11 files changed, 147 insertions, 115 deletions

diff --git a/arch/x86/boot/a20.c b/arch/x86/boot/a20.c
index 4063d630deff..fba8e9c6a504 100644
--- a/arch/x86/boot/a20.c
+++ b/arch/x86/boot/a20.c
@@ -2,6 +2,7 @@
  *
  *   Copyright (C) 1991, 1992 Linus Torvalds
  *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation
  *
  *   This file is part of the Linux kernel, and is made available under
  *   the terms of the GNU General Public License version 2.
@@ -15,16 +16,23 @@
 #include "boot.h"
 
 #define MAX_8042_LOOPS  100000
+#define MAX_8042_FF     32
 
 static int empty_8042(void)
 {
         u8 status;
         int loops = MAX_8042_LOOPS;
+        int ffs   = MAX_8042_FF;
 
         while (loops--) {
                 io_delay();
 
                 status = inb(0x64);
+                if (status == 0xff) {
+                        /* FF is a plausible, but very unlikely status */
+                        if (!--ffs)
+                                return -1; /* Assume no KBC present */
+                }
                 if (status & 1) {
                         /* Read and discard input data */
                         io_delay();
@@ -118,44 +126,43 @@ static void enable_a20_fast(void)
 
 int enable_a20(void)
 {
-#if defined(CONFIG_X86_ELAN)
-        /* Elan croaks if we try to touch the KBC */
-        enable_a20_fast();
-        while (!a20_test_long())
-                ;
-        return 0;
-#elif defined(CONFIG_X86_VOYAGER)
+#ifdef CONFIG_X86_VOYAGER
         /* On Voyager, a20_test() is unsafe? */
         enable_a20_kbc();
         return 0;
 #else
        int loops = A20_ENABLE_LOOPS;
-        while (loops--) {
-                /* First, check to see if A20 is already enabled
-                   (legacy free, etc.) */
-                if (a20_test_short())
-                        return 0;
-
-                /* Next, try the BIOS (INT 0x15, AX=0x2401) */
-                enable_a20_bios();
-                if (a20_test_short())
-                        return 0;
-
-                /* Try enabling A20 through the keyboard controller */
-                empty_8042();
-                if (a20_test_short())
-                        return 0; /* BIOS worked, but with delayed reaction */
-
-                enable_a20_kbc();
-                if (a20_test_long())
-                        return 0;
-
-                /* Finally, try enabling the "fast A20 gate" */
-                enable_a20_fast();
-                if (a20_test_long())
-                        return 0;
-        }
-
-        return -1;
+       int kbc_err;
+
+       while (loops--) {
+               /* First, check to see if A20 is already enabled
+                  (legacy free, etc.) */
+               if (a20_test_short())
+                       return 0;
+               
+               /* Next, try the BIOS (INT 0x15, AX=0x2401) */
+               enable_a20_bios();
+               if (a20_test_short())
+                       return 0;
+               
+               /* Try enabling A20 through the keyboard controller */
+               kbc_err = empty_8042();
+
+               if (a20_test_short())
+                       return 0; /* BIOS worked, but with delayed reaction */
+        
+               if (!kbc_err) {
+                       enable_a20_kbc();
+                       if (a20_test_long())
+                               return 0;
+               }
+               
+               /* Finally, try enabling the "fast A20 gate" */
+               enable_a20_fast();
+               if (a20_test_long())
+                       return 0;
+       }
+       
+       return -1;
 #endif
 }
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 40226999cbf8..05f2da7f387a 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -57,7 +57,6 @@ typedef struct { pgdval_t pgd; } pgd_t;
 typedef struct { pgprotval_t pgprot; } pgprot_t;
 
 extern int page_is_ram(unsigned long pagenr);
-extern int pagerange_is_ram(unsigned long start, unsigned long end);
 extern int devmem_is_allowed(unsigned long pagenr);
 extern void map_devmem(unsigned long pfn, unsigned long size,
                        pgprot_t vma_prot);
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 1c244b64573f..b788dfd20483 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -1431,14 +1431,7 @@ static inline void arch_leave_lazy_cpu_mode(void)
         PVOP_VCALL0(pv_cpu_ops.lazy_mode.leave);
 }
 
-static inline void arch_flush_lazy_cpu_mode(void)
-{
-        if (unlikely(paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU)) {
-                arch_leave_lazy_cpu_mode();
-                arch_enter_lazy_cpu_mode();
-        }
-}
-
+void arch_flush_lazy_cpu_mode(void);
 
 #define  __HAVE_ARCH_ENTER_LAZY_MMU_MODE
 static inline void arch_enter_lazy_mmu_mode(void)
@@ -1451,13 +1444,7 @@ static inline void arch_leave_lazy_mmu_mode(void)
         PVOP_VCALL0(pv_mmu_ops.lazy_mode.leave);
 }
 
