
- unsigned 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 = &flush_state[sender];
-
- if (!cpumask_test_cpu(cpu, to_cpumask(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 == this_cpu_read(cpu_tlbstate.active_mm)) {
- if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
- if (f->flush_va == TLB_FLUSH_ALL)
- local_flush_tlb();
- else
- __flush_tlb_one(f->flush_va);
- } else
- leave_mm(cpu);
- }
-out:
- ack_APIC_irq();
- smp_mb__before_clear_bit();
- cpumask_clear_cpu(cpu, to_cpumask(f->flush_cpumask));
- smp_mb__after_clear_bit();
- inc_irq_stat(irq_tlb_count);
-}
+ struct flush_tlb_info *f = info;
-static void flush_tlb_others_ipi(const struct cpumask *cpumask,
- struct mm_struct *mm, unsigned long va)
-{
- unsigned int sender;
- union smp_flush_state *f;
-
- /* Caller has disabled preemption */
- sender = this_cpu_read(tlb_vector_offset);
- f = &flush_state[sender];
-
- if (nr_cpu_ids > NUM_INVALIDATE_TLB_VECTORS)
- raw_spin_lock(&f->tlbstate_lock);
-
- f->flush_mm = mm;
- f->flush_va = va;
- if (cpumask_andnot(to_cpumask(f->flush_cpumask), cpumask, cpumask_of(smp_processor_id()))) {
- /*
- * We have to send the IPI only to
- * CPUs affected.
- */
- apic->send_IPI_mask(to_cpumask(f->flush_cpumask),
- INVALIDATE_TLB_VECTOR_START + sender);
-
- while (!cpumask_empty(to_cpumask(f->flush_cpumask)))
- cpu_relax();
- }
+ if (f->flush_mm != this_cpu_read(cpu_tlbstate.active_mm))
+ return;
+
+ if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
+ if (f->flush_end == TLB_FLUSH_ALL || !cpu_has_invlpg)
+ local_flush_tlb();
+ else if (!f->flush_end)
+ __flush_tlb_single(f->flush_start);
+ else {
+ unsigned long addr;
+ addr = f->flush_start;
+ while (addr < f->flush_end) {
+ __flush_tlb_single(addr);
+ addr += PAGE_SIZE;
+ }
+ }
+ } else
+ leave_mm(smp_processor_id());
- f->flush_mm = NULL;
- f->flush_va = 0;
- if (nr_cpu_ids > NUM_INVALIDATE_TLB_VECTORS)
- raw_spin_unlock(&f->tlbstate_lock);
}
void native_flush_tlb_others(const struct cpumask *cpumask,
- struct mm_struct *mm, unsigned long va)
+ struct mm_struct *mm, unsigned long start,
+ unsigned long end)
{
+ struct flush_tlb_info info;
+ info.flush_mm = mm;
+ info.flush_start = start;
+ info.flush_end = end;
+
if (is_uv_system()) {
unsigned int cpu;
cpu = smp_processor_id();
- cpumask = uv_flush_tlb_others(cpumask, mm, va, cpu);
+ cpumask = uv_flush_tlb_others(cpumask, mm, start, end, cpu);
if (cpumask)
- flush_tlb_others_ipi(cpumask, mm, va);
+ smp_call_function_many(cpumask, flush_tlb_func,
+ &info, 1);
return;
}
- flush_tlb_others_ipi(cpumask, mm, va);
+ smp_call_function_many(cpumask, flush_tlb_func, &info, 1);
}
-static void __cpuinit calculate_tlb_offset(void)
-{
- int cpu, node, nr_node_vecs, idx = 0;
- /*
- * we are changing tlb_vector_offset for each CPU in runtime, but this
- * will not cause inconsistency, as the write is atomic under X86. we
- * might see more lock contentions in a short time, but after all CPU's
- * tlb_vector_offset are changed, everything should go normal
- *
- * Note: if NUM_INVALIDATE_TLB_VECTORS % nr_online_nodes !=0, we might
- * waste some vectors.
