Skip to content

L
linux
Commit 7f9efd7d authored by Pavel Machek's avatar Pavel Machek Committed by Linus Torvalds
Browse files
Options

[PATCH] 2.5.20 swsusp: stop abusing headers with non-inlined functions 

swsusp kind-of abused include/asm-i386/suspend.h for stuff that
belonged to arch/i386/kernel/suspend.c. This moves code where it
belongs.
									Pavel
parent 0db8da19
Hide whitespace changes
Inline Side-by-side
Showing with 269 additions and 261 deletions
arch/i386/kernel/suspend.c
View file @ 7f9efd7d
...@@ -24,8 +24,156 @@ ...@@ -24,8 +24,156 @@
#include <linux/suspend.h> #include <linux/suspend.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/acpi.h> #include <asm/acpi.h>
#include <asm/tlbflush.h>
static struct saved_context saved_context;
/*
* save_processor_context
*
* Save the state of the processor before we go to sleep.
*
* return_stack is the value of the stack pointer (%esp) as the caller sees it.
* A good way could not be found to obtain it from here (don't want to make _too_
* many assumptions about the layout of the stack this far down.) Also, the
* handy little __builtin_frame_pointer(level) where level > 0, is blatantly
* buggy - it returns the value of the stack at the proper location, not the
* location, like it should (as of gcc 2.91.66)
*
* Note that the context and timing of this function is pretty critical.
* With a minimal amount of things going on in the caller and in here, gcc
* does a good job of being just a dumb compiler. Watch the assembly output
* if anything changes, though, and make sure everything is going in the right
* place.
*/
static inline void save_processor_context (void)
{
kernel_fpu_begin();
/*
* descriptor tables
*/
asm volatile ("sgdt (%0)" : "=m" (saved_context.gdt_limit));
asm volatile ("sidt (%0)" : "=m" (saved_context.idt_limit));
asm volatile ("sldt (%0)" : "=m" (saved_context.ldt));
asm volatile ("str (%0)" : "=m" (saved_context.tr));
/*
* save the general registers.
* note that gcc has constructs to specify output of certain registers,
* but they're not used here, because it assumes that you want to modify
* those registers, so it tries to be smart and save them beforehand.
* It's really not necessary, and kinda fishy (check the assembly output),
* so it's avoided.
*/
asm volatile ("movl %%esp, (%0)" : "=m" (saved_context.esp));
asm volatile ("movl %%eax, (%0)" : "=m" (saved_context.eax));
asm volatile ("movl %%ebx, (%0)" : "=m" (saved_context.ebx));
asm volatile ("movl %%ecx, (%0)" : "=m" (saved_context.ecx));
asm volatile ("movl %%edx, (%0)" : "=m" (saved_context.edx));
asm volatile ("movl %%ebp, (%0)" : "=m" (saved_context.ebp));
asm volatile ("movl %%esi, (%0)" : "=m" (saved_context.esi));
asm volatile ("movl %%edi, (%0)" : "=m" (saved_context.edi));
/*
* segment registers
*/
asm volatile ("movw %%es, %0" : "=r" (saved_context.es));
asm volatile ("movw %%fs, %0" : "=r" (saved_context.fs));
asm volatile ("movw %%gs, %0" : "=r" (saved_context.gs));
asm volatile ("movw %%ss, %0" : "=r" (saved_context.ss));
/*
* control registers
*/
asm volatile ("movl %%cr0, %0" : "=r" (saved_context.cr0));
asm volatile ("movl %%cr2, %0" : "=r" (saved_context.cr2));
asm volatile ("movl %%cr3, %0" : "=r" (saved_context.cr3));
asm volatile ("movl %%cr4, %0" : "=r" (saved_context.cr4));
/*
* eflags
*/
asm volatile ("pushfl ; popl (%0)" : "=m" (saved_context.eflags));
}
/*
* restore_processor_context
*
* Restore the processor context as it was before we went to sleep
* - descriptor tables
* - control registers
* - segment registers
* - flags
*
* Note that it is critical that this function is declared inline.
