[PATCH RESEND] scsi: ufs: revamp string descriptor reading

From: Tomas Winkler
Date: Sun Jul 21 2019 - 10:14:06 EST


Define new a type: uc_string_id for easier string
handling and less casting. Reduce number or string
copies in price of a dynamic allocation.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Tested-by: Avri Altman <avri.altman@xxxxxxx>
---

Resend: It was reviewed by not merged.

drivers/scsi/ufs/ufs-sysfs.c | 20 ++---
drivers/scsi/ufs/ufs.h | 2 +-
drivers/scsi/ufs/ufshcd.c | 164 +++++++++++++++++++++--------------
drivers/scsi/ufs/ufshcd.h | 9 +-
4 files changed, 115 insertions(+), 80 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index f478685122ff..13e357f01025 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -570,10 +570,11 @@ static ssize_t _name##_show(struct device *dev, \
struct ufs_hba *hba = dev_get_drvdata(dev); \
int ret; \
int desc_len = QUERY_DESC_MAX_SIZE; \
- u8 *desc_buf; \
+ char *desc_buf; \
+ \
desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_ATOMIC); \
- if (!desc_buf) \
- return -ENOMEM; \
+ if (!desc_buf) \
+ return -ENOMEM; \
ret = ufshcd_query_descriptor_retry(hba, \
UPIU_QUERY_OPCODE_READ_DESC, QUERY_DESC_IDN_DEVICE, \
0, 0, desc_buf, &desc_len); \
@@ -582,14 +583,13 @@ static ssize_t _name##_show(struct device *dev, \
goto out; \
} \
index = desc_buf[DEVICE_DESC_PARAM##_pname]; \
- memset(desc_buf, 0, QUERY_DESC_MAX_SIZE); \
- if (ufshcd_read_string_desc(hba, index, desc_buf, \
- QUERY_DESC_MAX_SIZE, true)) { \
- ret = -EINVAL; \
+ kfree(desc_buf); \
+ desc_buf = NULL; \
+ ret = ufshcd_read_string_desc(hba, index, &desc_buf, \
+ SD_ASCII_STD); \
+ if (ret < 0) \
goto out; \
- } \
- ret = snprintf(buf, PAGE_SIZE, "%s\n", \
- desc_buf + QUERY_DESC_HDR_SIZE); \
+ ret = snprintf(buf, PAGE_SIZE, "%s\n", desc_buf); \
out: \
kfree(desc_buf); \
return ret; \
diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 99a9c4d16f6b..b3e1b2a0f463 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -541,7 +541,7 @@ struct ufs_dev_info {
*/
struct ufs_dev_desc {
u16 wmanufacturerid;
- char model[MAX_MODEL_LEN + 1];
+ char *model;
};

/**
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a3b6cd1a623d..e2740353332a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -299,16 +299,6 @@ static void ufshcd_scsi_block_requests(struct ufs_hba *hba)
scsi_block_requests(hba->host);
}

-/* replace non-printable or non-ASCII characters with spaces */
-static inline void ufshcd_remove_non_printable(char *val)
-{
- if (!val)
- return;
-
- if (*val < 0x20 || *val > 0x7e)
- *val = ' ';
-}
-
static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag,
const char *str)
{
@@ -3130,7 +3120,7 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
enum desc_idn desc_id,
int desc_index,
u8 param_offset,
- u8 *param_read_buf,
+ void *param_read_buf,
u8 param_size)
{
int ret;
@@ -3198,7 +3188,7 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
static inline int ufshcd_read_desc(struct ufs_hba *hba,
enum desc_idn desc_id,
int desc_index,
- u8 *buf,
+ void *buf,
u32 size)
{
return ufshcd_read_desc_param(hba, desc_id, desc_index, 0, buf, size);
@@ -3216,49 +3206,78 @@ static int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size)
return ufshcd_read_desc(hba, QUERY_DESC_IDN_DEVICE, 0, buf, size);
}

