Re: [PATCH] pmdomain: amlogic: Constify struct meson_secure_pwrc_domain_desc

[Neil Armstrong]

On 01/07/2024 21:53, Christophe JAILLET wrote:
> 'struct meson_secure_pwrc_domain_desc' is not modified in this driver.
>
> Constifying this structure moves some data to a read-only section, so
> increase overall security.
>
> On a x86_64, with allmodconfig, as an example:
> Before:
> ======
>     text	   data	    bss	    dec	    hex	filename
>     4909	   4072	      0	   8981	   2315	drivers/pmdomain/amlogic/meson-secure-pwrc.o
>
> After:
> =====
>     text	   data	    bss	    dec	    hex	filename
>     8605	    392	      0	   8997	   2325	drivers/pmdomain/amlogic/meson-secure-pwrc.o
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> Compile tested-only.
>
> The .is_off() function is *always* set as pwrc_secure_is_off(), so it could
> make sense to remove this function pointer and call pwrc_secure_is_off()
> directly when needed.
> This would save some memory and useless indirection.
>
> I leave it as-is because it is maybe here for future use.
> ---
>   drivers/pmdomain/amlogic/meson-secure-pwrc.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pmdomain/amlogic/meson-secure-pwrc.c b/drivers/pmdomain/amlogic/meson-secure-pwrc.c
> index df5567418226..62857482f874 100644
> --- a/drivers/pmdomain/amlogic/meson-secure-pwrc.c
> +++ b/drivers/pmdomain/amlogic/meson-secure-pwrc.c
> @@ -46,7 +46,7 @@ struct meson_secure_pwrc_domain_desc {
>   
>   struct meson_secure_pwrc_domain_data {
>   	unsigned int count;
> -	struct meson_secure_pwrc_domain_desc *domains;
> +	const struct meson_secure_pwrc_domain_desc *domains;
>   };
>   
>   static bool pwrc_secure_is_off(struct meson_secure_pwrc_domain *pwrc_domain)
> @@ -110,7 +110,7 @@ static int meson_secure_pwrc_on(struct generic_pm_domain *domain)
>   	.parent = __parent,			\
>   }
>   
> -static struct meson_secure_pwrc_domain_desc a1_pwrc_domains[] = {
> +static const struct meson_secure_pwrc_domain_desc a1_pwrc_domains[] = {
>   	SEC_PD(DSPA,	0),
>   	SEC_PD(DSPB,	0),
>   	/* UART should keep working in ATF after suspend and before resume */
> @@ -137,7 +137,7 @@ static struct meson_secure_pwrc_domain_desc a1_pwrc_domains[] = {
>   	SEC_PD(RSA,	0),
>   };
>   
> -static struct meson_secure_pwrc_domain_desc a4_pwrc_domains[] = {
> +static const struct meson_secure_pwrc_domain_desc a4_pwrc_domains[] = {
>   	SEC_PD(A4_AUDIO,	0),
>   	SEC_PD(A4_SDIOA,	0),
>   	SEC_PD(A4_EMMC,	0),
> @@ -155,7 +155,7 @@ static struct meson_secure_pwrc_domain_desc a4_pwrc_domains[] = {
>   	SEC_PD(A4_AO_IR,	GENPD_FLAG_ALWAYS_ON),
>   };
>   
> -static struct meson_secure_pwrc_domain_desc c3_pwrc_domains[] = {
> +static const struct meson_secure_pwrc_domain_desc c3_pwrc_domains[] = {
>   	SEC_PD(C3_NNA,		0),
>   	SEC_PD(C3_AUDIO,	0),
>   	SEC_PD(C3_SDIOA,	0),
> @@ -172,7 +172,7 @@ static struct meson_secure_pwrc_domain_desc c3_pwrc_domains[] = {
>   	SEC_PD(C3_VCODEC,	0),
>   };
>   
> -static struct meson_secure_pwrc_domain_desc s4_pwrc_domains[] = {
> +static const struct meson_secure_pwrc_domain_desc s4_pwrc_domains[] = {
>   	SEC_PD(S4_DOS_HEVC,	0),
>   	SEC_PD(S4_DOS_VDEC,	0),
>   	SEC_PD(S4_VPU_HDMI,	0),
> @@ -184,7 +184,7 @@ static struct meson_secure_pwrc_domain_desc s4_pwrc_domains[] = {
>   	SEC_PD(S4_AUDIO,	0),
>   };
>   
> -static struct meson_secure_pwrc_domain_desc t7_pwrc_domains[] = {
> +static const struct meson_secure_pwrc_domain_desc t7_pwrc_domains[] = {
>   	SEC_PD(T7_DSPA,		0),
>   	SEC_PD(T7_DSPB,		0),
>   	TOP_PD(T7_DOS_HCODEC,	0, PWRC_T7_NIC3_ID),

Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>