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drm/xe/guc: Add string KLV encoding helper

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We also plan to encode a text data as KLV. Add helper for that too.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patch.msgid.link/20260707220816.677-5-michal.wajdeczko@intel.com
This commit is contained in:
Michal Wajdeczko
2026-07-08 00:08:06 +02:00
parent ac95833097
commit a408338d10
2 changed files with 36 additions and 0 deletions
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35
drivers/gpu/drm/xe/xe_guc_klv_helpers.c
View File

@@ -190,6 +190,11 @@ int xe_guc_klv_count(const u32 *klvs, u32 num_dwords)
return num_dwords ? -ENODATA : num_klvs;
}
static size_t to_num_bytes(u16 dwords)
{
return dwords * sizeof(u32);
}
static u16 to_num_dwords(size_t size)
{
return round_up(size, sizeof(u32)) / sizeof(u32);
@@ -245,3 +250,33 @@ u32 *xe_guc_klv_encode_u64(u32 *klvs, u32 avail, u16 key, u64 value)
*klvs++ = upper_32_bits(value);
return klvs;
}
/**
* xe_guc_klv_encode_string() - Encode string as KLV.
* @klvs: the buffer where to place KLV
* @avail: number of dwords (u32) available in the buffer
* @key: key to be used
* @s: string to be encoded
*
* Return: pointer to the buffer location past the encoded KLV or
* an ERR_PTR if there was no space to encode the KLV.
*/
u32 *xe_guc_klv_encode_string(u32 *klvs, u32 avail, u16 key, const char *s)
{
size_t longest = to_num_bytes(FIELD_MAX(GUC_KLV_0_LEN));
size_t size = strnlen(s, longest) + 1; /* \0 */
u16 len = to_num_dwords(size);
if (IS_ERR(klvs))
return klvs;
if (size > longest)
return ERR_PTR(-E2BIG);
if (avail < GUC_KLV_LEN_MIN + len)
return ERR_PTR(-ENOSPC);
*klvs++ = PREP_GUC_KLV(key, len);
strscpy_pad((void *)klvs, s, to_num_bytes(len));
return klvs + len;
}

1
drivers/gpu/drm/xe/xe_guc_klv_helpers.h
View File

@@ -19,6 +19,7 @@ int xe_guc_klv_count(const u32 *klvs, u32 num_dwords);
u32 *xe_guc_klv_encode_u32(u32 *klvs, u32 avail, u16 key, u32 value);
u32 *xe_guc_klv_encode_u64(u32 *klvs, u32 avail, u16 key, u64 value);
u32 *xe_guc_klv_encode_string(u32 *klvs, u32 avail, u16 key, const char *s);
/**
* PREP_GUC_KLV - Prepare KLV header value based on provided key and len.