Merge branch 'linus' into irq/genirq

22 files changed, 256 insertions, 151 deletions

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index ca5ffb2856b6..edc90f23e708 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -37,8 +37,6 @@ extern unsigned long asmlinkage efi_call_phys(void *, ...);
 
 #else /* !CONFIG_X86_32 */
 
-#define MAX_EFI_IO_PAGES        100
-
 extern u64 efi_call0(void *fp);
 extern u64 efi_call1(void *fp, u64 arg1);
 extern u64 efi_call2(void *fp, u64 arg1, u64 arg2);
diff --git a/arch/x86/include/asm/fixmap_64.h b/arch/x86/include/asm/fixmap_64.h
index 00a30ab9b1a5..8be740977db8 100644
--- a/arch/x86/include/asm/fixmap_64.h
+++ b/arch/x86/include/asm/fixmap_64.h
@@ -16,7 +16,6 @@
 #include <asm/apicdef.h>
 #include <asm/page.h>
 #include <asm/vsyscall.h>
-#include <asm/efi.h>
 
 /*
  * Here we define all the compile-time 'special' virtual
@@ -43,9 +42,6 @@ enum fixed_addresses {
         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
         FIX_IO_APIC_BASE_0,
         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
-        FIX_EFI_IO_MAP_LAST_PAGE,
-        FIX_EFI_IO_MAP_FIRST_PAGE = FIX_EFI_IO_MAP_LAST_PAGE
-                                  + MAX_EFI_IO_PAGES - 1,
 #ifdef CONFIG_PARAVIRT
         FIX_PARAVIRT_BOOTMAP,
 #endif
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 48f0004db8c9..71c9e5183982 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -172,7 +172,13 @@ static inline void __save_init_fpu(struct task_struct *tsk)
 
 #else  /* CONFIG_X86_32 */
 
-extern void finit(void);
+#ifdef CONFIG_MATH_EMULATION
+extern void finit_task(struct task_struct *tsk);
+#else
+static inline void finit_task(struct task_struct *tsk)
+{
+}
+#endif
 
 static inline void tolerant_fwait(void)
 {
diff --git a/arch/x86/include/asm/seccomp_32.h b/arch/x86/include/asm/seccomp_32.h
index a6ad87b352c4..b811d6f5780c 100644
--- a/arch/x86/include/asm/seccomp_32.h
+++ b/arch/x86/include/asm/seccomp_32.h
@@ -1,12 +1,6 @@
 #ifndef _ASM_X86_SECCOMP_32_H
 #define _ASM_X86_SECCOMP_32_H
 
-#include <linux/thread_info.h>
-
-#ifdef TIF_32BIT
-#error "unexpected TIF_32BIT on i386"
-#endif
-
 #include <linux/unistd.h>
 
 #define __NR_seccomp_read __NR_read
diff --git a/arch/x86/include/asm/seccomp_64.h b/arch/x86/include/asm/seccomp_64.h
index 4171bb794e9e..84ec1bd161a5 100644
--- a/arch/x86/include/asm/seccomp_64.h
+++ b/arch/x86/include/asm/seccomp_64.h
@@ -1,14 +1,6 @@
 #ifndef _ASM_X86_SECCOMP_64_H
 #define _ASM_X86_SECCOMP_64_H
 
-#include <linux/thread_info.h>
-
-#ifdef TIF_32BIT
-#error "unexpected TIF_32BIT on x86_64"
-#else
-#define TIF_32BIT TIF_IA32
-#endif
-
 #include <linux/unistd.h>
 #include <asm/ia32_unistd.h>
 
diff --git a/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c b/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
index b585e04cbc9e..3178c3acd97e 100644
--- a/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
+++ b/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
@@ -277,7 +277,6 @@ static struct cpufreq_driver p4clockmod_driver = {
         .name           = "p4-clockmod",
         .owner          = THIS_MODULE,
         .attr           = p4clockmod_attr,
-        .hide_interface = 1,
 };
 
 
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 169a120587be..87b67e3a765a 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -729,7 +729,7 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task,
 
         spin_unlock_irqrestore(&ds_lock, irq);
 
