* [PATCH] soc: mediatek: mtk-dvfsrc: use flex array
@ 2026-03-04 23:20 Rosen Penev
2026-03-06 4:20 ` Gustavo A. R. Silva
0 siblings, 1 reply; 3+ messages in thread
From: Rosen Penev @ 2026-03-04 23:20 UTC (permalink / raw)
To: linux-mediatek
Cc: Matthias Brugger, AngeloGioacchino Del Regno, Kees Cook,
Gustavo A. R. Silva, open list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support,
open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b
Simplifies allocation from kzalloc + kcaloc to one allocation.
Allows extra runtime analysis with __counted_by.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
drivers/soc/mediatek/mtk-dvfsrc.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/drivers/soc/mediatek/mtk-dvfsrc.c b/drivers/soc/mediatek/mtk-dvfsrc.c
index 548a28f50242..48b1fcf3e101 100644
--- a/drivers/soc/mediatek/mtk-dvfsrc.c
+++ b/drivers/soc/mediatek/mtk-dvfsrc.c
@@ -71,8 +71,8 @@ struct dvfsrc_opp {
};
struct dvfsrc_opp_desc {
- const struct dvfsrc_opp *opps;
u32 num_opp;
+ struct dvfsrc_opp opps[] __counted_by(num_opp);
};
struct dvfsrc_soc_data;
@@ -489,7 +489,6 @@ static u32 dvfsrc_get_opp_gear(struct mtk_dvfsrc *dvfsrc, u8 level)
static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
{
- struct dvfsrc_opp *dvfsrc_opps;
struct dvfsrc_opp_desc *desc;
u32 num_opps, gear_info;
u8 num_vcore, num_dram;
@@ -520,24 +519,19 @@ static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
num_opps, num_vcore, num_dram, num_emi);
/* Allocate everything now as anything else after that cannot fail */
- desc = devm_kzalloc(dvfsrc->dev, sizeof(*desc), GFP_KERNEL);
+ desc = devm_kzalloc(dvfsrc->dev, struct_size(desc, opps, num_ops + 1), GFP_KERNEL);
if (!desc)
return -ENOMEM;
- dvfsrc_opps = devm_kcalloc(dvfsrc->dev, num_opps + 1,
- sizeof(*dvfsrc_opps), GFP_KERNEL);
- if (!dvfsrc_opps)
- return -ENOMEM;
+ desc->num_opp = num_opps + 1;
/* Read the OPP table gear indices */
for (i = 0; i <= num_opps; i++) {
gear_info = dvfsrc_get_opp_gear(dvfsrc, num_opps - i);
- dvfsrc_opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
- dvfsrc_opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
- dvfsrc_opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
+ desc->opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
+ desc->opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
+ desc->opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
};
- desc->num_opp = num_opps + 1;
- desc->opps = dvfsrc_opps;
/* Assign to main structure now that everything is done! */
dvfsrc->curr_opps = desc;
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] soc: mediatek: mtk-dvfsrc: use flex array
2026-03-04 23:20 [PATCH] soc: mediatek: mtk-dvfsrc: use flex array Rosen Penev
@ 2026-03-06 4:20 ` Gustavo A. R. Silva
2026-03-06 19:25 ` Rosen Penev
0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2026-03-06 4:20 UTC (permalink / raw)
To: Rosen Penev, linux-mediatek
Cc: Matthias Brugger, AngeloGioacchino Del Regno, Kees Cook,
Gustavo A. R. Silva, open list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support,
open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b
On 3/5/26 08:20, Rosen Penev wrote:
> Simplifies allocation from kzalloc + kcaloc to one allocation.
>
> Allows extra runtime analysis with __counted_by.
>
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
> drivers/soc/mediatek/mtk-dvfsrc.c | 18 ++++++------------
> 1 file changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-dvfsrc.c b/drivers/soc/mediatek/mtk-dvfsrc.c
> index 548a28f50242..48b1fcf3e101 100644
> --- a/drivers/soc/mediatek/mtk-dvfsrc.c
> +++ b/drivers/soc/mediatek/mtk-dvfsrc.c
> @@ -71,8 +71,8 @@ struct dvfsrc_opp {
> };
>
> struct dvfsrc_opp_desc {
> - const struct dvfsrc_opp *opps;
> u32 num_opp;
> + struct dvfsrc_opp opps[] __counted_by(num_opp);
> };
>
> struct dvfsrc_soc_data;
> @@ -489,7 +489,6 @@ static u32 dvfsrc_get_opp_gear(struct mtk_dvfsrc *dvfsrc, u8 level)
>
> static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
> {
> - struct dvfsrc_opp *dvfsrc_opps;
> struct dvfsrc_opp_desc *desc;
> u32 num_opps, gear_info;
> u8 num_vcore, num_dram;
> @@ -520,24 +519,19 @@ static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
> num_opps, num_vcore, num_dram, num_emi);
>
> /* Allocate everything now as anything else after that cannot fail */
> - desc = devm_kzalloc(dvfsrc->dev, sizeof(*desc), GFP_KERNEL);
> + desc = devm_kzalloc(dvfsrc->dev, struct_size(desc, opps, num_ops + 1), GFP_KERNEL);
Mmhh... You should really consider building your code before submitting any patches.
