[PATCH v18 5/5] fpga: cardbmc-sec: add card BMC secure update functions

[Russ Weight]

Create firmware upload ops and call the Firmware Upload support of the
Firmware Loader subsystem to enable FPGA image uploads for secure
updates of BMC images, FPGA images, etc.

Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
---
v18:
  - Moved the firmware_upload_register() function here from an earlier
    patch since this is where the required ops are provided.
  - Moved the bmc_sec_remove() function here from an earlier patch to
    unregister the firmware driver and do cleanup.
v17:
  - Change "m10bmc" in symbol names to "cardbmc" to reflect the fact that the
    future devices will not necessarily use the MAX10.
  - Change from image_load class driver to the new firmware_upload 
    functionality of the firmware_loader.
  - fw_upload_ops functions will return "enum fw_upload_err" data types
    instead of integer values.
v16:
  - Use 0 instead of FPGA_IMAGE_ERR_NONE to indicate success.
  - The size alignment check was moved from the FPGA Image Load framework
    to the prepare() op.
  - Added cancel_request boolean flag to struct m10bmc_sec.
  - Moved the RSU cancellation logic from m10bmc_sec_cancel() to a new
    rsu_cancel() function.
  - The m10bmc_sec_cancel() function ONLY sets the cancel_request flag.
    The cancel_request flag is checked at the beginning of the
    m10bmc_sec_write() and m10bmc_sec_poll_complete() functions.
  - Adapt to changed prototypes for the prepare() and write() ops. The
    m10bmc_sec_write_blk() function has been renamed to
    m10bmc_sec_write().
  - Created a cleanup() op, m10bmc_sec_cleanup(), to attempt to cancel an
    ongoing op during when exiting the update process.
v15:
  - Adapted to changes in the FPGA Image Load framework:
    (1) All enum types (progress and errors) are now type u32
    (2) m10bmc_sec_write_blk() adds *blk_size and max_size parameters
        and uses *blk_size as provided by the caller.
    (3) m10bmc_sec_poll_complete() no long checks the driver_unload
        flag.
v14:
  - Changed symbol names to reflect the renaming of the Security Manager
    Class driver to FPGA Image Load.
v13:
  - No change
v12:
  - Updated Date and KernelVersion fields in ABI documentation
  - Removed size parameter from the write_blk() op. m10bmc_sec_write_blk()
    no longer has a size parameter, and the block size is determined
    in this (the lower-level) driver.
v11:
  - No change
v10:
  - No change
v9:
  - No change
v8:
  - Previously patch 5/6, otherwise no change
v7:
  - No change
v6:
  - Changed (size / stride) calculation to ((size + stride - 1) / stride)
    to ensure that the proper count is passed to regmap_bulk_write().
  - Removed unnecessary call to rsu_check_complete() in
    m10bmc_sec_poll_complete() and changed while loop to
    do/while loop.
v5:
  - No change
v4:
  - No change
v3:
  - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
  - Changed "MAX10 BMC Secure Engine driver" to "MAX10 BMC Secure Update
    driver"
  - Removed wrapper functions (m10bmc_raw_*, m10bmc_sys_*). The
    underlying functions are now called directly.
  - Changed calling functions of functions that return "enum fpga_sec_err"
    to check for (ret != FPGA_SEC_ERR_NONE) instead of (ret)
v2:
  - Reworked the rsu_start_done() function to make it more readable
  - Reworked while-loop condition/content in rsu_prog_ready()
  - Minor code cleanup per review comments
  - Added a comment to the m10bmc_sec_poll_complete() function to
    explain the context (could take 30+ minutes to complete).
  - Added m10bmc_ prefix to functions in m10bmc_iops structure
  - Moved MAX10 BMC address and function definitions to a separate
    patch.
---
 drivers/fpga/intel-cardbmc-sec-update.c | 377 ++++++++++++++++++++++++
 1 file changed, 377 insertions(+)

diff --git a/drivers/fpga/intel-cardbmc-sec-update.c b/drivers/fpga/intel-cardbmc-sec-update.c
index 41c828d6d65a..39d5590d582a 100644
--- a/drivers/fpga/intel-cardbmc-sec-update.c
+++ b/drivers/fpga/intel-cardbmc-sec-update.c
@@ -17,8 +17,14 @@
 struct bmc_sec {
 	struct device *dev;
 	struct intel_m10bmc *m10bmc;
+	struct fw_upload *fwl;
+	char *fw_name;
+	u32 fw_name_id;
+	bool cancel_request;
 };
 