-        ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
+        ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
         ds_resume_pebs(tracer);
 
         return tracer;
@@ -1029,5 +1029,4 @@ void ds_copy_thread(struct task_struct *tsk, struct task_struct *father)
 
 void ds_exit_thread(struct task_struct *tsk)
 {
-        WARN_ON(tsk->thread.ds_ctx);
 }
diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c
index 1119d247fe11..eb1ef3b67dd5 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -467,7 +467,7 @@ void __init efi_enter_virtual_mode(void)
         efi_memory_desc_t *md;
         efi_status_t status;
         unsigned long size;
-        u64 end, systab, addr, npages;
+        u64 end, systab, addr, npages, end_pfn;
         void *p, *va;
 
         efi.systab = NULL;
@@ -479,7 +479,10 @@ void __init efi_enter_virtual_mode(void)
                 size = md->num_pages << EFI_PAGE_SHIFT;
                 end = md->phys_addr + size;
 
-                if (PFN_UP(end) <= max_low_pfn_mapped)
+                end_pfn = PFN_UP(end);
+                if (end_pfn <= max_low_pfn_mapped
+                    || (end_pfn > (1UL << (32 - PAGE_SHIFT))
+                        && end_pfn <= max_pfn_mapped))
                         va = __va(md->phys_addr);
                 else
                         va = efi_ioremap(md->phys_addr, size);
diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
index 652c5287215f..cb783b92c50c 100644
--- a/arch/x86/kernel/efi_64.c
+++ b/arch/x86/kernel/efi_64.c
@@ -99,24 +99,11 @@ void __init efi_call_phys_epilog(void)
 
 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size)
 {
-        static unsigned pages_mapped __initdata;
-        unsigned i, pages;
-        unsigned long offset;
+        unsigned long last_map_pfn;
 
-        pages = PFN_UP(phys_addr + size) - PFN_DOWN(phys_addr);
-        offset = phys_addr & ~PAGE_MASK;
-        phys_addr &= PAGE_MASK;
-
-        if (pages_mapped + pages > MAX_EFI_IO_PAGES)
+        last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
+        if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size)
                 return NULL;
 
-        for (i = 0; i < pages; i++) {
-                __set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
-                             phys_addr, PAGE_KERNEL);
-                phys_addr += PAGE_SIZE;
-                pages_mapped++;
-        }
-
-        return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
-                                             (pages_mapped - pages)) + offset;
+        return (void __iomem *)__va(phys_addr);
 }
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index b0f61f0dcd0a..f2f8540a7f3d 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -136,7 +136,7 @@ int init_fpu(struct task_struct *tsk)
 #ifdef CONFIG_X86_32
         if (!HAVE_HWFP) {
                 memset(tsk->thread.xstate, 0, xstate_size);
-                finit();
+                finit_task(tsk);
                 set_stopped_child_used_math(tsk);
                 return 0;
         }
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 5a4c23d89892..06ca07f6ad86 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -1388,7 +1388,7 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
 #ifdef CONFIG_X86_32
 # define IS_IA32        1
 #elif defined CONFIG_IA32_EMULATION
-# define IS_IA32        test_thread_flag(TIF_IA32)
+# define IS_IA32        is_compat_task()
 #else
 # define IS_IA32        0
 #endif
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 2b46eb41643b..4526b3a75ed2 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -217,6 +217,14 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
                 },
         },
+        {       /* Handle problems with rebooting on Dell XPS710 */
+                .callback = set_bios_reboot,
+                .ident = "Dell XPS710",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
+                },
+        },
         { }
 };
 
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c461f6d69074..6a8811a69324 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -770,6 +770,9 @@ void __init setup_arch(char **cmdline_p)
 
         finish_e820_parsing();
 
+        if (efi_enabled)
+                efi_init();
+
         dmi_scan_machine();
 
         dmi_check_system(bad_bios_dmi_table);
@@ -789,8 +792,6 @@ void __init setup_arch(char **cmdline_p)
         insert_resource(&iomem_resource, &data_resource);
         insert_resource(&iomem_resource, &bss_resource);
 
-        if (efi_enabled)
-                efi_init();
 
