[PATCH 3/7] lib: sbi: Add sbi_domain_root_add_memregion() API

[Alistair Francis]

On Sat, 2021-04-10 at 12:48 +0530, Anup Patel wrote:
> We should allow platform support to add more root memory regions
> before domains are finalized. This will help platform support to
> protect critical M-mode only resources.
> 
> This patch adds sbi_domain_root_add_memregion() API for above
> described purpose.
> 
> Signed-off-by: Anup Patel <anup.patel at wdc.com>

Reviewed-by: Alistair Francis <alistair.francis at wdc.com>

Alistair

> ---
>  include/sbi/sbi_domain.h | 11 +++++++
>  lib/sbi/sbi_domain.c     | 62 +++++++++++++++++++++++++++++++++-------
>  2 files changed, 62 insertions(+), 11 deletions(-)
> 
> diff --git a/include/sbi/sbi_domain.h b/include/sbi/sbi_domain.h
> index f9f4f7d..b5f2f38 100644
> --- a/include/sbi/sbi_domain.h
> +++ b/include/sbi/sbi_domain.h
> @@ -170,6 +170,17 @@ void sbi_domain_dump_all(const char *suffix);
>  int sbi_domain_register(struct sbi_domain *dom,
>                         const struct sbi_hartmask *assign_mask);
>  
> +/**
> + * Add a memory region to the root domain
> + * @param reg pointer to the memory region to be added
> + * @param skip_conflict do nothing if a conflicting region is already
> + * present in the root domain
> + *
> + * @return 0 on success and negative error code on failure
> + */
> +int sbi_domain_root_add_memregion(const struct sbi_domain_memregion
> *reg,
> +                                  bool skip_conflict);
> +
>  /** Finalize domain tables and startup non-root domains */
>  int sbi_domain_finalize(struct sbi_scratch *scratch, u32 cold_hartid);
>  
> diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
> index 164f35c..8afdb5d 100644
> --- a/lib/sbi/sbi_domain.c
> +++ b/lib/sbi/sbi_domain.c
> @@ -24,10 +24,10 @@ static bool domain_finalized = false;
>  
>  static struct sbi_hartmask root_hmask = { 0 };
>  
> -#define ROOT_FW_REGION         0
> -#define ROOT_ALL_REGION        1
> -#define ROOT_END_REGION        2
> -static struct sbi_domain_memregion root_memregs[ROOT_END_REGION + 1] =
> { 0 };
> +#define ROOT_REGION_MAX        16
> +static u32 root_memregs_count = 0;
> +static struct sbi_domain_memregion root_fw_region;
> +static struct sbi_domain_memregion root_memregs[ROOT_REGION_MAX + 1] =
> { 0 };
>  
>  static struct sbi_domain root = {
>         .name = "root",
> @@ -69,7 +69,7 @@ void sbi_domain_memregion_initfw(struct
> sbi_domain_memregion *reg)
>         if (!reg)
>                 return;
>  
> -       sbi_memcpy(reg, &root_memregs[ROOT_FW_REGION], sizeof(*reg));
> +       sbi_memcpy(reg, &root_fw_region, sizeof(*reg));
>  }
>  
>  void sbi_domain_memregion_init(unsigned long addr,
> @@ -236,9 +236,9 @@ static int sanitize_domain(const struct
> sbi_platform *plat,
>         count = 0;
>         have_fw_reg = FALSE;
>         sbi_domain_for_each_memregion(dom, reg) {
> -               if (reg->order == root_memregs[ROOT_FW_REGION].order &&
> -                   reg->base == root_memregs[ROOT_FW_REGION].base &&
> -                   reg->flags == root_memregs[ROOT_FW_REGION].flags)
> +               if (reg->order == root_fw_region.order &&
> +                   reg->base == root_fw_region.base &&
> +                   reg->flags == root_fw_region.flags)
>                         have_fw_reg = TRUE;
>                 count++;
>         }
> @@ -468,6 +468,45 @@ int sbi_domain_register(struct sbi_domain *dom,
>         return 0;
>  }
>  
> +int sbi_domain_root_add_memregion(const struct sbi_domain_memregion
> *reg,
> +                                  bool skip_conflict)
> +{
> +       int rc;
> +       struct sbi_domain_memregion *nreg;
> +       const struct sbi_platform *plat = sbi_platform_thishart_ptr();
> +
> +       /* Sanity checks */
> +       if (!reg || domain_finalized ||
> +           (root.regions != root_memregs) ||
> +           (ROOT_REGION_MAX <= root_memregs_count))
> +               return SBI_EINVAL;
> +
> +       /* Check for conflicts */
> +       sbi_domain_for_each_memregion(&root, nreg) {
> +               if (is_region_conflict(reg, nreg))
> +                       return (skip_conflict) ? 0 : SBI_EINVAL;
> +       }
> +
> +       /* Append the region to root regions */
> +       nreg = &root_memregs[root_memregs_count];
> +       sbi_memcpy(nreg, reg, sizeof(*reg));
> +       root_memregs_count++;
> +       root_memregs[root_memregs_count].order = 0;
> +
> +       /* Sanitize the root domain so that root regions are sorted */
> +       rc = sanitize_domain(plat, &root);
> +       if (rc) {
> +               sbi_printf("%s: sanity checks failed for"
> +                          " %s (error %d)\n", __func__,
> +                          root.name, rc);
> +               nreg->order = 0;
> +               root_memregs_count--;
> +               return rc;
> +       }
> +
> +       return 0;
> +}
> +
>  int sbi_domain_finalize(struct sbi_scratch *scratch, u32 cold_hartid)
>  {
>         int rc;
> @@ -537,17 +576,18 @@ int sbi_domain_init(struct sbi_scratch *scratch,
> u32 cold_hartid)
>  
>         /* Root domain firmware memory region */
>         sbi_domain_memregion_init(scratch->fw_start, scratch->fw_size,
> 0,
> -                                 &root_memregs[ROOT_FW_REGION]);
> +                                 &root_fw_region);
> +       sbi_domain_memregion_initfw(&root_memregs[root_memregs_count++]
> );
>  
>         /* Root domain allow everything memory region */
>         sbi_domain_memregion_init(0, ~0UL,
>                                   (SBI_DOMAIN_MEMREGION_READABLE |
>                                    SBI_DOMAIN_MEMREGION_WRITEABLE |
>                                    SBI_DOMAIN_MEMREGION_EXECUTABLE),
> -                                 &root_memregs[ROOT_ALL_REGION]);
> +                                 &root_memregs[root_memregs_count++]);
>  
>         /* Root domain memory region end */
> -       root_memregs[ROOT_END_REGION].order = 0;
> +       root_memregs[root_memregs_count].order = 0;
>  
>         /* Use platform specific root memory regions when available */
>         memregs = sbi_platform_domains_root_regions(plat);