[PATCH] lib: reset: Add early_init api for fdt_reset_drv

Anup Patel apatel at ventanamicro.com
Fri Jun 16 23:43:29 PDT 2023


On Sat, Jun 17, 2023 at 10:57 AM <guoren at kernel.org> wrote:
>
> From: Guo Ren <guoren at linux.alibaba.com>
>
> The fdt_reset_thead driver needs to modify the __reset_thead_csr_stub
> text region for the secondary harts booting. After that, the
> sbi_hart_pmp_configure may lock down the text region with M_READABLE &
> M_EXECUTABLE attributes in the future. Currently, the M_READABLE &
> M_EXECUtABLE have no effect on m-mode, the L-bit in pmpcfg csr is
> useless for the current opensbi scenario. See:
>
> Priv-isa-spec 3.7.1.2. Locking and Privilege Mode
> When the L bit is clear, any M-mode access matching the PMP entry will
> succeed; the R/W/X permissions apply only to S and U modes.
>
> That's why current fdt_reset_thead could still work well after commit:
> 230278dcf127 ("lib: sbi: Add separate entries for firmware RX and RW
> regions"). So this patch fixes up a fake bug for the M-mode permission
> setting of the future.
>
> Fixes: 230278dcf127 ("lib: sbi: Add separate entries for firmware RX and RW regions")
> Link: http://lists.infradead.org/pipermail/opensbi/2023-June/005176.html
> Reported-by: Jessica Clarke <jrtc27 at jrtc27.com>
> Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren at kernel.org>
> ---
>  include/sbi_utils/reset/fdt_reset.h |  9 +++++----
>  lib/utils/reset/fdt_reset.c         | 20 +++++++++++++-------
>  lib/utils/reset/fdt_reset_thead.c   |  2 +-
>  platform/generic/platform.c         |  5 ++++-
>  platform/generic/sifive/fu740.c     |  2 +-
>  platform/generic/starfive/jh7110.c  |  2 +-
>  6 files changed, 25 insertions(+), 15 deletions(-)
>
> diff --git a/include/sbi_utils/reset/fdt_reset.h b/include/sbi_utils/reset/fdt_reset.h
> index ea8063b8a90e..2b1849534e2b 100644
> --- a/include/sbi_utils/reset/fdt_reset.h
> +++ b/include/sbi_utils/reset/fdt_reset.h
> @@ -15,6 +15,7 @@
>  struct fdt_reset {
>         const struct fdt_match *match_table;
>         int (*init)(void *fdt, int nodeoff, const struct fdt_match *match);
> +       int (*early_init)(void *fdt, int nodeoff, const struct fdt_match *match);
>  };
>
>  #ifdef CONFIG_FDT_RESET
> @@ -22,22 +23,22 @@ struct fdt_reset {
>  /**
>   * fdt_reset_driver_init() - initialize reset driver based on the device-tree
>   */
> -int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv);
> +int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv, bool early);
>
>  /**
>   * fdt_reset_init() - initialize reset drivers based on the device-tree
>   *
>   * This function shall be invoked in final init.
>   */
> -void fdt_reset_init(void);
> +void fdt_reset_init(bool early);
>
>  #else
>
> -static inline int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv)
> +static inline int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv, bool early)
>  {
>         return 0;
>  }
> -static inline void fdt_reset_init(void) { }
> +static inline void fdt_reset_init(bool early) { }
>
>  #endif
>
> diff --git a/lib/utils/reset/fdt_reset.c b/lib/utils/reset/fdt_reset.c
> index 4334586d39f7..a99d8ecc5907 100644
> --- a/lib/utils/reset/fdt_reset.c
> +++ b/lib/utils/reset/fdt_reset.c
> @@ -17,31 +17,37 @@
>  extern struct fdt_reset *fdt_reset_drivers[];
>  extern unsigned long fdt_reset_drivers_size;
>
> -int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv)
> +int fdt_reset_driver_init(void *fdt, struct fdt_reset *drv, bool early)
>  {
>         int noff, rc = SBI_ENODEV;
>         const struct fdt_match *match;
> +       int (*init)(void *fdt, int nodeoff, const struct fdt_match *match);
>
>         noff = fdt_find_match(fdt, -1, drv->match_table, &match);
>         if (noff < 0)
>                 return SBI_ENODEV;
>
> -       if (drv->init) {
> -               rc = drv->init(fdt, noff, match);
> +       if (early)
> +               init = drv->early_init;
> +       else
> +               init = drv->init;
> +
> +       if (init) {
> +               rc = init(fdt, noff, match);
>                 if (rc && rc != SBI_ENODEV) {
> -                       sbi_printf("%s: %s init failed, %d\n",
> -                                  __func__, match->compatible, rc);
> +                       sbi_printf("%s: %s %s-init failed, %d\n",
> +                                  __func__, match->compatible, early?"early":"final", rc);
>                 }
>         }
>
>         return rc;
>  }
>
> -void fdt_reset_init(void)
> +void fdt_reset_init(bool early)
>  {
>         int pos;
>         void *fdt = fdt_get_address();
>
>         for (pos = 0; pos < fdt_reset_drivers_size; pos++)
> -               fdt_reset_driver_init(fdt, fdt_reset_drivers[pos]);
> +               fdt_reset_driver_init(fdt, fdt_reset_drivers[pos], early);
>  }
> diff --git a/lib/utils/reset/fdt_reset_thead.c b/lib/utils/reset/fdt_reset_thead.c
> index e1d6885debae..4cae037b1db7 100644
> --- a/lib/utils/reset/fdt_reset_thead.c
> +++ b/lib/utils/reset/fdt_reset_thead.c
> @@ -130,5 +130,5 @@ static const struct fdt_match thead_reset_match[] = {
>
>  struct fdt_reset fdt_reset_thead = {
>         .match_table = thead_reset_match,
> -       .init = thead_reset_init
> +       .early_init = thead_reset_init
>  };
> diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> index eeefef4c9533..65134e2c3895 100644
> --- a/platform/generic/platform.c
> +++ b/platform/generic/platform.c
> @@ -146,6 +146,9 @@ static int generic_early_init(bool cold_boot)
>         if (!generic_plat || !generic_plat->early_init)
>                 return 0;
>
> +       if (cold_boot)
> +               fdt_reset_init(true);
> +
>         return generic_plat->early_init(cold_boot, generic_plat_match);
>  }
>
> @@ -155,7 +158,7 @@ static int generic_final_init(bool cold_boot)
>         int rc;
>
>         if (cold_boot)
> -               fdt_reset_init();
> +               fdt_reset_init(false);

