Merge pull request #1373 from jeenu-arm/ras-support

RAS support

4 files changed, 250 insertions, 11 deletions

diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S
index 620ec16ff..121ca4d30 100644
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -15,8 +15,8 @@
 	.global	fpregs_context_restore
 #endif
 	.global	save_gp_registers
+	.global	restore_gp_registers
 	.global	restore_gp_registers_eret
-	.global	restore_gp_registers_callee_eret
 	.global	el3_exit
 
 /* -----------------------------------------------------
@@ -332,30 +332,50 @@ func save_gp_registers
 	ret
 endfunc save_gp_registers
 
-func restore_gp_registers_eret
+/*
+ * This function restores all general purpose registers except x30 from the
+ * CPU context. x30 register must be explicitly restored by the caller.
+ */
+func restore_gp_registers
 	ldp	x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
 	ldp	x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
-	b	restore_gp_registers_callee_eret
-endfunc restore_gp_registers_eret
-
-func restore_gp_registers_callee_eret
 	ldp	x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
 	ldp	x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
 	ldp	x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
 	ldp	x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
 	ldp	x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
 	ldp	x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
+	ldp	x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
 	ldp	x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
 	ldp	x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
 	ldp	x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
 	ldp	x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
 	ldp	x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
+	ldr	x28, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0]
+	msr	sp_el0, x28
 	ldp	x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
-	ldp	x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
-	msr	sp_el0, x17
-	ldp	x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
+	ret
+endfunc restore_gp_registers
+
+/*
+ * Restore general purpose registers (including x30), and exit EL3 via. ERET to
+ * a lower exception level.
+ */
+func restore_gp_registers_eret
+	bl	restore_gp_registers
+	ldr	x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+
+#if IMAGE_BL31 && RAS_EXTENSION
+	/*
+	 * Issue Error Synchronization Barrier to synchronize SErrors before
+	 * exiting EL3. We're running with EAs unmasked, so any synchronized
+	 * errors would be taken immediately; therefore no need to inspect
+	 * DISR_EL1 register.
+	 */
+	esb
+#endif
 	eret
-endfunc	restore_gp_registers_callee_eret
+endfunc	restore_gp_registers_eret
 
 	/* -----------------------------------------------------
 	 * This routine assumes that the SP_EL3 is pointing to
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 2608d1fcc..76eecc188 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -114,6 +114,11 @@ static void cm_init_context_common(cpu_context_t *ctx, const entry_point_info_t
 	scr_el3 &= ~SCR_EA_BIT;
 #endif
 
