[PATCH] lib: utils/fdt: Allow to use reg-names when parsing ACLINT

[Anup Patel]

On Fri, Nov 17, 2023 at 10:34 AM Inochi Amaoto <inochiama at outlook.com> wrote:
>
> Currently, the fdt_parse_aclint_node() follows a fixed order to parse
> ACLINT timer. This may cause the undesirable result when the ACLINT
> device does not support mtime without adding an empty entry for it in
> the DT.
>
> To be robust, make fdt_parse_aclint_node() support "reg-names" property,
> so it can parse the DT in an order independent way. For compatibility,
> fdt_parse_aclint_node() only use "reg-names" when parsing ACLINT timer,
> and will fallback to the old way if "reg-names" property is not found.
>
> Signed-off-by: Inochi Amaoto <inochiama at outlook.com>
> Link: https://lore.kernel.org/all/20231114-skedaddle-precinct-66c8897227bb@squawk/
> ---
>  lib/utils/fdt/fdt_helper.c | 107 +++++++++++++++++++++++++++++++------
>  1 file changed, 91 insertions(+), 16 deletions(-)
>
> diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
> index 9ae7f09..0f42d68 100644
> --- a/lib/utils/fdt/fdt_helper.c
> +++ b/lib/utils/fdt/fdt_helper.c
> @@ -216,6 +216,32 @@ int fdt_get_node_addr_size(void *fdt, int node, int index,
>         return 0;
>  }
>
> +int fdt_get_node_addr_size_by_name(void *fdt, int node, const char *name,
> +                                  uint64_t *addr, uint64_t *size)

Declare fdt_get_node_addr_size_by_name() in fdt_helper.h

> +{
> +       int i, j, count;
> +       const char *val;
> +       const char *regname;
> +
> +       if (!fdt || node < 0 || !name)
> +               return SBI_EINVAL;
> +
> +       val = fdt_getprop(fdt, node, "reg-names", &count);
> +       if (!val)
> +               return SBI_ENODEV;
> +
> +       for (i = 0, j = 0; i < count; i++, j++) {
> +               regname = val + i;
> +
> +               if (strcmp(name, regname) == 0)
> +                       return fdt_get_node_addr_size(fdt, node, j, addr, size);
> +
> +               i += strlen(regname);
> +       }
> +
> +       return SBI_ENODEV;
> +}
> +
>  bool fdt_node_is_enabled(void *fdt, int nodeoff)
>  {
>         int len;
> @@ -873,13 +899,66 @@ int fdt_parse_plic(void *fdt, struct plic_data *plic, const char *compat)
>         return fdt_parse_plic_node(fdt, nodeoffset, plic);
>  }
>
> +int fdt_get_aclint_addr_size_by_name(void *fdt, int nodeoffset,
> +                                    unsigned long *out_addr1,
> +                                    unsigned long *out_size1,
> +                                    unsigned long *out_addr2,
> +                                    unsigned long *out_size2)

Make this static.

> +{
> +       int rc;
> +       uint64_t reg_addr, reg_size;
> +
> +       rc = fdt_get_node_addr_size_by_name(fdt, nodeoffset, "mtime",
> +                                           &reg_addr, &reg_size);
> +       if (rc < 0 || !reg_size)
> +               reg_addr = reg_size = 0;
> +       *out_addr1 = reg_addr;
> +       *out_size1 = reg_size;
> +
> +       rc = fdt_get_node_addr_size_by_name(fdt, nodeoffset, "mtimecmp",
> +                                           &reg_addr, &reg_size);
> +       if (rc < 0 || !reg_size)
> +               return SBI_ENODEV;
> +       *out_addr2 = reg_addr;
> +       *out_size2 = reg_size;
> +
> +       return 0;
> +}
> +
> +int fdt_get_aclint_addr_size(void *fdt, int nodeoffset,
> +                            unsigned long *out_addr1,
> +                            unsigned long *out_size1,
> +                            unsigned long *out_addr2,
> +                            unsigned long *out_size2)

Make this static.

> +{
> +       int rc;
> +       uint64_t reg_addr, reg_size;
> +
> +       rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
> +                                   &reg_addr, &reg_size);
> +       if (rc < 0 || !reg_size)
> +               return SBI_ENODEV;
> +       *out_addr1 = reg_addr;
> +       *out_size1 = reg_size;
> +
> +       rc = fdt_get_node_addr_size(fdt, nodeoffset, 1,
> +                                   &reg_addr, &reg_size);
> +       if (rc < 0 || !reg_size)
> +               reg_addr = reg_size = 0;
> +       if (out_addr2)
> +               *out_addr2 = reg_addr;
> +       if (out_size2)
> +               *out_size2 = reg_size;
> +
> +       return 0;
> +}
> +
>  int fdt_parse_aclint_node(void *fdt, int nodeoffset, bool for_timer,
>                           unsigned long *out_addr1, unsigned long *out_size1,
>                           unsigned long *out_addr2, unsigned long *out_size2,
>                           u32 *out_first_hartid, u32 *out_hart_count)
>  {
>         const fdt32_t *val;
> -       uint64_t reg_addr, reg_size;
>         int i, rc, count, cpu_offset, cpu_intc_offset;
>         u32 phandle, hwirq, hartid, first_hartid, last_hartid, hart_count;
>         u32 match_hwirq = (for_timer) ? IRQ_M_TIMER : IRQ_M_SOFT;
> @@ -889,21 +968,17 @@ int fdt_parse_aclint_node(void *fdt, int nodeoffset, bool for_timer,
>             !out_first_hartid || !out_hart_count)
>                 return SBI_EINVAL;
>
> -       rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
> -                                   &reg_addr, &reg_size);
> -       if (rc < 0 || !reg_size)
> -               return SBI_ENODEV;
> -       *out_addr1 = reg_addr;
> -       *out_size1 = reg_size;
> -
> -       rc = fdt_get_node_addr_size(fdt, nodeoffset, 1,
> -                                   &reg_addr, &reg_size);
> -       if (rc < 0 || !reg_size)
> -               reg_addr = reg_size = 0;
> -       if (out_addr2)
> -               *out_addr2 = reg_addr;
> -       if (out_size2)
> -               *out_size2 = reg_size;
> +       if (for_timer && out_addr2 && out_size2 &&
> +           fdt_getprop(fdt, nodeoffset, "reg-names", NULL))
> +               rc = fdt_get_aclint_addr_size_by_name(fdt, nodeoffset,
> +                                                     out_addr1, out_size1,
> +                                                     out_addr2, out_size2);
> +       else
> +               rc = fdt_get_aclint_addr_size(fdt, nodeoffset,
> +                                             out_addr1, out_size1,
> +                                             out_addr2, out_size2);
> +       if (rc)
> +               return rc;
>
>         *out_first_hartid = 0;
>         *out_hart_count = 0;
> --
> 2.42.1
>

Regards,
Anup