We don't need this "early" flag business in fdt_reset_init().

Just move the fdt_reset_init() call to generic_early_init() before
"if (!generic_plat || !generic_plat->early_init)".

Regards,
Anup

>
>         if (generic_plat && generic_plat->final_init) {
>                 rc = generic_plat->final_init(cold_boot, generic_plat_match);
> diff --git a/platform/generic/sifive/fu740.c b/platform/generic/sifive/fu740.c
> index fe71ce6a9ea5..5d3f1388beef 100644
> --- a/platform/generic/sifive/fu740.c
> +++ b/platform/generic/sifive/fu740.c
> @@ -233,7 +233,7 @@ static int sifive_fu740_final_init(bool cold_boot,
>         void *fdt = fdt_get_address();
>
>         if (cold_boot) {
> -               rc = fdt_reset_driver_init(fdt, &fdt_reset_da9063);
> +               rc = fdt_reset_driver_init(fdt, &fdt_reset_da9063, false);
>                 if (rc)
>                         sbi_printf("%s: failed to find da9063 for reset\n",
>                                    __func__);
> diff --git a/platform/generic/starfive/jh7110.c b/platform/generic/starfive/jh7110.c
> index dcd6306be5fc..f21fe85c6560 100644
> --- a/platform/generic/starfive/jh7110.c
> +++ b/platform/generic/starfive/jh7110.c
> @@ -277,7 +277,7 @@ static int starfive_jh7110_final_init(bool cold_boot,
>         void *fdt = fdt_get_address();
>
>         if (cold_boot) {
> -               fdt_reset_driver_init(fdt, &fdt_reset_pmic);
> +               fdt_reset_driver_init(fdt, &fdt_reset_pmic, false);
>                 return starfive_jh7110_inst_init(fdt);
>         }
>
> --
> 2.36.1
>
>
> --
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