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Subject[PATCH 7/9] x86-64 move thread_info into task_struct
On x86-64, move thread_info from the stack into task_struct.  This has
benefits for the use of registers in entry.S when current is moved into
a register. Take the easy approach of making GET_THREAD_INFO() return
a pointer to current and make the asm-offset.c aware of this new usage.

---

arch/i386/oprofile/nmi_int.c | 1 +
arch/x86_64/kernel/asm-offsets.c | 2 +-
arch/x86_64/kernel/genapic_cluster.c | 1 +
arch/x86_64/kernel/genapic_flat.c | 1 +
arch/x86_64/kernel/setup64.c | 2 +-
include/asm-x86_64/desc.h | 1 +
include/asm-x86_64/processor.h | 10 +++-------
include/asm-x86_64/system.h | 6 ++----
include/asm-x86_64/thread_info.h | 31 ++++++++++++++-----------------
9 files changed, 25 insertions(+), 30 deletions(-)

applies-to: 747a43be5747e1c8e25f5769bdb9e4a1b8029138
bb489ebe1733165426cbbaba24a2ed51d6952d88
diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c
index 0493e8b..1e91d22 100644
--- a/arch/i386/oprofile/nmi_int.c
+++ b/arch/i386/oprofile/nmi_int.c
@@ -13,6 +13,7 @@
#include <linux/oprofile.h>
#include <linux/sysdev.h>
#include <linux/slab.h>
+#include <linux/sched.h>
#include <asm/nmi.h>
#include <asm/msr.h>
#include <asm/apic.h>
diff --git a/arch/x86_64/kernel/asm-offsets.c b/arch/x86_64/kernel/asm-offsets.c
index aaa6d38..66ebe60 100644
--- a/arch/x86_64/kernel/asm-offsets.c
+++ b/arch/x86_64/kernel/asm-offsets.c
@@ -29,7 +29,7 @@ int main(void)
ENTRY(pid);
BLANK();
#undef ENTRY
-#define ENTRY(entry) DEFINE(threadinfo_ ## entry, offsetof(struct thread_info, entry))
+#define ENTRY(entry) DEFINE(threadinfo_ ## entry, offsetof(struct task_struct, thread.info.entry))
ENTRY(flags);
ENTRY(addr_limit);
ENTRY(preempt_count);
diff --git a/arch/x86_64/kernel/genapic_cluster.c b/arch/x86_64/kernel/genapic_cluster.c
index a472d62..42531a9 100644
--- a/arch/x86_64/kernel/genapic_cluster.c
+++ b/arch/x86_64/kernel/genapic_cluster.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
+#include <linux/sched.h>
#include <asm/smp.h>
#include <asm/ipi.h>

diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c
index 9da3edb..28b775f 100644
--- a/arch/x86_64/kernel/genapic_flat.c
+++ b/arch/x86_64/kernel/genapic_flat.c
@@ -15,6 +15,7 @@
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
+#include <linux/sched.h>
#include <asm/smp.h>
#include <asm/ipi.h>

diff --git a/arch/x86_64/kernel/setup64.c b/arch/x86_64/kernel/setup64.c
index 06dc354..3e81a04 100644
--- a/arch/x86_64/kernel/setup64.c
+++ b/arch/x86_64/kernel/setup64.c
@@ -126,7 +126,7 @@ void pda_init(int cpu)
pda->cpunumber = cpu;
pda->irqcount = -1;
pda->kernelstack =
- (unsigned long)stack_thread_info() - PDA_STACKOFFSET + THREAD_SIZE;
+ (unsigned long)current->thread_info - PDA_STACKOFFSET + THREAD_SIZE;
pda->active_mm = &init_mm;
pda->mmu_state = 0;

diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h
index 3376486..ece54d4 100644
--- a/include/asm-x86_64/desc.h
+++ b/include/asm-x86_64/desc.h
@@ -9,6 +9,7 @@

