Re: [PATCH 2.6.21 2/3] x86_64: EFI64 support

Eric W. Biederman
2007-06-01T18:51:38Z

Chandramouli Narayanan <mouli@linux.intel.com> writes:

> diff -uprN -X linux-2.6.21rc7-git2-orig/Documentation/dontdiff
> linux-2.6.21rc7-git2-orig/arch/x86_64/kernel/reboot.c
> linux-2.6.21rc7-git2-uefi-finaltest/arch/x86_64/kernel/reboot.c
> --- linux-2.6.21rc7-git2-orig/arch/x86_64/kernel/reboot.c 2007-02-04
> 10:44:54.000000000 -0800
> +++ linux-2.6.21rc7-git2-uefi-finaltest/arch/x86_64/kernel/reboot.c 2007-04-19
> 13:01:02.000000000 -0700
> @@ -7,6 +7,7 @@
> #include <linux/ctype.h>
> #include <linux/string.h>
> #include <linux/pm.h>
> +#include <linux/efi.h>
> #include <asm/io.h>
> #include <asm/kdebug.h>
> #include <asm/delay.h>
> @@ -116,9 +117,15 @@ void machine_emergency_restart(void)
> {
> int i;
>
> + /* If EFI enabled, reset system through EFI protocol. */
> + if (efi_enabled) {
> + efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL);
> + return;
> + }
> +
> /* Tell the BIOS if we want cold or warm reboot */
> *((unsigned short *)__va(0x472)) = reboot_mode;
> -
> +

Don't do this.

Instead add an architecture specific pointer that the EFI
initialization code can override. That should be a lot less
intrusive and more maintainable.

> for (;;) {
> /* Could also try the reset bit in the Hammer NB */
> switch (reboot_type) {
> diff -uprN -X linux-2.6.21rc7-git2-orig/Documentation/dontdiff
> linux-2.6.21rc7-git2-orig/arch/x86_64/kernel/setup.c
> linux-2.6.21rc7-git2-uefi-finaltest/arch/x86_64/kernel/setup.c
> --- linux-2.6.21rc7-git2-orig/arch/x86_64/kernel/setup.c 2007-04-19
> 12:39:39.000000000 -0700
> +++ linux-2.6.21rc7-git2-uefi-finaltest/arch/x86_64/kernel/setup.c 2007-04-19
> 13:01:02.000000000 -0700
> @@ -44,6 +44,7 @@
> #include <linux/dmi.h>
> #include <linux/dma-mapping.h>
> #include <linux/ctype.h>
> +#include <linux/efi.h>
>
> #include <asm/mtrr.h>
> #include <asm/uaccess.h>
> @@ -69,6 +70,10 @@
> * Machine setup..
> */
>
> +#ifdef CONFIG_EFI
> +int efi_enabled = 0;
> +EXPORT_SYMBOL(efi_enabled);
> +#endif

Please remove this variable.

I didn't see a single use where it appears to be actually needed.

Eric