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authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-15 14:07:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-15 14:07:53 -0700
commitae3b29e67ca361f0876dad6be2061699de95d126 (patch)
tree26063709aa45ac714b2b10e22b62d23247a5a19d /arch/x86
parent652df602f8c5e99a3cec7d8e0c114e29d93b342f (diff)
parentcf8b166d5c1c89aad6c436a954fa40fd18a75bfb (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: - Fix for a CPU hot-add deadlock in microcode update code - Fix for idle consolidation fallout - Documentation update for initial kernel direct mapping * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Add missing comments for initial kernel direct mapping x86/microcode: Add local mutex to fix physical CPU hot-add deadlock x86: Fix idle consolidation fallout
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/microcode_intel_early.c5
-rw-r--r--arch/x86/kernel/process.c5
-rw-r--r--arch/x86/mm/init.c19
3 files changed, 23 insertions, 6 deletions
diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
index d893e8ed8ac9..2e9e12871c2b 100644
--- a/arch/x86/kernel/microcode_intel_early.c
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -487,6 +487,7 @@ static inline void show_saved_mc(void)
#endif
#if defined(CONFIG_MICROCODE_INTEL_EARLY) && defined(CONFIG_HOTPLUG_CPU)
+static DEFINE_MUTEX(x86_cpu_microcode_mutex);
/*
* Save this mc into mc_saved_data. So it will be loaded early when a CPU is
* hot added or resumes.
@@ -507,7 +508,7 @@ int save_mc_for_early(u8 *mc)
* Hold hotplug lock so mc_saved_data is not accessed by a CPU in
* hotplug.
*/
- cpu_hotplug_driver_lock();
+ mutex_lock(&x86_cpu_microcode_mutex);
mc_saved_count_init = mc_saved_data.mc_saved_count;
mc_saved_count = mc_saved_data.mc_saved_count;
@@ -544,7 +545,7 @@ int save_mc_for_early(u8 *mc)
}
out:
- cpu_hotplug_driver_unlock();
+ mutex_unlock(&x86_cpu_microcode_mutex);
return ret;
}
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 607af0d4d5ef..4e7a37ff03ab 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -312,6 +312,8 @@ void arch_cpu_idle(void)
{
if (cpuidle_idle_call())
x86_idle();
+ else
+ local_irq_enable();
}
/*
@@ -368,9 +370,6 @@ void amd_e400_remove_cpu(int cpu)
*/
static void amd_e400_idle(void)
{
- if (need_resched())
- return;
-
if (!amd_e400_c1e_detected) {
u32 lo, hi;
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index fdc5dca14fb3..eaac1743def7 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -359,7 +359,17 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
}
/*
- * would have hole in the middle or ends, and only ram parts will be mapped.
+ * We need to iterate through the E820 memory map and create direct mappings
+ * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply
+ * create direct mappings for all pfns from [0 to max_low_pfn) and
+ * [4GB to max_pfn) because of possible memory holes in high addresses
+ * that cannot be marked as UC by fixed/variable range MTRRs.
+ * Depending on the alignment of E820 ranges, this may possibly result
+ * in using smaller size (i.e. 4K instead of 2M or 1G) page tables.
+ *
+ * init_mem_mapping() calls init_range_memory_mapping() with big range.
+ * That range would have hole in the middle or ends, and only ram parts
+ * will be mapped in init_range_memory_mapping().
*/
static unsigned long __init init_range_memory_mapping(
unsigned long r_start,
@@ -419,6 +429,13 @@ void __init init_mem_mapping(void)
max_pfn_mapped = 0; /* will get exact value next */
min_pfn_mapped = real_end >> PAGE_SHIFT;
last_start = start = real_end;
+
+ /*
+ * We start from the top (end of memory) and go to the bottom.
+ * The memblock_find_in_range() gets us a block of RAM from the
+ * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
+ * for page table.
+ */
while (last_start > ISA_END_ADDRESS) {
if (last_start > step_size) {
start = round_down(last_start - 1, step_size);