Messages in this thread | | | Subject | Re: [PATCH V5 2/2] scsi: ufs: Add configfs support for ufs provisioning | From | Sayali Lokhande <> | Date | Mon, 16 Jul 2018 13:40:21 +0530 |
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Hi Evan,
On 7/9/2018 11:18 PM, Evan Green wrote: > Hi Sayali, > Thanks for the prompt spin. > > On Thu, Jul 5, 2018 at 11:21 PM Sayali Lokhande <sayalil@codeaurora.org> wrote: >> This patch adds configfs support to provision ufs device at > s/ufs/UFS/ Will update. >> 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/ufshcd/ufs_provision >> 2) To provision ufs device: >> echo <config_desc_buf> > /config/ufshcd/ufs_provision >> >> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org> >> --- >> Documentation/ABI/testing/configfs-driver-ufs | 18 +++ >> drivers/scsi/ufs/Makefile | 1 + >> drivers/scsi/ufs/ufs-configfs.c | 172 ++++++++++++++++++++++++++ >> drivers/scsi/ufs/ufshcd.c | 2 + >> drivers/scsi/ufs/ufshcd.h | 19 +++ >> 5 files changed, 212 insertions(+) >> 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..dd16842 >> --- /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 > Can this be a regular dash, rather than some sort of exotic 0xE2 byte. > >> + 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> > I wonder if at this point we should be using a binary attribute rather > than a text one. Since now you're basically just converting text to > bytes, it's not very human anymore. Use of binary attr was ruled out before. Pasting previous comments from Greg : "binary attributes are meant for hardware value pass-through" type stuff. Unless this is "raw" data straight from the hardware, binary does not work. >> + > /config/ufshcd/ufs_provision >> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile >> index 918f579..d438e74 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_CONFIGFS_FS) += 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..7d207fc >> --- /dev/null >> +++ b/drivers/scsi/ufs/ufs-configfs.c >> @@ -0,0 +1,172 @@ >> +// 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 hba ? 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; >> + int i, ret, curr_len = 0; >> + struct ufs_hba *hba = config_item_to_hba(item); >> + >> + if (!hba) >> + return snprintf(buf, PAGE_SIZE, "ufs hba is NULL!\n"); >> + >> + ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC, >> + QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &buff_len); >> + >> + if (ret) >> + return snprintf(buf, PAGE_SIZE, >> + "Failed reading descriptor. desc_idn %d, opcode %x ret %d\n", >> + QUERY_DESC_IDN_CONFIGURATION, >> + UPIU_QUERY_OPCODE_READ_DESC, 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; >> + char *token; >> + int i, ret, value; >> + u32 bConfigDescrLock = 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); >> + >> + if (!hba) >> + goto out; >> + >> + /* 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, &bConfigDescrLock); >> + if (ret) { >> + dev_err(hba->dev, "%s: Failed reading bConfigDescrLock %d, cannot re-provision device!\n", >> + __func__, ret); > I think ufshcd_query_attr has its own prints on failure, we probably > don't need this one. Will check and update. >> + goto out; >> + } >> + if (bConfigDescrLock) { >> + dev_err(hba->dev, "%s: bConfigDescrLock already set to %u, cannot re-provision device!\n", >> + __func__, bConfigDescrLock); >> + goto out; >> + } >> + >> + for (i = 0; i < QUERY_DESC_CONFIGURATION_DEF_SIZE; i++) { >> + token = strsep(&strbuf, " "); >> + if (!token && i) { >> + dev_dbg(hba->dev, "%s: token %s, i %d\n", >> + __func__, token, i); > You're printing token, which you know to be null. Is this print really useful? Will check and update/remove this print. >> + break; >> + } >> + >> + ret = kstrtoint(token, 0, &value); >> + if (ret) { >> + dev_err(hba->dev, "%s: kstrtoint failed %d %s\n", >> + __func__, ret, token); >> + break; >> + } >> + desc_buf[i] = (u8)value; >> + dev_dbg(hba->dev, " desc_buf[%d] 0x%x", i, desc_buf[i]); > This print is probably a bit noisy. If you really want to dump the > contents in the debug spew there's a print_hex_dump you can do after > you break out of the loop. Then you could also remove the print for > "token %s, i %d". Will check and update. >> + } >> + >> + /* 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: Failed writing descriptor. desc_idn %d, opcode %x ret %d\n", >> + __func__, QUERY_DESC_IDN_CONFIGURATION, >> + UPIU_QUERY_OPCODE_WRITE_DESC, ret); > This is basically already covered by prints inside > ufshcd_query_descriptor_retry. Will update. >> + else >> + dev_err(hba->dev, "%s: UFS Provisioning done, reboot now!\n", >> + __func__); >> + >> +out: >> + kfree(strbuf_copy); >> + 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 = 0666, > This seems too permissive. You don't want just anybody to be able to > re-provision the disk. Maybe 0644? Agreed. will update. >> + .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_namebuf = "ufshcd", >> + .ci_type = &ufscfg_type, >> + }, >> + }, >> +}; >> + >> +int ufshcd_configfs_init(struct ufs_hba *hba) >> +{ >> + int ret; >> + struct configfs_subsystem *subsys = &hba->subsys; >> + >> + subsys->su_group = ufscfg_subsys.su_group; >> + config_group_init(&subsys->su_group); >> + mutex_init(&subsys->su_mutex); >> + ret = configfs_register_subsystem(subsys); > Wait so for every host controller, you register a subsystem called > "ufshcd"? Won't that result in a naming conflict when the second > controller comes along? I was expecting to see subsystem registration > happen once, probably in a driver init function, and then some sort of > device specific registration happen here. You'd need a unique name for > each controller, maybe the device name itself? Agreed. Will check and pass device name itself during init. > -Evan
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