 #ifdef CONFIG_X86_32
         if (ppro_with_ram_bug()) {
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 92f1c6f3e19d..960a8d9c049c 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -343,6 +343,11 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx,
                  * flush_tlb_user() for both user and kernel mappings unless
                  * the Page Global Enable (PGE) feature bit is set. */
                 *dx |= 0x00002000;
+                /* We also lie, and say we're family id 5.  6 or greater
+                 * leads to a rdmsr in early_init_intel which we can't handle.
+                 * Family ID is returned as bits 8-12 in ax. */
+                *ax &= 0xFFFFF0FF;
+                *ax |= 0x00000500;
                 break;
         case 0x80000000:
                 /* Futureproof this a little: if they ask how much extended
@@ -589,19 +594,21 @@ static void __init lguest_init_IRQ(void)
                 /* Some systems map "vectors" to interrupts weirdly.  Lguest has
                  * a straightforward 1 to 1 mapping, so force that here. */
                 __get_cpu_var(vector_irq)[vector] = i;
-                if (vector != SYSCALL_VECTOR) {
-                        set_intr_gate(vector,
-                                      interrupt[vector-FIRST_EXTERNAL_VECTOR]);
-                        set_irq_chip_and_handler_name(i, &lguest_irq_controller,
-                                                      handle_level_irq,
-                                                      "level");
-                }
+                if (vector != SYSCALL_VECTOR)
+                        set_intr_gate(vector, interrupt[i]);
         }
         /* This call is required to set up for 4k stacks, where we have
          * separate stacks for hard and soft interrupts. */
         irq_ctx_init(smp_processor_id());
 }
 
+void lguest_setup_irq(unsigned int irq)
+{
+        irq_to_desc_alloc_cpu(irq, 0);
+        set_irq_chip_and_handler_name(irq, &lguest_irq_controller,
+                                      handle_level_irq, "level");
+}
+
 /*
  * Time.
  *
diff --git a/arch/x86/math-emu/fpu_aux.c b/arch/x86/math-emu/fpu_aux.c
index 491e737ce547..aa0987088774 100644
--- a/arch/x86/math-emu/fpu_aux.c
+++ b/arch/x86/math-emu/fpu_aux.c
@@ -30,20 +30,29 @@ static void fclex(void)
 }
 
 /* Needs to be externally visible */
-void finit(void)
+void finit_task(struct task_struct *tsk)
 {
-        control_word = 0x037f;
-        partial_status = 0;
-        top = 0;                /* We don't keep top in the status word internally. */
-        fpu_tag_word = 0xffff;
+        struct i387_soft_struct *soft = &tsk->thread.xstate->soft;
+        struct address *oaddr, *iaddr;
+        soft->cwd = 0x037f;
+        soft->swd = 0;
+        soft->ftop = 0; /* We don't keep top in the status word internally. */
+        soft->twd = 0xffff;
         /* The behaviour is different from that detailed in
            Section 15.1.6 of the Intel manual */
-        operand_address.offset = 0;
-        operand_address.selector = 0;
-        instruction_address.offset = 0;
-        instruction_address.selector = 0;
-        instruction_address.opcode = 0;
-        no_ip_update = 1;
+        oaddr = (struct address *)&soft->foo;
+        oaddr->offset = 0;
+        oaddr->selector = 0;
+        iaddr = (struct address *)&soft->fip;
+        iaddr->offset = 0;
+        iaddr->selector = 0;
+        iaddr->opcode = 0;
+        soft->no_update = 1;
+}
+
+void finit(void)
+{
+        finit_task(current);
 }
 
 /*
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e6d36b490250..b1352250096e 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -714,6 +714,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
         pos = start_pfn << PAGE_SHIFT;
         end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
                         << (PMD_SHIFT - PAGE_SHIFT);
+        if (end_pfn > (end >> PAGE_SHIFT))
+                end_pfn = end >> PAGE_SHIFT;
         if (start_pfn < end_pfn) {
                 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
                 pos = end_pfn << PAGE_SHIFT;
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 6c2b1af16926..04102d42ff42 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -20,23 +20,16 @@
 #include <asm/pat.h>
 #include <linux/module.h>
 
-#ifdef CONFIG_X86_PAE
-int
-is_io_mapping_possible(resource_size_t base, unsigned long size)
-{
-        return 1;
-}
-#else
-int
-is_io_mapping_possible(resource_size_t base, unsigned long size)
+int is_io_mapping_possible(resource_size_t base, unsigned long size)
 {
+#ifndef CONFIG_X86_PAE
         /* There is no way to map greater than 1 << 32 address without PAE */
         if (base + size > 0x100000000ULL)
                 return 0;
-
+#endif
         return 1;
 }
-#endif
+EXPORT_SYMBOL_GPL(is_io_mapping_possible);
 
