x86, acpi, tboot: Have a ACPI os prepare sleep instead of calling tboot_sleep.

The ACPI suspend path makes a call to tboot_sleep right before
it writes the PM1A, PM1B values. We replace the direct call to
tboot via an registration callback similar to __acpi_register_gsi.

CC: Len Brown <len.brown@intel.com>
Acked-by: Joseph Cihula <joseph.cihula@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
[v1: Added __attribute__ ((unused))]
[v2: Introduced a wrapper instead of changing tboot_sleep return values]
[v3: Added return value AE_CTRL_SKIP for acpi_os_sleep_prepare]
Signed-off-by: Tang Liang <liang.tang@oracle.com>
[v1: Fix compile issues on IA64 and PPC64]
[v2: Fix where __acpi_os_prepare_sleep==NULL and did not go in sleep properly]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/kernel/tboot.c

@@ -297,6 +297,12 @@ void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 
 	tboot_shutdown(acpi_shutdown_map[sleep_state]);
 }
+static int tboot_sleep_wrapper(u8 sleep_state, u32 pm1a_control,
+			       u32 pm1b_control)
+{
+	tboot_sleep(sleep_state, pm1a_control, pm1b_control);
+	return 0;
+}
 
 static atomic_t ap_wfs_count;
 
@@ -345,6 +351,8 @@ static __init int tboot_late_init(void)
 
 	atomic_set(&ap_wfs_count, 0);
 	register_hotcpu_notifier(&tboot_cpu_notifier);
+
+	acpi_os_set_prepare_sleep(&tboot_sleep_wrapper);
 	return 0;
 }
 

drivers/acpi/acpica/hwsleep.c

@@ -43,9 +43,9 @@
  */
 
 #include <acpi/acpi.h>
+#include <linux/acpi.h>
 #include "accommon.h"
 #include "actables.h"
-#include <linux/tboot.h>
 #include <linux/module.h>
 
 #define _COMPONENT          ACPI_HARDWARE
@@ -344,8 +344,12 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 
 	ACPI_FLUSH_CPU_CACHE();
 
-	tboot_sleep(sleep_state, pm1a_control, pm1b_control);
+	status = acpi_os_prepare_sleep(sleep_state, pm1a_control,
-
+				       pm1b_control);
+	if (ACPI_SKIP(status))
+		return_ACPI_STATUS(AE_OK);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
 	/* Write #2: Write both SLP_TYP + SLP_EN */
 
 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);

drivers/acpi/osl.c

@@ -76,6 +76,9 @@ EXPORT_SYMBOL(acpi_in_debugger);
 extern char line_buf[80];
 #endif				/*ENABLE_DEBUGGER */
 
+static int (*__acpi_os_prepare_sleep)(u8 sleep_state, u32 pm1a_ctrl,
+				      u32 pm1b_ctrl);
+
 static acpi_osd_handler acpi_irq_handler;
 static void *acpi_irq_context;
 static struct workqueue_struct *kacpid_wq;
@@ -1659,3 +1662,24 @@ acpi_status acpi_os_terminate(void)
 
 	return AE_OK;
 }
+
+acpi_status acpi_os_prepare_sleep(u8 sleep_state, u32 pm1a_control,
+				  u32 pm1b_control)
+{
+	int rc = 0;
+	if (__acpi_os_prepare_sleep)
+		rc = __acpi_os_prepare_sleep(sleep_state,
+					     pm1a_control, pm1b_control);
+	if (rc < 0)
+		return AE_ERROR;
+	else if (rc > 0)
+		return AE_CTRL_SKIP;
+
+	return AE_OK;
+}
+
+void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
+			       u32 pm1a_ctrl, u32 pm1b_ctrl))
+{
+	__acpi_os_prepare_sleep = func;
+}

include/acpi/acexcep.h

@@ -57,6 +57,7 @@
 #define ACPI_SUCCESS(a)                 (!(a))
 #define ACPI_FAILURE(a)                 (a)
 
+#define ACPI_SKIP(a)                    (a == AE_CTRL_SKIP)
 #define AE_OK                           (acpi_status) 0x0000
 
 /*

include/linux/acpi.h

@@ -359,4 +359,14 @@ static inline int suspend_nvs_register(unsigned long a, unsigned long b)
 }
 #endif
 
+#ifdef CONFIG_ACPI
+void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
+			       u32 pm1a_ctrl,  u32 pm1b_ctrl));
+
+acpi_status acpi_os_prepare_sleep(u8 sleep_state,
+				  u32 pm1a_control, u32 pm1b_control);
+#else
+#define acpi_os_set_prepare_sleep(func, pm1a_ctrl, pm1b_ctrl) do { } while (0)
+#endif
+
 #endif	/*_LINUX_ACPI_H*/

include/linux/tboot.h

@@ -143,7 +143,6 @@ static inline int tboot_enabled(void)
 
 extern void tboot_probe(void);
 extern void tboot_shutdown(u32 shutdown_type);
-extern void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control);
 extern struct acpi_table_header *tboot_get_dmar_table(
 				      struct acpi_table_header *dmar_tbl);
 extern int tboot_force_iommu(void);