1 files changed, 590 insertions, 0 deletions

diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c
new file mode 100644
index 000000000..c830e98df
--- /dev/null
+++ b/drivers/platform/x86/intel/sdsi.c
@@ -0,0 +1,590 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Software Defined Silicon driver
+ *
+ * Copyright (c) 2022, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: "David E. Box" <david.e.box@linux.intel.com>
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "vsec.h"
+
+#define ACCESS_TYPE_BARID		2
+#define ACCESS_TYPE_LOCAL		3
+
+#define SDSI_MIN_SIZE_DWORDS		276
+#define SDSI_SIZE_CONTROL		8
+#define SDSI_SIZE_MAILBOX		1024
+#define SDSI_SIZE_REGS			72
+#define SDSI_SIZE_CMD			sizeof(u64)
+
+/*
+ * Write messages are currently up to the size of the mailbox
+ * while read messages are up to 4 times the size of the
+ * mailbox, sent in packets
+ */
+#define SDSI_SIZE_WRITE_MSG		SDSI_SIZE_MAILBOX
+#define SDSI_SIZE_READ_MSG		(SDSI_SIZE_MAILBOX * 4)
+
+#define SDSI_ENABLED_FEATURES_OFFSET	16
+#define SDSI_ENABLED			BIT(3)
+#define SDSI_SOCKET_ID_OFFSET		64
+#define SDSI_SOCKET_ID			GENMASK(3, 0)
+
+#define SDSI_MBOX_CMD_SUCCESS		0x40
+#define SDSI_MBOX_CMD_TIMEOUT		0x80
+
+#define MBOX_TIMEOUT_US			2000
+#define MBOX_TIMEOUT_ACQUIRE_US		1000
+#define MBOX_POLLING_PERIOD_US		100
+#define MBOX_ACQUIRE_NUM_RETRIES	5
+#define MBOX_ACQUIRE_RETRY_DELAY_MS	500
+#define MBOX_MAX_PACKETS		4
+
+#define MBOX_OWNER_NONE			0x00
+#define MBOX_OWNER_INBAND		0x01
+
+#define CTRL_RUN_BUSY			BIT(0)
+#define CTRL_READ_WRITE			BIT(1)
+#define CTRL_SOM			BIT(2)
+#define CTRL_EOM			BIT(3)
+#define CTRL_OWNER			GENMASK(5, 4)
+#define CTRL_COMPLETE			BIT(6)
+#define CTRL_READY			BIT(7)
+#define CTRL_STATUS			GENMASK(15, 8)
+#define CTRL_PACKET_SIZE		GENMASK(31, 16)
+#define CTRL_MSG_SIZE			GENMASK(63, 48)
+
+#define DISC_TABLE_SIZE			12
+#define DT_ACCESS_TYPE			GENMASK(3, 0)
+#define DT_SIZE				GENMASK(27, 12)
+#define DT_TBIR				GENMASK(2, 0)
+#define DT_OFFSET(v)			((v) & GENMASK(31, 3))
+
+enum sdsi_command {
+	SDSI_CMD_PROVISION_AKC		= 0x04,
+	SDSI_CMD_PROVISION_CAP		= 0x08,
+	SDSI_CMD_READ_STATE		= 0x10,
+};
+
+struct sdsi_mbox_info {
+	u64	*payload;
+	void	*buffer;
+	int	size;
+};
+
+struct disc_table {
+	u32	access_info;
+	u32	guid;
+	u32	offset;
+};
+
+struct sdsi_priv {
+	struct mutex		mb_lock;	/* Mailbox access lock */
+	struct device		*dev;
+	void __iomem		*control_addr;
+	void __iomem		*mbox_addr;
+	void __iomem		*regs_addr;
+	u32			guid;
+	bool			sdsi_enabled;
+};
+
+/* SDSi mailbox operations must be performed using 64bit mov instructions */
+static __always_inline void
+sdsi_memcpy64_toio(u64 __iomem *to, const u64 *from, size_t count_bytes)
+{
+	size_t count = count_bytes / sizeof(*to);
+	int i;
+
+	for (i = 0; i < count; i++)
+		writeq(from[i], &to[i]);
+}
+
+static __always_inline void
+sdsi_memcpy64_fromio(u64 *to, const u64 __iomem *from, size_t count_bytes)
+{
+	size_t count = count_bytes / sizeof(*to);