 /* Map 'pfn' using fixed map 'type' and protections 'prot'
  */
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 93d82038af4b..6a518dd08a36 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -32,11 +32,14 @@ struct kmmio_fault_page {
         struct list_head list;
         struct kmmio_fault_page *release_next;
         unsigned long page; /* location of the fault page */
+        bool old_presence; /* page presence prior to arming */
+        bool armed;
 
         /*
          * Number of times this page has been registered as a part
          * of a probe. If zero, page is disarmed and this may be freed.
-         * Used only by writers (RCU).
+         * Used only by writers (RCU) and post_kmmio_handler().
+         * Protected by kmmio_lock, when linked into kmmio_page_table.
          */
         int count;
 };
@@ -105,57 +108,85 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page)
         return NULL;
 }
 
-static void set_page_present(unsigned long addr, bool present,
-                                                        unsigned int *pglevel)
+static void set_pmd_presence(pmd_t *pmd, bool present, bool *old)
+{
+        pmdval_t v = pmd_val(*pmd);
+        *old = !!(v & _PAGE_PRESENT);
+        v &= ~_PAGE_PRESENT;
+        if (present)
+                v |= _PAGE_PRESENT;
+        set_pmd(pmd, __pmd(v));
+}
+
+static void set_pte_presence(pte_t *pte, bool present, bool *old)
+{
+        pteval_t v = pte_val(*pte);
+        *old = !!(v & _PAGE_PRESENT);
+        v &= ~_PAGE_PRESENT;
+        if (present)
+                v |= _PAGE_PRESENT;
+        set_pte_atomic(pte, __pte(v));
+}
+
+static int set_page_presence(unsigned long addr, bool present, bool *old)
 {
-        pteval_t pteval;
-        pmdval_t pmdval;
         unsigned int level;
-        pmd_t *pmd;
         pte_t *pte = lookup_address(addr, &level);
 
         if (!pte) {
                 pr_err("kmmio: no pte for page 0x%08lx\n", addr);
-                return;
+                return -1;
         }
 
-        if (pglevel)
-                *pglevel = level;
-
         switch (level) {
         case PG_LEVEL_2M:
-                pmd = (pmd_t *)pte;
-                pmdval = pmd_val(*pmd) & ~_PAGE_PRESENT;
-                if (present)
-                        pmdval |= _PAGE_PRESENT;
-                set_pmd(pmd, __pmd(pmdval));
+                set_pmd_presence((pmd_t *)pte, present, old);
                 break;
-
         case PG_LEVEL_4K:
-                pteval = pte_val(*pte) & ~_PAGE_PRESENT;
-                if (present)
-                        pteval |= _PAGE_PRESENT;
-                set_pte_atomic(pte, __pte(pteval));
+                set_pte_presence(pte, present, old);
                 break;
-
         default:
                 pr_err("kmmio: unexpected page level 0x%x.\n", level);
-                return;
+                return -1;
         }
 
         __flush_tlb_one(addr);
+        return 0;
 }
 
-/** Mark the given page as not present. Access to it will trigger a fault. */
-static void arm_kmmio_fault_page(unsigned long page, unsigned int *pglevel)
+/*
+ * Mark the given page as not present. Access to it will trigger a fault.
+ *
+ * Struct kmmio_fault_page is protected by RCU and kmmio_lock, but the
+ * protection is ignored here. RCU read lock is assumed held, so the struct
+ * will not disappear unexpectedly. Furthermore, the caller must guarantee,
+ * that double arming the same virtual address (page) cannot occur.
+ *
+ * Double disarming on the other hand is allowed, and may occur when a fault
+ * and mmiotrace shutdown happen simultaneously.
+ */
+static int arm_kmmio_fault_page(struct kmmio_fault_page *f)
 {
-        set_page_present(page & PAGE_MASK, false, pglevel);
+        int ret;
+        WARN_ONCE(f->armed, KERN_ERR "kmmio page already armed.\n");
+        if (f->armed) {
+                pr_warning("kmmio double-arm: page 0x%08lx, ref %d, old %d\n",
+                                        f->page, f->count, f->old_presence);
+        }
+        ret = set_page_presence(f->page, false, &f->old_presence);
+        WARN_ONCE(ret < 0, KERN_ERR "kmmio arming 0x%08lx failed.\n", f->page);
+        f->armed = true;
+        return ret;
 }
 
