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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
- * Copyright (C) 2019-2020 Linaro Limited.
- */
- #define LOG_CATEGORY UCLASS_SCMI_AGENT
- #include <common.h>
- #include <cpu_func.h>
- #include <dm.h>
- #include <dm/device_compat.h>
- #include <errno.h>
- #include <scmi_agent.h>
- #include <asm/cache.h>
- #include <asm/system.h>
- #include <dm/ofnode.h>
- #include <linux/compat.h>
- #include <linux/io.h>
- #include <linux/ioport.h>
- #include "smt.h"
- /**
- * Get shared memory configuration defined by the referred DT phandle
- * Return with a errno compliant value.
- */
- int scmi_dt_get_smt_buffer(struct udevice *dev, struct scmi_smt *smt)
- {
- int ret;
- struct ofnode_phandle_args args;
- struct resource resource;
- ret = dev_read_phandle_with_args(dev, "shmem", NULL, 0, 0, &args);
- if (ret)
- return ret;
- ret = ofnode_read_resource(args.node, 0, &resource);
- if (ret)
- return ret;
- smt->size = resource_size(&resource);
- if (smt->size < sizeof(struct scmi_smt_header)) {
- dev_err(dev, "Shared memory buffer too small\n");
- return -EINVAL;
- }
- smt->buf = devm_ioremap(dev, resource.start, smt->size);
- if (!smt->buf)
- return -ENOMEM;
- #ifdef CONFIG_ARM
- if (dcache_status())
- mmu_set_region_dcache_behaviour(ALIGN_DOWN((uintptr_t)smt->buf, MMU_SECTION_SIZE),
- ALIGN(smt->size, MMU_SECTION_SIZE),
- DCACHE_OFF);
- #endif
- return 0;
- }
- /**
- * Write SCMI message @msg into a SMT shared buffer @smt.
- * Return 0 on success and with a negative errno in case of error.
- */
- int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
- struct scmi_msg *msg)
- {
- struct scmi_smt_header *hdr = (void *)smt->buf;
- if ((!msg->in_msg && msg->in_msg_sz) ||
- (!msg->out_msg && msg->out_msg_sz))
- return -EINVAL;
- if (!(hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE)) {
- dev_dbg(dev, "Channel busy\n");
- return -EBUSY;
- }
- if (smt->size < (sizeof(*hdr) + msg->in_msg_sz) ||
- smt->size < (sizeof(*hdr) + msg->out_msg_sz)) {
- dev_dbg(dev, "Buffer too small\n");
- return -ETOOSMALL;
- }
- /* Load message in shared memory */
- hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
- hdr->length = msg->in_msg_sz + sizeof(hdr->msg_header);
- hdr->msg_header = SMT_HEADER_TOKEN(0) |
- SMT_HEADER_MESSAGE_TYPE(0) |
- SMT_HEADER_PROTOCOL_ID(msg->protocol_id) |
- SMT_HEADER_MESSAGE_ID(msg->message_id);
- memcpy_toio(hdr->msg_payload, msg->in_msg, msg->in_msg_sz);
- return 0;
- }
- /**
- * Read SCMI message from a SMT shared buffer @smt and copy it into @msg.
- * Return 0 on success and with a negative errno in case of error.
- */
- int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
- struct scmi_msg *msg)
- {
- struct scmi_smt_header *hdr = (void *)smt->buf;
- if (!(hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE)) {
- dev_err(dev, "Channel unexpectedly busy\n");
- return -EBUSY;
- }
- if (hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR) {
- dev_err(dev, "Channel error reported, reset channel\n");
- return -ECOMM;
- }
- if (hdr->length > msg->out_msg_sz + sizeof(hdr->msg_header)) {
- dev_err(dev, "Buffer to small\n");
- return -ETOOSMALL;
- }
- /* Get the data */
- msg->out_msg_sz = hdr->length - sizeof(hdr->msg_header);
- memcpy_fromio(msg->out_msg, hdr->msg_payload, msg->out_msg_sz);
- return 0;
- }
- /**
- * Clear SMT flags in shared buffer to allow further message exchange
- */
- void scmi_clear_smt_channel(struct scmi_smt *smt)
- {
- struct scmi_smt_header *hdr = (void *)smt->buf;
- hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
- }
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