+	int i;
+
+	for (i = 0; i < count; i++)
+		to[i] = readq(&from[i]);
+}
+
+static inline void sdsi_complete_transaction(struct sdsi_priv *priv)
+{
+	u64 control = FIELD_PREP(CTRL_COMPLETE, 1);
+
+	lockdep_assert_held(&priv->mb_lock);
+	writeq(control, priv->control_addr);
+}
+
+static int sdsi_status_to_errno(u32 status)
+{
+	switch (status) {
+	case SDSI_MBOX_CMD_SUCCESS:
+		return 0;
+	case SDSI_MBOX_CMD_TIMEOUT:
+		return -ETIMEDOUT;
+	default:
+		return -EIO;
+	}
+}
+
+static int sdsi_mbox_cmd_read(struct sdsi_priv *priv, struct sdsi_mbox_info *info,
+			      size_t *data_size)
+{
+	struct device *dev = priv->dev;
+	u32 total, loop, eom, status, message_size;
+	u64 control;
+	int ret;
+
+	lockdep_assert_held(&priv->mb_lock);
+
+	/* Format and send the read command */
+	control = FIELD_PREP(CTRL_EOM, 1) |
+		  FIELD_PREP(CTRL_SOM, 1) |
+		  FIELD_PREP(CTRL_RUN_BUSY, 1) |
+		  FIELD_PREP(CTRL_PACKET_SIZE, info->size);
+	writeq(control, priv->control_addr);
+
+	/* For reads, data sizes that are larger than the mailbox size are read in packets. */
+	total = 0;
+	loop = 0;
+	do {
+		void *buf = info->buffer + (SDSI_SIZE_MAILBOX * loop);
+		u32 packet_size;
+
+		/* Poll on ready bit */
+		ret = readq_poll_timeout(priv->control_addr, control, control & CTRL_READY,
+					 MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_US);
+		if (ret)
+			break;
+
+		eom = FIELD_GET(CTRL_EOM, control);
+		status = FIELD_GET(CTRL_STATUS, control);
+		packet_size = FIELD_GET(CTRL_PACKET_SIZE, control);
+		message_size = FIELD_GET(CTRL_MSG_SIZE, control);
+
+		ret = sdsi_status_to_errno(status);
+		if (ret)
+			break;
+
+		/* Only the last packet can be less than the mailbox size. */
+		if (!eom && packet_size != SDSI_SIZE_MAILBOX) {
+			dev_err(dev, "Invalid packet size\n");
+			ret = -EPROTO;
+			break;
+		}
+
+		if (packet_size > SDSI_SIZE_MAILBOX) {
+			dev_err(dev, "Packet size too large\n");
+			ret = -EPROTO;
+			break;
+		}
+
+		sdsi_memcpy64_fromio(buf, priv->mbox_addr, round_up(packet_size, SDSI_SIZE_CMD));
+
+		total += packet_size;
+
+		sdsi_complete_transaction(priv);
+	} while (!eom && ++loop < MBOX_MAX_PACKETS);
+
+	if (ret) {
+		sdsi_complete_transaction(priv);
+		return ret;
+	}
+
+	if (!eom) {
+		dev_err(dev, "Exceeded read attempts\n");
+		return -EPROTO;
+	}
+
+	/* Message size check is only valid for multi-packet transfers */
+	if (loop && total != message_size)
+		dev_warn(dev, "Read count %u differs from expected count %u\n",
+			 total, message_size);
+
+	*data_size = total;
+
+	return 0;
+}
+
+static int sdsi_mbox_cmd_write(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
+{
+	u64 control;
+	u32 status;
+	int ret;
+
+	lockdep_assert_held(&priv->mb_lock);
+
+	/* Write rest of the payload */
+	sdsi_memcpy64_toio(priv->mbox_addr + SDSI_SIZE_CMD, info->payload + 1,
+			   info->size - SDSI_SIZE_CMD);
+
+	/* Format and send the write command */
+	control = FIELD_PREP(CTRL_EOM, 1) |
+		  FIELD_PREP(CTRL_SOM, 1) |