-Gustavo
> if (!desc)
> return -ENOMEM;
>
> - dvfsrc_opps = devm_kcalloc(dvfsrc->dev, num_opps + 1,
> - sizeof(*dvfsrc_opps), GFP_KERNEL);
> - if (!dvfsrc_opps)
> - return -ENOMEM;
> + desc->num_opp = num_opps + 1;
>
> /* Read the OPP table gear indices */
> for (i = 0; i <= num_opps; i++) {
> gear_info = dvfsrc_get_opp_gear(dvfsrc, num_opps - i);
> - dvfsrc_opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
> - dvfsrc_opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
> - dvfsrc_opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
> + desc->opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
> + desc->opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
> + desc->opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
> };
> - desc->num_opp = num_opps + 1;
> - desc->opps = dvfsrc_opps;
>
> /* Assign to main structure now that everything is done! */
> dvfsrc->curr_opps = desc;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] soc: mediatek: mtk-dvfsrc: use flex array
2026-03-06 4:20 ` Gustavo A. R. Silva
@ 2026-03-06 19:25 ` Rosen Penev
0 siblings, 0 replies; 3+ messages in thread
From: Rosen Penev @ 2026-03-06 19:25 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: linux-mediatek, Matthias Brugger, AngeloGioacchino Del Regno,
Kees Cook, Gustavo A. R. Silva,
open list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support,
open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b
On Fri, Mar 6, 2026 at 11:21 AM Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
>
>
>
> On 3/5/26 08:20, Rosen Penev wrote:
> > Simplifies allocation from kzalloc + kcaloc to one allocation.
> >
> > Allows extra runtime analysis with __counted_by.
> >
> > Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > ---
> > drivers/soc/mediatek/mtk-dvfsrc.c | 18 ++++++------------
> > 1 file changed, 6 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/soc/mediatek/mtk-dvfsrc.c b/drivers/soc/mediatek/mtk-dvfsrc.c
> > index 548a28f50242..48b1fcf3e101 100644
> > --- a/drivers/soc/mediatek/mtk-dvfsrc.c
> > +++ b/drivers/soc/mediatek/mtk-dvfsrc.c
> > @@ -71,8 +71,8 @@ struct dvfsrc_opp {
> > };
> >
> > struct dvfsrc_opp_desc {
> > - const struct dvfsrc_opp *opps;
> > u32 num_opp;
> > + struct dvfsrc_opp opps[] __counted_by(num_opp);
> > };
> >
> > struct dvfsrc_soc_data;
> > @@ -489,7 +489,6 @@ static u32 dvfsrc_get_opp_gear(struct mtk_dvfsrc *dvfsrc, u8 level)
> >
> > static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
> > {
> > - struct dvfsrc_opp *dvfsrc_opps;
> > struct dvfsrc_opp_desc *desc;
> > u32 num_opps, gear_info;
> > u8 num_vcore, num_dram;
> > @@ -520,24 +519,19 @@ static int dvfsrc_get_hw_opps_v4(struct mtk_dvfsrc *dvfsrc)
> > num_opps, num_vcore, num_dram, num_emi);
> >
> > /* Allocate everything now as anything else after that cannot fail */
> > - desc = devm_kzalloc(dvfsrc->dev, sizeof(*desc), GFP_KERNEL);
> > + desc = devm_kzalloc(dvfsrc->dev, struct_size(desc, opps, num_ops + 1), GFP_KERNEL);
>
> Mmhh... You should really consider building your code before submitting any patches.
This one specifically I failed at the make parameters.
This patch should be rescinded. Not correct.
>
> -Gustavo
>
> > if (!desc)
> > return -ENOMEM;
> >
> > - dvfsrc_opps = devm_kcalloc(dvfsrc->dev, num_opps + 1,
> > - sizeof(*dvfsrc_opps), GFP_KERNEL);
> > - if (!dvfsrc_opps)
> > - return -ENOMEM;
> > + desc->num_opp = num_opps + 1;
> >
> > /* Read the OPP table gear indices */
> > for (i = 0; i <= num_opps; i++) {
> > gear_info = dvfsrc_get_opp_gear(dvfsrc, num_opps - i);
> > - dvfsrc_opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
> > - dvfsrc_opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
> > - dvfsrc_opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
> > + desc->opps[i].vcore_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_VCORE, gear_info);
> > + desc->opps[i].dram_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_DRAM, gear_info);
> > + desc->opps[i].emi_opp = FIELD_GET(DVFSRC_V4_GEAR_INFO_EMI, gear_info);
> > };
> > - desc->num_opp = num_opps + 1;
> > - desc->opps = dvfsrc_opps;
> >
> > /* Assign to main structure now that everything is done! */
> > dvfsrc->curr_opps = desc;
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-03-04 23:20 [PATCH] soc: mediatek: mtk-dvfsrc: use flex array Rosen Penev
2026-03-06 4:20 ` Gustavo A. R. Silva
2026-03-06 19:25 ` Rosen Penev
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