Re: [PATCH V10 2/2] scsi: ufs: Add configfs support for UFS provisioning

[Adrian Hunter]

On 28/08/18 13:23, Sayali Lokhande wrote:
> Hi Adrian,
> 
> On 8/24/2018 2:15 PM, Adrian Hunter wrote:
>> On 24/08/18 08:33, Sayali Lokhande 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 :
>>> ÂÂÂ cat /config/XXXX.ufshc/ufs_provision
>>> 2) To provision ufs device:
>>> ÂÂÂ echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision
>>>
>>> Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
>>> ---
>>> Â Documentation/ABI/testing/configfs-driver-ufs |Â 18 +++
>>> Â drivers/scsi/ufs/KconfigÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 10 ++
>>> Â drivers/scsi/ufs/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |ÂÂ 1 +
>>> Â drivers/scsi/ufs/ufs-configfs.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | 155
>>> ++++++++++++++++++++++++++
>>> Â drivers/scsi/ufs/ufshcd.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |ÂÂ 3 +-
>>> Â drivers/scsi/ufs/ufshcd.hÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 17 +++
>>> Â 6 files changed, 203 insertions(+), 1 deletion(-)
>>> Â create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
>>> Â 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:ÂÂÂÂÂÂÂ /config/ufshcd/ufs_provision
>> You are using the device name as the config subsystem name, so this is
>> really:
>>
>> ÂÂÂÂWhat:ÂÂÂÂÂÂÂ /config/*/ufs_provision
> Agree. Will update.
>>> +Date:ÂÂÂÂÂÂÂ Jun 2018
>>> +KernelVersion:ÂÂÂ 4.14
>> 4.19 maybe
> Done.
>>> +Description:
>>> +ÂÂÂÂÂÂÂ This file shows the current ufs configuration descriptor set in
>>> device.
>> It is only the first config descriptor though isn't it? There is no support
>> for the other 3. Shouldn't we support config descriptors fully?
> Yes, we should support config descriptors fully. My current implementation
> only supports config desc (index = 00h).
> I m thinking I can add separate "index" field along with "ufs_provision"
> field and can use this index (instead of hard coding to 0)
> to write repective config_desc. In this way, we should first set the "index"
> and then read/write to "ufs_provision".
> Let me know if you have any concern with this approach ?

One file for each config descriptor would seem more normal.

> 
>>> +ÂÂÂÂÂÂÂ This can be used to provision ufs device if bConfigDescrLock is 0.
>>> +ÂÂÂÂÂÂÂ For more details, refer 14.1.6.3 Configuration Descriptor and
>>> +ÂÂÂÂÂÂÂ Table 14-12 - Unit Descriptor configurable parameters from specs
>>> for
>>> +ÂÂÂÂÂÂÂ description of each configuration descriptor parameter.
>>> +ÂÂÂÂÂÂÂ Configuration descriptor buffer needs to be passed in space
>>> separated
>>> +ÂÂÂÂÂÂÂ format specificied as below:
>> specificied -> specified
> Done
>>> +ÂÂÂÂÂÂÂ echo <bLength> <bDescriptorIDN> <bConfDescContinue> <bBootEnable>
>>> +ÂÂÂÂÂÂÂ <bDescrAccessEn> <bInitPowerMode> <bHighPriorityLUN>
>>> +ÂÂÂÂÂÂÂ <bSecureRemovalType> <bInitActiveICCLevel> <wPeriodicRTCUpdate>
>>> +ÂÂÂÂÂÂÂ <0Bh:0Fh_ReservedAs_0> <bLUEnable> <bBootLunID> <bLUWriteProtect>
>>> +ÂÂÂÂÂÂÂ <bMemoryType> <dNumAllocUnits> <bDataReliability>
>>> <bLogicalBlockSize>
>>> +ÂÂÂÂÂÂÂ <bProvisioningType> <wContextCapabilities> <0Dh:0Fh_ReservedAs_0>
>> This format is not exactly correct anymore because each byte has to be
>> represented separately. Also theoretically it can be change, so maybe
>> better just to refer the user to the UFS specification.
> Agree. Will update to just refer to UFS spec (for Config_desc format).
> 
>>> +ÂÂÂÂÂÂÂ > /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
>>> Â ÂÂÂÂÂÂÂ Select this if you have UFS controller on QCOM chipset.