+static DEFINE_XARRAY_ALLOC(fw_upload_xa);
+
 /* Root Entry Hash (REH) support */
 #define REH_SHA256_SIZE		32
 #define REH_SHA384_SIZE		48
@@ -178,9 +184,349 @@ static const struct attribute_group *bmc_sec_attr_groups[] = {
 	NULL,
 };
 
+static void log_error_regs(struct bmc_sec *sec, u32 doorbell)
+{
+	u32 auth_result;
+
+	dev_err(sec->dev, "RSU error status: 0x%08x\n", doorbell);
+
+	if (!m10bmc_sys_read(sec->m10bmc, M10BMC_AUTH_RESULT, &auth_result))
+		dev_err(sec->dev, "RSU auth result: 0x%08x\n", auth_result);
+}
+
+static enum fw_upload_err rsu_check_idle(struct bmc_sec *sec)
+{
+	u32 doorbell;
+	int ret;
+
+	ret = m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell);
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	if (rsu_prog(doorbell) != RSU_PROG_IDLE &&
+	    rsu_prog(doorbell) != RSU_PROG_RSU_DONE) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_BUSY;
+	}
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+static inline bool rsu_start_done(u32 doorbell)
+{
+	u32 status, progress;
+
+	if (doorbell & DRBL_RSU_REQUEST)
+		return false;
+
+	status = rsu_stat(doorbell);
+	if (status == RSU_STAT_ERASE_FAIL || status == RSU_STAT_WEAROUT)
+		return true;
+
+	progress = rsu_prog(doorbell);
+	if (progress != RSU_PROG_IDLE && progress != RSU_PROG_RSU_DONE)
+		return true;
+
+	return false;
+}
+
+static enum fw_upload_err rsu_update_init(struct bmc_sec *sec)
+{
+	u32 doorbell, status;
+	int ret;
+
+	ret = regmap_update_bits(sec->m10bmc->regmap,
+				 M10BMC_SYS_BASE + M10BMC_DOORBELL,
+				 DRBL_RSU_REQUEST | DRBL_HOST_STATUS,
+				 DRBL_RSU_REQUEST |
+				 FIELD_PREP(DRBL_HOST_STATUS,
+					    HOST_STATUS_IDLE));
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	ret = regmap_read_poll_timeout(sec->m10bmc->regmap,
+				       M10BMC_SYS_BASE + M10BMC_DOORBELL,
+				       doorbell,
+				       rsu_start_done(doorbell),
+				       NIOS_HANDSHAKE_INTERVAL_US,
+				       NIOS_HANDSHAKE_TIMEOUT_US);
+
+	if (ret == -ETIMEDOUT) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_TIMEOUT;
+	} else if (ret) {
+		return FW_UPLOAD_ERR_RW_ERROR;
+	}
+
+	status = rsu_stat(doorbell);
+	if (status == RSU_STAT_WEAROUT) {
+		dev_warn(sec->dev, "Excessive flash update count detected\n");
+		return FW_UPLOAD_ERR_WEAROUT;
+	} else if (status == RSU_STAT_ERASE_FAIL) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_HW_ERROR;
+	}
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+static enum fw_upload_err rsu_prog_ready(struct bmc_sec *sec)
+{
+	unsigned long poll_timeout;
+	u32 doorbell, progress;
+	int ret;
+
+	ret = m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell);
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	poll_timeout = jiffies + msecs_to_jiffies(RSU_PREP_TIMEOUT_MS);
+	while (rsu_prog(doorbell) == RSU_PROG_PREPARE) {
+		msleep(RSU_PREP_INTERVAL_MS);
+		if (time_after(jiffies, poll_timeout))
+			break;
+
+		ret = m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell);
+		if (ret)
+			return FW_UPLOAD_ERR_RW_ERROR;
+	}
+
+	progress = rsu_prog(doorbell);
+	if (progress == RSU_PROG_PREPARE) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_TIMEOUT;
+	} else if (progress != RSU_PROG_READY) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_HW_ERROR;
+	}
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+static enum fw_upload_err rsu_send_data(struct bmc_sec *sec)
+{
+	u32 doorbell;
+	int ret;
+
+	ret = regmap_update_bits(sec->m10bmc->regmap,
+				 M10BMC_SYS_BASE + M10BMC_DOORBELL,
+				 DRBL_HOST_STATUS,
+				 FIELD_PREP(DRBL_HOST_STATUS,
+					    HOST_STATUS_WRITE_DONE));
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	ret = regmap_read_poll_timeout(sec->m10bmc->regmap,
+				       M10BMC_SYS_BASE + M10BMC_DOORBELL,
+				       doorbell,
+				       rsu_prog(doorbell) != RSU_PROG_READY,
+				       NIOS_HANDSHAKE_INTERVAL_US,
+				       NIOS_HANDSHAKE_TIMEOUT_US);
+
+	if (ret == -ETIMEDOUT) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_TIMEOUT;
+	} else if (ret) {
+		return FW_UPLOAD_ERR_RW_ERROR;
+	}
+
+	switch (rsu_stat(doorbell)) {
+	case RSU_STAT_NORMAL:
+	case RSU_STAT_NIOS_OK:
+	case RSU_STAT_USER_OK:
+	case RSU_STAT_FACTORY_OK:
+		break;
+	default:
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_HW_ERROR;
+	}
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+static int rsu_check_complete(struct bmc_sec *sec, u32 *doorbell)
+{
+	if (m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, doorbell))
