Re: wakeup code translated to .c

Rafael J. Wysocki
2008-02-03T23:20:14Z

On Sunday, 3 of February 2008, Rafael J. Wysocki wrote:
> On Sunday, 3 of February 2008, Pavel Machek wrote:
> > Hi!
> >
> > > > This version works on 32-bit, and builds on 64-bit (but I'm pretty
> > > > sure it does not work. 32-bit code probably needs to go into rm/....)
> > > >
> > >
> > > Do you have an updated version or is this the latest one?
> >
> > I'm glad you ask ;-). Here's reasonably-recent version (I have
> > slightly cleaner one, but it got obscured by 2.6.24-git merge), I
> > eventually got it to work on 64-bit, by reusing trampoline.S code.
>
> I needed to rebase it against the current mainline (Makefile conflict).
>
> Some remarks:
>
> - It looks like arch/x86/kernel/acpi/wakeup.S is not necessary any more.
>
> - These warnings:
>
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c: In function ‘acpi_save_state_mem’:
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:41: warning: initialization makes pointer from integer without a cast
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:50: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:50: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long unsigned int’
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:70: warning: ISO C90 forbids mixed declarations and code
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:82: warning: assignment makes integer from pointer without a cast
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:83: warning: assignment makes integer from pointer without a cast
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:84: warning: ISO C90 forbids mixed declarations and code
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:87: warning: ISO C90 forbids mixed declarations and code
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:90: warning: assignment makes integer from pointer without a cast
> /home/rafael/src/linux-2.6/arch/x86/kernel/acpi/sleep.c:91: warning: ISO C90 forbids mixed declarations and code
>
> look pretty scary.

Below is the arch/x86/kernel/acpi/sleep.c part without the warnings (untested).

It still contains some hardcoded magic numbers and extern declarations, so
I guess the #include list is not complete or another header is necessary.

BTW:
1) why exactly is acpi_wakeup_address not (void *)?
2) header->level3_ident_pgt and header->level3_ident_pgt could be (char *) IMO

--- linux-2.6.orig/arch/x86/kernel/acpi/sleep.c
+++ linux-2.6/arch/x86/kernel/acpi/sleep.c
@@ -11,29 +11,92 @@
#include <linux/cpumask.h>

#include <asm/smp.h>
+#include "rm/wakeup.h"

/* address in low memory of the wakeup routine. */
-unsigned long acpi_wakeup_address = 0;
+static unsigned long acpi_realmode;
+unsigned long acpi_wakeup_address;
unsigned long acpi_realmode_flags;
-extern char wakeup_start, wakeup_end;

+extern char wakeup_code_start, wakeup_code_end;
extern unsigned long acpi_copy_wakeup_routine(unsigned long);
+extern unsigned long setup_trampoline(void);
+extern void wakeup_long64(void);
+
+extern unsigned long saved_video_mode;
+extern long saved_magic;
+extern char level3_ident_pgt[PAGE_SIZE];
+extern char level3_kernel_pgt[PAGE_SIZE];
+extern volatile unsigned long init_rsp;
+extern void (*initial_code)(void);
+#ifndef CONFIG_64BIT
+extern int wakeup_pmode_return;
+extern char swsusp_pg_dir[PAGE_SIZE];
+#endif
+
+static char temp_stack[10240];

/**
* acpi_save_state_mem - save kernel state
*
* Create an identity mapped page table and copy the wakeup routine to
* low memory.
+ *
+ * Note that this is too late to change acpi_wakeup_address.
*/
int acpi_save_state_mem(void)
{
- if (!acpi_wakeup_address) {
- printk(KERN_ERR "Could not allocate memory during boot, S3 disabled\n");
+ struct wakeup_header *header;
+
+ printk("acpi_save_state_mem\n");
+
+ if (!acpi_realmode) {
+ printk(KERN_ERR "Could not allocate memory during boot, "
+ "S3 disabled\n");
return -ENOMEM;
}
- memcpy((void *)acpi_wakeup_address, &wakeup_start,
- &wakeup_end - &wakeup_start);
- acpi_copy_wakeup_routine(acpi_wakeup_address);
+
+ memcpy((void *)acpi_realmode, &wakeup_code_start, 4*PAGE_SIZE);
+
+ header = (struct wakeup_header *)(acpi_realmode + 0x3f00);
+ if (header->signature != 0x51ee1111) {
+ printk(KERN_ERR "wakeup header does not match\n");
+ return -EINVAL;
+ }
+
+ header->video_mode = saved_video_mode;
+ printk("Video mode = %lu, realmode flags = %lu\n",
+ saved_video_mode, acpi_realmode_flags);
+ mdelay(1000);
+
+#ifndef CONFIG_64BIT
+ store_gdt(&header->pmode_gdt);
+
+ header->pmode_efer_low = nx_enabled;
+ if (header->pmode_efer_low & 1) {
+ /* This is strange, why not save efer, always? */
+ rdmsr(MSR_EFER, header->pmode_efer_low,
+ header->pmode_efer_high);
+ }
+#endif /* !CONFIG_64BIT */
+
+ header->pmode_cr0 = read_cr0();
+ header->pmode_cr4 = read_cr4();
+ header->realmode_flags = acpi_realmode_flags;
+ header->real_magic = 0x12345678;
+
+#ifndef CONFIG_64BIT
+ header->pmode_entry = &wakeup_pmode_return;
+ header->pmode_cr3 = swsusp_pg_dir - __PAGE_OFFSET;
+ saved_magic = 0x12345678;
+#else /* CONFIG_64BIT */
+ header->level3_ident_pgt = (u64)level3_ident_pgt;
+ header->level3_kernel_pgt = (u64)level3_kernel_pgt;
+ header->trampoline_segment = setup_trampoline() >> 4;
+ init_rsp = (unsigned long)temp_stack + 4096;
+ initial_code = wakeup_long64;
+ saved_magic = 0x123456789abcdef0;
+#endif /* CONFIG_64BIT */

return 0;
}
@@ -56,15 +119,20 @@ void acpi_restore_state_mem(void)
*/
void __init acpi_reserve_bootmem(void)
{
- if ((&wakeup_end - &wakeup_start) > PAGE_SIZE*2) {
+ if ((&wakeup_code_end - &wakeup_code_start) > PAGE_SIZE*4) {
printk(KERN_ERR
"ACPI: Wakeup code way too big, S3 disabled.\n");
return;
}

- acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE*2);
- if (!acpi_wakeup_address)
+ acpi_realmode = (unsigned long)alloc_bootmem_low(PAGE_SIZE*4);
+
+ if (!acpi_realmode) {
printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
+ return;
+ }
+
+ acpi_wakeup_address = acpi_realmode;
}