5 files changed, 13 insertions, 121 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index a4ea02351f4d..43d61daea966 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -72,7 +72,6 @@ extern u16 __read_mostly tlb_lld_4k[NR_INFO];
 extern u16 __read_mostly tlb_lld_2m[NR_INFO];
 extern u16 __read_mostly tlb_lld_4m[NR_INFO];
 extern u16 __read_mostly tlb_lld_1g[NR_INFO];
-extern s8  __read_mostly tlb_flushall_shift;
 
 /*
  *  CPU type and hardware bug flags. Kept separately for each CPU.
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ce8b8ff0e0ef..a1a53d094987 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -741,11 +741,6 @@ static unsigned int amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 }
 #endif
 
-static void cpu_set_tlb_flushall_shift(struct cpuinfo_x86 *c)
-{
-        tlb_flushall_shift = 6;
-}
-
 static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
 {
         u32 ebx, eax, ecx, edx;
@@ -793,8 +788,6 @@ static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
                 tlb_lli_2m[ENTRIES] = eax & mask;
 
         tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
-
-        cpu_set_tlb_flushall_shift(c);
 }
 
 static const struct cpu_dev amd_cpu_dev = {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2cbbf88d8f2c..2c1782085121 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -480,26 +480,17 @@ u16 __read_mostly tlb_lld_2m[NR_INFO];
 u16 __read_mostly tlb_lld_4m[NR_INFO];
 u16 __read_mostly tlb_lld_1g[NR_INFO];
 
-/*
- * tlb_flushall_shift shows the balance point in replacing cr3 write
- * with multiple 'invlpg'. It will do this replacement when
- *   flush_tlb_lines <= active_lines/2^tlb_flushall_shift.
- * If tlb_flushall_shift is -1, means the replacement will be disabled.
- */
-s8  __read_mostly tlb_flushall_shift = -1;
-
 void cpu_detect_tlb(struct cpuinfo_x86 *c)
 {
         if (this_cpu->c_detect_tlb)
                 this_cpu->c_detect_tlb(c);
 
         printk(KERN_INFO "Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n"
-                "Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n"
-                "tlb_flushall_shift: %d\n",
+                "Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
                 tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
                 tlb_lli_4m[ENTRIES], tlb_lld_4k[ENTRIES],
                 tlb_lld_2m[ENTRIES], tlb_lld_4m[ENTRIES],
-                tlb_lld_1g[ENTRIES], tlb_flushall_shift);
+                tlb_lld_1g[ENTRIES]);
 }
 
 void detect_ht(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index a80029035bf2..cd61755de49b 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -634,31 +634,6 @@ static void intel_tlb_lookup(const unsigned char desc)
         }
 }
 
-static void intel_tlb_flushall_shift_set(struct cpuinfo_x86 *c)
-{
-        switch ((c->x86 << 8) + c->x86_model) {
-        case 0x60f: /* original 65 nm celeron/pentium/core2/xeon, "Merom"/"Conroe" */
-        case 0x616: /* single-core 65 nm celeron/core2solo "Merom-L"/"Conroe-L" */
-        case 0x617: /* current 45 nm celeron/core2/xeon "Penryn"/"Wolfdale" */
-        case 0x61d: /* six-core 45 nm xeon "Dunnington" */
-                tlb_flushall_shift = -1;
-                break;
-        case 0x63a: /* Ivybridge */
-                tlb_flushall_shift = 2;
-                break;
-        case 0x61a: /* 45 nm nehalem, "Bloomfield" */
-        case 0x61e: /* 45 nm nehalem, "Lynnfield" */
-        case 0x625: /* 32 nm nehalem, "Clarkdale" */
-        case 0x62c: /* 32 nm nehalem, "Gulftown" */
-        case 0x62e: /* 45 nm nehalem-ex, "Beckton" */
-        case 0x62f: /* 32 nm Xeon E7 */
-        case 0x62a: /* SandyBridge */
-        case 0x62d: /* SandyBridge, "Romely-EP" */
-        default:
-                tlb_flushall_shift = 6;
-        }
-}
-
 static void intel_detect_tlb(struct cpuinfo_x86 *c)
 {
         int i, j, n;
@@ -683,7 +658,6 @@ static void intel_detect_tlb(struct cpuinfo_x86 *c)
                 for (j = 1 ; j < 16 ; j++)
                         intel_tlb_lookup(desc[j]);
         }
-        intel_tlb_flushall_shift_set(c);
 }
 
 static const struct cpu_dev intel_cpu_dev = {
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 378fbef279d2..dff6ddebc45f 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -158,13 +158,14 @@ void flush_tlb_current_task(void)
         preempt_enable();
 }
 
+/* in units of pages */
+unsigned long tlb_single_page_flush_ceiling = 1;
+
 void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
                                 unsigned long end, unsigned long vmflag)
 {
-        bool need_flush_others_all = true;
+        int need_flush_others_all = 1;
         unsigned long addr;
-        unsigned act_entries, tlb_entries = 0;
-        unsigned long nr_base_pages;
 
         preempt_disable();
         if (current->active_mm != mm)
@@ -175,29 +176,16 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
                 goto out;
         }
 
-        if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1
-                                        || vmflag & VM_HUGETLB) {
+        if (end == TLB_FLUSH_ALL || vmflag & VM_HUGETLB) {
                 local_flush_tlb();
                 goto out;
         }
 
-        /* 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 = tlb_entries >> tlb_flushall_shift;
-        act_entries = mm->total_vm > act_entries ? act_entries : mm->total_vm;
-        nr_base_pages = (end - start) >> PAGE_SHIFT;
-
-        /* tlb_flushall_shift is on balance point, details in commit log */
-        if (nr_base_pages > act_entries) {
+        if ((end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
                 count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
                 local_flush_tlb();
         } else {
-                need_flush_others_all = false;
+                need_flush_others_all = 0;
                 /* flush range by one by one 'invlpg' */
                 for (addr = start; addr < end;  addr += PAGE_SIZE) {
                         count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
@@ -259,68 +247,15 @@ static void do_kernel_range_flush(void *info)
 
 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)
-
+        if (end == TLB_FLUSH_ALL ||
+            (end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
                 on_each_cpu(do_flush_tlb_all, NULL, 1);
-        else {
+        } else {
+                struct flush_tlb_info info;
                 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 < -1 || shift >= BITS_PER_LONG)
-                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 __init create_tlb_flushall_shift(void)
-{
-        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