+		  FIELD_PREP(CTRL_RUN_BUSY, 1) |
+		  FIELD_PREP(CTRL_READ_WRITE, 1) |
+		  FIELD_PREP(CTRL_PACKET_SIZE, info->size);
+	writeq(control, priv->control_addr);
+
+	/* Poll on ready bit */
+	ret = readq_poll_timeout(priv->control_addr, control, control & CTRL_READY,
+				 MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_US);
+
+	if (ret)
+		goto release_mbox;
+
+	status = FIELD_GET(CTRL_STATUS, control);
+	ret = sdsi_status_to_errno(status);
+
+release_mbox:
+	sdsi_complete_transaction(priv);
+
+	return ret;
+}
+
+static int sdsi_mbox_acquire(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
+{
+	u64 control;
+	u32 owner;
+	int ret, retries = 0;
+
+	lockdep_assert_held(&priv->mb_lock);
+
+	/* Check mailbox is available */
+	control = readq(priv->control_addr);
+	owner = FIELD_GET(CTRL_OWNER, control);
+	if (owner != MBOX_OWNER_NONE)
+		return -EBUSY;
+
+	/*
+	 * If there has been no recent transaction and no one owns the mailbox,
+	 * we should acquire it in under 1ms. However, if we've accessed it
+	 * recently it may take up to 2.1 seconds to acquire it again.
+	 */
+	do {
+		/* Write first qword of payload */
+		writeq(info->payload[0], priv->mbox_addr);
+
+		/* Check for ownership */
+		ret = readq_poll_timeout(priv->control_addr, control,
+			FIELD_GET(CTRL_OWNER, control) == MBOX_OWNER_INBAND,
+			MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_ACQUIRE_US);
+
+		if (FIELD_GET(CTRL_OWNER, control) == MBOX_OWNER_NONE &&
+		    retries++ < MBOX_ACQUIRE_NUM_RETRIES) {
+			msleep(MBOX_ACQUIRE_RETRY_DELAY_MS);
+			continue;
+		}
+
+		/* Either we got it or someone else did. */
+		break;
+	} while (true);
+
+	return ret;
+}
+
+static int sdsi_mbox_write(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
+{
+	int ret;
+
+	lockdep_assert_held(&priv->mb_lock);
+
+	ret = sdsi_mbox_acquire(priv, info);
+	if (ret)
+		return ret;
+
+	return sdsi_mbox_cmd_write(priv, info);
+}
+
+static int sdsi_mbox_read(struct sdsi_priv *priv, struct sdsi_mbox_info *info, size_t *data_size)
+{
+	int ret;
+
+	lockdep_assert_held(&priv->mb_lock);
+
+	ret = sdsi_mbox_acquire(priv, info);
+	if (ret)
+		return ret;
+
+	return sdsi_mbox_cmd_read(priv, info, data_size);
+}
+
+static ssize_t sdsi_provision(struct sdsi_priv *priv, char *buf, size_t count,
+			      enum sdsi_command command)
+{
+	struct sdsi_mbox_info info;
+	int ret;
+
+	if (!priv->sdsi_enabled)
+		return -EPERM;
+
+	if (count > (SDSI_SIZE_WRITE_MSG - SDSI_SIZE_CMD))
+		return -EOVERFLOW;
+
+	/* Qword aligned message + command qword */
+	info.size = round_up(count, SDSI_SIZE_CMD) + SDSI_SIZE_CMD;
+
+	info.payload = kzalloc(info.size, GFP_KERNEL);
+	if (!info.payload)
+		return -ENOMEM;
+
+	/* Copy message to payload buffer */
+	memcpy(info.payload, buf, count);
+
+	/* Command is last qword of payload buffer */
+	info.payload[(info.size - SDSI_SIZE_CMD) / SDSI_SIZE_CMD] = command;
+
+	ret = mutex_lock_interruptible(&priv->mb_lock);
+	if (ret)
+		goto free_payload;