-static inline void arch_flush_lazy_mmu_mode(void)
-{
-        if (unlikely(paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU)) {
-                arch_leave_lazy_mmu_mode();
-                arch_enter_lazy_mmu_mode();
-        }
-}
+void arch_flush_lazy_mmu_mode(void);
 
 static inline void __set_fixmap(unsigned /* enum fixed_addresses */ idx,
                                 unsigned long phys, pgprot_t flags)
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 388254f69a2a..a00545fe5cdd 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -269,6 +269,8 @@ static void hpet_set_mode(enum clock_event_mode mode,
                 now = hpet_readl(HPET_COUNTER);
                 cmp = now + (unsigned long) delta;
                 cfg = hpet_readl(HPET_Tn_CFG(timer));
+                /* Make sure we use edge triggered interrupts */
+                cfg &= ~HPET_TN_LEVEL;
                 cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
                        HPET_TN_SETVAL | HPET_TN_32BIT;
                 hpet_writel(cfg, HPET_Tn_CFG(timer));
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index cea11c8e3049..6dc4dca255e4 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -286,6 +286,32 @@ enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
         return __get_cpu_var(paravirt_lazy_mode);
 }
 
+void arch_flush_lazy_mmu_mode(void)
+{
+        preempt_disable();
+
+        if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
+                WARN_ON(preempt_count() == 1);
+                arch_leave_lazy_mmu_mode();
+                arch_enter_lazy_mmu_mode();
+        }
+
+        preempt_enable();
+}
+
+void arch_flush_lazy_cpu_mode(void)
+{
+        preempt_disable();
+
+        if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
+                WARN_ON(preempt_count() == 1);
+                arch_leave_lazy_cpu_mode();
+                arch_enter_lazy_cpu_mode();
+        }
+
+        preempt_enable();
+}
+
 struct pv_info pv_info = {
         .name = "bare hardware",
         .paravirt_enabled = 0,
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 7ec39ab37a2d..d2f7cd5b2c83 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -805,12 +805,16 @@ static void ptrace_bts_untrace(struct task_struct *child)
 
 static void ptrace_bts_detach(struct task_struct *child)
 {
-        if (unlikely(child->bts)) {
-                ds_release_bts(child->bts);
-                child->bts = NULL;
-
-                ptrace_bts_free_buffer(child);
-        }
+        /*
+         * Ptrace_detach() races with ptrace_untrace() in case
+         * the child dies and is reaped by another thread.
+         *
+         * We only do the memory accounting at this point and
+         * leave the buffer deallocation and the bts tracer
+         * release to ptrace_bts_untrace() which will be called
+         * later on with tasklist_lock held.
+         */
+        release_locked_buffer(child->bts_buffer, child->bts_size);
 }
 #else
 static inline void ptrace_bts_fork(struct task_struct *tsk) {}
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 1448bcb7f22f..433f7bd4648a 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -134,25 +134,6 @@ int page_is_ram(unsigned long pagenr)
         return 0;
 }
 
-int pagerange_is_ram(unsigned long start, unsigned long end)
-{
-        int ram_page = 0, not_rampage = 0;
-        unsigned long page_nr;
-
-        for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
-             ++page_nr) {
-                if (page_is_ram(page_nr))
-                        ram_page = 1;
-                else
-                        not_rampage = 1;
-
-                if (ram_page == not_rampage)
-                        return -1;
-        }
-
-        return ram_page;
-}
-
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 84ba74820ad6..8ca0d8566fc8 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -575,7 +575,6 @@ static int __change_page_attr(struct cpa_data *cpa, int primary)
                 address = cpa->vaddr[cpa->curpage];
         else
                 address = *cpa->vaddr;
-
 repeat:
         kpte = lookup_address(address, &level);
         if (!kpte)
@@ -812,6 +811,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 
         vm_unmap_aliases();
 
+        /*
+         * If we're called with lazy mmu updates enabled, the
+         * in-memory pte state may be stale.  Flush pending updates to
+         * bring them up to date.
+         */
+        arch_flush_lazy_mmu_mode();
+
         cpa.vaddr = addr;
         cpa.numpages = numpages;
         cpa.mask_set = mask_set;
@@ -854,6 +860,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
         } else
                 cpa_flush_all(cache);
 
+        /*
+         * If we've been called with lazy mmu updates enabled, then
+         * make sure that everything gets flushed out before we
+         * return.
+         */
+        arch_flush_lazy_mmu_mode();
+
 out:
         return ret;
 }
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 9127e31c7268..05f9aef6818a 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -220,6 +220,33 @@ chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type)
 static struct memtype *cached_entry;
 static u64 cached_start;
 
