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