>>> ÂÂÂÂÂÂÂ If unsure, say N.
>>> +
>>> +config UFS_PROVISION
>>> +ÂÂÂ tristate "Runtime UFS Provisioning support"
>>> +ÂÂÂ depends on SCSI_UFSHCD && CONFIGFS_FS
>>> +ÂÂÂ help
>>> +ÂÂÂÂÂ This enables runtime UFS provisioning support. This can be used
>>> +ÂÂÂÂÂ primarily during assembly line as some devices may be required to
>>> +ÂÂÂÂÂ be configured multiple times during initial development phase.
>>> +
>>> +ÂÂÂÂÂ 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-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) +=
>>> tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
>>> Â obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
>>> Â obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
>>> Â ufshcd-core-objs := ufshcd.o ufs-sysfs.o
>>> +obj-$(CONFIG_UFS_PROVISION) += ufs-configfs.o
>>> Â obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
>>> Â obj-$(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..74563a4
>>> --- /dev/null
>>> +++ b/drivers/scsi/ufs/ufs-configfs.c
>>> @@ -0,0 +1,155 @@
>>> +// 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)
>>> +{
>>> +ÂÂÂ struct config_group *group = to_config_group(item);
>>> +ÂÂÂ struct configfs_subsystem *subsys = to_configfs_subsystem(group);
>>> +ÂÂÂ struct ufs_hba *hba = container_of(subsys, struct ufs_hba, subsys);
>>> +
>>> +ÂÂÂ return subsys ? hba : NULL;
>>> +}
>>> +
>>> +static ssize_t ufs_provision_show(struct config_item *item, char *buf)
>>> +{
>>> +ÂÂÂ u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
>> Is it really ok to hard-code the descriptor size?
> I will use ufshcd_read_desc_length() api for each index as required. Will
> remove this hard-code.

Alternatively, I see there is already hba->desc_size.conf_desc

>>> +ÂÂÂ int desc_buf_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
>>> +ÂÂÂ int i, ret, curr_len = 0;
>>> +ÂÂÂ struct ufs_hba *hba = config_item_to_hba(item);
>>> +
>>> +ÂÂÂ ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
>>> +ÂÂÂÂÂÂÂ QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &desc_buf_len);
>>> +
>>> +ÂÂÂ if (ret)
>>> +ÂÂÂÂÂÂÂ return ret;
>>> +
>>> +ÂÂÂ for (i = 0; i < desc_buf_len; i++)
>>> +ÂÂÂÂÂÂÂ curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ "0x%x ", desc_buf[i]);
>>> +
>>> +ÂÂÂ return curr_len;
>>> +}
>>> +
>>> +ssize_t ufshcd_desc_configfs_store(struct ufs_hba *hba,
>>> +ÂÂÂÂÂÂÂ const char *buf, size_t count)
>>> +{
>>> +ÂÂÂ char *strbuf;
>>> +ÂÂÂ char *strbuf_copy;
>>> +ÂÂÂ u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
>>> +ÂÂÂ int desc_buf_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
>>> +ÂÂÂ char *token;
>>> +ÂÂÂ int i, ret, value;
>>> +ÂÂÂ u32 config_desc_lock = 0;
>>> +
>>> +ÂÂÂ /* reserve one byte for null termination */
>>> +ÂÂÂ strbuf = kmalloc(count + 1, GFP_KERNEL);
>>> +ÂÂÂ if (!strbuf)
>>> +ÂÂÂÂÂÂÂ return -ENOMEM;
>>> +
>>> +ÂÂÂ strbuf_copy = strbuf;
>>> +ÂÂÂ strlcpy(strbuf, buf, count + 1);
>>> +
>>> +ÂÂÂ /* Just return if bConfigDescrLock is already set */
>>> +ÂÂÂ ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
>>> +ÂÂÂÂÂÂÂ QUERY_ATTR_IDN_CONF_DESC_LOCK, 0, 0, &config_desc_lock);
