Re: [linux-pm] Re: wakeup code translated to .c

Rafael J. Wysocki
2008-02-03T23:30:27Z

On Monday, 4 of February 2008, Rafael J. Wysocki wrote:
> 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).

Now also tested on x86-64 (works just fine :-)).

> 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;
> }
>
>

Greetings,
Rafael