* It was separated out from restore_state to make that function
* a little clearer, but it needs to be inlined because we won't have a
* stack when we get here (so we can't push a return address).
*/
static inline void restore_processor_context (void)
{
/*
* first restore %ds, so we can access our data properly
*/
asm volatile (".align 4");
asm volatile ("movw %0, %%ds" :: "r" ((u16)__KERNEL_DS));
/*
* control registers
*/
asm volatile ("movl %0, %%cr4" :: "r" (saved_context.cr4));
asm volatile ("movl %0, %%cr3" :: "r" (saved_context.cr3));
asm volatile ("movl %0, %%cr2" :: "r" (saved_context.cr2));
asm volatile ("movl %0, %%cr0" :: "r" (saved_context.cr0));
/*
* segment registers
*/
asm volatile ("movw %0, %%es" :: "r" (saved_context.es));
asm volatile ("movw %0, %%fs" :: "r" (saved_context.fs));
asm volatile ("movw %0, %%gs" :: "r" (saved_context.gs));
asm volatile ("movw %0, %%ss" :: "r" (saved_context.ss));
/*
* the other general registers
*
* note that even though gcc has constructs to specify memory
* input into certain registers, it will try to be too smart
* and save them at the beginning of the function. This is esp.
* bad since we don't have a stack set up when we enter, and we
* want to preserve the values on exit. So, we set them manually.
*/
asm volatile ("movl %0, %%esp" :: "m" (saved_context.esp));
asm volatile ("movl %0, %%ebp" :: "m" (saved_context.ebp));
asm volatile ("movl %0, %%eax" :: "m" (saved_context.eax));
asm volatile ("movl %0, %%ebx" :: "m" (saved_context.ebx));
asm volatile ("movl %0, %%ecx" :: "m" (saved_context.ecx));
asm volatile ("movl %0, %%edx" :: "m" (saved_context.edx));
asm volatile ("movl %0, %%esi" :: "m" (saved_context.esi));
asm volatile ("movl %0, %%edi" :: "m" (saved_context.edi));
/*
* now restore the descriptor tables to their proper values
* ltr is done i fix_processor_context().
*/
asm volatile ("lgdt (%0)" :: "m" (saved_context.gdt_limit));
asm volatile ("lidt (%0)" :: "m" (saved_context.idt_limit));
asm volatile ("lldt (%0)" :: "m" (saved_context.ldt));
fix_processor_context();
/*
* the flags
*/
asm volatile ("pushl %0 ; popfl" :: "m" (saved_context.eflags));
do_fpu_end();
}
#ifdef CONFIG_ACPI_SLEEP
void do_suspend_lowlevel(int resume) void do_suspend_lowlevel(int resume)
{ {
/* /*
...@@ -44,3 +192,111 @@ void do_suspend_lowlevel(int resume) ...@@ -44,3 +192,111 @@ void do_suspend_lowlevel(int resume)
acpi_restore_register_state(); acpi_restore_register_state();
restore_processor_context(); restore_processor_context();
} }
#endif
void fix_processor_context(void)
{
int nr = smp_processor_id();
struct tss_struct * t = &init_tss[nr];
set_tss_desc(nr,t); /* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy tsc or some similar stupidity. */
gdt_table[__TSS(nr)].b &= 0xfffffdff;
load_TR(nr); /* This does ltr */
load_LDT(&current->mm->context); /* This does lldt */
/*
* Now maybe reload the debug registers
*/
if (current->thread.debugreg[7]){
loaddebug(&current->thread, 0);
loaddebug(&current->thread, 1);
loaddebug(&current->thread, 2);
loaddebug(&current->thread, 3);
/* no 4 and 5 */
loaddebug(&current->thread, 6);
loaddebug(&current->thread, 7);
}
}
static void
do_fpu_end(void)
{
/* restore FPU regs if necessary */
/* Do it out of line so that gcc does not move cr0 load to some stupid place */
kernel_fpu_end();
}
/* Local variables for do_magic */
static int loop __nosavedata = 0;
static int loop2 __nosavedata = 0;
/*
* (KG): Since we affect stack here, we make this function as flat and easy
* as possible in order to not provoke gcc to use local variables on the stack.