+		return -EIO;
+
+	switch (rsu_stat(*doorbell)) {
+	case RSU_STAT_NORMAL:
+	case RSU_STAT_NIOS_OK:
+	case RSU_STAT_USER_OK:
+	case RSU_STAT_FACTORY_OK:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (rsu_prog(*doorbell)) {
+	case RSU_PROG_IDLE:
+	case RSU_PROG_RSU_DONE:
+		return 0;
+	case RSU_PROG_AUTHENTICATING:
+	case RSU_PROG_COPYING:
+	case RSU_PROG_UPDATE_CANCEL:
+	case RSU_PROG_PROGRAM_KEY_HASH:
+		return -EAGAIN;
+	default:
+		return -EINVAL;
+	}
+}
+
+static enum fw_upload_err rsu_cancel(struct bmc_sec *sec)
+{
+	u32 doorbell;
+	int ret;
+
+	ret = m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell);
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	if (rsu_prog(doorbell) != RSU_PROG_READY)
+		return FW_UPLOAD_ERR_BUSY;
+
+	ret = regmap_update_bits(sec->m10bmc->regmap,
+				 M10BMC_SYS_BASE + M10BMC_DOORBELL,
+				 DRBL_HOST_STATUS,
+				 FIELD_PREP(DRBL_HOST_STATUS,
+					    HOST_STATUS_ABORT_RSU));
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	return FW_UPLOAD_ERR_CANCELED;
+}
+
+static enum fw_upload_err bmc_sec_prepare(struct fw_upload *fwl,
+					  const u8 *data, u32 size)
+{
+	struct bmc_sec *sec = fwl->dd_handle;
+	u32 ret;
+
+	sec->cancel_request = false;
+
+	if (!size || size & 0x3 || size > M10BMC_STAGING_SIZE)
+		return FW_UPLOAD_ERR_INVALID_SIZE;
+
+	ret = rsu_check_idle(sec);
+	if (ret != FW_UPLOAD_ERR_NONE)
+		return ret;
+
+	ret = rsu_update_init(sec);
+	if (ret != FW_UPLOAD_ERR_NONE)
+		return ret;
+
+	ret = rsu_prog_ready(sec);
+	if (ret != FW_UPLOAD_ERR_NONE)
+		return ret;
+
+	if (sec->cancel_request)
+		return rsu_cancel(sec);
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+#define WRITE_BLOCK_SIZE 0x4000	/* Default write-block size is 0x4000 bytes */
+
+static enum fw_upload_err bmc_sec_write(struct fw_upload *fwl, const u8 *data,
+					u32 offset, u32 size, u32 *written)
+{
+	struct bmc_sec *sec = fwl->dd_handle;
+	unsigned int stride = regmap_get_reg_stride(sec->m10bmc->regmap);
+	u32 blk_size, doorbell;
+	int ret;
+
+	if (sec->cancel_request)
+		return rsu_cancel(sec);
+
+	ret = m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell);
+	if (ret) {
+		return FW_UPLOAD_ERR_RW_ERROR;
+	} else if (rsu_prog(doorbell) != RSU_PROG_READY) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_HW_ERROR;
+	}
+
+	blk_size = min_t(u32, WRITE_BLOCK_SIZE, size);
+	ret = regmap_bulk_write(sec->m10bmc->regmap,
+				M10BMC_STAGING_BASE + offset,
+				(void *)data + offset,
+				(blk_size + stride - 1) / stride);
+
+	if (ret)
+		return FW_UPLOAD_ERR_RW_ERROR;
+
+	*written = blk_size;
+	return FW_UPLOAD_ERR_NONE;
+}
+
+static enum fw_upload_err bmc_sec_poll_complete(struct fw_upload *fwl)
+{
+	struct bmc_sec *sec = fwl->dd_handle;
+	unsigned long poll_timeout;
+	u32 doorbell, result;
+	int ret;
+
+	if (sec->cancel_request)
+		return rsu_cancel(sec);
+
+	result = rsu_send_data(sec);
+	if (result != FW_UPLOAD_ERR_NONE)
+		return result;
+
+	poll_timeout = jiffies + msecs_to_jiffies(RSU_COMPLETE_TIMEOUT_MS);
+	do {
+		msleep(RSU_COMPLETE_INTERVAL_MS);
+		ret = rsu_check_complete(sec, &doorbell);
+	} while (ret == -EAGAIN && !time_after(jiffies, poll_timeout));
+
+	if (ret == -EAGAIN) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_TIMEOUT;
+	} else if (ret == -EIO) {
+		return FW_UPLOAD_ERR_RW_ERROR;
+	} else if (ret) {
+		log_error_regs(sec, doorbell);
+		return FW_UPLOAD_ERR_HW_ERROR;
+	}
+
+	return FW_UPLOAD_ERR_NONE;
+}
+
+/*
+ * bmc_sec_cancel() may be called asynchronously with an on-going update.
+ * All other functions are called sequentially in a single thread. To avoid
+ * contention on register accesses, bmc_sec_cancel() must only update
+ * the cancel_request flag. Other functions will check this flag and handle
+ * the cancel request synchronously.
+ */
+static void bmc_sec_cancel(struct fw_upload *fwl)
+{
+	struct bmc_sec *sec = fwl->dd_handle;
+
+	sec->cancel_request = true;
+}
+
+static void bmc_sec_cleanup(struct fw_upload *fwl)
+{
+	struct bmc_sec *sec = fwl->dd_handle;
+
+	(void)rsu_cancel(sec);
+}
+
+static const struct fw_upload_ops cardbmc_ops = {
+	.prepare = bmc_sec_prepare,
+	.write = bmc_sec_write,
+	.poll_complete = bmc_sec_poll_complete,
+	.cancel = bmc_sec_cancel,
+	.cleanup = bmc_sec_cleanup,
+};
+
 #define SEC_UPDATE_LEN_MAX 32
 static int bmc_sec_probe(struct platform_device *pdev)
 {
+	char buf[SEC_UPDATE_LEN_MAX];
+	struct fw_upload *fwl;
+	unsigned int len, ret;
 	struct bmc_sec *sec;
 
