diff options
| author | Daniel Drake <dsd@laptop.org> | 2011-06-25 17:34:11 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2011-07-06 14:44:32 -0700 |
| commit | 97c4cb71c18fe045a763ff6681a8ebbbbbec0b2b (patch) | |
| tree | 66874802ab61cbf45c1d4d8d645b93e7600cdc0c /arch/x86/platform/olpc/xo1-wakeup.S | |
| parent | a3128588b3c6be634a9013a375903e0b55668f0a (diff) | |
x86, olpc: Add XO-1 suspend/resume support
Add code needed for basic suspend/resume of the XO-1 laptop.
Based on earlier work by Jordan Crouse, Andres Salomon, and others.
This patch incorporates all earlier feedback from Thomas Gleixner. To
clarify a certain point (now more obvious in the code itself):
On resume, OpenFirmware returns execution to Linux in protected mode
with a kernel-compatible GDT already set up. The changes and
simplifications suggested have all been included.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-5-git-send-email-dsd@laptop.org
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/platform/olpc/xo1-wakeup.S')
| -rw-r--r-- | arch/x86/platform/olpc/xo1-wakeup.S | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/xo1-wakeup.S b/arch/x86/platform/olpc/xo1-wakeup.S new file mode 100644 index 000000000000..948deb289753 --- /dev/null +++ b/arch/x86/platform/olpc/xo1-wakeup.S @@ -0,0 +1,124 @@ +.text +#include <linux/linkage.h> +#include <asm/segment.h> +#include <asm/page.h> +#include <asm/pgtable_32.h> + + .macro writepost,value + movb $0x34, %al + outb %al, $0x70 + movb $\value, %al + outb %al, $0x71 + .endm + +wakeup_start: + # OFW lands us here, running in protected mode, with a + # kernel-compatible GDT already setup. + + # Clear any dangerous flags + pushl $0 + popfl + + writepost 0x31 + + # Set up %cr3 + movl $initial_page_table - __PAGE_OFFSET, %eax + movl %eax, %cr3 + + movl saved_cr4, %eax + movl %eax, %cr4 + + movl saved_cr0, %eax + movl %eax, %cr0 + + # Control registers were modified, pipeline resync is needed + jmp 1f +1: + + movw $__KERNEL_DS, %ax + movw %ax, %ss + movw %ax, %ds + movw %ax, %es + movw %ax, %fs + movw %ax, %gs + + lgdt saved_gdt + lidt saved_idt + lldt saved_ldt + ljmp $(__KERNEL_CS),$1f +1: + movl %cr3, %eax + movl %eax, %cr3 + wbinvd + + # Go back to the return point + jmp ret_point + +save_registers: + sgdt saved_gdt + sidt saved_idt + sldt saved_ldt + + pushl %edx + movl %cr4, %edx + movl %edx, saved_cr4 + + movl %cr0, %edx + movl %edx, saved_cr0 + + popl %edx + + movl %ebx, saved_context_ebx + movl %ebp, saved_context_ebp + movl %esi, saved_context_esi + movl %edi, saved_context_edi + + pushfl + popl saved_context_eflags + + ret + +restore_registers: + movl saved_context_ebp, %ebp + movl saved_context_ebx, %ebx + movl saved_context_esi, %esi + movl saved_context_edi, %edi + + pushl saved_context_eflags + popfl + + ret + +ENTRY(do_olpc_suspend_lowlevel) + call save_processor_state + call save_registers + + # This is the stack context we want to remember + movl %esp, saved_context_esp + + pushl $3 + call xo1_do_sleep + + jmp wakeup_start + .p2align 4,,7 +ret_point: + movl saved_context_esp, %esp + + writepost 0x32 + + call restore_registers + call restore_processor_state + ret + +.data +saved_gdt: .long 0,0 +saved_idt: .long 0,0 +saved_ldt: .long 0 +saved_cr4: .long 0 +saved_cr0: .long 0 +saved_context_esp: .long 0 +saved_context_edi: .long 0 +saved_context_esi: .long 0 +saved_context_ebx: .long 0 +saved_context_ebp: .long 0 +saved_context_eflags: .long 0 |