- **/
- if (nr_online_nodes > NUM_INVALIDATE_TLB_VECTORS)
- nr_node_vecs = 1;
- else
- nr_node_vecs = NUM_INVALIDATE_TLB_VECTORS/nr_online_nodes;
-
- for_each_online_node(node) {
- int node_offset = (idx % NUM_INVALIDATE_TLB_VECTORS) *
- nr_node_vecs;
- int cpu_offset = 0;
- for_each_cpu(cpu, cpumask_of_node(node)) {
- per_cpu(tlb_vector_offset, cpu) = node_offset +
- cpu_offset;
- cpu_offset++;
- cpu_offset = cpu_offset % nr_node_vecs;
- }
- idx++;
- }
-}
-
-static int __cpuinit tlb_cpuhp_notify(struct notifier_block *n,
- unsigned long action, void *hcpu)
-{
- switch (action & 0xf) {
- case CPU_ONLINE:
- case CPU_DEAD:
- calculate_tlb_offset();
- }
- return NOTIFY_OK;
-}
-
-static int __cpuinit init_smp_flush(void)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(flush_state); i++)
- raw_spin_lock_init(&flush_state[i].tlbstate_lock);
-
- calculate_tlb_offset();
- hotcpu_notifier(tlb_cpuhp_notify, 0);
- return 0;
-}
-core_initcall(init_smp_flush);
-
void flush_tlb_current_task(void)
{
struct mm_struct *mm = current->mm;
@@ -282,27 +149,91 @@ void flush_tlb_current_task(void)
local_flush_tlb();
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, TLB_FLUSH_ALL);
+ flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
preempt_enable();
}
-void flush_tlb_mm(struct mm_struct *mm)
+/*
+ * It can find out the THP large page, or
+ * HUGETLB page in tlb_flush when THP disabled
+ */
+static inline unsigned long has_large_page(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ unsigned long addr = ALIGN(start, HPAGE_SIZE);
+ for (; addr < end; addr += HPAGE_SIZE) {
+ pgd = pgd_offset(mm, addr);
+ if (likely(!pgd_none(*pgd))) {
+ pud = pud_offset(pgd, addr);
+ if (likely(!pud_none(*pud))) {
+ pmd = pmd_offset(pud, addr);
+ if (likely(!pmd_none(*pmd)))
+ if (pmd_large(*pmd))
+ return addr;
+ }
+ }
+ }
+ return 0;
+}
+
+void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
+ unsigned long end, unsigned long vmflag)
{
+ unsigned long addr;
+ unsigned act_entries, tlb_entries = 0;
+
preempt_disable();
+ if (current->active_mm != mm)
+ goto flush_all;
- if (current->active_mm == mm) {
- if (current->mm)
+ if (!current->mm) {
+ leave_mm(smp_processor_id());
+ goto flush_all;
+ }
+
+ if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1
+ || vmflag == VM_HUGETLB) {
+ local_flush_tlb();
+ goto flush_all;
+ }
+
+ /* In modern CPU, last level tlb used for both data/ins */
+ if (vmflag & VM_EXEC)
+ tlb_entries = tlb_lli_4k[ENTRIES];
+ else
+ tlb_entries = tlb_lld_4k[ENTRIES];
+ /* Assume all of TLB entries was occupied by this task */
+ act_entries = mm->total_vm > tlb_entries ? tlb_entries : mm->total_vm;
+
+ /* tlb_flushall_shift is on balance point, details in commit log */
+ if ((end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift)
+ local_flush_tlb();
+ else {
+ if (has_large_page(mm, start, end)) {
local_flush_tlb();
- else
- leave_mm(smp_processor_id());
+ goto flush_all;
+ }
+ /* flush range by one by one 'invlpg' */
+ for (addr = start; addr < end; addr += PAGE_SIZE)
+ __flush_tlb_single(addr);
+
+ if (cpumask_any_but(mm_cpumask(mm),
+ smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(mm_cpumask(mm), mm, start, end);
+ preempt_enable();
+ return;
}
- if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, TLB_FLUSH_ALL);
+flush_all:
+ if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long start)
{
struct mm_struct *mm = vma->vm_mm;
@@ -310,13 +241,13 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
if (current->active_mm == mm) {
if (current->mm)
- __flush_tlb_one(va);
+ __flush_tlb_one(start);
else
leave_mm(smp_processor_id());
}
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, va);
+ flush_tlb_others(mm_cpumask(mm), mm, start, 0UL);
preempt_enable();
}
@@ -332,3 +263,83 @@ void flush_tlb_all(void)
{
on_each_cpu(do_flush_tlb_all, NULL, 1);
}
+
+static void do_kernel_range_flush(void *info)
+{
+ struct flush_tlb_info *f = info;
+ unsigned long addr;
+
+ /* flush range by one by one 'invlpg' */
+ for (addr = f->flush_start; addr < f->flush_end; addr += PAGE_SIZE)
+ __flush_tlb_single(addr);
+}
+
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+ unsigned act_entries;
+ struct flush_tlb_info info;
+
+ /* In modern CPU, last level tlb used for both data/ins */
+ act_entries = tlb_lld_4k[ENTRIES];
+
+ /* Balance as user space task's flush, a bit conservative */
+ if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1 ||
+ (end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift)
+
+ on_each_cpu(do_flush_tlb_all, NULL, 1);
+ else {
+ info.flush_start = start;
+ info.flush_end = end;
+ on_each_cpu(do_kernel_range_flush, &info, 1);
+ }
+}
+
+#ifdef CONFIG_DEBUG_TLBFLUSH
+static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[32];
+ unsigned int len;
+
+ len = sprintf(buf, "%hd\n", tlb_flushall_shift);
+ return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t tlbflush_write_file(struct file *file,
+ const char __user *user_buf, size_t count, loff_t *ppos)
+{
+ char buf[32];
+ ssize_t len;
+ s8 shift;
+
+ len = min(count, sizeof(buf) - 1);
+ if (copy_from_user(buf, user_buf, len))
+ return -EFAULT;
+
+ buf[len] = '\0';
+ if (kstrtos8(buf, 0, &shift))
+ return -EINVAL;
+
+ if (shift > 64)
+ return -EINVAL;
+
+ tlb_flushall_shift = shift;
+ return count;
+}
+
+static const struct file_operations fops_tlbflush = {
+ .read = tlbflush_read_file,
+ .write = tlbflush_write_file,
+ .llseek = default_llseek,
+};
+
+static int __cpuinit create_tlb_flushall_shift(void)
+{
+ if (cpu_has_invlpg) {
+ debugfs_create_file("tlb_flushall_shift", S_IRUSR | S_IWUSR,
+ arch_debugfs_dir, NULL, &fops_tlbflush);
+ }
+ return 0;
+}
+late_initcall(create_tlb_flushall_shift);
+#endif