 	sec = devm_kzalloc(&pdev->dev, sizeof(*sec), GFP_KERNEL);
@@ -191,6 +537,36 @@ static int bmc_sec_probe(struct platform_device *pdev)
 	sec->m10bmc = dev_get_drvdata(pdev->dev.parent);
 	dev_set_drvdata(&pdev->dev, sec);
 
+	ret = xa_alloc(&fw_upload_xa, &sec->fw_name_id, sec,
+		       xa_limit_32b, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	len = scnprintf(buf, SEC_UPDATE_LEN_MAX, "secure-update%d",
+			sec->fw_name_id);
+	sec->fw_name = kmemdup_nul(buf, len, GFP_KERNEL);
+
+	fwl = firmware_upload_register(THIS_MODULE, sec->dev, sec->fw_name,
+				       &cardbmc_ops, sec);
+	if (IS_ERR(fwl)) {
+		dev_err(sec->dev, "Firmware Upload driver failed to start\n");
+		kfree(sec->fw_name);
+		xa_erase(&fw_upload_xa, sec->fw_name_id);
+		return PTR_ERR(fwl);
+	}
+
+	sec->fwl = fwl;
+	return 0;
+}
+
+static int bmc_sec_remove(struct platform_device *pdev)
+{
+	struct bmc_sec *sec = dev_get_drvdata(&pdev->dev);
+
+	firmware_upload_unregister(sec->fwl);
+	kfree(sec->fw_name);
+	xa_erase(&fw_upload_xa, sec->fw_name_id);
+
 	return 0;
 }
 
@@ -203,6 +579,7 @@ static const struct platform_device_id intel_cardbmc_sec_ids[] = {
 
 static struct platform_driver intel_cardbmc_sec_driver = {
 	.probe = bmc_sec_probe,
+	.remove = bmc_sec_remove,
 	.driver = {
 		.name = "intel-cardbmc-sec-update",
 		.dev_groups = bmc_sec_attr_groups,
-- 
2.25.1