1 // SPDX-License-Identifier: GPL-2.0
5  * Copyright (C) 2019-2024 ARM Ltd.
20  * SCMI specification requires all parameters, message headers, return
37 static void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,  in shmem_tx_prepare()  argument
47 	 * overwriting its response with new message payload or vice-versa.  in shmem_tx_prepare()
49 	 * not to bail-out on intermittent issues where the platform is  in shmem_tx_prepare()
52 	 * Note that after a timeout is detected we bail-out and carry on but  in shmem_tx_prepare()
55 	 * due to a misbehaving SCMI firmware.  in shmem_tx_prepare()
57 	stop = ktime_add_ms(ktime_get(), 2 * cinfo->rx_timeout_ms);  in shmem_tx_prepare()
58 	spin_until_cond((ioread32(&shmem->channel_status) &  in shmem_tx_prepare()
61 	if (!(ioread32(&shmem->channel_status) &  in shmem_tx_prepare()
64 		dev_err(cinfo->dev,  in shmem_tx_prepare()
70 	iowrite32(0x0, &shmem->channel_status);  in shmem_tx_prepare()
71 	iowrite32(xfer->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,  in shmem_tx_prepare()
72 		  &shmem->flags);  in shmem_tx_prepare()
73 	iowrite32(sizeof(shmem->msg_header) + xfer->tx.len, &shmem->length);  in shmem_tx_prepare()
74 	iowrite32(pack_scmi_header(&xfer->hdr), &shmem->msg_header);  in shmem_tx_prepare()
75 	if (xfer->tx.buf)  in shmem_tx_prepare()
76 		memcpy_toio(shmem->msg_payload, xfer->tx.buf, xfer->tx.len);  in shmem_tx_prepare()
79 static u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem)  in shmem_read_header()  argument
81 	return ioread32(&shmem->msg_header);  in shmem_read_header()
84 static void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,  in shmem_fetch_response()  argument
87 	size_t len = ioread32(&shmem->length);  in shmem_fetch_response()
89 	xfer->hdr.status = ioread32(shmem->msg_payload);  in shmem_fetch_response()
90 	/* Skip the length of header and status in shmem area i.e 8 bytes */  in shmem_fetch_response()
91 	xfer->rx.len = min_t(size_t, xfer->rx.len, len > 8 ? len - 8 : 0);  in shmem_fetch_response()
94 	memcpy_fromio(xfer->rx.buf, shmem->msg_payload + 4, xfer->rx.len);  in shmem_fetch_response()
97 static void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,  in shmem_fetch_notification()  argument
100 	size_t len = ioread32(&shmem->length);  in shmem_fetch_notification()
102 	/* Skip only the length of header in shmem area i.e 4 bytes */  in shmem_fetch_notification()
103 	xfer->rx.len = min_t(size_t, max_len, len > 4 ? len - 4 : 0);  in shmem_fetch_notification()
106 	memcpy_fromio(xfer->rx.buf, shmem->msg_payload, xfer->rx.len);  in shmem_fetch_notification()
109 static void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem)  in shmem_clear_channel()  argument
111 	iowrite32(SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE, &shmem->channel_status);  in shmem_clear_channel()
114 static bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,  in shmem_poll_done()  argument
119 	xfer_id = MSG_XTRACT_TOKEN(ioread32(&shmem->msg_header));  in shmem_poll_done()
121 	if (xfer->hdr.seq != xfer_id)  in shmem_poll_done()
124 	return ioread32(&shmem->channel_status) &  in shmem_poll_done()
129 static bool shmem_channel_free(struct scmi_shared_mem __iomem *shmem)  in shmem_channel_free()  argument
131 	return (ioread32(&shmem->channel_status) &  in shmem_channel_free()
135 static bool shmem_channel_intr_enabled(struct scmi_shared_mem __iomem *shmem)  in shmem_channel_intr_enabled()  argument
137 	return ioread32(&shmem->flags) & SCMI_SHMEM_FLAG_INTR_ENABLED;  in shmem_channel_intr_enabled()
144 	struct device_node *shmem __free(device_node);  in shmem_setup_iomap()
147 	struct device *cdev = cinfo->dev;  in shmem_setup_iomap()
152 	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);  in shmem_setup_iomap()
153 	if (!shmem)  in shmem_setup_iomap()
154 		return IOMEM_ERR_PTR(-ENODEV);  in shmem_setup_iomap()
156 	if (!of_device_is_compatible(shmem, "arm,scmi-shmem"))  in shmem_setup_iomap()
157 		return IOMEM_ERR_PTR(-ENXIO);  in shmem_setup_iomap()
159 	/* Use a local on-stack as a working area when not provided */  in shmem_setup_iomap()
163 	ret = of_address_to_resource(shmem, 0, res);  in shmem_setup_iomap()
165 		dev_err(cdev, "failed to get SCMI %s shared memory\n", desc);  in shmem_setup_iomap()
170 	addr = devm_ioremap(dev, res->start, size);  in shmem_setup_iomap()
172 		dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc);  in shmem_setup_iomap()
173 		return IOMEM_ERR_PTR(-EADDRNOTAVAIL);  in shmem_setup_iomap()