+/**
+ * struct uc_string_id - unicode string
+ *
+ * @len: size of this descriptor inclusive
+ * @type: descriptor type
+ * @uc: unicode string character
+ */
+struct uc_string_id {
+ u8 len;
+ u8 type;
+ wchar_t uc[0];
+} __packed;
+
+/* replace non-printable or non-ASCII characters with spaces */
+static inline char ufshcd_remove_non_printable(char ch)
+{
+ return (ch >= 0x20 && ch <= 0x7e) ? ch : ' ';
+}
+
/**
* ufshcd_read_string_desc - read string descriptor
* @hba: pointer to adapter instance
* @desc_index: descriptor index
- * @buf: pointer to buffer where descriptor would be read
- * @size: size of buf
+ * @buf: pointer to buffer where descriptor would be read,
+ * the caller should free the memory.
* @ascii: if true convert from unicode to ascii characters
+ * null terminated string.
*
- * Return 0 in case of success, non-zero otherwise
+ * Return:
+ * * string size on success.
+ * * -ENOMEM: on allocation failure
+ * * -EINVAL: on a wrong parameter
*/
-int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
- u8 *buf, u32 size, bool ascii)
+int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index,
+ char **buf, bool ascii)
{
- int err = 0;
+ struct uc_string_id *uc_str;
+ char *str;
+ int ret;

- err = ufshcd_read_desc(hba,
- QUERY_DESC_IDN_STRING, desc_index, buf, size);
+ if (!buf)
+ return -EINVAL;

- if (err) {
- dev_err(hba->dev, "%s: reading String Desc failed after %d retries. err = %d\n",
- __func__, QUERY_REQ_RETRIES, err);
+ uc_str = kzalloc(QUERY_DESC_MAX_SIZE, GFP_KERNEL);
+ if (!uc_str)
+ return -ENOMEM;
+
+ ret = ufshcd_read_desc(hba, QUERY_DESC_IDN_STRING,
+ desc_index, uc_str,
+ QUERY_DESC_MAX_SIZE);
+ if (ret < 0) {
+ dev_err(hba->dev, "Reading String Desc failed after %d retries. err = %d\n",
+ QUERY_REQ_RETRIES, ret);
+ str = NULL;
+ goto out;
+ }
+
+ if (uc_str->len <= QUERY_DESC_HDR_SIZE) {
+ dev_dbg(hba->dev, "String Desc is of zero length\n");
+ str = NULL;
+ ret = 0;
goto out;
}

if (ascii) {
- int desc_len;
- int ascii_len;
+ ssize_t ascii_len;
int i;
- char *buff_ascii;
-
- desc_len = buf[0];
/* remove header and divide by 2 to move from UTF16 to UTF8 */
- ascii_len = (desc_len - QUERY_DESC_HDR_SIZE) / 2 + 1;
- if (size < ascii_len + QUERY_DESC_HDR_SIZE) {
- dev_err(hba->dev, "%s: buffer allocated size is too small\n",
- __func__);
- err = -ENOMEM;
- goto out;
- }
-
- buff_ascii = kmalloc(ascii_len, GFP_KERNEL);
- if (!buff_ascii) {
- err = -ENOMEM;
+ ascii_len = (uc_str->len - QUERY_DESC_HDR_SIZE) / 2 + 1;
+ str = kzalloc(ascii_len, GFP_KERNEL);
+ if (!str) {
+ ret = -ENOMEM;
goto out;
}

@@ -3266,22 +3285,29 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
* the descriptor contains string in UTF16 format
* we need to convert to utf-8 so it can be displayed
*/
- utf16s_to_utf8s((wchar_t *)&buf[QUERY_DESC_HDR_SIZE],
- desc_len - QUERY_DESC_HDR_SIZE,
- UTF16_BIG_ENDIAN, buff_ascii, ascii_len);
+ ret = utf16s_to_utf8s(uc_str->uc,
+ uc_str->len - QUERY_DESC_HDR_SIZE,
+ UTF16_BIG_ENDIAN, str, ascii_len);

/* replace non-printable or non-ASCII characters with spaces */
- for (i = 0; i < ascii_len; i++)
- ufshcd_remove_non_printable(&buff_ascii[i]);
+ for (i = 0; i < ret; i++)
+ str[i] = ufshcd_remove_non_printable(str[i]);

