firmware: arm_sdei: Add driver for Software Delegated Exceptions

The Software Delegated Exception Interface (SDEI) is an ARM standard
for registering callbacks from the platform firmware into the OS.
This is typically used to implement firmware notifications (such as
firmware-first RAS) or promote an IRQ that has been promoted to a
firmware-assisted NMI.

Add the code for detecting the SDEI version and the framework for
registering and unregistering events. Subsequent patches will add the
arch-specific backend code and the necessary power management hooks.

Only shared events are supported, power management, private events and
discovery for ACPI systems will be added by later patches.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 73 insertions, 0 deletions

diff --git a/include/uapi/linux/arm_sdei.h b/include/uapi/linux/arm_sdei.h
new file mode 100644
index 000000000000..af0630ba5437
--- /dev/null
+++ b/include/uapi/linux/arm_sdei.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (C) 2017 Arm Ltd. */
+#ifndef _UAPI_LINUX_ARM_SDEI_H
+#define _UAPI_LINUX_ARM_SDEI_H
+
+#define SDEI_1_0_FN_BASE			0xC4000020
+#define SDEI_1_0_MASK				0xFFFFFFE0
+#define SDEI_1_0_FN(n)				(SDEI_1_0_FN_BASE + (n))
+
+#define SDEI_1_0_FN_SDEI_VERSION			SDEI_1_0_FN(0x00)
+#define SDEI_1_0_FN_SDEI_EVENT_REGISTER			SDEI_1_0_FN(0x01)
+#define SDEI_1_0_FN_SDEI_EVENT_ENABLE			SDEI_1_0_FN(0x02)
+#define SDEI_1_0_FN_SDEI_EVENT_DISABLE			SDEI_1_0_FN(0x03)
+#define SDEI_1_0_FN_SDEI_EVENT_CONTEXT			SDEI_1_0_FN(0x04)
+#define SDEI_1_0_FN_SDEI_EVENT_COMPLETE			SDEI_1_0_FN(0x05)
+#define SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME	SDEI_1_0_FN(0x06)
+#define SDEI_1_0_FN_SDEI_EVENT_UNREGISTER		SDEI_1_0_FN(0x07)
+#define SDEI_1_0_FN_SDEI_EVENT_STATUS			SDEI_1_0_FN(0x08)
+#define SDEI_1_0_FN_SDEI_EVENT_GET_INFO			SDEI_1_0_FN(0x09)
+#define SDEI_1_0_FN_SDEI_EVENT_ROUTING_SET		SDEI_1_0_FN(0x0A)
+#define SDEI_1_0_FN_SDEI_PE_MASK			SDEI_1_0_FN(0x0B)
+#define SDEI_1_0_FN_SDEI_PE_UNMASK			SDEI_1_0_FN(0x0C)
+#define SDEI_1_0_FN_SDEI_INTERRUPT_BIND			SDEI_1_0_FN(0x0D)
+#define SDEI_1_0_FN_SDEI_INTERRUPT_RELEASE		SDEI_1_0_FN(0x0E)
+#define SDEI_1_0_FN_SDEI_PRIVATE_RESET			SDEI_1_0_FN(0x11)
+#define SDEI_1_0_FN_SDEI_SHARED_RESET			SDEI_1_0_FN(0x12)
+
+#define SDEI_VERSION_MAJOR_SHIFT			48
+#define SDEI_VERSION_MAJOR_MASK				0x7fff
+#define SDEI_VERSION_MINOR_SHIFT			32
+#define SDEI_VERSION_MINOR_MASK				0xffff
+#define SDEI_VERSION_VENDOR_SHIFT			0
+#define SDEI_VERSION_VENDOR_MASK			0xffffffff
+
+#define SDEI_VERSION_MAJOR(x)	(x>>SDEI_VERSION_MAJOR_SHIFT & SDEI_VERSION_MAJOR_MASK)
+#define SDEI_VERSION_MINOR(x)	(x>>SDEI_VERSION_MINOR_SHIFT & SDEI_VERSION_MINOR_MASK)
+#define SDEI_VERSION_VENDOR(x)	(x>>SDEI_VERSION_VENDOR_SHIFT & SDEI_VERSION_VENDOR_MASK)
+
+/* SDEI return values */
+#define SDEI_SUCCESS		0
+#define SDEI_NOT_SUPPORTED	-1
+#define SDEI_INVALID_PARAMETERS	-2
+#define SDEI_DENIED		-3
+#define SDEI_PENDING		-5
+#define SDEI_OUT_OF_RESOURCE	-10
+
+/* EVENT_REGISTER flags */
+#define SDEI_EVENT_REGISTER_RM_ANY	0
+#define SDEI_EVENT_REGISTER_RM_PE	1
+
+/* EVENT_STATUS return value bits */
+#define SDEI_EVENT_STATUS_RUNNING	2
+#define SDEI_EVENT_STATUS_ENABLED	1
+#define SDEI_EVENT_STATUS_REGISTERED	0
+
+/* EVENT_COMPLETE status values */
+#define SDEI_EV_HANDLED	0
+#define SDEI_EV_FAILED	1
+
+/* GET_INFO values */
+#define SDEI_EVENT_INFO_EV_TYPE			0
+#define SDEI_EVENT_INFO_EV_SIGNALED		1
+#define SDEI_EVENT_INFO_EV_PRIORITY		2
+#define SDEI_EVENT_INFO_EV_ROUTING_MODE		3
+#define SDEI_EVENT_INFO_EV_ROUTING_AFF		4
+
+/* and their results */
+#define SDEI_EVENT_TYPE_PRIVATE			0
+#define SDEI_EVENT_TYPE_SHARED			1
+#define SDEI_EVENT_PRIORITY_NORMAL		0
+#define SDEI_EVENT_PRIORITY_CRITICAL		1
+
+#endif /* _UAPI_LINUX_ARM_SDEI_H */