* Note that on resume, all (expect nosave) variables will have the state from
* the time of writing (suspend_save_image) and the registers (including the
* stack pointer, but excluding the instruction pointer) will be loaded with
* the values saved at save_processor_context() time.
*/
void do_magic(int resume)
{
/* DANGER WILL ROBINSON!
*
* If this function is too difficult for gcc to optimize, it will crash and burn!
* see above.
*
* DO NOT TOUCH.
*/
if (!resume) {
do_magic_suspend_1();
save_processor_context(); /* We need to capture registers and memory at "same time" */
do_magic_suspend_2(); /* If everything goes okay, this function does not return */
return;
}
/* We want to run from swapper_pg_dir, since swapper_pg_dir is stored in constant
* place in memory
*/
__asm__( "movl %%ecx,%%cr3\n" ::"c"(__pa(swapper_pg_dir)));
/*
* Final function for resuming: after copying the pages to their original
* position, it restores the register state.
*
* What about page tables? Writing data pages may toggle
* accessed/dirty bits in our page tables. That should be no problems
* with 4MB page tables. That's why we require have_pse.
*
* This loops destroys stack from under itself, so it better should
* not use any stack space, itself. When this function is entered at
* resume time, we move stack to _old_ place. This is means that this
* function must use no stack and no local variables in registers,
* until calling restore_processor_context();
*
* Critical section here: noone should touch saved memory after
* do_magic_resume_1; copying works, because nr_copy_pages,
* pagedir_nosave, loop and loop2 are nosavedata.
*/
do_magic_resume_1();
for (loop=0; loop < nr_copy_pages; loop++) {
/* You may not call something (like copy_page) here: see above */
for (loop2=0; loop2 < PAGE_SIZE; loop2++) {
*(((char *)((pagedir_nosave+loop)->orig_address))+loop2) =
*(((char *)((pagedir_nosave+loop)->address))+loop2);
__flush_tlb();
}
}
restore_processor_context();
/* Ahah, we now run with our old stack, and with registers copied from
suspend time */
do_magic_resume_2();
}
include/asm-i386/suspend.h
View file @ 7f9efd7d
...@@ -33,266 +33,14 @@ struct saved_context { ...@@ -33,266 +33,14 @@ struct saved_context {
u32 eflags; u32 eflags;
} __attribute__((packed)); } __attribute__((packed));
static struct saved_context saved_context;
#define loaddebug(thread,register) \ #define loaddebug(thread,register) \
__asm__("movl %0,%%db" #register \ __asm__("movl %0,%%db" #register \
: /* no output */ \ : /* no output */ \
:"r" ((thread)->debugreg[register])) :"r" ((thread)->debugreg[register]))
extern void do_fpu_end(void);
/* extern void fix_processor_context(void);
* save_processor_context extern void do_magic(int resume);
*
* Save the state of the processor before we go to sleep.
*
* return_stack is the value of the stack pointer (%esp) as the caller sees it.
* A good way could not be found to obtain it from here (don't want to make _too_
* many assumptions about the layout of the stack this far down.) Also, the
* handy little __builtin_frame_pointer(level) where level > 0, is blatantly
* buggy - it returns the value of the stack at the proper location, not the
* location, like it should (as of gcc 2.91.66)
*
* Note that the context and timing of this function is pretty critical.
* With a minimal amount of things going on in the caller and in here, gcc
* does a good job of being just a dumb compiler. Watch the assembly output
* if anything changes, though, and make sure everything is going in the right
* place.
