1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/bus/fsl-mc/mc-sys.c b/drivers/bus/fsl-mc/mc-sys.c
new file mode 100644
index 000000000000..bd03f1524ecb
--- /dev/null
+++ b/drivers/bus/fsl-mc/mc-sys.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * Copyright 2013-2016 Freescale Semiconductor Inc.
+ *
+ * I/O services to send MC commands to the MC hardware
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/fsl/mc.h>
+
+#include "fsl-mc-private.h"
+
+/**
+ * Timeout in milliseconds to wait for the completion of an MC command
+ */
+#define MC_CMD_COMPLETION_TIMEOUT_MS	500
+
+/*
+ * usleep_range() min and max values used to throttle down polling
+ * iterations while waiting for MC command completion
+ */
+#define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
+#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
+
+static enum mc_cmd_status mc_cmd_hdr_read_status(struct mc_command *cmd)
+{
+	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
+
+	return (enum mc_cmd_status)hdr->status;
+}
+
+static u16 mc_cmd_hdr_read_cmdid(struct mc_command *cmd)
+{
+	struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
+	u16 cmd_id = le16_to_cpu(hdr->cmd_id);
+
+	return cmd_id;
+}
+
+static int mc_status_to_error(enum mc_cmd_status status)
+{
+	static const int mc_status_to_error_map[] = {
+		[MC_CMD_STATUS_OK] = 0,
+		[MC_CMD_STATUS_AUTH_ERR] = -EACCES,
+		[MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
+		[MC_CMD_STATUS_DMA_ERR] = -EIO,
+		[MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
+		[MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
+		[MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
+		[MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
+		[MC_CMD_STATUS_BUSY] = -EBUSY,
+		[MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
+		[MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
+	};
+
+	if ((u32)status >= ARRAY_SIZE(mc_status_to_error_map))
+		return -EINVAL;
+
+	return mc_status_to_error_map[status];
+}
+
+static const char *mc_status_to_string(enum mc_cmd_status status)
+{
+	static const char *const status_strings[] = {
+		[MC_CMD_STATUS_OK] = "Command completed successfully",
+		[MC_CMD_STATUS_READY] = "Command ready to be processed",
+		[MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
+		[MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
+		[MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
+		[MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
+		[MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
+		[MC_CMD_STATUS_NO_RESOURCE] = "No resources",
+		[MC_CMD_STATUS_NO_MEMORY] = "No memory available",
+		[MC_CMD_STATUS_BUSY] = "Device is busy",
+		[MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
+		[MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
+	};
+
+	if ((unsigned int)status >= ARRAY_SIZE(status_strings))
+		return "Unknown MC error";
+
+	return status_strings[status];
+}
+
+/**
+ * mc_write_command - writes a command to a Management Complex (MC) portal
+ *
+ * @portal: pointer to an MC portal
+ * @cmd: pointer to a filled command
+ */
+static inline void mc_write_command(struct mc_command __iomem *portal,
+				    struct mc_command *cmd)
+{
+	int i;
+
+	/* copy command parameters into the portal */
+	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
+		/*
+		 * Data is already in the expected LE byte-order. Do an
+		 * extra LE -> CPU conversion so that the CPU -> LE done in
+		 * the device io write api puts it back in the right order.
+		 */
+		writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);
+
+	/* submit the command by writing the header */
+	writeq(le64_to_cpu(cmd->header), &portal->header);
+}
+
+/**
+ * mc_read_response - reads the response for the last MC command from a
+ * Management Complex (MC) portal
+ *
+ * @portal: pointer to an MC portal
+ * @resp: pointer to command response buffer
+ *
+ * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
+ */
+static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem *
+						  portal,
+						  struct mc_command *resp)
+{
+	int i;
+	enum mc_cmd_status status;
+
+	/* Copy command response header from MC portal: */
+	resp->header = cpu_to_le64(readq_relaxed(&portal->header));
+	status = mc_cmd_hdr_read_status(resp);
+	if (status != MC_CMD_STATUS_OK)
+		return status;
+
+	/* Copy command response data from MC portal: */
+	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
+		/*
+		 * Data is expected to be in LE byte-order. Do an
+		 * extra CPU -> LE to revert the LE -> CPU done in
+		 * the device io read api.