>>> +ÂÂÂ if (ret)
>>> +ÂÂÂÂÂÂÂ goto out;
>>> +
>>> +ÂÂÂ if (config_desc_lock) {
>>> +ÂÂÂÂÂÂÂ dev_err(hba->dev, "%s: bConfigDescrLock already set to %u,
>>> cannot re-provision device!\n",
>>> +ÂÂÂÂÂÂÂ __func__, config_desc_lock);
>>> +ÂÂÂÂÂÂÂ ret = -EINVAL;
>>> +ÂÂÂÂÂÂÂ goto out;
>>> +ÂÂÂ }
>>> +
>>> +ÂÂÂ for (i = 0; i < QUERY_DESC_CONFIGURATION_DEF_SIZE; i++) {
>>> +ÂÂÂÂÂÂÂ token = strsep(&strbuf, " ");
>>> +ÂÂÂÂÂÂÂ if (!token && i)
>>> +ÂÂÂÂÂÂÂÂÂÂÂ break;
>>> +
>>> +ÂÂÂÂÂÂÂ ret = kstrtoint(token, 0, &value);
>>> +ÂÂÂÂÂÂÂ if (ret) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ dev_err(hba->dev, "%s: kstrtoint failed %d %s\n",
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __func__, ret, token);
>>> +ÂÂÂÂÂÂÂÂÂÂÂ ret = -EINVAL;
>>> +ÂÂÂÂÂÂÂÂÂÂÂ goto out;
>>> +ÂÂÂÂÂÂÂ }
>>> +ÂÂÂÂÂÂÂ desc_buf[i] = (u8)value;
>>> +ÂÂÂ }
>>> +
>>> +ÂÂÂ /* Write configuration descriptor to provision ufs */
>>> +ÂÂÂ ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_WRITE_DESC,
>>> +ÂÂÂÂÂÂÂ QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &desc_buf_len);
>>> +
>>> +ÂÂÂ if (!ret)
>>> +ÂÂÂÂÂÂÂ dev_info(hba->dev, "%s: UFS Provisioning done, reboot now!\n",
>> That is not necessarily true - bConfDescContinue might have been used or
>> bConfigDescrLock might need to be set. Better just to say that
>> configuration descriptor 0 was written.
> Agree. Will update.
>>
>>> +ÂÂÂÂÂÂÂ __func__);
>>> +
>>> +out:
>>> +ÂÂÂ kfree(strbuf_copy);
>>> +ÂÂÂ if (ret)
>>> +ÂÂÂÂÂÂÂ return ret;
>>> +ÂÂÂ return count;
>>> +}
>>> +
>>> +static ssize_t ufs_provision_store(struct config_item *item,
>>> +ÂÂÂÂÂÂÂ const char *buf, size_t count)
>>> +{
>>> +ÂÂÂ struct ufs_hba *hba = config_item_to_hba(item);
>>> +
>>> +ÂÂÂ return ufshcd_desc_configfs_store(hba, buf, count);
>>> +}
>>> +
>>> +static struct configfs_attribute ufshcd_attr_provision = {
>>> +ÂÂÂ .ca_nameÂÂÂ = "ufs_provision",
>>> +ÂÂÂ .ca_modeÂÂÂ = 0644,
>>> +ÂÂÂ .ca_ownerÂÂÂ = THIS_MODULE,
>>> +ÂÂÂ .showÂÂÂÂÂÂÂ = ufs_provision_show,
>>> +ÂÂÂ .storeÂÂÂÂÂÂÂ = ufs_provision_store,
>>> +};
>>> +
>>> +static struct configfs_attribute *ufshcd_attrs[] = {
>>> +ÂÂÂ &ufshcd_attr_provision,
>>> +ÂÂÂ NULL,
>>> +};
>>> +
>>> +static struct config_item_type ufscfg_type = {
>>> +ÂÂÂ .ct_attrsÂÂÂ = ufshcd_attrs,
>>> +ÂÂÂ .ct_ownerÂÂÂ = THIS_MODULE,
>>> +};
>>> +
>>> +static struct configfs_subsystem ufscfg_subsys = {
>>> +ÂÂÂ .su_group = {
>>> +ÂÂÂÂÂÂÂ .cg_item = {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ .ci_type = &ufscfg_type,
>>> +ÂÂÂÂÂÂÂ },
>>> +ÂÂÂ },
>>> +};
>>> +
>>> +void ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
>>> +{
>>> +ÂÂÂ int ret;
>>> +ÂÂÂ struct configfs_subsystem *subsys = &hba->subsys;
>>> +
>>> +ÂÂÂ strncpy(ufscfg_subsys.su_group.cg_item.ci_namebuf, name, strlen(name));
>>> +ÂÂÂ subsys->su_group = ufscfg_subsys.su_group;
>> configfs_subsystem cannot share su_group with other configfs_subsystem i.e
>> you are not allowing for there being more than 1 hba
> Agree. I think I will have to move above
> declarations(ufscfg_subsys/ufscfg_type/ufshcd_attrs) in driver .c/.h file
> (to make it per ufs hba/probe).
