[PATCH v6 9/9] scsi: ufs: connect to RPMB subsystem

Tomas Winkler
2016-09-13T13:23:04Z

Register UFS RPMB LUN with the RPMB subsystem and provide
implementation for the RPMB access operations. RPMB partition is
accessed via a sequence of security protocol in and security protocol
out commands with UFS specific parameters. This multi step process is
abstracted into 4 basic RPMB commands.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
V2: resend
V3: resend
V4: Kconfig: use select RPMB to ensure valid configuration
V5: Revamp code using new sequence command.
V5: resend

drivers/scsi/ufs/Kconfig | 1 +
drivers/scsi/ufs/ufshcd.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/scsi/ufs/ufshcd.h | 2 +
3 files changed, 186 insertions(+)

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index 47966909286d..86bbf3a16dbf 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -38,6 +38,7 @@ config SCSI_UFSHCD
select PM_DEVFREQ
select DEVFREQ_GOV_SIMPLE_ONDEMAND
select NLS
+ select RPMB
---help---
This selects the support for UFS devices in Linux, say Y and make
sure that you know the name of your UFS host adapter (the card
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index f08d41a2d70b..2a18e6b26641 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -37,10 +37,13 @@
* license terms, and distributes only under these terms.
*/

+#include <asm/unaligned.h>
#include <linux/async.h>
#include <linux/devfreq.h>
#include <linux/nls.h>
#include <linux/of.h>
+#include <linux/rpmb.h>
+
#include "ufshcd.h"
#include "ufs_quirks.h"
#include "unipro.h"
@@ -4750,6 +4753,178 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba)

