PM: Optional beeping during resume from suspend to RAM

Add a feature allowing the user to make the system beep during a resume from
suspend to RAM, on x86_64 and i386.

This is useful for the users with broken resume from RAM, so that they can
verify if the control reaches the kernel after a wake-up event.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 76 insertions, 0 deletions

diff --git a/arch/i386/kernel/acpi/wakeup.S b/arch/i386/kernel/acpi/wakeup.S
index a2295a34b2c7..b4e2ec3c3928 100644
--- a/arch/i386/kernel/acpi/wakeup.S
+++ b/arch/i386/kernel/acpi/wakeup.S
@@ -13,6 +13,21 @@
 # cs = 0x1234, eip = 0x05
 # 
 
+#define BEEP \
+        inb     $97, %al;       \
+        outb    %al, $0x80;     \
+        movb    $3, %al;        \
+        outb    %al, $97;       \
+        outb    %al, $0x80;     \
+        movb    $-74, %al;      \
+        outb    %al, $67;       \
+        outb    %al, $0x80;     \
+        movb    $-119, %al;     \
+        outb    %al, $66;       \
+        outb    %al, $0x80;     \
+        movb    $15, %al;       \
+        outb    %al, $66;
+
 ALIGN
         .align  4096
 ENTRY(wakeup_start)
@@ -31,6 +46,11 @@ wakeup_code:
         movw    %cs, %ax
         movw    %ax, %ds                                        # Make ds:0 point to wakeup_start
         movw    %ax, %ss
+
+        testl   $1, beep_flags - wakeup_code
+        jz      1f
+        BEEP
+1:
         mov     $(wakeup_stack - wakeup_code), %sp              # Private stack is needed for ASUS board
         movw    $0x0e00 + 'S', %fs:(0x12)
 
@@ -88,6 +108,10 @@ wakeup_code:
         cmpl    $0x12345678, %eax
         jne     bogus_real_magic
 
+        testl   $2, beep_flags - wakeup_code
+        jz      1f
+        BEEP
+1:
         ljmpl   $__KERNEL_CS,$wakeup_pmode_return
 
 real_save_gdt:  .word 0
@@ -98,6 +122,7 @@ real_save_cr4:	.long 0
 real_magic:     .long 0
 video_mode:     .long 0
 video_flags:    .long 0
+beep_flags:     .long 0
 real_efer_save_restore: .long 0
 real_save_efer_edx:     .long 0
 real_save_efer_eax:     .long 0
@@ -262,6 +287,8 @@ ENTRY(acpi_copy_wakeup_routine)
         movl    %edx, video_mode - wakeup_start (%eax)
         movl    acpi_video_flags, %edx
         movl    %edx, video_flags - wakeup_start (%eax)
+        movl    s2ram_beep, %edx
+        movl    %edx, beep_flags - wakeup_start (%eax)
         movl    $0x12345678, real_magic - wakeup_start (%eax)
         movl    $0x12345678, saved_magic
         popl    %ebx
diff --git a/arch/x86_64/kernel/acpi/wakeup.S b/arch/x86_64/kernel/acpi/wakeup.S
index 8550a6ffa275..ed63d1845792 100644
--- a/arch/x86_64/kernel/acpi/wakeup.S
+++ b/arch/x86_64/kernel/acpi/wakeup.S
@@ -16,6 +16,21 @@
 # cs = 0x1234, eip = 0x05
 #
 
+#define BEEP \
+        inb     $97, %al;       \
+        outb    %al, $0x80;     \
+        movb    $3, %al;        \
+        outb    %al, $97;       \
+        outb    %al, $0x80;     \
+        movb    $-74, %al;      \
+        outb    %al, $67;       \
+        outb    %al, $0x80;     \
+        movb    $-119, %al;     \
+        outb    %al, $66;       \
+        outb    %al, $0x80;     \
+        movb    $15, %al;       \
+        outb    %al, $66;
+
 
 ALIGN
         .align  16
@@ -33,6 +48,13 @@ wakeup_code:
         movw    %cs, %ax
         movw    %ax, %ds                # Make ds:0 point to wakeup_start
         movw    %ax, %ss
+
+        # Data segment must be set up before we can see whether to beep.
+        testl   $1, beep_flags - wakeup_code
+        jz      1f
+        BEEP
+1:
+
                                         # Private stack is needed for ASUS board
         mov     $(wakeup_stack - wakeup_code), %sp
 
@@ -229,6 +251,7 @@ gdt_48a:
         .long   gdta - wakeup_code              # gdt base (relocated in later)
         
 real_magic:     .quad 0
+beep_flags:     .quad 0
 video_mode:     .quad 0
 video_flags:    .quad 0
 
@@ -344,6 +367,8 @@ ENTRY(acpi_copy_wakeup_routine)
         pushq   %rax
         pushq   %rdx
 
+        movl    s2ram_beep, %edx
+        movl    %edx, beep_flags - wakeup_start (,%rdi)
         movl    saved_video_mode, %edx
         movl    %edx, video_mode - wakeup_start (,%rdi)
         movl    acpi_video_flags, %edx
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index fccd8b548d93..c0ccdd720363 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -123,6 +123,7 @@ extern int pci_mmcfg_config_num;
 
 extern int sbf_port;
 extern unsigned long acpi_video_flags;
+extern unsigned long s2ram_beep;
 
 #else   /* !CONFIG_ACPI */
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 32147b57c3bf..c74a56436d8b 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -332,6 +332,27 @@ static ssize_t state_store(struct kset *kset, const char *buf, size_t n)
 
 power_attr(state);
 
+unsigned long s2ram_beep = 0;
+
+static ssize_t s2ram_beep_show(struct kset *kset, char *buf)
+{
+        return sprintf(buf, "%d\n", s2ram_beep);
+}
+
+static ssize_t
+s2ram_beep_store(struct kset *kset, const char *buf, size_t n)
+{
+        int val;
+
+        if (sscanf(buf, "%d", &val) > 0) {
+                s2ram_beep = val;
+                return n;
+        }
+        return -EINVAL;
+}
+
+power_attr(s2ram_beep);
+
 #ifdef CONFIG_PM_TRACE
 int pm_trace_enabled;
 
@@ -357,11 +378,13 @@ power_attr(pm_trace);
 static struct attribute * g[] = {
         &state_attr.attr,
         &pm_trace_attr.attr,
+        &s2ram_beep_attr.attr,
         NULL,
 };
 #else
 static struct attribute * g[] = {
         &state_attr.attr,
+        &s2ram_beep_attr.attr,
         NULL,
 };
 #endif /* CONFIG_PM_TRACE */