> Will check and update.
>>> +ÂÂÂ config_group_init(&subsys->su_group);
>>> +ÂÂÂ mutex_init(&subsys->su_mutex);
>>> +ÂÂÂ ret = configfs_register_subsystem(subsys);
>>> +ÂÂÂ if (ret)
>>> +ÂÂÂÂÂÂÂ pr_err("Error %d while registering subsystem %s\n",
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ret,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ subsys->su_group.cg_item.ci_namebuf);
>>> +}
>>> +
>>> +void ufshcd_configfs_exit(void)
>>> +{
>>> +ÂÂÂ configfs_unregister_subsystem(&ufscfg_subsys);
>>> +}
>>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>>> index e01cdc0..32a67b0 100644
>>> --- a/drivers/scsi/ufs/ufshcd.c
>>> +++ b/drivers/scsi/ufs/ufshcd.c
>>> @@ -7711,6 +7711,7 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>>> Â void ufshcd_remove(struct ufs_hba *hba)
>>> Â {
>>> ÂÂÂÂÂ ufs_sysfs_remove_nodes(hba->dev);
>>> +ÂÂÂ ufshcd_configfs_exit();
>>> ÂÂÂÂÂ scsi_remove_host(hba->host);
>>> ÂÂÂÂÂ /* disable interrupts */
>>> ÂÂÂÂÂ ufshcd_disable_intr(hba, hba->intr_mask);
>>> @@ -7965,7 +7966,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem
>>> *mmio_base, unsigned int irq)
>>> Â ÂÂÂÂÂ async_schedule(ufshcd_async_scan, hba);
>>> ÂÂÂÂÂ ufs_sysfs_add_nodes(hba->dev);
>>> -
>>> +ÂÂÂ ufshcd_configfs_init(hba, dev_name(hba->dev));
>>> ÂÂÂÂÂ return 0;
>>> Â Â out_remove_scsi_host:
>>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>>> index 45013b6..2275032 100644
>>> --- a/drivers/scsi/ufs/ufshcd.h
>>> +++ b/drivers/scsi/ufs/ufshcd.h
>>> @@ -37,6 +37,7 @@
>>> Â #ifndef _UFSHCD_H
>>> Â #define _UFSHCD_H
>>> Â +#include <linux/configfs.h>
>>> Â #include <linux/module.h>
>>> Â #include <linux/kernel.h>
>>> Â #include <linux/init.h>
>>> @@ -515,6 +516,9 @@ struct ufs_hba {
>>> Â ÂÂÂÂÂ struct Scsi_Host *host;
>>> ÂÂÂÂÂ struct device *dev;
>>> +#ifdef CONFIG_UFS_PROVISION
>>> +ÂÂÂ struct configfs_subsystem subsys;
>>> +#endif
>>> ÂÂÂÂÂ /*
>>> ÂÂÂÂÂÂ * This field is to keep a reference to "scsi_device" corresponding to
>>> ÂÂÂÂÂÂ * "UFS device" W-LU.
>>> @@ -868,6 +872,19 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, int
>>> desc_index,
>>> Â int ufshcd_hold(struct ufs_hba *hba, bool async);
>>> Â void ufshcd_release(struct ufs_hba *hba);
>>> Â +/* Expose UFS configfs API's */
>>> +#ifndef CONFIG_UFS_PROVISION
>>> +static inline void ufshcd_configfs_init(struct ufs_hba *hba, const char
>>> *name)
>>> +{
>>> +}
>>> +static inline void ufshcd_configfs_exit(void)
>>> +{
>>> +}
>>> +#else
>>> +void ufshcd_configfs_init(struct ufs_hba *hba, const char *name);
>>> +void ufshcd_configfs_exit(void);
>>> +#endif
>>> +
>>> Â int ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn
>>> desc_id,
>>> ÂÂÂÂÂ int *desc_length);
>>> Â
> 
>