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ata: libata: Add support to parse equal sign in libata.force

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Currently, no libata.force parameter supports an arbitrary value.

All allowed values, e.g. udma/16, udma/25, udma/33, udma/44, udma/66,
udma/100, udma/133 have hardcoded entries in the force_tbl table.

Add code to allow a libata.force param with the format
libata.force=param=param_value, where param_value can be an arbitrary
value.

This code will be used in a follow up commit.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
This commit is contained in:
Niklas Cassel 2025-12-02 13:21:34 +01:00 • committed by Damien Le Moal
parent dfd975151d
commit 45c4c5a615
1 changed files with 36 additions and 2 deletions
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38
drivers/ata/libata-core.c
View file

@ -6490,6 +6490,13 @@ EXPORT_SYMBOL_GPL(ata_platform_remove_one);
{ "no" #name, .quirk_on = (flag) }, \
{ #name, .quirk_off = (flag) }
/*
* If the ata_force_param struct member 'name' ends with '=', then the value
* after the equal sign will be parsed as an u64, and will be saved in the
* ata_force_param struct member 'value'. This works because each libata.force
* entry (struct ata_force_ent) is separated by commas, so each entry represents
* a single quirk, and can thus only have a single value.
*/
static const struct ata_force_param force_tbl[] __initconst = {
force_cbl(40c, ATA_CBL_PATA40),
force_cbl(80c, ATA_CBL_PATA80),
@ -6577,8 +6584,9 @@ static int __init ata_parse_force_one(char **cur,
const char **reason)
{
char *start = *cur, *p = *cur;
char *id, *val, *endp;
char *id, *val, *endp, *equalsign, *char_after_equalsign;
const struct ata_force_param *match_fp = NULL;
u64 val_after_equalsign;
int nr_matches = 0, i;
/* find where this param ends and update *cur */
@ -6621,10 +6629,36 @@ static int __init ata_parse_force_one(char **cur,
}
parse_val:
/* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
equalsign = strchr(val, '=');
if (equalsign) {
char_after_equalsign = equalsign + 1;
if (!strlen(char_after_equalsign) ||
kstrtoull(char_after_equalsign, 10, &val_after_equalsign)) {
*reason = "invalid value after equal sign";
return -EINVAL;
}
}
/* Parse the parameter value. */
for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
const struct ata_force_param *fp = &force_tbl[i];
/*
* If val contains equal sign, match has to be exact, i.e.
* shortcuts are not supported.
*/
if (equalsign &&
(strncasecmp(val, fp->name,
char_after_equalsign - val) == 0)) {
force_ent->param = *fp;
force_ent->param.value = val_after_equalsign;
return 0;
}
/*
* If val does not contain equal sign, allow shortcuts so that
* both 1.5 and 1.5Gbps work.
*/
if (strncasecmp(val, fp->name, strlen(val)))
continue;