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-rw-r--r--arch/x86/platform/olpc/xo1-wakeup.S126
1 files changed, 126 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 000000000..3a5abffe5
--- /dev/null
+++ b/arch/x86/platform/olpc/xo1-wakeup.S
@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+.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
+
+SYM_CODE_START(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
+SYM_CODE_END(do_olpc_suspend_lowlevel)
+
+.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