RAS: Add support for node registration

Previous patches added frameworks for handling RAS errors. This patch
introduces features that the platform can use to enumerate and iterate
RAS nodes:

  - The REGISTER_RAS_NODES() can be used to expose an array of
    ras_node_info_t structures. Each ras_node_info_t describes a RAS
    node, along with handlers for probing the node for error, and if
    did record an error, another handler to handle it.

  - The macro for_each_ras_node() can be used to iterate over the
    registered RAS nodes, probe for, and handle any errors.

The common platform EA handler has been amended using error handling
primitives introduced by both this and previous patches.

Change-Id: I2e13f65a88357bc48cd97d608db6c541fad73853
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

include/lib/extensions/ras.h

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __RAS_COMMON__
+#define __RAS_COMMON__
+
+#define ERR_HANDLER_VERSION	1
+
+/* Error record access mechanism */
+#define ERR_ACCESS_SYSREG	0
+#define ERR_ACCESS_MEMMAP	1
+
+/*
+ * Register all error records on the platform.
+ *
+ * This macro must be used in the same file as the array of error record info
+ * are declared. Only then would ARRAY_SIZE() yield a meaningful value.
+ */
+#define REGISTER_ERR_RECORD_INFO(_records) \
+	const struct err_record_mapping err_record_mapping = { \
+		.err_records = _records, \
+		.num_err_records = ARRAY_SIZE(_records), \
+	}
+
+/* Error record info iterator */
+#define for_each_err_record_info(_i, _info) \
+	for (_i = 0, _info = err_record_mapping.err_records; \
+		_i < err_record_mapping.num_err_records; \
+		_i++, _info++)
+
+#define _ERR_RECORD_COMMON(_probe, _handler, _aux) \
+	.probe = _probe, \
+	.handler = _handler, \
+	.aux_data = _aux,
+
+#define ERR_RECORD_SYSREG_V1(_idx_start, _num_idx, _probe, _handler, _aux) \
+	{ \
+		.version = 1, \
+		.sysreg.idx_start = _idx_start, \
+		.sysreg.num_idx = _num_idx, \
+		.access = ERR_ACCESS_SYSREG, \
+		_ERR_RECORD_COMMON(_probe, _handler, _aux) \
+	}
+
+#define ERR_RECORD_MEMMAP_V1(_base_addr, _size_num_k, _probe, _handler, _aux) \
+	{ \
+		.version = 1, \
+		.memmap.base_addr = _base_addr, \
+		.memmap.size_num_k = _size_num_k, \
+		.access = ERR_ACCESS_MEMMAP, \
+		_ERR_RECORD_COMMON(_probe, _handler, _aux) \
+	}
+
+#ifndef __ASSEMBLY__
+
+#include <assert.h>
+#include <ras_arch.h>
+
+struct err_record_info;
+
+/* Function to probe a error record group for error */
+typedef int (*err_record_probe_t)(const struct err_record_info *info,
+		int *probe_data);
+
+/* Data passed to error record group handler */
+struct err_handler_data {
+	/* Info passed on from top-level exception handler */
+	uint64_t flags;
+	void *cookie;
+	void *handle;
+
+	/* Data structure version */
+	unsigned int version;
+
+	/* Reason for EA: one the ERROR_* constants */
+	unsigned int ea_reason;
+
+	/*
+	 * For EAs received at vector, the value read from ESR; for an EA
+	 * synchronized by ESB, the value of DISR.
+	 */
+	uint32_t syndrome;
+};
+
+/* Function to handle error from an error record group */
+typedef int (*err_record_handler_t)(const struct err_record_info *info,
+		int probe_data, const struct err_handler_data *const data);
+
+/* Error record information */
+struct err_record_info {
+	/* Function to probe error record group for errors */
+	err_record_probe_t probe;
+
+	/* Function to handle error record group errors */
+	err_record_handler_t handler;
+
+	/* Opaque group-specific data */
+	void *aux_data;
+
+	/* Additional information for Standard Error Records */
+	union {
+		struct {
+			/*
+			 * For a group accessed via. memory-mapped register,
+			 * base address of the page hosting error records, and
+			 * the size of the record group.
+			 */
+			uintptr_t base_addr;
+
+			/* Size of group in number of KBs */
+			unsigned int size_num_k;
+		} memmap;
+
+		struct {
+			/*
+			 * For error records accessed via. system register, index of
+			 * the error record.
+			 */
+			unsigned int idx_start;
+			unsigned int num_idx;
+		} sysreg;
+	};
+
+	/* Data structure version */
+	unsigned int version;
+
+	/* Error record access mechanism */
+	unsigned int access:1;
+};
+
+struct err_record_mapping {
+	struct err_record_info *err_records;
+	size_t num_err_records;
+};
+
+extern const struct err_record_mapping err_record_mapping;
+
+
+/*
+ * Helper functions to probe memory-mapped and system registers implemented in
+ * Standard Error Record format
+ */
+static inline int ras_err_ser_probe_memmap(const struct err_record_info *info,
+		int *probe_data)
+{
+	assert(info->version == ERR_HANDLER_VERSION);
+
+	return ser_probe_memmap(info->memmap.base_addr, info->memmap.size_num_k,
+		probe_data);
+}
+
+static inline int ras_err_ser_probe_sysreg(const struct err_record_info *info,
+		int *probe_data)
+{
+	assert(info->version == ERR_HANDLER_VERSION);
+
+	return ser_probe_sysreg(info->sysreg.idx_start, info->sysreg.num_idx,
+			probe_data);
+}
+
+int ras_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
+		void *handle, uint64_t flags);
+
+#endif /* __ASSEMBLY__ */
+#endif /* __RAS_COMMON__ */

