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Subject2.5.20 swsusp: stop abusing headers with non-inlined functions
Hi!

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. Please apply,
Pavel
--- linux-swsusp.test/arch/i386/kernel/suspend.c Wed Jun 5 13:26:33 2002
+++ linux-swsusp/arch/i386/kernel/suspend.c Wed Jun 5 13:49:19 2002
@@ -24,7 +24,155 @@
#include <linux/suspend.h>
#include <asm/uaccess.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)
{
/*
@@ -42,4 +190,112 @@
acpi_sleep_done:
acpi_restore_register_state();
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();
}
--- linux-swsusp.test/include/asm-i386/suspend.h Wed Jun 5 13:18:42 2002
+++ linux-swsusp/include/asm-i386/suspend.h Wed Jun 5 13:59:13 2002
@@ -33,266 +33,14 @@
u32 eflags;
} __attribute__((packed));

-static struct saved_context saved_context;
-
#define loaddebug(thread,register) \
__asm__("movl %0,%%db" #register \
: /* no output */ \
:"r" ((thread)->debugreg[register]))

-
-/*
- * 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));
-}
-
-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
+extern void do_fpu_end(void);
+extern void fix_processor_context(void);
+extern void do_magic(int resume);

#ifdef CONFIG_ACPI_SLEEP
extern unsigned long saved_eip;
--- linux-swsusp.test/include/linux/suspend.h Wed Jun 5 13:18:42 2002
+++ linux-swsusp/include/linux/suspend.h Wed Jun 5 13:59:13 2002
@@ -55,6 +55,10 @@
extern int unregister_suspend_notifier(struct notifier_block *);
extern void refrigerator(unsigned long);

+extern unsigned int nr_copy_pages __nosavedata;
+extern suspend_pagedir_t *pagedir_nosave __nosavedata;
+
+
#else
#define software_suspend() do { } while(0)
#define software_resume() do { } while(0)
--- linux-swsusp.test/kernel/suspend.c Mon Jun 3 18:41:41 2002
+++ linux-swsusp/kernel/suspend.c Wed Jun 5 13:40:23 2002
@@ -106,7 +106,7 @@
static char resume_file[256] = ""; /* For resume= kernel option */
static kdev_t resume_device;
/* 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;

@@ -119,7 +119,7 @@
allocated at time of resume, that travels through memory not to
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 int pagedir_order __nosavedata = 0;

@@ -783,7 +783,7 @@
* Magic happens here
*/

-static void do_magic_resume_1(void)
+void do_magic_resume_1(void)
{
barrier();
mb();
@@ -795,7 +795,7 @@
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)
panic("nr_copy_pages changed?!");
@@ -817,14 +817,14 @@
#endif
}

-static void do_magic_suspend_1(void)
+void do_magic_suspend_1(void)
{
mb();
barrier();
spin_lock_irq(&suspend_pagedir_lock);
}

-static void do_magic_suspend_2(void)
+void do_magic_suspend_2(void)
{
read_swapfiles();
if (!suspend_save_image())
--
(about SSSCA) "I don't say this lightly. However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
-
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