+static int pat_pagerange_is_ram(unsigned long start, unsigned long end)
+{
+        int ram_page = 0, not_rampage = 0;
+        unsigned long page_nr;
+
+        for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+             ++page_nr) {
+                /*
+                 * For legacy reasons, physical address range in the legacy ISA
+                 * region is tracked as non-RAM. This will allow users of
+                 * /dev/mem to map portions of legacy ISA region, even when
+                 * some of those portions are listed(or not even listed) with
+                 * different e820 types(RAM/reserved/..)
+                 */
+                if (page_nr >= (ISA_END_ADDRESS >> PAGE_SHIFT) &&
+                    page_is_ram(page_nr))
+                        ram_page = 1;
+                else
+                        not_rampage = 1;
+
+                if (ram_page == not_rampage)
+                        return -1;
+        }
+
+        return ram_page;
+}
+
 /*
  * For RAM pages, mark the pages as non WB memory type using
  * PageNonWB (PG_arch_1). We allow only one set_memory_uc() or
@@ -345,20 +372,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
         if (new_type)
                 *new_type = actual_type;
 
-        /*
-         * For legacy reasons, some parts of the physical address range in the
-         * legacy 1MB region is treated as non-RAM (even when listed as RAM in
-         * the e820 tables).  So we will track the memory attributes of this
-         * legacy 1MB region using the linear memtype_list always.
-         */
-        if (end >= ISA_END_ADDRESS) {
-                is_range_ram = pagerange_is_ram(start, end);
-                if (is_range_ram == 1)
-                        return reserve_ram_pages_type(start, end, req_type,
-                                                      new_type);
-                else if (is_range_ram < 0)
-                        return -EINVAL;
-        }
+        is_range_ram = pat_pagerange_is_ram(start, end);
+        if (is_range_ram == 1)
+                return reserve_ram_pages_type(start, end, req_type,
+                                              new_type);
+        else if (is_range_ram < 0)
+                return -EINVAL;
 
         new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
         if (!new)
@@ -455,19 +474,11 @@ int free_memtype(u64 start, u64 end)
         if (is_ISA_range(start, end - 1))
                 return 0;
 
-        /*
-         * For legacy reasons, some parts of the physical address range in the
-         * legacy 1MB region is treated as non-RAM (even when listed as RAM in
-         * the e820 tables).  So we will track the memory attributes of this
-         * legacy 1MB region using the linear memtype_list always.
-         */
-        if (end >= ISA_END_ADDRESS) {
-                is_range_ram = pagerange_is_ram(start, end);
-                if (is_range_ram == 1)
-                        return free_ram_pages_type(start, end);
-                else if (is_range_ram < 0)
-                        return -EINVAL;
-        }
+        is_range_ram = pat_pagerange_is_ram(start, end);
+        if (is_range_ram == 1)
+                return free_ram_pages_type(start, end);
+        else if (is_range_ram < 0)
+                return -EINVAL;
 
         spin_lock(&memtype_lock);
         list_for_each_entry(entry, &memtype_list, nd) {
@@ -635,17 +646,13 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
         unsigned long flags;
         unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
 
-        is_ram = pagerange_is_ram(paddr, paddr + size);
+        is_ram = pat_pagerange_is_ram(paddr, paddr + size);
 
-        if (is_ram != 0) {
-                /*
-                 * For mapping RAM pages, drivers need to call
-                 * set_memory_[uc|wc|wb] directly, for reserve and free, before
-                 * setting up the PTE.
-                 */
-                WARN_ON_ONCE(1);
-                return 0;
-        }
+        /*
+         * reserve_pfn_range() doesn't support RAM pages.
+         */
+        if (is_ram != 0)
+                return -EINVAL;
 
         ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
         if (ret)
@@ -702,7 +709,7 @@ static void free_pfn_range(u64 paddr, unsigned long size)
 {
         int is_ram;
 
-        is_ram = pagerange_is_ram(paddr, paddr + size);
+        is_ram = pat_pagerange_is_ram(paddr, paddr + size);
         if (is_ram == 0)
                 free_memtype(paddr, paddr + size);
 }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 323561582c10..7dc04ff5ab89 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1304,5 +1304,6 @@ void vmemmap_populate_print_last(void);
 
 extern void *alloc_locked_buffer(size_t size);
 extern void free_locked_buffer(void *buffer, size_t size);
+extern void release_locked_buffer(void *buffer, size_t size);
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */
diff --git a/mm/mlock.c b/mm/mlock.c
index 037161d61b4e..cbe9e0581b75 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -660,7 +660,7 @@ void *alloc_locked_buffer(size_t size)
         return buffer;
 }
 
-void free_locked_buffer(void *buffer, size_t size)
+void release_locked_buffer(void *buffer, size_t size)
 {
         unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
 
@@ -670,6 +670,11 @@ void free_locked_buffer(void *buffer, size_t size)
         current->mm->locked_vm -= pgsz;
 
         up_write(&current->mm->mmap_sem);
+}
+
+void free_locked_buffer(void *buffer, size_t size)
+{
+        release_locked_buffer(buffer, size);
 
         kfree(buffer);
 }