+		 */
+		resp->params[i] =
+			cpu_to_le64(readq_relaxed(&portal->params[i]));
+
+	return status;
+}
+
+/**
+ * Waits for the completion of an MC command doing preemptible polling.
+ * uslepp_range() is called between polling iterations.
+ *
+ * @mc_io: MC I/O object to be used
+ * @cmd: command buffer to receive MC response
+ * @mc_status: MC command completion status
+ */
+static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
+				       struct mc_command *cmd,
+				       enum mc_cmd_status *mc_status)
+{
+	enum mc_cmd_status status;
+	unsigned long jiffies_until_timeout =
+		jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
+
+	/*
+	 * Wait for response from the MC hardware:
+	 */
+	for (;;) {
+		status = mc_read_response(mc_io->portal_virt_addr, cmd);
+		if (status != MC_CMD_STATUS_READY)
+			break;
+
+		/*
+		 * TODO: When MC command completion interrupts are supported
+		 * call wait function here instead of usleep_range()
+		 */
+		usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
+			     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
+
+		if (time_after_eq(jiffies, jiffies_until_timeout)) {
+			dev_dbg(mc_io->dev,
+				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
+				 &mc_io->portal_phys_addr,
+				 (unsigned int)mc_cmd_hdr_read_token(cmd),
+				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
+
+			return -ETIMEDOUT;
+		}
+	}
+
+	*mc_status = status;
+	return 0;
+}
+
+/**
+ * Waits for the completion of an MC command doing atomic polling.
+ * udelay() is called between polling iterations.
+ *
+ * @mc_io: MC I/O object to be used
+ * @cmd: command buffer to receive MC response
+ * @mc_status: MC command completion status
+ */
+static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
+				  struct mc_command *cmd,
+				  enum mc_cmd_status *mc_status)
+{
+	enum mc_cmd_status status;
+	unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
+
+	BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
+		     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
+
+	for (;;) {
+		status = mc_read_response(mc_io->portal_virt_addr, cmd);
+		if (status != MC_CMD_STATUS_READY)
+			break;
+
+		udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
+		timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
+		if (timeout_usecs == 0) {
+			dev_dbg(mc_io->dev,
+				"MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
+				 &mc_io->portal_phys_addr,
+				 (unsigned int)mc_cmd_hdr_read_token(cmd),
+				 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
+
+			return -ETIMEDOUT;
+		}
+	}
+
+	*mc_status = status;
+	return 0;
+}
+
+/**
+ * Sends a command to the MC device using the given MC I/O object
+ *
+ * @mc_io: MC I/O object to be used
+ * @cmd: command to be sent
+ *
+ * Returns '0' on Success; Error code otherwise.
+ */
+int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd)
+{
+	int error;
+	enum mc_cmd_status status;
+	unsigned long irq_flags = 0;
+
+	if (in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
+		return -EINVAL;
+
+	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
+		spin_lock_irqsave(&mc_io->spinlock, irq_flags);
+	else
+		mutex_lock(&mc_io->mutex);
+
+	/*
+	 * Send command to the MC hardware:
+	 */
+	mc_write_command(mc_io->portal_virt_addr, cmd);
+
+	/*
+	 * Wait for response from the MC hardware:
+	 */
+	if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
+		error = mc_polling_wait_preemptible(mc_io, cmd, &status);
+	else
+		error = mc_polling_wait_atomic(mc_io, cmd, &status);
+
+	if (error < 0)
+		goto common_exit;
+
+	if (status != MC_CMD_STATUS_OK) {
+		dev_dbg(mc_io->dev,
+			"MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
+			 &mc_io->portal_phys_addr,
+			 (unsigned int)mc_cmd_hdr_read_token(cmd),
+			 (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
+			 mc_status_to_string(status),
+			 (unsigned int)status);
+
+		error = mc_status_to_error(status);
+		goto common_exit;
+	}
+
+	error = 0;
+common_exit:
+	if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
+		spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
+	else
+		mutex_unlock(&mc_io->mutex);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(mc_send_command);