Add bl31 support common across Broadcom platforms
Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
Change-Id: Ic1a392a633b447935fa3a7528326c97845f5b1bc
diff --git a/plat/brcm/common/brcm_scpi.c b/plat/brcm/common/brcm_scpi.c
new file mode 100644
index 0000000..0a703cb
--- /dev/null
+++ b/plat/brcm/common/brcm_scpi.c
@@ -0,0 +1,252 @@
+/*
+ * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <lib/utils.h>
+#include <plat/common/platform.h>
+
+#include <brcm_mhu.h>
+#include <brcm_scpi.h>
+#include <platform_def.h>
+
+#define SCPI_SHARED_MEM_SCP_TO_AP (PLAT_SCP_COM_SHARED_MEM_BASE)
+#define SCPI_SHARED_MEM_AP_TO_SCP (PLAT_SCP_COM_SHARED_MEM_BASE \
+ + 0x100)
+
+/* Header and payload addresses for commands from AP to SCP */
+#define SCPI_CMD_HEADER_AP_TO_SCP \
+ ((scpi_cmd_t *) SCPI_SHARED_MEM_AP_TO_SCP)
+#define SCPI_CMD_PAYLOAD_AP_TO_SCP \
+ ((void *) (SCPI_SHARED_MEM_AP_TO_SCP + sizeof(scpi_cmd_t)))
+
+/* Header and payload addresses for responses from SCP to AP */
+#define SCPI_RES_HEADER_SCP_TO_AP \
+ ((scpi_cmd_t *) SCPI_SHARED_MEM_SCP_TO_AP)
+#define SCPI_RES_PAYLOAD_SCP_TO_AP \
+ ((void *) (SCPI_SHARED_MEM_SCP_TO_AP + sizeof(scpi_cmd_t)))
+
+/* ID of the MHU slot used for the SCPI protocol */
+#define SCPI_MHU_SLOT_ID 0
+
+static void scpi_secure_message_start(void)
+{
+ mhu_secure_message_start(SCPI_MHU_SLOT_ID);
+}
+
+static void scpi_secure_message_send(size_t payload_size)
+{
+ /*
+ * Ensure that any write to the SCPI payload area is seen by SCP before
+ * we write to the MHU register. If these 2 writes were reordered by
+ * the CPU then SCP would read stale payload data
+ */
+ dmbst();
+
+ mhu_secure_message_send(SCPI_MHU_SLOT_ID);
+}
+
+static void scpi_secure_message_receive(scpi_cmd_t *cmd)
+{
+ uint32_t mhu_status;
+
+ assert(cmd != NULL);
+
+ mhu_status = mhu_secure_message_wait();
+
+ /* Expect an SCPI message, reject any other protocol */
+ if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
+ ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
+ mhu_status);
+ panic();
+ }
+
+ /*
+ * Ensure that any read to the SCPI payload area is done after reading
+ * the MHU register. If these 2 reads were reordered then the CPU would
+ * read invalid payload data
+ */
+ dmbld();
+
+ memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd));
+}
+
+static void scpi_secure_message_end(void)
+{
+ mhu_secure_message_end(SCPI_MHU_SLOT_ID);
+}
+
+int scpi_wait_ready(void)
+{
+ scpi_cmd_t scpi_cmd;
+
+ VERBOSE("Waiting for SCP_READY command...\n");
+
+ /* Get a message from the SCP */
+ scpi_secure_message_start();
+ scpi_secure_message_receive(&scpi_cmd);
+ scpi_secure_message_end();
+
+ /* We are expecting 'SCP Ready', produce correct error if it's not */
+ scpi_status_t status = SCP_OK;
+
+ if (scpi_cmd.id != SCPI_CMD_SCP_READY) {
+ ERROR("Unexpected SCP command: expected #%u, received #%u\n",
+ SCPI_CMD_SCP_READY, scpi_cmd.id);
+ status = SCP_E_SUPPORT;
+ } else if (scpi_cmd.size != 0) {
+ ERROR("SCP_READY cmd has incorrect size: expected 0, got %u\n",
+ scpi_cmd.size);
+ status = SCP_E_SIZE;
+ }
+
+ VERBOSE("Sending response for SCP_READY command\n");
+
+ /*
+ * Send our response back to SCP.
+ * We are using the same SCPI header, just update the status field.