*/
static inline void save_processor_context (void)
{
kernel_fpu_begin();
/*
* descriptor tables
*/
asm volatile ("sgdt (%0)" : "=m" (saved_context.gdt_limit));
asm volatile ("sidt (%0)" : "=m" (saved_context.idt_limit));
asm volatile ("sldt (%0)" : "=m" (saved_context.ldt));
asm volatile ("str (%0)" : "=m" (saved_context.tr));
/*
* save the general registers.
* note that gcc has constructs to specify output of certain registers,
* but they're not used here, because it assumes that you want to modify
* those registers, so it tries to be smart and save them beforehand.
* It's really not necessary, and kinda fishy (check the assembly output),
* so it's avoided.
*/
asm volatile ("movl %%esp, (%0)" : "=m" (saved_context.esp));
asm volatile ("movl %%eax, (%0)" : "=m" (saved_context.eax));
asm volatile ("movl %%ebx, (%0)" : "=m" (saved_context.ebx));
asm volatile ("movl %%ecx, (%0)" : "=m" (saved_context.ecx));
asm volatile ("movl %%edx, (%0)" : "=m" (saved_context.edx));
asm volatile ("movl %%ebp, (%0)" : "=m" (saved_context.ebp));
asm volatile ("movl %%esi, (%0)" : "=m" (saved_context.esi));
asm volatile ("movl %%edi, (%0)" : "=m" (saved_context.edi));
/*
* segment registers
*/
asm volatile ("movw %%es, %0" : "=r" (saved_context.es));
asm volatile ("movw %%fs, %0" : "=r" (saved_context.fs));
asm volatile ("movw %%gs, %0" : "=r" (saved_context.gs));
asm volatile ("movw %%ss, %0" : "=r" (saved_context.ss));
/*
* control registers
*/
asm volatile ("movl %%cr0, %0" : "=r" (saved_context.cr0));
asm volatile ("movl %%cr2, %0" : "=r" (saved_context.cr2));
asm volatile ("movl %%cr3, %0" : "=r" (saved_context.cr3));
asm volatile ("movl %%cr4, %0" : "=r" (saved_context.cr4));
/*
* eflags
*/
asm volatile ("pushfl ; popl (%0)" : "=m" (saved_context.eflags));
}
static void fix_processor_context(void)
{
int nr = smp_processor_id();
struct tss_struct * t = &init_tss[nr];
set_tss_desc(nr,t); /* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy tsc or some similar stupidity. */
gdt_table[__TSS(nr)].b &= 0xfffffdff;
load_TR(nr); /* This does ltr */
load_LDT(&current->mm->context); /* This does lldt */
/*
* Now maybe reload the debug registers
*/
if (current->thread.debugreg[7]){
loaddebug(&current->thread, 0);
loaddebug(&current->thread, 1);
loaddebug(&current->thread, 2);
loaddebug(&current->thread, 3);
/* no 4 and 5 */
loaddebug(&current->thread, 6);
loaddebug(&current->thread, 7);
}
}
static void
do_fpu_end(void)
{
/* restore FPU regs if necessary */
/* Do it out of line so that gcc does not move cr0 load to some stupid place */
kernel_fpu_end();
}
/*
* restore_processor_context
*
* Restore the processor context as it was before we went to sleep
* - descriptor tables
* - control registers
* - segment registers
* - flags
*
* Note that it is critical that this function is declared inline.
* It was separated out from restore_state to make that function
* a little clearer, but it needs to be inlined because we won't have a
* stack when we get here (so we can't push a return address).
*/
static inline void restore_processor_context (void)
{
/*
* first restore %ds, so we can access our data properly
*/
asm volatile (".align 4");
asm volatile ("movw %0, %%ds" :: "r" ((u16)__KERNEL_DS));
/*
* control registers
*/
asm volatile ("movl %0, %%cr4" :: "r" (saved_context.cr4));
asm volatile ("movl %0, %%cr3" :: "r" (saved_context.cr3));
asm volatile ("movl %0, %%cr2" :: "r" (saved_context.cr2));
asm volatile ("movl %0, %%cr0" :: "r" (saved_context.cr0));
/*
* segment registers
*/
asm volatile ("movw %0, %%es" :: "r" (saved_context.es));
asm volatile ("movw %0, %%fs" :: "r" (saved_context.fs));
asm volatile ("movw %0, %%gs" :: "r" (saved_context.gs));
asm volatile ("movw %0, %%ss" :: "r" (saved_context.ss));
/*
* the other general registers
*
* note that even though gcc has constructs to specify memory
* input into certain registers, it will try to be too smart
* and save them at the beginning of the function. This is esp.
