tree 34c75749c74fd83193bf0ef56e8e7e40787a9bca
parent 2a14e541ed87bca0c125b82961ca3c6f808607d2
author Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1335150198 -0400
committer H. Peter Anvin <hpa@linux.intel.com> 1335212958 -0700

x86, acpi: Call acpi_enter_sleep_state via an asmlinkage C function from assembler

With commit a2ef5c4fd44ce3922435139393b89f2cce47f576
"ACPI: Move module parameter gts and bfs to sleep.c" the
wake_sleep_flags is required when calling acpi_enter_sleep_state.

The assembler code in wakeup_*.S did not do that. One solution
is to call it from assembler and stick the wake_sleep_flags on
the stack (for 32-bit) or in %esi (for 64-bit). hpa and rafael
both suggested however to create a wrapper function to call
acpi_enter_sleep_state and call said wrapper function
("acpi_enter_s3") from assembler.

For 32-bit, the acpi_enter_s3 ends up looking as so:

  push   %ebp
  mov    %esp,%ebp
  sub    $0x8,%esp
  movzbl 0xc1809314,%eax [wake_sleep_flags]
  movl   $0x3,(%esp)
  mov    %eax,0x4(%esp)
  call   0xc12d1fa0 <acpi_enter_sleep_state>
  leave
  ret

And 64-bit:

  movzbl 0x9afde1(%rip),%esi        [wake_sleep_flags]
  push   %rbp
  mov    $0x3,%edi
  mov    %rsp,%rbp
  callq  0xffffffff812e9800 <acpi_enter_sleep_state>
  leaveq
  retq

Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
[v2: Remove extra assembler operations, per hpa review]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1335150198-21899-3-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>