* [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches
@ 2009-02-08 14:58 Brian Gerst
2009-02-08 14:58 ` [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load Brian Gerst
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Brian Gerst @ 2009-02-08 14:58 UTC (permalink / raw)
To: Tejun Heo; +Cc: Ingo Molnar, linux-kernel
Impact: bug fix
IA-64 needs to put percpu data in the seperate section even on UP.
Fixes regression caused by "percpu: refactor percpu.h"
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
---
arch/ia64/include/asm/percpu.h | 4 ++--
include/linux/percpu.h | 8 +++++++-
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/ia64/include/asm/percpu.h b/arch/ia64/include/asm/percpu.h
index 77f30b6..30cf465 100644
--- a/arch/ia64/include/asm/percpu.h
+++ b/arch/ia64/include/asm/percpu.h
@@ -27,12 +27,12 @@ extern void *per_cpu_init(void);
#else /* ! SMP */
-#define PER_CPU_ATTRIBUTES __attribute__((__section__(".data.percpu")))
-
#define per_cpu_init() (__phys_per_cpu_start)
#endif /* SMP */
+#define PER_CPU_BASE_SECTION ".data.percpu"
+
/*
* Be extremely careful when taking the address of this variable! Due to virtual
* remapping, it is different from the canonical address returned by __get_cpu_var(var)!
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 0e24202..3577ffd 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -8,8 +8,15 @@
#include <asm/percpu.h>
+#ifndef PER_CPU_BASE_SECTION
#ifdef CONFIG_SMP
#define PER_CPU_BASE_SECTION ".data.percpu"
+#else
+#define PER_CPU_BASE_SECTION ".data"
+#endif
+#endif
+
+#ifdef CONFIG_SMP
#ifdef MODULE
#define PER_CPU_SHARED_ALIGNED_SECTION ""
@@ -20,7 +27,6 @@
#else
-#define PER_CPU_BASE_SECTION ".data"
#define PER_CPU_SHARED_ALIGNED_SECTION ""
#define PER_CPU_FIRST_SECTION ""
--
1.6.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load
2009-02-08 14:58 [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Brian Gerst
@ 2009-02-08 14:58 ` Brian Gerst
2009-02-09 9:29 ` Ingo Molnar
2009-02-08 14:58 ` [PATCH 3/3] x86: Fix abuse of per_cpu_offset Brian Gerst
2009-02-09 9:29 ` [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Ingo Molnar
2 siblings, 1 reply; 7+ messages in thread
From: Brian Gerst @ 2009-02-08 14:58 UTC (permalink / raw)
To: Tejun Heo; +Cc: Ingo Molnar, linux-kernel, Jiri Slaby
Impact: cleanup and bug fix
Use the linker to create symbols for certain per-cpu variables
that are offset by __per_cpu_load. This allows the removal of
the runtime fixup of the GDT pointer, which fixes a bug with
resume reported by Jiri Slaby.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
---
arch/x86/include/asm/percpu.h | 22 ++++++++++++++++++++++
arch/x86/include/asm/processor.h | 2 ++
arch/x86/kernel/cpu/common.c | 6 +-----
arch/x86/kernel/head_64.S | 21 ++-------------------
arch/x86/kernel/vmlinux_64.lds.S | 8 ++++++++
5 files changed, 35 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 0b64af4..aee103b 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -34,6 +34,12 @@
#define PER_CPU_VAR(var) per_cpu__##var
#endif /* SMP */
+#ifdef CONFIG_X86_64_SMP
+#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
+#else
+#define INIT_PER_CPU_VAR(var) per_cpu__##var
+#endif
+
#else /* ...!ASSEMBLY */
#include <linux/stringify.h>
@@ -45,6 +51,22 @@
#define __percpu_arg(x) "%" #x
#endif
+/*
+ * Initialized pointers to per-cpu variables needed for the boot
+ * processor need to use these macros to get the proper address
+ * offset from __per_cpu_load on SMP.
+ *
+ * There also must be an entry in vmlinux_64.lds.S
+ */
+#define DECLARE_INIT_PER_CPU(var) \
+ extern typeof(per_cpu_var(var)) init_per_cpu_var(var)
+
+#ifdef CONFIG_X86_64_SMP
+#define init_per_cpu_var(var) init_per_cpu__##var
+#else
+#define init_per_cpu_var(var) per_cpu_var(var)
+#endif
+
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
extern void __bad_percpu_size(void);
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 656d02e..373d3f6 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -393,6 +393,8 @@ union irq_stack_union {
};
DECLARE_PER_CPU(union irq_stack_union, irq_stack_union);
+DECLARE_INIT_PER_CPU(irq_stack_union);
+
DECLARE_PER_CPU(char *, irq_stack_ptr);
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 0f73ea4..41b0de6 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -902,12 +902,8 @@ struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
DEFINE_PER_CPU_FIRST(union irq_stack_union,
irq_stack_union) __aligned(PAGE_SIZE);
-#ifdef CONFIG_SMP
-DEFINE_PER_CPU(char *, irq_stack_ptr); /* will be set during per cpu init */
-#else
DEFINE_PER_CPU(char *, irq_stack_ptr) =
- per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
-#endif
+ init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
DEFINE_PER_CPU(unsigned long, kernel_stack) =
(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index a0a2b5c..2e648e3 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -205,19 +205,6 @@ ENTRY(secondary_startup_64)
pushq $0
popfq
-#ifdef CONFIG_SMP
- /*
- * Fix up static pointers that need __per_cpu_load added. The assembler
- * is unable to do this directly. This is only needed for the boot cpu.
