powerpc/powernv Platform dump interface

This enables support for userspace to fetch and initiate FSP and
Platform dumps from the service processor (via firmware) through sysfs.

Based on original patch from Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

Flow:
  - We register for OPAL notification events.
  - OPAL sends new dump available notification.
  - We make information on dump available via sysfs
  - Userspace requests dump contents
  - We retrieve the dump via OPAL interface
  - User copies the dump data
  - userspace sends ack for dump
  - We send ACK to OPAL.

sysfs files:
  - We add the /sys/firmware/opal/dump directory
  - echoing 1 (well, anything, but in future we may support
    different dump types) to /sys/firmware/opal/dump/initiate_dump
    will initiate a dump.
  - Each dump that we've been notified of gets a directory
    in /sys/firmware/opal/dump/ with a name of the dump type and ID (in hex,
    as this is what's used elsewhere to identify the dump).
  - Each dump has files: id, type, dump and acknowledge
    dump is binary and is the dump itself.
    echoing 'ack' to acknowledge (currently any string will do) will
    acknowledge the dump and it will soon after disappear from sysfs.

OPAL APIs:
  - opal_dump_init()
  - opal_dump_info()
  - opal_dump_read()
  - opal_dump_ack()
  - opal_dump_resend_notification()

Currently we are only ever notified for one dump at a time (until
the user explicitly acks the current dump, then we get a notification
of the next dump), but this kernel code should "just work" when OPAL
starts notifying us of all the dumps present.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 933adde1bdea..2636acfcd340 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -159,9 +159,15 @@ extern int opal_enter_rtas(struct rtas_args *args,
 #define OPAL_FLASH_VALIDATE			76
 #define OPAL_FLASH_MANAGE			77
 #define OPAL_FLASH_UPDATE			78
+#define OPAL_DUMP_INIT				81
+#define OPAL_DUMP_INFO				82
+#define OPAL_DUMP_READ				83
+#define OPAL_DUMP_ACK				84
 #define OPAL_GET_MSG				85
 #define OPAL_CHECK_ASYNC_COMPLETION		86
+#define OPAL_DUMP_RESEND			91
 #define OPAL_SYNC_HOST_REBOOT			87
+#define OPAL_DUMP_INFO2				94
 
 #ifndef __ASSEMBLY__
 
@@ -242,6 +248,7 @@ enum OpalPendingState {
 	OPAL_EVENT_EPOW			= 0x80,
 	OPAL_EVENT_LED_STATUS		= 0x100,
 	OPAL_EVENT_PCI_ERROR		= 0x200,
+	OPAL_EVENT_DUMP_AVAIL		= 0x400,
 	OPAL_EVENT_MSG_PENDING		= 0x800,
 };
 
@@ -838,6 +845,12 @@ void opal_resend_pending_logs(void);
 int64_t opal_validate_flash(uint64_t buffer, uint32_t *size, uint32_t *result);
 int64_t opal_manage_flash(uint8_t op);
 int64_t opal_update_flash(uint64_t blk_list);
+int64_t opal_dump_init(uint8_t dump_type);
+int64_t opal_dump_info(uint32_t *dump_id, uint32_t *dump_size);
+int64_t opal_dump_info2(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type);
+int64_t opal_dump_read(uint32_t dump_id, uint64_t buffer);
+int64_t opal_dump_ack(uint32_t dump_id);
+int64_t opal_dump_resend_notification(void);
 
 int64_t opal_get_msg(uint64_t buffer, size_t size);
 int64_t opal_check_completion(uint64_t buffer, size_t size, uint64_t token);
@@ -876,6 +889,7 @@ extern unsigned long opal_get_boot_time(void);
 extern void opal_nvram_init(void);
 extern void opal_flash_init(void);
 extern int opal_elog_init(void);
+extern void opal_platform_dump_init(void);
 
 extern int opal_machine_check(struct pt_regs *regs);
 extern bool opal_mce_check_early_recovery(struct pt_regs *regs);