feat(fvp): delegate FFH RAS handling to SP
This setup helps to mimic an end-to-end RAS handling flow inspired
by real world design with a dedicated RAS secure partition managed
by SPMC.
The detailed steps are documented as comments in the relevant source
files introduced in this patch.
Change-Id: I97737c66649f6e49840fa0bdf2e0af4fb6b08fc7
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/plat/arm/board/fvp/aarch64/fvp_lsp_ras_sp.c b/plat/arm/board/fvp/aarch64/fvp_lsp_ras_sp.c
new file mode 100644
index 0000000..5324fec
--- /dev/null
+++ b/plat/arm/board/fvp/aarch64/fvp_lsp_ras_sp.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2024, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+
+#include <lib/el3_runtime/context_mgmt.h>
+#include <lib/extensions/ras.h>
+
+#include <plat/common/platform.h>
+#include <services/el3_spmd_logical_sp.h>
+#include <services/ffa_svc.h>
+#include <services/sdei.h>
+
+
+#define CACTUS_SP_RAS_DELEGATE_CMD 0x72617365
+#define EVENT_NOTIFY_OS_RAS_ERROR U(5000)
+
+/*
+ * Note: Typical RAS error handling flow with Firmware First Handling
+ *
+ * Step 1: Exception resulting from a RAS error in the normal world is routed to
+ * EL3.
+ * Step 2: This exception is typically signaled as either a synchronous external
+ * abort or SError or interrupt. TF-A (EL3 firmware) delegates the
+ * control to platform specific handler built on top of the RAS helper
+ * utilities.
+ * Step 3: With the help of a Logical Secure Partition, TF-A sends a direct
+ * message to dedicated S-EL0 (or S-EL1) RAS Partition managed by SPMC.
+ * TF-A also populates a shared buffer with a data structure containing
+ * enough information (such as system registers) to identify and triage
+ * the RAS error.
+ * Step 4: RAS SP generates the Common Platform Error Record (CPER) and shares
+ * it with normal world firmware and/or OS kernel through a reserved
+ * buffer memory.
+ * Step 5: RAS SP responds to the direct message with information necessary for
+ * TF-A to notify the OS kernel.
+ * Step 6: Consequently, TF-A dispatches an SDEI event to notify the OS kernel
+ * about the CPER records for further logging.
+ */
+
+static int injected_fault_handler(const struct err_record_info *info,
+ int probe_data, const struct err_handler_data *const data)
+{
+ /*
+ * At the moment, an FF-A compatible SP that supports RAS firmware is
+ * not available. Hence the sequence below does not exactly follow the
+ * steps outlined above. Therefore, some steps are essentially spoofed.
+ * The handling of RAS error is completely done in EL3 firmware.
+ */
+ uint64_t status, cactus_cmd_ret;
+ int ret, event_num;
+ cpu_context_t *ns_cpu_context;
+
+ /* Get a reference to the non-secure context */
+ ns_cpu_context = cm_get_context(NON_SECURE);
+ assert(ns_cpu_context != NULL);
+
+ /*
+ * The faulting error record is already selected by the SER probe
+ * function.
+ */
+ status = read_erxstatus_el1();
+
+ ERROR("Fault reported by system error record %d on 0x%lx: status=0x%" PRIx64 "\n",
+ probe_data, read_mpidr_el1(), status);
+ ERROR(" exception reason=%u syndrome=0x%" PRIx64 "\n", data->ea_reason,
+ data->flags);
+
+ /* Clear error */
+ write_erxstatus_el1(status);
+
+ /*
+ * Initiate an EL3 direct message from LSP to Cactus RAS Secure
+ * Partition (ID 8001). Currently, the payload is being spoofed.
+ * The direct message response contains the SDEI event ID for the
+ * associated RAS error.
+ */
+ (void)plat_spmd_logical_sp_smc_handler(0, 0, 0, CACTUS_SP_RAS_DELEGATE_CMD,
+ EVENT_NOTIFY_OS_RAS_ERROR,
+ NULL, ns_cpu_context, 0);
+
+ cactus_cmd_ret = read_ctx_reg(get_gpregs_ctx(ns_cpu_context), CTX_GPREG_X3);
+ event_num = (int)read_ctx_reg(get_gpregs_ctx(ns_cpu_context), CTX_GPREG_X4);
+
+ if (cactus_cmd_ret != 0) {
+ ERROR("RAS error could not be handled by SP: %lx\n", cactus_cmd_ret);
+ panic();
+ }
+
+ if (event_num != EVENT_NOTIFY_OS_RAS_ERROR) {
+ ERROR("Unexpected event id sent by RAS SP: %d\n", event_num);
+ panic();
+ }
+
+ /* Dispatch the event to the SDEI client */
+ ret = sdei_dispatch_event(event_num);
+ if (ret < 0) {
+ ERROR("Can't dispatch event to SDEI\n");
+ panic();
+ } else {
+ INFO("SDEI event dispatched\n");
+ }
+
+ return 0;
+}
+
+struct ras_interrupt fvp_ras_interrupts[] = {
+};
+
+struct err_record_info fvp_err_records[] = {
+ /* Record for injected fault */
+ ERR_RECORD_SYSREG_V1(0, 2, ras_err_ser_probe_sysreg,
+ injected_fault_handler, NULL),
+};
+
+REGISTER_ERR_RECORD_INFO(fvp_err_records);
+REGISTER_RAS_INTERRUPTS(fvp_ras_interrupts);