- memset(buf + QUERY_DESC_HDR_SIZE, 0,
- size - QUERY_DESC_HDR_SIZE);
- memcpy(buf + QUERY_DESC_HDR_SIZE, buff_ascii, ascii_len);
- buf[QUERY_DESC_LENGTH_OFFSET] = ascii_len + QUERY_DESC_HDR_SIZE;
- kfree(buff_ascii);
+ str[ret++] = '\0';
+
+ } else {
+ str = kzalloc(uc_str->len, GFP_KERNEL);
+ if (!str) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memcpy(str, uc_str, uc_str->len);
+ ret = uc_str->len;
}
out:
- return err;
+ *buf = str;
+ kfree(uc_str);
+ return ret;
}

/**
@@ -6452,6 +6478,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba,
u8 model_index;
u8 *desc_buf;

+ if (!dev_desc)
+ return -EINVAL;
+
buff_len = max_t(size_t, hba->desc_size.dev_desc,
QUERY_DESC_MAX_SIZE + 1);
desc_buf = kmalloc(buff_len, GFP_KERNEL);
@@ -6475,31 +6504,31 @@ static int ufs_get_device_desc(struct ufs_hba *hba,
desc_buf[DEVICE_DESC_PARAM_MANF_ID + 1];

model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
-
- /* Zero-pad entire buffer for string termination. */
- memset(desc_buf, 0, buff_len);
-
- err = ufshcd_read_string_desc(hba, model_index, desc_buf,
- QUERY_DESC_MAX_SIZE, true/*ASCII*/);
- if (err) {
+ err = ufshcd_read_string_desc(hba, model_index,
+ &dev_desc->model, SD_ASCII_STD);
+ if (err < 0) {
dev_err(hba->dev, "%s: Failed reading Product Name. err = %d\n",
__func__, err);
goto out;
}

- desc_buf[QUERY_DESC_MAX_SIZE] = '\0';
- strlcpy(dev_desc->model, (desc_buf + QUERY_DESC_HDR_SIZE),
- min_t(u8, desc_buf[QUERY_DESC_LENGTH_OFFSET],
- MAX_MODEL_LEN));
-
- /* Null terminate the model string */
- dev_desc->model[MAX_MODEL_LEN] = '\0';
+ /*
+ * ufshcd_read_string_desc returns size of the string
+ * reset the error value
+ */
+ err = 0;

out:
kfree(desc_buf);
return err;
}

+static void ufs_put_device_desc(struct ufs_dev_desc *dev_desc)
+{
+ kfree(dev_desc->model);
+ dev_desc->model = NULL;
+}
+
static void ufs_fixup_device_setup(struct ufs_hba *hba,
struct ufs_dev_desc *dev_desc)
{
@@ -6508,8 +6537,9 @@ static void ufs_fixup_device_setup(struct ufs_hba *hba,
for (f = ufs_fixups; f->quirk; f++) {
if ((f->card.wmanufacturerid == dev_desc->wmanufacturerid ||
f->card.wmanufacturerid == UFS_ANY_VENDOR) &&
- (STR_PRFX_EQUAL(f->card.model, dev_desc->model) ||
- !strcmp(f->card.model, UFS_ANY_MODEL)))
+ ((dev_desc->model &&
+ STR_PRFX_EQUAL(f->card.model, dev_desc->model)) ||
+ !strcmp(f->card.model, UFS_ANY_MODEL)))
hba->dev_quirks |= f->quirk;
}
}
@@ -6860,6 +6890,8 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
}

ufs_fixup_device_setup(hba, &card);
+ ufs_put_device_desc(&card);
+
ufshcd_tune_unipro_params(hba);

/* UFS device is also active now */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 994d73d03207..10935548d1fc 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -885,14 +885,17 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
enum desc_idn desc_id,
int desc_index,
u8 param_offset,
- u8 *param_read_buf,
+ void *param_read_buf,
u8 param_size);
int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
enum attr_idn idn, u8 index, u8 selector, u32 *attr_val);
int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
enum flag_idn idn, bool *flag_res);
-int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
- u8 *buf, u32 size, bool ascii);
+
+#define SD_ASCII_STD true
+#define SD_RAW false
+int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index,
+ char **buf, bool ascii);

int ufshcd_hold(struct ufs_hba *hba, bool async);
void ufshcd_release(struct ufs_hba *hba);
--
2.20.1