-/** Mark the given page as present. */
-static void disarm_kmmio_fault_page(unsigned long page, unsigned int *pglevel)
+/** Restore the given page to saved presence state. */
+static void disarm_kmmio_fault_page(struct kmmio_fault_page *f)
 {
-        set_page_present(page & PAGE_MASK, true, pglevel);
+        bool tmp;
+        int ret = set_page_presence(f->page, f->old_presence, &tmp);
+        WARN_ONCE(ret < 0,
+                        KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page);
+        f->armed = false;
 }
 
 /*
@@ -202,28 +233,32 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
 
         ctx = &get_cpu_var(kmmio_ctx);
         if (ctx->active) {
-                disarm_kmmio_fault_page(faultpage->page, NULL);
                 if (addr == ctx->addr) {
                         /*
-                         * On SMP we sometimes get recursive probe hits on the
-                         * same address. Context is already saved, fall out.
+                         * A second fault on the same page means some other
+                         * condition needs handling by do_page_fault(), the
+                         * page really not being present is the most common.
                          */
-                        pr_debug("kmmio: duplicate probe hit on CPU %d, for "
-                                                "address 0x%08lx.\n",
-                                                smp_processor_id(), addr);
-                        ret = 1;
-                        goto no_kmmio_ctx;
-                }
-                /*
-                 * Prevent overwriting already in-flight context.
-                 * This should not happen, let's hope disarming at least
-                 * prevents a panic.
-                 */
-                pr_emerg("kmmio: recursive probe hit on CPU %d, "
+                        pr_debug("kmmio: secondary hit for 0x%08lx CPU %d.\n",
+                                        addr, smp_processor_id());
+
+                        if (!faultpage->old_presence)
+                                pr_info("kmmio: unexpected secondary hit for "
+                                        "address 0x%08lx on CPU %d.\n", addr,
+                                        smp_processor_id());
+                } else {
+                        /*
+                         * Prevent overwriting already in-flight context.
+                         * This should not happen, let's hope disarming at
+                         * least prevents a panic.
+                         */
+                        pr_emerg("kmmio: recursive probe hit on CPU %d, "
                                         "for address 0x%08lx. Ignoring.\n",
                                         smp_processor_id(), addr);
-                pr_emerg("kmmio: previous hit was at 0x%08lx.\n",
-                                        ctx->addr);
+                        pr_emerg("kmmio: previous hit was at 0x%08lx.\n",
+                                                ctx->addr);
+                        disarm_kmmio_fault_page(faultpage);
+                }
                 goto no_kmmio_ctx;
         }
         ctx->active++;
@@ -244,7 +279,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
         regs->flags &= ~X86_EFLAGS_IF;
 
         /* Now we set present bit in PTE and single step. */
-        disarm_kmmio_fault_page(ctx->fpage->page, NULL);
+        disarm_kmmio_fault_page(ctx->fpage);
 
         /*
          * If another cpu accesses the same page while we are stepping,
@@ -275,7 +310,7 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs)
         struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx);
 
         if (!ctx->active) {
-                pr_debug("kmmio: spurious debug trap on CPU %d.\n",
+                pr_warning("kmmio: spurious debug trap on CPU %d.\n",
                                                         smp_processor_id());
                 goto out;
         }
@@ -283,7 +318,11 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs)
         if (ctx->probe && ctx->probe->post_handler)
                 ctx->probe->post_handler(ctx->probe, condition, regs);
 
-        arm_kmmio_fault_page(ctx->fpage->page, NULL);
+        /* Prevent racing against release_kmmio_fault_page(). */
+        spin_lock(&kmmio_lock);
+        if (ctx->fpage->count)
+                arm_kmmio_fault_page(ctx->fpage);
+        spin_unlock(&kmmio_lock);
 
         regs->flags &= ~X86_EFLAGS_TF;
         regs->flags |= ctx->saved_flags;
@@ -315,20 +354,24 @@ static int add_kmmio_fault_page(unsigned long page)
         f = get_kmmio_fault_page(page);
         if (f) {
                 if (!f->count)
-                        arm_kmmio_fault_page(f->page, NULL);
+                        arm_kmmio_fault_page(f);
                 f->count++;
                 return 0;
         }
 