- * These values are set up with the correct base addresses by C code for
- * secondary cpus.
- */
- movq initial_gs(%rip), %rax
- cmpl $0, per_cpu__cpu_number(%rax)
- jne 1f
- addq %rax, early_gdt_descr_base(%rip)
-1:
-#endif
/*
* We must switch to a new descriptor in kernel space for the GDT
* because soon the kernel won't have access anymore to the userspace
@@ -275,11 +262,7 @@ ENTRY(secondary_startup_64)
ENTRY(initial_code)
.quad x86_64_start_kernel
ENTRY(initial_gs)
-#ifdef CONFIG_SMP
- .quad __per_cpu_load
-#else
- .quad PER_CPU_VAR(irq_stack_union)
-#endif
+ .quad INIT_PER_CPU_VAR(irq_stack_union)
__FINITDATA
ENTRY(stack_start)
@@ -425,7 +408,7 @@ NEXT_PAGE(level2_spare_pgt)
early_gdt_descr:
.word GDT_ENTRIES*8-1
early_gdt_descr_base:
- .quad per_cpu__gdt_page
+ .quad INIT_PER_CPU_VAR(gdt_page)
ENTRY(phys_base)
/* This must match the first entry in level2_kernel_pgt */
diff --git a/arch/x86/kernel/vmlinux_64.lds.S b/arch/x86/kernel/vmlinux_64.lds.S
index 07f62d2..087a7f2 100644
--- a/arch/x86/kernel/vmlinux_64.lds.S
+++ b/arch/x86/kernel/vmlinux_64.lds.S
@@ -257,6 +257,14 @@ SECTIONS
DWARF_DEBUG
}
+ /*
+ * Per-cpu symbols which need to be offset from __per_cpu_load
+ * for the boot processor.
+ */
+#define INIT_PER_CPU(x) init_per_cpu__##x = per_cpu__##x + __per_cpu_load
+INIT_PER_CPU(gdt_page);
+INIT_PER_CPU(irq_stack_union);
+
/*
* Build-time check on the image size:
*/
--
1.6.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 3/3] x86: Fix abuse of per_cpu_offset
2009-02-08 14:58 [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Brian Gerst
2009-02-08 14:58 ` [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load Brian Gerst
@ 2009-02-08 14:58 ` Brian Gerst
2009-02-09 9:31 ` Ingo Molnar
2009-02-09 9:29 ` [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Ingo Molnar
2 siblings, 1 reply; 7+ messages in thread
From: Brian Gerst @ 2009-02-08 14:58 UTC (permalink / raw)
To: Tejun Heo; +Cc: Ingo Molnar, linux-kernel
Impact: bug fix
Don't use per_cpu_offset() to determine if it valid to access a
per-cpu variable for a given cpu number. It is not a valid assumption
on x86-64 anymore. Use cpu_possible() instead.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/mm/numa_64.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 08d140f..deb1c1a 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -702,7 +702,7 @@ void __cpuinit numa_set_node(int cpu, int node)
}
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
- if (cpu >= nr_cpu_ids || !per_cpu_offset(cpu)) {
+ if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
dump_stack();
return;
@@ -790,7 +790,7 @@ int early_cpu_to_node(int cpu)
if (early_per_cpu_ptr(x86_cpu_to_node_map))
return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
- if (!per_cpu_offset(cpu)) {
+ if (!cpu_possible(cpu)) {
printk(KERN_WARNING
"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
dump_stack();
--
1.6.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches
2009-02-08 14:58 [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Brian Gerst
2009-02-08 14:58 ` [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load Brian Gerst
2009-02-08 14:58 ` [PATCH 3/3] x86: Fix abuse of per_cpu_offset Brian Gerst
@ 2009-02-09 9:29 ` Ingo Molnar
2 siblings, 0 replies; 7+ messages in thread
From: Ingo Molnar @ 2009-02-09 9:29 UTC (permalink / raw)
To: Brian Gerst; +Cc: Tejun Heo, linux-kernel
* Brian Gerst <brgerst@gmail.com> wrote:
> Impact: bug fix
>
> IA-64 needs to put percpu data in the seperate section even on UP.