}

+#define SEC_PROTOCOL_UFS 0xEC
+#define SEC_SPECIFIC_UFS_RPMB 0x0001
+
+#define SEC_PROTOCOL_CMD_SIZE 12
+#define SEC_PROTOCOL_RETRIES 3
+#define SEC_PROTOCOL_RETRIES_ON_RESET 10
+#define SEC_PROTOCOL_TIMEOUT msecs_to_jiffies(1000)
+
+static int
+ufshcd_rpmb_security_out(struct scsi_device *sdev,
+ struct rpmb_frame *frames, u32 cnt)
+{
+ struct scsi_sense_hdr sshdr;
+ u32 trans_len = cnt * sizeof(struct rpmb_frame);
+ int reset_retries = SEC_PROTOCOL_RETRIES_ON_RESET;
+ int ret;
+ u8 cmd[SEC_PROTOCOL_CMD_SIZE];
+
+ memset(cmd, 0, SEC_PROTOCOL_CMD_SIZE);
+ cmd[0] = SECURITY_PROTOCOL_OUT;
+ cmd[1] = SEC_PROTOCOL_UFS;
+ put_unaligned_be16(SEC_SPECIFIC_UFS_RPMB, cmd + 2);
+ cmd[4] = 0; /* inc_512 bit 7 set to 0 */
+ put_unaligned_be32(trans_len, cmd + 6); /* transfer length */
+
+retry:
+ ret = scsi_execute_req_flags(sdev, cmd, DMA_TO_DEVICE,
+ frames, trans_len, &sshdr,
+ SEC_PROTOCOL_TIMEOUT, SEC_PROTOCOL_RETRIES,
+ NULL, 0);
+
+ if (ret && scsi_sense_valid(&sshdr) &&
+ sshdr.sense_key == UNIT_ATTENTION &&
+ sshdr.asc == 0x29 && sshdr.ascq == 0x00)
+ /*
+ * Device reset might occur several times,
+ * give it one more chance
+ */
+ if (--reset_retries > 0)
+ goto retry;
+
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s: failed with err %0x\n",
+ __func__, ret);
+
+ if (driver_byte(ret) & DRIVER_SENSE)
+ scsi_print_sense_hdr(sdev, "rpmb: security out", &sshdr);
+
+ return ret;
+}
+
+static int
+ufshcd_rpmb_security_in(struct scsi_device *sdev,
+ struct rpmb_frame *frames, u32 cnt)
+{
+ struct scsi_sense_hdr sshdr;
+ u32 alloc_len = cnt * sizeof(struct rpmb_frame);
+ int reset_retries = SEC_PROTOCOL_RETRIES_ON_RESET;
+ int ret;
+ u8 cmd[SEC_PROTOCOL_CMD_SIZE];
+
+ memset(cmd, 0, SEC_PROTOCOL_CMD_SIZE);
+ cmd[0] = SECURITY_PROTOCOL_IN;
+ cmd[1] = SEC_PROTOCOL_UFS;
+ put_unaligned_be16(SEC_SPECIFIC_UFS_RPMB, cmd + 2);
+ cmd[4] = 0; /* inc_512 bit 7 set to 0 */
+ put_unaligned_be32(alloc_len, cmd + 6); /* allocation length */
+
+retry:
+ ret = scsi_execute_req_flags(sdev, cmd, DMA_FROM_DEVICE,
+ frames, alloc_len, &sshdr,
+ SEC_PROTOCOL_TIMEOUT, SEC_PROTOCOL_RETRIES,
+ NULL, 0);
+
+ if (ret && scsi_sense_valid(&sshdr) &&
+ sshdr.sense_key == UNIT_ATTENTION &&
+ sshdr.asc == 0x29 && sshdr.ascq == 0x00)
+ /*
+ * Device reset might occur several times,
+ * give it one more chance
+ */
+ if (--reset_retries > 0)
+ goto retry;
+
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s: failed with err %0x\n",
+ __func__, ret);
+
+ if (driver_byte(ret) & DRIVER_SENSE)
+ scsi_print_sense_hdr(sdev, "rpmb: security in", &sshdr);
+
+ return ret;
+}
+
+static int ufshcd_rpmb_cmd_seq(struct device *dev,
+ struct rpmb_cmd *cmds, u32 ncmds)
+{
+ unsigned long flags;
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ struct scsi_device *sdev;
+ struct rpmb_cmd *cmd;
+ int i;
+ int ret;
+
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ sdev = hba->sdev_ufs_rpmb;
+ if (sdev) {
+ ret = scsi_device_get(sdev);
+ if (!ret && !scsi_device_online(sdev)) {
+ ret = -ENODEV;
+ scsi_device_put(sdev);
+ }
+ } else {
+ ret = -ENODEV;
+ }
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+ if (ret)
+ return ret;
+
+ for (ret = 0, i = 0; i < ncmds && !ret; i++) {
+ cmd = &cmds[i];
+ if (cmd->flags & RPMB_F_WRITE)
+ ret = ufshcd_rpmb_security_out(sdev, cmd->frames,
+ cmd->nframes);
+ else
+ ret = ufshcd_rpmb_security_in(sdev, cmd->frames,
+ cmd->nframes);
+ }
+ scsi_device_put(sdev);
+ return ret;
+}
+
+static struct rpmb_ops ufshcd_rpmb_dev_ops = {
+ .cmd_seq = ufshcd_rpmb_cmd_seq,
+ .type = RPMB_TYPE_UFS,
+};
+
+static inline void ufshcd_rpmb_add(struct ufs_hba *hba)
+{
+ struct rpmb_dev *rdev;
+
+ scsi_device_get(hba->sdev_ufs_rpmb);
+ rdev = rpmb_dev_register(hba->dev, &ufshcd_rpmb_dev_ops);
+ if (IS_ERR(rdev)) {
+ dev_warn(hba->dev, "%s: cannot register to rpmb %ld\n",
+ dev_name(hba->dev), PTR_ERR(rdev));
+ goto out_put_dev;
+ }
+
+ return;
+
+out_put_dev:
+ scsi_device_put(hba->sdev_ufs_rpmb);
+ hba->sdev_ufs_rpmb = NULL;
+}
+
+static inline void ufshcd_rpmb_remove(struct ufs_hba *hba)
+{
+ unsigned long flags;
+
+ if (!hba->sdev_ufs_rpmb)
+ return;
+
+ spin_lock_irqsave(hba->host->host_lock, flags);
+
+ rpmb_dev_unregister(hba->dev);
+ scsi_device_put(hba->sdev_ufs_rpmb);
+ hba->sdev_ufs_rpmb = NULL;
+
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+}
+
/**
* ufshcd_scsi_add_wlus - Adds required W-LUs
* @hba: per-adapter instance
@@ -4805,7 +4980,11 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
ret = PTR_ERR(sdev_rpmb);
goto remove_sdev_boot;
}
+ hba->sdev_ufs_rpmb = sdev_rpmb;
+
+ ufshcd_rpmb_add(hba);
scsi_device_put(sdev_rpmb);
+
goto out;

remove_sdev_boot:
@@ -6174,6 +6353,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
goto out;
}

+ ufshcd_rpmb_remove(hba);
+
ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
out:
if (ret)
@@ -6190,6 +6371,8 @@ EXPORT_SYMBOL(ufshcd_shutdown);
*/
void ufshcd_remove(struct ufs_hba *hba)
{
+ ufshcd_rpmb_remove(hba);
+
scsi_remove_host(hba->host);
/* disable interrupts */
ufshcd_disable_intr(hba, hba->intr_mask);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 430bef111293..a8bd7216825a 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -348,6 +348,7 @@ struct ufs_init_prefetch {
* @utmrdl_dma_addr: UTMRDL DMA address
* @host: Scsi_Host instance of the driver
* @dev: device handle
+ * @sdev_ufs_rpmb: reference to RPMB device W-LU
* @lrb: local reference block
* @lrb_in_use: lrb in use
* @outstanding_tasks: Bits representing outstanding task requests
@@ -410,6 +411,7 @@ struct ufs_hba {
* "UFS device" W-LU.
*/
struct scsi_device *sdev_ufs_device;
+ struct scsi_device *sdev_ufs_rpmb;

enum ufs_dev_pwr_mode curr_dev_pwr_mode;
enum uic_link_state uic_link_state;
--
2.7.4