-        f = kmalloc(sizeof(*f), GFP_ATOMIC);
+        f = kzalloc(sizeof(*f), GFP_ATOMIC);
         if (!f)
                 return -1;
 
         f->count = 1;
         f->page = page;
-        list_add_rcu(&f->list, kmmio_page_list(f->page));
 
-        arm_kmmio_fault_page(f->page, NULL);
+        if (arm_kmmio_fault_page(f)) {
+                kfree(f);
+                return -1;
+        }
+
+        list_add_rcu(&f->list, kmmio_page_list(f->page));
 
         return 0;
 }
@@ -347,7 +390,7 @@ static void release_kmmio_fault_page(unsigned long page,
         f->count--;
         BUG_ON(f->count < 0);
         if (!f->count) {
-                disarm_kmmio_fault_page(f->page, NULL);
+                disarm_kmmio_fault_page(f);
                 f->release_next = *release_list;
                 *release_list = f;
         }
@@ -408,23 +451,24 @@ static void rcu_free_kmmio_fault_pages(struct rcu_head *head)
 
 static void remove_kmmio_fault_pages(struct rcu_head *head)
 {
-        struct kmmio_delayed_release *dr = container_of(
-                                                head,
-                                                struct kmmio_delayed_release,
-                                                rcu);
+        struct kmmio_delayed_release *dr =
+                container_of(head, struct kmmio_delayed_release, rcu);
         struct kmmio_fault_page *p = dr->release_list;
         struct kmmio_fault_page **prevp = &dr->release_list;
         unsigned long flags;
+
         spin_lock_irqsave(&kmmio_lock, flags);
         while (p) {
-                if (!p->count)
+                if (!p->count) {
                         list_del_rcu(&p->list);
-                else
+                        prevp = &p->release_next;
+                } else {
                         *prevp = p->release_next;
-                prevp = &p->release_next;
+                }
                 p = p->release_next;
         }
         spin_unlock_irqrestore(&kmmio_lock, flags);
+
         /* This is the real RCU destroy call. */
         call_rcu(&dr->rcu, rcu_free_kmmio_fault_pages);
 }
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 7be47d1a97e4..7233bd7e357b 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -515,6 +515,17 @@ static int split_large_page(pte_t *kpte, unsigned long address)
          * primary protection behavior:
          */
         __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
+
+        /*
+         * Intel Atom errata AAH41 workaround.
+         *
+         * The real fix should be in hw or in a microcode update, but
+         * we also probabilistically try to reduce the window of having
+         * a large TLB mixed with 4K TLBs while instruction fetches are
+         * going on.
+         */
+        __flush_tlb_all();
+
         base = NULL;
 
 out_unlock:
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index aebbf67a79d0..e0ab173b6974 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -11,6 +11,7 @@
 #include <linux/bootmem.h>
 #include <linux/debugfs.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/gfp.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
@@ -868,6 +869,7 @@ pgprot_t pgprot_writecombine(pgprot_t prot)
         else
                 return pgprot_noncached(prot);
 }
+EXPORT_SYMBOL_GPL(pgprot_writecombine);
 
 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
 
diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
index ab50a8d7402c..427fd1b56df5 100644
--- a/arch/x86/mm/testmmiotrace.c
+++ b/arch/x86/mm/testmmiotrace.c
@@ -1,5 +1,5 @@
 /*
- * Written by Pekka Paalanen, 2008 <pq@iki.fi>
+ * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi>
  */
 #include <linux/module.h>
 #include <linux/io.h>
@@ -9,35 +9,74 @@
 
 static unsigned long mmio_address;
 module_param(mmio_address, ulong, 0);
-MODULE_PARM_DESC(mmio_address, "Start address of the mapping of 16 kB.");
+MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
+                                "(or 8 MB if read_far is non-zero).");
+
+static unsigned long read_far = 0x400100;
+module_param(read_far, ulong, 0);
+MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
+                                "(default: 0x400100).");
+
+static unsigned v16(unsigned i)
+{
+        return i * 12 + 7;
+}
+
+static unsigned v32(unsigned i)
+{
+        return i * 212371 + 13;
+}
 