+	ret = sdsi_mbox_write(priv, &info);
+	mutex_unlock(&priv->mb_lock);
+
+free_payload:
+	kfree(info.payload);
+
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t provision_akc_write(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *attr, char *buf, loff_t off,
+				   size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sdsi_priv *priv = dev_get_drvdata(dev);
+
+	if (off)
+		return -ESPIPE;
+
+	return sdsi_provision(priv, buf, count, SDSI_CMD_PROVISION_AKC);
+}
+static BIN_ATTR_WO(provision_akc, SDSI_SIZE_WRITE_MSG);
+
+static ssize_t provision_cap_write(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *attr, char *buf, loff_t off,
+				   size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sdsi_priv *priv = dev_get_drvdata(dev);
+
+	if (off)
+		return -ESPIPE;
+
+	return sdsi_provision(priv, buf, count, SDSI_CMD_PROVISION_CAP);
+}
+static BIN_ATTR_WO(provision_cap, SDSI_SIZE_WRITE_MSG);
+
+static long state_certificate_read(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *attr, char *buf, loff_t off,
+				   size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sdsi_priv *priv = dev_get_drvdata(dev);
+	u64 command = SDSI_CMD_READ_STATE;
+	struct sdsi_mbox_info info;
+	size_t size;
+	int ret;
+
+	if (!priv->sdsi_enabled)
+		return -EPERM;
+
+	if (off)
+		return 0;
+
+	/* Buffer for return data */
+	info.buffer = kmalloc(SDSI_SIZE_READ_MSG, GFP_KERNEL);
+	if (!info.buffer)
+		return -ENOMEM;
+
+	info.payload = &command;
+	info.size = sizeof(command);
+
+	ret = mutex_lock_interruptible(&priv->mb_lock);
+	if (ret)
+		goto free_buffer;
+	ret = sdsi_mbox_read(priv, &info, &size);
+	mutex_unlock(&priv->mb_lock);
+	if (ret < 0)
+		goto free_buffer;
+
+	if (size > count)
+		size = count;
+
+	memcpy(buf, info.buffer, size);
+
+free_buffer:
+	kfree(info.buffer);
+
+	if (ret)
+		return ret;
+
+	return size;
+}
+static BIN_ATTR(state_certificate, 0400, state_certificate_read, NULL, SDSI_SIZE_READ_MSG);
+
+static ssize_t registers_read(struct file *filp, struct kobject *kobj,
+			      struct bin_attribute *attr, char *buf, loff_t off,
+			      size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sdsi_priv *priv = dev_get_drvdata(dev);
+	void __iomem *addr = priv->regs_addr;
+
+	memcpy_fromio(buf, addr + off, count);
+
+	return count;
+}
+static BIN_ATTR(registers, 0400, registers_read, NULL, SDSI_SIZE_REGS);
+
+static struct bin_attribute *sdsi_bin_attrs[] = {
+	&bin_attr_registers,
+	&bin_attr_state_certificate,
+	&bin_attr_provision_akc,
+	&bin_attr_provision_cap,
+	NULL
+};
+
+static ssize_t guid_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct sdsi_priv *priv = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "0x%x\n", priv->guid);
+}
+static DEVICE_ATTR_RO(guid);
+
+static struct attribute *sdsi_attrs[] = {
+	&dev_attr_guid.attr,
+	NULL
+};
+
+static const struct attribute_group sdsi_group = {
+	.attrs = sdsi_attrs,
+	.bin_attrs = sdsi_bin_attrs,
+};
+__ATTRIBUTE_GROUPS(sdsi);
