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SubjectRe: [PATCH V9 2/2] scsi: ufs: Add configfs support for UFS provisioning
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On 8/23/2018 10:49 PM, Evan Green wrote:
> On Tue, Aug 21, 2018 at 3:19 AM Sayali Lokhande <sayalil@codeaurora.org> wrote:
>> This patch adds configfs support to provision UFS device at
>> runtime. This feature can be primarily useful in factory or
>> assembly line as some devices may be required to be configured
>> multiple times during initial system development phase.
>> Configuration Descriptors can be written multiple times until
>> bConfigDescrLock attribute is zero.
>>
>> Configuration descriptor buffer consists of Device and Unit
>> descriptor configurable parameters which are parsed from vendor
>> specific provisioning file and then passed via configfs node at
>> runtime to provision ufs device.
>> CONFIG_CONFIGFS_FS needs to be enabled for using this feature.
>>
>> Usage:
>> 1) To read current configuration descriptor :
>> cat /config/XXXX.ufshc/ufs_provision
>> 2) To provision ufs device:
>> echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision
>>
>> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
>> ---
>> Documentation/ABI/testing/configfs-driver-ufs | 18 +++
>> drivers/scsi/ufs/Kconfig | 10 ++
>> drivers/scsi/ufs/Makefile | 1 +
>> drivers/scsi/ufs/ufs-configfs.c | 157 ++++++++++++++++++++++++++
>> drivers/scsi/ufs/ufshcd.c | 3 +-
>> drivers/scsi/ufs/ufshcd.h | 18 +++
>> 6 files changed, 206 insertions(+), 1 deletion(-)
>> create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
>> create mode 100644 drivers/scsi/ufs/ufs-configfs.c
>>
>> diff --git a/Documentation/ABI/testing/configfs-driver-ufs b/Documentation/ABI/testing/configfs-driver-ufs
>> new file mode 100644
>> index 0000000..eeee499c
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/configfs-driver-ufs
>> @@ -0,0 +1,18 @@
>> +What: /config/ufshcd/ufs_provision
>> +Date: Jun 2018
>> +KernelVersion: 4.14
>> +Description:
>> + This file shows the current ufs configuration descriptor set in device.
>> + This can be used to provision ufs device if bConfigDescrLock is 0.
>> + For more details, refer 14.1.6.3 Configuration Descriptor and
>> + Table 14-12 - Unit Descriptor configurable parameters from specs for
>> + description of each configuration descriptor parameter.
>> + Configuration descriptor buffer needs to be passed in space separated
>> + format specificied as below:
>> + echo <bLength> <bDescriptorIDN> <bConfDescContinue> <bBootEnable>
>> + <bDescrAccessEn> <bInitPowerMode> <bHighPriorityLUN>
>> + <bSecureRemovalType> <bInitActiveICCLevel> <wPeriodicRTCUpdate>
>> + <0Bh:0Fh_ReservedAs_0> <bLUEnable> <bBootLunID> <bLUWriteProtect>
>> + <bMemoryType> <dNumAllocUnits> <bDataReliability> <bLogicalBlockSize>
>> + <bProvisioningType> <wContextCapabilities> <0Dh:0Fh_ReservedAs_0>
>> + > /config/XXXX.ufshc/ufs_provision
>> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
>> index e27b4d4..a9a0a58 100644
>> --- a/drivers/scsi/ufs/Kconfig
>> +++ b/drivers/scsi/ufs/Kconfig
>> @@ -100,3 +100,13 @@ config SCSI_UFS_QCOM
>>
>> Select this if you have UFS controller on QCOM chipset.
>> If unsure, say N.
>> +
>> +config UFS_PROVISION
>> + tristate "Runtime UFS Provisioning support"
>> + depends on SCSI_UFSHCD && CONFIGFS_FS
>> + help
>> + This enables runtime UFS provisioning support. This can be used
>> + primarily during assembly line as some devices may be required to
>> + be configured multiple times during initial development phase.
>> +
>> + If unsure, say N.
>> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
>> index 918f579..00110ea 100644
>> --- a/drivers/scsi/ufs/Makefile
>> +++ b/drivers/scsi/ufs/Makefile
>> @@ -5,5 +5,6 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
>> obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
>> obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
>> ufshcd-core-objs := ufshcd.o ufs-sysfs.o
>> +obj-$(CONFIG_UFS_PROVISION) += ufs-configfs.o
>> obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
>> obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
>> diff --git a/drivers/scsi/ufs/ufs-configfs.c b/drivers/scsi/ufs/ufs-configfs.c
>> new file mode 100644
>> index 0000000..09607e5
>> --- /dev/null
>> +++ b/drivers/scsi/ufs/ufs-configfs.c
>> @@ -0,0 +1,157 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +// Copyright (c) 2018, Linux Foundation.
>> +
>> +#include <linux/configfs.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +
>> +#include "ufs.h"
>> +#include "ufshcd.h"
>> +
>> +static inline struct ufs_hba *config_item_to_hba(struct config_item *item)
>> +{
>> + struct config_group *group = to_config_group(item);
>> + struct configfs_subsystem *subsys = to_configfs_subsystem(group);
>> + struct ufs_hba *hba = container_of(subsys, struct ufs_hba, subsys);
>> +
>> + return subsys ? hba : NULL;
>> +}
>> +
>> +static ssize_t ufs_provision_show(struct config_item *item, char *buf)
>> +{
>> + u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
>> + int buff_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
> This is a nit, but buff_len is really desc_buf_len. It's confusing
> because you also do have a buffer named buf, which this variable is
> not the length of.
Agree. Will rename it to desc_buf_len to avoid confusion.
>> + int i, ret, curr_len = 0;
>> + struct ufs_hba *hba = config_item_to_hba(item);
>> +
>> + ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
>> + QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &buff_len);
>> +
>> + if (ret)
>> + return ret;
>> +
>> + for (i = 0; i < buff_len; i++)
>> + curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
>> + "0x%x ", desc_buf[i]);
>> +
>> + return curr_len;
>> +}
>> +
>> +ssize_t ufshcd_desc_configfs_store(struct ufs_hba *hba,
>> + const char *buf, size_t count)
>> +{
>> + char *strbuf;
>> + char *strbuf_copy;
>> + u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
>> + int buff_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
> Same thing here, I suppose.
Done.
>> + char *token;
>> + int i, ret, value;
>> + u32 config_desc_lock = 0;
>> +
>> + /* reserve one byte for null termination */
>> + strbuf = kmalloc(count + 1, GFP_KERNEL);
>> + if (!strbuf)
>> + return -ENOMEM;
>> +
>> + strbuf_copy = strbuf;
>> + strlcpy(strbuf, buf, count + 1);
>> +
>> + /* Just return if bConfigDescrLock is already set */
>> + ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
>> + QUERY_ATTR_IDN_CONF_DESC_LOCK, 0, 0, &config_desc_lock);
>> + if (ret)
>> + goto out;
>> +
>> + if (config_desc_lock) {
>> + dev_err(hba->dev, "%s: bConfigDescrLock already set to %u, cannot re-provision device!\n",
>> + __func__, config_desc_lock);
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + for (i = 0; i < QUERY_DESC_CONFIGURATION_DEF_SIZE; i++) {
>> + token = strsep(&strbuf, " ");
>> + if (!token && i)
>> + break;
> What happens if you pass an empty buffer (eg !token && !i)?
> I just tried it. kstrtoint seems to fail gracefully, and I get the
> print below. Fine.
Ok . it looks Fine.
>> +
>> + ret = kstrtoint(token, 0, &value);
>> + if (ret) {
>> + dev_err(hba->dev, "%s: kstrtoint failed %d %s\n",
>> + __func__, ret, token);
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + desc_buf[i] = (u8)value;
>> + }
>> +
>> + /* Write configuration descriptor to provision ufs */
>> + ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_WRITE_DESC,
>> + QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &buff_len);
>> +
>> + if (!ret)
>> + dev_err(hba->dev, "%s: UFS Provisioning done, reboot now!\n",
>> + __func__);
> I wonder if this should maybe just be an info or debug message. It's
> really not an error, it's a celebration!
