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