#include <linux/string.h>
#include <linux/smp.h>
+#include <linux/sched.h>

#include <asm/segment.h>
#include <asm/mmu.h>
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index 4861246..7f24beb 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -20,6 +20,7 @@
#include <asm/mmsegment.h>
#include <asm/percpu.h>
#include <linux/personality.h>
+#include <linux/thread_info.h>

#define TF_MASK 0x00000100
#define IF_MASK 0x00000200
@@ -230,6 +231,7 @@ DECLARE_PER_CPU(struct tss_struct,init_t
#define ARCH_MIN_TASKALIGN 16

struct thread_struct {
+ struct thread_info info;
unsigned long rsp0;
unsigned long rsp;
unsigned long userrsp; /* Copy from PDA */
@@ -257,6 +259,7 @@ struct thread_struct {
} __attribute__((aligned(16)));

#define INIT_THREAD { \
+ .info = INIT_THREAD_INFO(init_task), \
.rsp0 = (unsigned long)&init_stack + sizeof(init_stack) \
}

@@ -467,13 +470,6 @@ static inline void __mwait(unsigned long
: :"a" (eax), "c" (ecx));
}

-#define stack_current() \
-({ \
- struct thread_info *ti; \
- asm("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK)); \
- ti->task; \
-})
-
#define cache_line_size() (boot_cpu_data.x86_cache_alignment)

extern unsigned long boot_option_idle_override;
diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h
index 85348e0..d2cbbc3 100644
--- a/include/asm-x86_64/system.h
+++ b/include/asm-x86_64/system.h
@@ -34,17 +34,15 @@
".globl thread_return\n" \
"thread_return:\n\t" \
"movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
- "movq %P[thread_info](%%rsi),%%r8\n\t" \
- LOCK "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
+ LOCK "btr %[tif_fork],%P[ti_flags](%%rsi)\n\t" \
"movq %%rax,%%rdi\n\t" \
"jc ret_from_fork\n\t" \
RESTORE_CONTEXT \
: "=a" (last) \
: [next] "S" (next), [prev] "D" (prev), \
[threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
- [ti_flags] "i" (offsetof(struct thread_info, flags)),\
+ [ti_flags] "i" (offsetof(struct task_struct, thread.info.flags)),\
[tif_fork] "i" (TIF_FORK), \
- [thread_info] "i" (offsetof(struct task_struct, thread_info)), \
[pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \
: "memory", "cc" __EXTRA_CLOBBER)

diff --git a/include/asm-x86_64/thread_info.h b/include/asm-x86_64/thread_info.h
index 08eb6e4..0c90a18 100644
--- a/include/asm-x86_64/thread_info.h
+++ b/include/asm-x86_64/thread_info.h
@@ -57,20 +57,16 @@ struct thread_info {
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)

-static inline struct thread_info *current_thread_info(void)
-{
- struct thread_info *ti;
- ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
- return ti;
-}
-
-/* do not use in interrupt context */
-static inline struct thread_info *stack_thread_info(void)
-{
- struct thread_info *ti;
- __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
- return ti;
-}
+#define task_thread_info(t) (&(t)->thread.info)
+#define current_thread_info() task_thread_info(current)
+
+#define setup_thread_stack(p, org) ({ \
+ task_thread_info(p)->task = (p); \
+})
+
+#define end_of_stack(p) ((unsigned long *)(p)->thread_info + 1)
+
+#define __HAVE_THREAD_FUNCTIONS

/* thread information allocation */
#define alloc_thread_info(tsk) \
@@ -81,10 +77,11 @@ static inline struct thread_info *stack_

#else /* !__ASSEMBLY__ */

-/* how to get the thread information struct from ASM */
+/* How to get the thread information struct from ASM. We use a pointer to
+ * current and make the asm offsets point to * ->thread.info.<field>
+ */
#define GET_THREAD_INFO(reg) \
- movq %gs:pda_kernelstack,reg ; \
- subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
+ movq %gs:pda_pcurrent,reg

#endif

---
0.99.9.GIT
-
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