[GIT PULL] x86 fixes for 2.6.36-rc2

From: H. Peter Anvin
Date: Fri Aug 20 2010 - 16:14:49 EST


Hi Linus,

The following changes since commit 763008c4357b73c8d18396dfd8d79dc58fa3f99d:

Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 (2010-08-18 15:45:23 -0700)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-fixes-for-linus

Borislav Petkov (1):
x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues

Daniel Kiper (1):
x86, apic: Fix apic=debug boot crash

H. Peter Anvin (1):
x86-32: Fix dummy trampoline-related inline stubs

Hans Rosenfeld (1):
x86, cpu: Fix regression in AMD errata checking code

Joerg Roedel (1):
x86-32: Separate 1:1 pagetables from swapper_pg_dir

arch/x86/Kconfig | 5 +++
arch/x86/include/asm/pgtable_32.h | 1 +
arch/x86/include/asm/trampoline.h | 5 +++-
arch/x86/kernel/apic/io_apic.c | 2 +
arch/x86/kernel/cpu/amd.c | 2 +-
arch/x86/kernel/head_32.S | 8 +++++-
arch/x86/kernel/setup.c | 2 +
arch/x86/kernel/smpboot.c | 51 +++++++++++++++++++++++-------------
arch/x86/kernel/trampoline.c | 18 +++++++++++++
9 files changed, 72 insertions(+), 22 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a84fc34..ac7827f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -245,6 +245,11 @@ config ARCH_HWEIGHT_CFLAGS

config KTIME_SCALAR
def_bool X86_32
+
+config ARCH_CPU_PROBE_RELEASE
+ def_bool y
+ depends on HOTPLUG_CPU
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"

diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 2984a25..f686f49 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -26,6 +26,7 @@ struct mm_struct;
struct vm_area_struct;

extern pgd_t swapper_pg_dir[1024];
+extern pgd_t trampoline_pg_dir[1024];

static inline void pgtable_cache_init(void) { }
static inline void check_pgt_cache(void) { }
diff --git a/arch/x86/include/asm/trampoline.h b/arch/x86/include/asm/trampoline.h
index cb507bb..4dde797 100644
--- a/arch/x86/include/asm/trampoline.h
+++ b/arch/x86/include/asm/trampoline.h
@@ -13,14 +13,17 @@ extern unsigned char *trampoline_base;

extern unsigned long init_rsp;
extern unsigned long initial_code;
+extern unsigned long initial_page_table;
extern unsigned long initial_gs;

#define TRAMPOLINE_SIZE roundup(trampoline_end - trampoline_data, PAGE_SIZE)

extern unsigned long setup_trampoline(void);
+extern void __init setup_trampoline_page_table(void);
extern void __init reserve_trampoline_memory(void);
#else
-static inline void reserve_trampoline_memory(void) {};
+static inline void setup_trampoline_page_table(void) {}
+static inline void reserve_trampoline_memory(void) {}
#endif /* CONFIG_X86_TRAMPOLINE */

#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 4dc0084..f1efeba 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1728,6 +1728,8 @@ __apicdebuginit(void) print_IO_APIC(void)
struct irq_pin_list *entry;

cfg = desc->chip_data;
+ if (!cfg)
+ continue;
entry = cfg->irq_2_pin;
if (!entry)
continue;
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 60a57b1..ba5f62f 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -669,7 +669,7 @@ bool cpu_has_amd_erratum(const int *erratum)
}

/* OSVW unavailable or ID unknown, match family-model-stepping range */
- ms = (cpu->x86_model << 8) | cpu->x86_mask;
+ ms = (cpu->x86_model << 4) | cpu->x86_mask;
while ((range = *erratum++))
if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
(ms >= AMD_MODEL_RANGE_START(range)) &&
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index ff4c453..fa8c1b8 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -334,7 +334,7 @@ ENTRY(startup_32_smp)
/*
* Enable paging
*/
- movl $pa(swapper_pg_dir),%eax
+ movl pa(initial_page_table), %eax
movl %eax,%cr3 /* set the page table pointer.. */
movl %cr0,%eax
orl $X86_CR0_PG,%eax
@@ -614,6 +614,8 @@ ignore_int:
.align 4
ENTRY(initial_code)
.long i386_start_kernel
+ENTRY(initial_page_table)
+ .long pa(swapper_pg_dir)