+
+static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *parent,
+				   struct disc_table *disc_table, struct resource *disc_res)
+{
+	u32 access_type = FIELD_GET(DT_ACCESS_TYPE, disc_table->access_info);
+	u32 size = FIELD_GET(DT_SIZE, disc_table->access_info);
+	u32 tbir = FIELD_GET(DT_TBIR, disc_table->offset);
+	u32 offset = DT_OFFSET(disc_table->offset);
+	u32 features_offset;
+	struct resource res = {};
+
+	/* Starting location of SDSi MMIO region based on access type */
+	switch (access_type) {
+	case ACCESS_TYPE_LOCAL:
+		if (tbir) {
+			dev_err(priv->dev, "Unsupported BAR index %u for access type %u\n",
+				tbir, access_type);
+			return -EINVAL;
+		}
+
+		/*
+		 * For access_type LOCAL, the base address is as follows:
+		 * base address = end of discovery region + base offset + 1
+		 */
+		res.start = disc_res->end + offset + 1;
+		break;
+
+	case ACCESS_TYPE_BARID:
+		res.start = pci_resource_start(parent, tbir) + offset;
+		break;
+
+	default:
+		dev_err(priv->dev, "Unrecognized access_type %u\n", access_type);
+		return -EINVAL;
+	}
+
+	res.end = res.start + size * sizeof(u32) - 1;
+	res.flags = IORESOURCE_MEM;
+
+	priv->control_addr = devm_ioremap_resource(priv->dev, &res);
+	if (IS_ERR(priv->control_addr))
+		return PTR_ERR(priv->control_addr);
+
+	priv->mbox_addr = priv->control_addr + SDSI_SIZE_CONTROL;
+	priv->regs_addr = priv->mbox_addr + SDSI_SIZE_MAILBOX;
+
+	features_offset = readq(priv->regs_addr + SDSI_ENABLED_FEATURES_OFFSET);
+	priv->sdsi_enabled = !!(features_offset & SDSI_ENABLED);
+
+	return 0;
+}
+
+static int sdsi_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
+{
+	struct intel_vsec_device *intel_cap_dev = auxdev_to_ivdev(auxdev);
+	struct disc_table disc_table;
+	struct resource *disc_res;
+	void __iomem *disc_addr;
+	struct sdsi_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &auxdev->dev;
+	mutex_init(&priv->mb_lock);
+	auxiliary_set_drvdata(auxdev, priv);
+
+	/* Get the SDSi discovery table */
+	disc_res = &intel_cap_dev->resource[0];
+	disc_addr = devm_ioremap_resource(&auxdev->dev, disc_res);
+	if (IS_ERR(disc_addr))
+		return PTR_ERR(disc_addr);
+
+	memcpy_fromio(&disc_table, disc_addr, DISC_TABLE_SIZE);
+
+	priv->guid = disc_table.guid;
+
+	/* Map the SDSi mailbox registers */
+	ret = sdsi_map_mbox_registers(priv, intel_cap_dev->pcidev, &disc_table, disc_res);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct auxiliary_device_id sdsi_aux_id_table[] = {
+	{ .name = "intel_vsec.sdsi" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, sdsi_aux_id_table);
+
+static struct auxiliary_driver sdsi_aux_driver = {
+	.driver = {
+		.dev_groups = sdsi_groups,
+	},
+	.id_table	= sdsi_aux_id_table,
+	.probe		= sdsi_probe,
+	/* No remove. All resources are handled under devm */
+};
+module_auxiliary_driver(sdsi_aux_driver);
+
+MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
+MODULE_DESCRIPTION("Intel Software Defined Silicon driver");
+MODULE_LICENSE("GPL");