+#if FAULT_INJECTION_SUPPORT
+	/* Enable fault injection from lower ELs */
+	scr_el3 |= SCR_FIEN_BIT;
+#endif
+
 #ifdef IMAGE_BL31
 	/*
 	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ rounting as
diff --git a/lib/extensions/ras/ras_common.c b/lib/extensions/ras/ras_common.c
new file mode 100644
index 000000000..0335a7bcb
--- /dev/null
+++ b/lib/extensions/ras/ras_common.c
@@ -0,0 +1,138 @@
+/*
+ * 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>
+
+#ifndef PLAT_RAS_PRI
+# error Platform must define RAS priority value
+#endif
+
+/* 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,
+		.interrupt = 0,
+		.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);
+}
+
+#if ENABLE_ASSERTIONS
+static void assert_interrupts_sorted(void)
+{
+	unsigned int i, last;
+	struct ras_interrupt *start = ras_interrupt_mapping.intrs;
+
+	if (ras_interrupt_mapping.num_intrs == 0)
+		return;
+
+	last = start[0].intr_number;
+	for (i = 1; i < ras_interrupt_mapping.num_intrs; i++) {
+		assert(start[i].intr_number > last);
+		last = start[i].intr_number;
+	}
+}
+#endif
+
+/*
+ * Given an RAS interrupt number, locate the registered handler and call it. If
+ * no handler was found for the interrupt number, this function panics.
+ */
+static int ras_interrupt_handler(uint32_t intr_raw, uint32_t flags,
+		void *handle, void *cookie)
+{
+	struct ras_interrupt *ras_inrs = ras_interrupt_mapping.intrs;
+	struct ras_interrupt *selected = NULL;
+	int start, end, mid, probe_data, ret __unused;
+
+	const struct err_handler_data err_data = {
+		.version = ERR_HANDLER_VERSION,
+		.interrupt = intr_raw,
+		.flags = flags,
+		.cookie = cookie,
+		.handle = handle
+	};
+
+	assert(ras_interrupt_mapping.num_intrs > 0);
+
+	start = 0;
+	end = ras_interrupt_mapping.num_intrs;
+	while (start <= end) {
+		mid = ((end + start) / 2);
+		if (intr_raw == ras_inrs[mid].intr_number) {
+			selected = &ras_inrs[mid];
+			break;
+		} else if (intr_raw < ras_inrs[mid].intr_number) {
+			/* Move left */
+			end = mid - 1;
+		} else {
+			/* Move right */
+			start = mid + 1;
+		}
+	}
+
+	if (selected == NULL) {
+		ERROR("RAS interrupt %u has no handler!\n", intr_raw);
+		panic();
+	}
+
+
+	ret = selected->err_record->probe(selected->err_record, &probe_data);
+	assert(ret != 0);
+
+	/* Call error handler for the record group */
+	assert(selected->err_record->handler != NULL);
+	selected->err_record->handler(selected->err_record, probe_data,
+			&err_data);
+
+	return 0;
+}
+
+void ras_init(void)
+{
+#if ENABLE_ASSERTIONS
+	/* Check RAS interrupts are sorted */
+	assert_interrupts_sorted();
+#endif
+
+	/* Register RAS priority handler */
+	ehf_register_priority_handler(PLAT_RAS_PRI, ras_interrupt_handler);
+}
diff --git a/lib/extensions/ras/std_err_record.c b/lib/extensions/ras/std_err_record.c
new file mode 100644
index 000000000..65c007f9e
--- /dev/null
+++ b/lib/extensions/ras/std_err_record.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <ras_arch.h>
+#include <utils_def.h>
+
+/*
+ * Probe for error in memory-mapped registers containing error records
+ * implemented Standard Error Record format. Upon detecting an error, set probe
+ * data to the index of the record in error, and return 1; otherwise, return 0.
+ */
+int ser_probe_memmap(uintptr_t base, unsigned int size_num_k, int *probe_data)
+{
+	int num_records, num_group_regs, i;
+	uint64_t gsr;
+
+	assert(base != 0);
+
+	/* Only 4K supported for now */
+	assert(size_num_k == STD_ERR_NODE_SIZE_NUM_K);
+
+	num_records = (mmio_read_32(ERR_DEVID(base, size_num_k)) & ERR_DEVID_MASK);
+
+	/* A group register shows error status for 2^6 error records */
+	num_group_regs = (num_records >> 6) + 1;
+
+	/* Iterate through group registers to find a record in error */
+	for (i = 0; i < num_group_regs; i++) {
+		gsr = mmio_read_64(ERR_GSR(base, size_num_k, i));
+		if (gsr == 0)
+			continue;
+
+		/* Return the index of the record in error */
+		if (probe_data != NULL)
+			*probe_data = ((i << 6) + __builtin_ctz(gsr));
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Probe for error in System Registers where error records are implemented in
+ * Standard Error Record format. Upon detecting an error, set probe data to the
+ * index of the record in error, and return 1; otherwise, return 0.
+ */
+int ser_probe_sysreg(unsigned int idx_start, unsigned int num_idx, int *probe_data)
+{
+	int i;
+	uint64_t status;
+	unsigned int max_idx __unused = read_erridr_el1() & ERRIDR_MASK;
+
+	assert(idx_start < max_idx);
+	assert(check_u32_overflow(idx_start, num_idx) == 0);
+	assert((idx_start + num_idx - 1) < max_idx);
+
+	for (i = 0; i < num_idx; i++) {
+		/* Select the error record */
+		ser_sys_select_record(idx_start + i);
+
+		/* Retrieve status register from the error record */
+		status = read_erxstatus_el1();
+
+		/* Check for valid field in status */
+		if (ERR_STATUS_GET_FIELD(status, V)) {
+			if (probe_data != NULL)
+				*probe_data = i;
+			return 1;
+		}
+	}
+
+	return 0;
+}