Agree.  :)
>> +
>> +out:
>> + kfree(strbuf_copy);
>> + if (ret)
>> + return ret;
>> + return count;
>> +}
>> +
>> +static ssize_t ufs_provision_store(struct config_item *item,
>> + const char *buf, size_t count)
>> +{
>> + struct ufs_hba *hba = config_item_to_hba(item);
>> +
>> + return ufshcd_desc_configfs_store(hba, buf, count);
>> +}
>> +
>> +static struct configfs_attribute ufshcd_attr_provision = {
>> + .ca_name = "ufs_provision",
>> + .ca_mode = 0644,
>> + .ca_owner = THIS_MODULE,
>> + .show = ufs_provision_show,
>> + .store = ufs_provision_store,
>> +};
>> +
>> +static struct configfs_attribute *ufshcd_attrs[] = {
>> + &ufshcd_attr_provision,
>> + NULL,
>> +};
>> +
>> +static struct config_item_type ufscfg_type = {
>> + .ct_attrs = ufshcd_attrs,
>> + .ct_owner = THIS_MODULE,
>> +};
>> +
>> +static struct configfs_subsystem ufscfg_subsys = {
>> + .su_group = {
>> + .cg_item = {
>> + .ci_type = &ufscfg_type,
>> + },
>> + },
>> +};
>> +
>> +int ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
>> +{
>> + int ret;
>> + struct configfs_subsystem *subsys = &hba->subsys;
>> +
>> + strncpy(ufscfg_subsys.su_group.cg_item.ci_namebuf, name, strlen(name));
>> + subsys->su_group = ufscfg_subsys.su_group;
>> + config_group_init(&subsys->su_group);
>> + mutex_init(&subsys->su_mutex);
>> + ret = configfs_register_subsystem(subsys);
>> + if (ret)
>> + pr_err("Error %d while registering subsystem %s\n",
>> + ret,
>> + subsys->su_group.cg_item.ci_namebuf);
>> +
>> + return ret;
>> +}
>> +
>> +void ufshcd_configfs_exit(void)
>> +{
>> + configfs_unregister_subsystem(&ufscfg_subsys);
>> +}
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index e946844..11b28bf 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -7713,6 +7713,7 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>> void ufshcd_remove(struct ufs_hba *hba)
>> {
>> ufs_sysfs_remove_nodes(hba->dev);
>> + ufshcd_configfs_exit();
>> scsi_remove_host(hba->host);
>> /* disable interrupts */
>> ufshcd_disable_intr(hba, hba->intr_mask);
>> @@ -7967,7 +7968,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>>
>> async_schedule(ufshcd_async_scan, hba);
>> ufs_sysfs_add_nodes(hba->dev);
>> -
>> + ufshcd_configfs_init(hba, dev_name(hba->dev));
> You init function has a return int, but you never check it. Either
> remove the return type if you consider configfs initialization errors
> non-fatal, or check the error here.
Agree. It should be void type.
>> return 0;
>>
>> out_remove_scsi_host:
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index 45013b6..c5956b2 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -37,6 +37,7 @@
>> #ifndef _UFSHCD_H
>> #define _UFSHCD_H
>>
>> +#include <linux/configfs.h>
>> #include <linux/module.h>
>> #include <linux/kernel.h>
>> #include <linux/init.h>
>> @@ -515,6 +516,9 @@ struct ufs_hba {
>>
>> struct Scsi_Host *host;
>> struct device *dev;
>> +#ifdef CONFIG_UFS_PROVISION
>> + struct configfs_subsystem subsys;
>> +#endif
>> /*
>> * This field is to keep a reference to "scsi_device" corresponding to
>> * "UFS device" W-LU.
>> @@ -868,6 +872,20 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
>> int ufshcd_hold(struct ufs_hba *hba, bool async);
>> void ufshcd_release(struct ufs_hba *hba);
>>
>> +/* Expose UFS configfs API's */
>> +#ifndef CONFIG_UFS_PROVISION
>> +static inline int ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
>> +{
>> + return 0;
>> +}
>> +static inline void ufshcd_configfs_exit(void)
>> +{
>> +}
>> +#else
>> +int ufshcd_configfs_init(struct ufs_hba *hba, const char *name);
>> +void ufshcd_configfs_exit(void);
>> +#endif
>> +
>> int ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn desc_id,
>> int *desc_length);
>>
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project
>>

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