> Fixes regression caused by "percpu: refactor percpu.h"
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> Acked-by: Tony Luck <tony.luck@intel.com>
> ---
> arch/ia64/include/asm/percpu.h | 4 ++--
> include/linux/percpu.h | 8 +++++++-
> 2 files changed, 9 insertions(+), 3 deletions(-)
Applied to tip/core/percpu, thanks!
Ingo
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load
2009-02-08 14:58 ` [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load Brian Gerst
@ 2009-02-09 9:29 ` Ingo Molnar
2009-02-11 22:53 ` Jiri Slaby
0 siblings, 1 reply; 7+ messages in thread
From: Ingo Molnar @ 2009-02-09 9:29 UTC (permalink / raw)
To: Brian Gerst; +Cc: Tejun Heo, linux-kernel, Jiri Slaby
* Brian Gerst <brgerst@gmail.com> wrote:
> Impact: cleanup and bug fix
>
> Use the linker to create symbols for certain per-cpu variables
> that are offset by __per_cpu_load. This allows the removal of
> the runtime fixup of the GDT pointer, which fixes a bug with
> resume reported by Jiri Slaby.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> Cc: Jiri Slaby <jirislaby@gmail.com>
> ---
> arch/x86/include/asm/percpu.h | 22 ++++++++++++++++++++++
> arch/x86/include/asm/processor.h | 2 ++
> arch/x86/kernel/cpu/common.c | 6 +-----
> arch/x86/kernel/head_64.S | 21 ++-------------------
> arch/x86/kernel/vmlinux_64.lds.S | 8 ++++++++
> 5 files changed, 35 insertions(+), 24 deletions(-)
applied to tip/core/percpu, thanks!
Also added these tags:
Reported-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Ingo
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 3/3] x86: Fix abuse of per_cpu_offset
2009-02-08 14:58 ` [PATCH 3/3] x86: Fix abuse of per_cpu_offset Brian Gerst
@ 2009-02-09 9:31 ` Ingo Molnar
0 siblings, 0 replies; 7+ messages in thread
From: Ingo Molnar @ 2009-02-09 9:31 UTC (permalink / raw)
To: Brian Gerst; +Cc: Tejun Heo, linux-kernel, Thomas Gleixner, H. Peter Anvin
* Brian Gerst <brgerst@gmail.com> wrote:
> Impact: bug fix
>
> Don't use per_cpu_offset() to determine if it valid to access a
> per-cpu variable for a given cpu number. It is not a valid assumption
> on x86-64 anymore. Use cpu_possible() instead.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> ---
> arch/x86/mm/numa_64.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
Applied to tip/core/perpcu, thanks Brian!
Ingo
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load
2009-02-09 9:29 ` Ingo Molnar
@ 2009-02-11 22:53 ` Jiri Slaby
0 siblings, 0 replies; 7+ messages in thread
From: Jiri Slaby @ 2009-02-11 22:53 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Brian Gerst, Tejun Heo, linux-kernel
On 02/09/2009 10:29 AM, Ingo Molnar wrote:
> * Brian Gerst <brgerst@gmail.com> wrote:
>
>> Impact: cleanup and bug fix
>>
>> Use the linker to create symbols for certain per-cpu variables
>> that are offset by __per_cpu_load. This allows the removal of
>> the runtime fixup of the GDT pointer, which fixes a bug with
>> resume reported by Jiri Slaby.
>>
>> Signed-off-by: Brian Gerst <brgerst@gmail.com>
>> Cc: Jiri Slaby <jirislaby@gmail.com>
>> ---
>> arch/x86/include/asm/percpu.h | 22 ++++++++++++++++++++++
>> arch/x86/include/asm/processor.h | 2 ++
>> arch/x86/kernel/cpu/common.c | 6 +-----
>> arch/x86/kernel/head_64.S | 21 ++-------------------
>> arch/x86/kernel/vmlinux_64.lds.S | 8 ++++++++
>> 5 files changed, 35 insertions(+), 24 deletions(-)
>
> applied to tip/core/percpu, thanks!
>
> Also added these tags:
>
> Reported-by: Jiri Slaby <jirislaby@gmail.com>
> Acked-by: Jiri Slaby <jirislaby@gmail.com>
Ok, fixes the problem for me, thanks.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-02-11 22:53 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2009-02-08 14:58 [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Brian Gerst
2009-02-08 14:58 ` [PATCH 2/3] x86: Use linker to offset symbols by __per_cpu_load Brian Gerst
2009-02-09 9:29 ` Ingo Molnar
2009-02-11 22:53 ` Jiri Slaby
2009-02-08 14:58 ` [PATCH 3/3] x86: Fix abuse of per_cpu_offset Brian Gerst
2009-02-09 9:31 ` Ingo Molnar
2009-02-09 9:29 ` [PATCH 1/3] percpu: Make PER_CPU_BASE_SECTION overridable by arches Ingo Molnar
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