 static void do_write_test(void __iomem *p)
 {
         unsigned int i;
+        pr_info(MODULE_NAME ": write test.\n");
         mmiotrace_printk("Write test.\n");
+
         for (i = 0; i < 256; i++)
                 iowrite8(i, p + i);
+
         for (i = 1024; i < (5 * 1024); i += 2)
-                iowrite16(i * 12 + 7, p + i);
+                iowrite16(v16(i), p + i);
+
         for (i = (5 * 1024); i < (16 * 1024); i += 4)
-                iowrite32(i * 212371 + 13, p + i);
+                iowrite32(v32(i), p + i);
 }
 
 static void do_read_test(void __iomem *p)
 {
         unsigned int i;
+        unsigned errs[3] = { 0 };
+        pr_info(MODULE_NAME ": read test.\n");
         mmiotrace_printk("Read test.\n");
+
         for (i = 0; i < 256; i++)
-                ioread8(p + i);
+                if (ioread8(p + i) != i)
+                        ++errs[0];
+
         for (i = 1024; i < (5 * 1024); i += 2)
-                ioread16(p + i);
+                if (ioread16(p + i) != v16(i))
+                        ++errs[1];
+
         for (i = (5 * 1024); i < (16 * 1024); i += 4)
-                ioread32(p + i);
+                if (ioread32(p + i) != v32(i))
+                        ++errs[2];
+
+        mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
+                                                errs[0], errs[1], errs[2]);
 }
 
-static void do_test(void)
+static void do_read_far_test(void __iomem *p)
 {
-        void __iomem *p = ioremap_nocache(mmio_address, 0x4000);
+        pr_info(MODULE_NAME ": read far test.\n");
+        mmiotrace_printk("Read far test.\n");
+
+        ioread32(p + read_far);
+}
+
+static void do_test(unsigned long size)
+{
+        void __iomem *p = ioremap_nocache(mmio_address, size);
         if (!p) {
                 pr_err(MODULE_NAME ": could not ioremap, aborting.\n");
                 return;
@@ -45,11 +84,15 @@ static void do_test(void)
         mmiotrace_printk("ioremap returned %p.\n", p);
         do_write_test(p);
         do_read_test(p);
+        if (read_far && read_far < size - 4)
+                do_read_far_test(p);
         iounmap(p);
 }
 
 static int __init init(void)
 {
+        unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
+
         if (mmio_address == 0) {
                 pr_err(MODULE_NAME ": you have to use the module argument "
                                                         "mmio_address.\n");
@@ -58,10 +101,11 @@ static int __init init(void)
                 return -ENXIO;
         }
 
-        pr_warning(MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx "
-                                        "in PCI address space, and writing "
-                                        "rubbish in there.\n", mmio_address);
-        do_test();
+        pr_warning(MODULE_NAME ": WARNING: mapping %lu kB @ 0x%08lx in PCI "
+                "address space, and writing 16 kB of rubbish in there.\n",
+                 size >> 10, mmio_address);
+        do_test(size);
+        pr_info(MODULE_NAME ": All done.\n");
         return 0;
 }
 
diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c
index e9f80c744cf3..10131fbdaada 100644
--- a/arch/x86/oprofile/op_model_ppro.c
+++ b/arch/x86/oprofile/op_model_ppro.c
@@ -78,8 +78,18 @@ static void ppro_setup_ctrs(struct op_msrs const * const msrs)
         if (cpu_has_arch_perfmon) {
                 union cpuid10_eax eax;
                 eax.full = cpuid_eax(0xa);
-                if (counter_width < eax.split.bit_width)
-                        counter_width = eax.split.bit_width;
+
+                /*
+                 * For Core2 (family 6, model 15), don't reset the
+                 * counter width:
+                 */
+                if (!(eax.split.version_id == 0 &&
+                        current_cpu_data.x86 == 6 &&
+                                current_cpu_data.x86_model == 15)) {
+
+                        if (counter_width < eax.split.bit_width)
+                                counter_width = eax.split.bit_width;
+                }
         }
 
         /* clear all counters */