* bad since we don't have a stack set up when we enter, and we
* want to preserve the values on exit. So, we set them manually.
*/
asm volatile ("movl %0, %%esp" :: "m" (saved_context.esp));
asm volatile ("movl %0, %%ebp" :: "m" (saved_context.ebp));
asm volatile ("movl %0, %%eax" :: "m" (saved_context.eax));
asm volatile ("movl %0, %%ebx" :: "m" (saved_context.ebx));
asm volatile ("movl %0, %%ecx" :: "m" (saved_context.ecx));
asm volatile ("movl %0, %%edx" :: "m" (saved_context.edx));
asm volatile ("movl %0, %%esi" :: "m" (saved_context.esi));
asm volatile ("movl %0, %%edi" :: "m" (saved_context.edi));
/*
* now restore the descriptor tables to their proper values
* ltr is done i fix_processor_context().
*/
asm volatile ("lgdt (%0)" :: "m" (saved_context.gdt_limit));
asm volatile ("lidt (%0)" :: "m" (saved_context.idt_limit));
asm volatile ("lldt (%0)" :: "m" (saved_context.ldt));
fix_processor_context();
/*
* the flags
*/
asm volatile ("pushl %0 ; popfl" :: "m" (saved_context.eflags));
do_fpu_end();
}
#ifdef SUSPEND_C
/* Local variables for do_magic */
static int loop __nosavedata = 0;
static int loop2 __nosavedata = 0;
/*
* (KG): Since we affect stack here, we make this function as flat and easy
* as possible in order to not provoke gcc to use local variables on the stack.
* Note that on resume, all (expect nosave) variables will have the state from
* the time of writing (suspend_save_image) and the registers (including the
* stack pointer, but excluding the instruction pointer) will be loaded with
* the values saved at save_processor_context() time.
*/
static void do_magic(int resume)
{
/* DANGER WILL ROBINSON!
*
* If this function is too difficult for gcc to optimize, it will crash and burn!
* see above.
*
* DO NOT TOUCH.
*/
if (!resume) {
do_magic_suspend_1();
save_processor_context(); /* We need to capture registers and memory at "same time" */
do_magic_suspend_2(); /* If everything goes okay, this function does not return */
return;
}
/* We want to run from swapper_pg_dir, since swapper_pg_dir is stored in constant
* place in memory
*/
__asm__( "movl %%ecx,%%cr3\n" ::"c"(__pa(swapper_pg_dir)));
/*
* Final function for resuming: after copying the pages to their original
* position, it restores the register state.
*
* What about page tables? Writing data pages may toggle
* accessed/dirty bits in our page tables. That should be no problems
* with 4MB page tables. That's why we require have_pse.
*
* This loops destroys stack from under itself, so it better should
* not use any stack space, itself. When this function is entered at
* resume time, we move stack to _old_ place. This is means that this
* function must use no stack and no local variables in registers,
* until calling restore_processor_context();
*
* Critical section here: noone should touch saved memory after
* do_magic_resume_1; copying works, because nr_copy_pages,
* pagedir_nosave, loop and loop2 are nosavedata.