lib/extensions/ras/ras_common.c

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <debug.h>
+#include <ea_handle.h>
+#include <ehf.h>
+#include <platform.h>
+#include <ras.h>
+#include <ras_arch.h>
+
+/* Handler that receives External Aborts on RAS-capable systems */
+int ras_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
+		void *handle, uint64_t flags)
+{
+	unsigned int i, n_handled = 0, ret;
+	int probe_data;
+	struct err_record_info *info;
+
+	const struct err_handler_data err_data = {
+		.version = ERR_HANDLER_VERSION,
+		.ea_reason = ea_reason,
+		.syndrome = syndrome,
+		.flags = flags,
+		.cookie = cookie,
+		.handle = handle
+	};
+
+	for_each_err_record_info(i, info) {
+		assert(info->probe != NULL);
+		assert(info->handler != NULL);
+
+		/* Continue probing until the record group signals no error */
+		while (1) {
+			if (info->probe(info, &probe_data) == 0)
+				break;
+
+			/* Handle error */
+			ret = info->handler(info, probe_data, &err_data);
+			if (ret != 0)
+				return ret;
+
+			n_handled++;
+		}
+	}
+
+	return (n_handled != 0);
+}

plat/common/aarch64/plat_common.c

@@ -8,6 +8,9 @@
 #include <assert.h>
 #include <console.h>
 #include <platform.h>
+#if RAS_EXTENSION
+#include <ras.h>
+#endif
 #include <xlat_mmu_helpers.h>
 
 /*
@@ -112,6 +115,13 @@ int plat_sdei_validate_entry_point(uintptr_t ep, unsigned int client_mode)
 void plat_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
 		void *handle, uint64_t flags)
 {
+#if RAS_EXTENSION
+	/* Call RAS EA handler */
+	int handled = ras_ea_handler(ea_reason, syndrome, cookie, handle, flags);
+	if (handled != 0)
+		return;
+#endif
+
 	ERROR("Unhandled External Abort received on 0x%lx at EL3!\n",
 			read_mpidr_el1());
 	ERROR(" exception reason=%u syndrome=0x%lx\n", ea_reason, syndrome);