+ */
+ scpi_cmd.status = status;
+ scpi_secure_message_start();
+ memcpy((void *) SCPI_SHARED_MEM_AP_TO_SCP, &scpi_cmd, sizeof(scpi_cmd));
+ scpi_secure_message_send(0);
+ scpi_secure_message_end();
+
+ return status == SCP_OK ? 0 : -1;
+}
+
+void scpi_set_brcm_power_state(unsigned int mpidr,
+ scpi_power_state_t cpu_state, scpi_power_state_t cluster_state,
+ scpi_power_state_t brcm_state)
+{
+ scpi_cmd_t *cmd;
+ uint32_t state = 0;
+ uint32_t *payload_addr;
+
+#if ARM_PLAT_MT
+ /*
+ * The current SCPI driver only caters for single-threaded platforms.
+ * Hence we ignore the thread ID (which is always 0) for such platforms.
+ */
+ state |= (mpidr >> MPIDR_AFF1_SHIFT) & 0x0f; /* CPU ID */
+ state |= ((mpidr >> MPIDR_AFF2_SHIFT) & 0x0f) << 4; /* Cluster ID */
+#else
+ state |= mpidr & 0x0f; /* CPU ID */
+ state |= (mpidr & 0xf00) >> 4; /* Cluster ID */
+#endif /* ARM_PLAT_MT */
+
+ state |= cpu_state << 8;
+ state |= cluster_state << 12;
+ state |= brcm_state << 16;
+
+ scpi_secure_message_start();
+
+ /* Populate the command header */
+ cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+ cmd->id = SCPI_CMD_SET_POWER_STATE;
+ cmd->set = SCPI_SET_NORMAL;
+ cmd->sender = 0;
+ cmd->size = sizeof(state);
+ /* Populate the command payload */
+ payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
+ *payload_addr = state;
+ scpi_secure_message_send(sizeof(state));
+
+ /*
+ * SCP does not reply to this command in order to avoid MHU interrupts
+ * from the sender, which could interfere with its power state request.
+ */
+ scpi_secure_message_end();
+}
+
+/*
+ * Query and obtain power state from SCP.
+ *
+ * In response to the query, SCP returns power states of all CPUs in all
+ * clusters of the system. The returned response is then filtered based on the
+ * supplied MPIDR. Power states of requested cluster and CPUs within are updated
+ * via. supplied non-NULL pointer arguments.
+ *
+ * Returns 0 on success, or -1 on errors.
+ */
+int scpi_get_brcm_power_state(unsigned int mpidr, unsigned int *cpu_state_p,
+ unsigned int *cluster_state_p)
+{
+ scpi_cmd_t *cmd;
+ scpi_cmd_t response;
+ int power_state, cpu, cluster, rc = -1;
+
+ /*
+ * Extract CPU and cluster membership of the given MPIDR. SCPI caters
+ * for only up to 0xf clusters, and 8 CPUs per cluster
+ */
+ cpu = mpidr & MPIDR_AFFLVL_MASK;
+ cluster = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
+ if (cpu >= 8 || cluster >= 0xf)
+ return -1;
+
+ scpi_secure_message_start();
+
+ /* Populate request headers */
+ zeromem(SCPI_CMD_HEADER_AP_TO_SCP, sizeof(*cmd));
+ cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+ cmd->id = SCPI_CMD_GET_POWER_STATE;
+
+ /*
+ * Send message and wait for SCP's response
+ */
+ scpi_secure_message_send(0);
+ scpi_secure_message_receive(&response);
+
+ if (response.status != SCP_OK)
+ goto exit;
+
+ /* Validate SCP response */
+ if (!CHECK_RESPONSE(response, cluster))
+ goto exit;
+
+ /* Extract power states for required cluster */
+ power_state = *(((uint16_t *) SCPI_RES_PAYLOAD_SCP_TO_AP) + cluster);
+ if (CLUSTER_ID(power_state) != cluster)
+ goto exit;
+
+ /* Update power state via. pointers */
+ if (cluster_state_p)
+ *cluster_state_p = CLUSTER_POWER_STATE(power_state);
+ if (cpu_state_p)
+ *cpu_state_p = CPU_POWER_STATE(power_state);
+ rc = 0;
+
+exit:
+ scpi_secure_message_end();
+ return rc;
+}
+
+uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
+{
+ scpi_cmd_t *cmd;
+ uint8_t *payload_addr;
+
+ scpi_secure_message_start();
+
+ /* Populate the command header */
+ cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+ cmd->id = SCPI_CMD_SYS_POWER_STATE;
+ cmd->set = 0;
+ cmd->sender = 0;
+ cmd->size = sizeof(*payload_addr);
+ /* Populate the command payload */
+ payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
+ *payload_addr = system_state & 0xff;
+ scpi_secure_message_send(sizeof(*payload_addr));
+
+ scpi_secure_message_end();
+
+ return SCP_OK;
+}