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Diffstat (limited to '')
-rw-r--r-- | drivers/bus/fsl-mc/mc-sys.c | 296 |
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 000000000..85a0225db --- /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 fsl_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 fsl_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 fsl_mc_command __iomem *portal, + struct fsl_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 fsl_mc_command __iomem + *portal, + struct fsl_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 fsl_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 fsl_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 fsl_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) + raw_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) + raw_spin_unlock_irqrestore(&mc_io->spinlock, irq_flags); + else + mutex_unlock(&mc_io->mutex); + + return error; +} +EXPORT_SYMBOL_GPL(mc_send_command); |