/*
* BSS section
@@ -629,6 +631,10 @@ ENTRY(swapper_pg_dir)
#endif
swapper_pg_fixmap:
.fill 1024,4,0
+#ifdef CONFIG_X86_TRAMPOLINE
+ENTRY(trampoline_pg_dir)
+ .fill 1024,4,0
+#endif
ENTRY(empty_zero_page)
.fill 4096,1,0

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b008e78..c3a4fbb 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1014,6 +1014,8 @@ void __init setup_arch(char **cmdline_p)
paging_init();
x86_init.paging.pagetable_setup_done(swapper_pg_dir);

+ setup_trampoline_page_table();
+
tboot_probe();

#ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a5e928b..8b3bfc4 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -73,7 +73,6 @@

#ifdef CONFIG_X86_32
u8 apicid_2_node[MAX_APICID];
-static int low_mappings;
#endif

/* State of each CPU */
@@ -91,6 +90,25 @@ DEFINE_PER_CPU(int, cpu_state) = { 0 };
static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
+
+/*
+ * We need this for trampoline_base protection from concurrent accesses when
+ * off- and onlining cores wildly.
+ */
+static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
+
+void cpu_hotplug_driver_lock()
+{
+ mutex_lock(&x86_cpu_hotplug_driver_mutex);
+}
+
+void cpu_hotplug_driver_unlock()
+{
+ mutex_unlock(&x86_cpu_hotplug_driver_mutex);
+}
+
+ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
+ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
#else
static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
#define get_idle_for_cpu(x) (idle_thread_array[(x)])
@@ -281,6 +299,18 @@ notrace static void __cpuinit start_secondary(void *unused)
* fragile that we want to limit the things done here to the
* most necessary things.
*/
+
+#ifdef CONFIG_X86_32
+ /*
+ * Switch away from the trampoline page-table
+ *
+ * Do this before cpu_init() because it needs to access per-cpu
+ * data which may not be mapped in the trampoline page-table.
+ */
+ load_cr3(swapper_pg_dir);
+ __flush_tlb_all();
+#endif
+
vmi_bringup();
cpu_init();
preempt_disable();
@@ -299,12 +329,6 @@ notrace static void __cpuinit start_secondary(void *unused)
legacy_pic->chip->unmask(0);
}

-#ifdef CONFIG_X86_32
- while (low_mappings)
- cpu_relax();
- __flush_tlb_all();
-#endif
-
/* This must be done before setting cpu_online_mask */
set_cpu_sibling_map(raw_smp_processor_id());
wmb();
@@ -750,6 +774,7 @@ do_rest:
#ifdef CONFIG_X86_32
/* Stack for startup_32 can be just as for start_secondary onwards */
irq_ctx_init(cpu);
+ initial_page_table = __pa(&trampoline_pg_dir);
#else
clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
initial_gs = per_cpu_offset(cpu);
@@ -897,20 +922,8 @@ int __cpuinit native_cpu_up(unsigned int cpu)

per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;

-#ifdef CONFIG_X86_32
- /* init low mem mapping */
- clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
- min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
- flush_tlb_all();
- low_mappings = 1;
-
err = do_boot_cpu(apicid, cpu);

- zap_low_mappings(false);
- low_mappings = 0;
-#else
- err = do_boot_cpu(apicid, cpu);
-#endif
if (err) {
pr_debug("do_boot_cpu failed %d\n", err);
return -EIO;
diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c
index c652ef6..a874495 100644
--- a/arch/x86/kernel/trampoline.c
+++ b/arch/x86/kernel/trampoline.c
@@ -1,6 +1,7 @@
#include <linux/io.h>

#include <asm/trampoline.h>
+#include <asm/pgtable.h>
#include <asm/e820.h>

#if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
@@ -37,3 +38,20 @@ unsigned long __trampinit setup_trampoline(void)
memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
return virt_to_phys(trampoline_base);
}
+
+void __init setup_trampoline_page_table(void)
+{
+#ifdef CONFIG_X86_32
+ /* Copy kernel address range */
+ clone_pgd_range(trampoline_pg_dir + KERNEL_PGD_BOUNDARY,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ min_t(unsigned long, KERNEL_PGD_PTRS,
+ KERNEL_PGD_BOUNDARY));
+
+ /* Initialize low mappings */
+ clone_pgd_range(trampoline_pg_dir,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ min_t(unsigned long, KERNEL_PGD_PTRS,
+ KERNEL_PGD_BOUNDARY));
+#endif
+}
--
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