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

From: Adrian Hunter
Date: Tue Aug 28 2018 - 08:08:27 EST


On 28/08/18 14:40, Sayali Lokhande wrote:
>
> On 8/28/2018 4:56 PM, Adrian Hunter wrote:
>> 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 :
>>>>> ÂÂÂÂ cat /config/XXXX.ufshc/ufs_provision
>>>>> 2) To provision ufs device:
>>>>> ÂÂÂÂ echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision
>>>>>
>>>>> Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
>>>>> ---
>>>>> ÂÂ Documentation/ABI/testing/configfs-driver-ufs |Â 18 +++
>>>>> ÂÂ drivers/scsi/ufs/KconfigÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 10 ++
>>>>> ÂÂ drivers/scsi/ufs/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |ÂÂ 1 +
>>>>> ÂÂ drivers/scsi/ufs/ufs-configfs.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | 155
>>>>> ++++++++++++++++++++++++++
>>>>> ÂÂ drivers/scsi/ufs/ufshcd.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |ÂÂ 3 +-
>>>>> ÂÂ drivers/scsi/ufs/ufshcd.hÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 17 +++
>>>>> ÂÂ 6 files changed, 203 insertions(+), 1 deletion(-)
>>>>> ÂÂ create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
>>>>> ÂÂ 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:
>>>>
>>>> ÂÂÂÂÂWhat: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.
> I can make separate file for each config descriptor index(say
> ufs_provision_0/1/2/3), but still show() and store() api's can remain common.
> Will try it out and update.
>>>>> +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
>>>>> ÂÂ ÂÂÂÂÂÂÂ Select this if you have UFS controller on QCOM chipset.
>>>>> ÂÂÂÂÂÂÂÂ 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-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) +=
>>>>> tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
>>>>> ÂÂ obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
>>>>> ÂÂ obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
>>>>> ÂÂ ufshcd-core-objs := ufshcd.o ufs-sysfs.o
>>>>> +obj-$(CONFIG_UFS_PROVISION) += ufs-configfs.o
>>>>> ÂÂ obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
>>>>> ÂÂ obj-$(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
> hba->desc_size.conf_desc is actually size for index 0. I thought what if
> desc size various per index.
> So better to read for each index. What say ?

Based on the 'B' and 'L' values defined in the spec., all configuration
descriptors have the same length.

>>
>>>>> +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)
>>>>> ÂÂ void ufshcd_remove(struct ufs_hba *hba)
>>>>> ÂÂ {
>>>>> ÂÂÂÂÂÂ ufs_sysfs_remove_nodes(hba->dev);
>>>>> +ÂÂÂ ufshcd_configfs_exit();
>>>>> ÂÂÂÂÂÂ scsi_remove_host(hba->host);
>>>>> ÂÂÂÂÂÂ /* disable interrupts */
>>>>> ÂÂÂÂÂÂ 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)
>>>>> ÂÂ ÂÂÂÂÂ async_schedule(ufshcd_async_scan, hba);
>>>>> ÂÂÂÂÂÂ ufs_sysfs_add_nodes(hba->dev);
>>>>> -
>>>>> +ÂÂÂ ufshcd_configfs_init(hba, dev_name(hba->dev));
>>>>> ÂÂÂÂÂÂ return 0;
>>>>> ÂÂ 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 @@
>>>>> ÂÂ #ifndef _UFSHCD_H
>>>>> ÂÂ #define _UFSHCD_H
>>>>> ÂÂ +#include <linux/configfs.h>
>>>>> ÂÂ #include <linux/module.h>
>>>>> ÂÂ #include <linux/kernel.h>
>>>>> ÂÂ #include <linux/init.h>
>>>>> @@ -515,6 +516,9 @@ struct ufs_hba {
>>>>> ÂÂ ÂÂÂÂÂ struct Scsi_Host *host;
>>>>> ÂÂÂÂÂÂ struct device *dev;
>>>>> +#ifdef CONFIG_UFS_PROVISION
>>>>> +ÂÂÂ struct configfs_subsystem subsys;
>>>>> +#endif
>>>>> ÂÂÂÂÂÂ /*
>>>>> ÂÂÂÂÂÂÂ * This field is to keep a reference to "scsi_device"
>>>>> corresponding to
>>>>> ÂÂÂÂÂÂÂ * "UFS device" W-LU.
>>>>> @@ -868,6 +872,19 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, int
>>>>> desc_index,
>>>>> ÂÂ int ufshcd_hold(struct ufs_hba *hba, bool async);
>>>>> ÂÂ void ufshcd_release(struct ufs_hba *hba);
>>>>> ÂÂ +/* 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
>>>>> +
>>>>> ÂÂ int ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn
>>>>> desc_id,
>>>>> ÂÂÂÂÂÂ int *desc_length);
>>>>> Â
>>>
>
>