powerpc/pseries: Add support for IO event interrupts

This patch adds support for handling IO Event interrupts which come
through at the /event-sources/ibm,io-events device tree node.

The interrupts come through ibm,io-events device tree node are generated
by the firmware to report IO events. The firmware uses the same interrupt
to report multiple types of events for multiple devices. Each device may
have its own event handler. This patch implements a plateform interrupt
handler that is triggered by the IO event interrupts come through
ibm,io-events device tree node, pull in the IO events from RTAS and call
device event handlers registered in the notifier list.

Device event handlers are expected to use atomic_notifier_chain_register()
and atomic_notifier_chain_unregister() to register/unregister their
event handler in pseries_ioei_notifier_list list with IO event interrupt.
Device event handlers are responsible to identify if the event belongs
to the device event handler. The device event handle should return NOTIFY_OK
after the event is handled if the event belongs to the device event handler,
or NOTIFY_DONE otherwise.

Signed-off-by: Tseng-Hui (Frank) Lin <thlin@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/io_event_irq.h b/arch/powerpc/include/asm/io_event_irq.h
new file mode 100644
index 00000000000..b1a9a1be3c2
--- /dev/null
+++ b/arch/powerpc/include/asm/io_event_irq.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010, 2011 Mark Nelson and Tseng-Hui (Frank) Lin, IBM Corporation
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _ASM_POWERPC_IO_EVENT_IRQ_H
+#define _ASM_POWERPC_IO_EVENT_IRQ_H
+
+#include <linux/types.h>
+#include <linux/notifier.h>
+
+#define PSERIES_IOEI_RPC_MAX_LEN 216
+
+#define PSERIES_IOEI_TYPE_ERR_DETECTED		0x01
+#define PSERIES_IOEI_TYPE_ERR_RECOVERED		0x02
+#define PSERIES_IOEI_TYPE_EVENT			0x03
+#define PSERIES_IOEI_TYPE_RPC_PASS_THRU		0x04
+
+#define PSERIES_IOEI_SUBTYPE_NOT_APP		0x00
+#define PSERIES_IOEI_SUBTYPE_REBALANCE_REQ	0x01
+#define PSERIES_IOEI_SUBTYPE_NODE_ONLINE	0x03
+#define PSERIES_IOEI_SUBTYPE_NODE_OFFLINE	0x04
+#define PSERIES_IOEI_SUBTYPE_DUMP_SIZE_CHANGE	0x05
+#define PSERIES_IOEI_SUBTYPE_TORRENT_IRV_UPDATE	0x06
+#define PSERIES_IOEI_SUBTYPE_TORRENT_HFI_CFGED	0x07
+
+#define PSERIES_IOEI_SCOPE_NOT_APP		0x00
+#define PSERIES_IOEI_SCOPE_RIO_HUB		0x36
+#define PSERIES_IOEI_SCOPE_RIO_BRIDGE		0x37
+#define PSERIES_IOEI_SCOPE_PHB			0x38
+#define PSERIES_IOEI_SCOPE_EADS_GLOBAL		0x39
+#define PSERIES_IOEI_SCOPE_EADS_SLOT		0x3A
+#define PSERIES_IOEI_SCOPE_TORRENT_HUB		0x3B
+#define PSERIES_IOEI_SCOPE_SERVICE_PROC		0x51
+
+/* Platform Event Log Format, Version 6, data portition of IO event section */
+struct pseries_io_event {
+	uint8_t event_type;		/* 0x00 IO-Event Type		*/
+	uint8_t rpc_data_len;		/* 0x01 RPC data length		*/
+	uint8_t scope;			/* 0x02 Error/Event Scope	*/
+	uint8_t event_subtype;		/* 0x03 I/O-Event Sub-Type	*/
+	uint32_t drc_index;		/* 0x04 DRC Index		*/
+	uint8_t rpc_data[PSERIES_IOEI_RPC_MAX_LEN];
+					/* 0x08 RPC Data (0-216 bytes,	*/
+					/* padded to 4 bytes alignment)	*/
+};
+
+extern struct atomic_notifier_head pseries_ioei_notifier_list;
+
+#endif /* _ASM_POWERPC_IO_EVENT_IRQ_H */