*/
do_magic_resume_1();
for (loop=0; loop < nr_copy_pages; loop++) {
/* You may not call something (like copy_page) here: see above */
for (loop2=0; loop2 < PAGE_SIZE; loop2++) {
*(((char *)((pagedir_nosave+loop)->orig_address))+loop2) =
*(((char *)((pagedir_nosave+loop)->address))+loop2);
__flush_tlb();
}
}
restore_processor_context();
/* Ahah, we now run with our old stack, and with registers copied from
suspend time */
do_magic_resume_2();
}
#endif
#ifdef CONFIG_ACPI_SLEEP #ifdef CONFIG_ACPI_SLEEP
extern unsigned long saved_eip; extern unsigned long saved_eip;
......
include/linux/suspend.h
View file @ 7f9efd7d
...@@ -55,6 +55,10 @@ extern int register_suspend_notifier(struct notifier_block *); ...@@ -55,6 +55,10 @@ extern int register_suspend_notifier(struct notifier_block *);
extern int unregister_suspend_notifier(struct notifier_block *); extern int unregister_suspend_notifier(struct notifier_block *);
extern void refrigerator(unsigned long); extern void refrigerator(unsigned long);
extern unsigned int nr_copy_pages __nosavedata;
extern suspend_pagedir_t *pagedir_nosave __nosavedata;
#else #else
#define software_suspend() do { } while(0) #define software_suspend() do { } while(0)
#define software_resume() do { } while(0) #define software_resume() do { } while(0)
......
kernel/suspend.c
View file @ 7f9efd7d
...@@ -106,7 +106,7 @@ static int resume_status = 0; ...@@ -106,7 +106,7 @@ static int resume_status = 0;
static char resume_file[256] = ""; /* For resume= kernel option */ static char resume_file[256] = ""; /* For resume= kernel option */
static kdev_t resume_device; static kdev_t resume_device;
/* Local variables that should not be affected by save */ /* Local variables that should not be affected by save */
static unsigned int nr_copy_pages __nosavedata = 0; unsigned int nr_copy_pages __nosavedata = 0;
static int pm_suspend_state = 0; static int pm_suspend_state = 0;
...@@ -119,7 +119,7 @@ static int pm_suspend_state = 0; ...@@ -119,7 +119,7 @@ static int pm_suspend_state = 0;
allocated at time of resume, that travels through memory not to allocated at time of resume, that travels through memory not to
collide with anything. collide with anything.
*/ */
static suspend_pagedir_t *pagedir_nosave __nosavedata = NULL; suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
static suspend_pagedir_t *pagedir_save; static suspend_pagedir_t *pagedir_save;
static int pagedir_order __nosavedata = 0; static int pagedir_order __nosavedata = 0;
...@@ -783,7 +783,7 @@ void suspend_power_down(void) ...@@ -783,7 +783,7 @@ void suspend_power_down(void)
* Magic happens here * Magic happens here
*/ */
static void do_magic_resume_1(void) void do_magic_resume_1(void)
{ {
barrier(); barrier();
mb(); mb();
...@@ -795,7 +795,7 @@ static void do_magic_resume_1(void) ...@@ -795,7 +795,7 @@ static void do_magic_resume_1(void)
driver scheduled DMA, we have good chance for DMA to finish ;-). */ driver scheduled DMA, we have good chance for DMA to finish ;-). */
} }
static void do_magic_resume_2(void) void do_magic_resume_2(void)
{ {
if (nr_copy_pages_check != nr_copy_pages) if (nr_copy_pages_check != nr_copy_pages)
panic("nr_copy_pages changed?!"); panic("nr_copy_pages changed?!");
...@@ -817,14 +817,14 @@ static void do_magic_resume_2(void) ...@@ -817,14 +817,14 @@ static void do_magic_resume_2(void)
#endif #endif
} }
static void do_magic_suspend_1(void) void do_magic_suspend_1(void)
{ {
mb(); mb();
barrier(); barrier();
spin_lock_irq(&suspend_pagedir_lock); spin_lock_irq(&suspend_pagedir_lock);
} }
static void do_magic_suspend_2(void) void do_magic_suspend_2(void)
{ {
read_swapfiles(); read_swapfiles();
if (!suspend_save_image()) if (!suspend_save_image())
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7