On Mon, 4 Sep 2023 23:54:30 +0300
Andrey Skvortsov <andrej.skvort...@gmail.com> wrote:
Hi Andrey,
> When using SCPI as the PSCI backend, firmware can wake up the CPUs and
> cluster from sleep, so CPU idle states are available for loaded OS to
> use. TF-A modifies DTB to advertise available CPU idle states, when
> SCPI is detected. This change copies nodes added by TF-A to any new
> dtb that is used for loaded OS.
Why do you need that, exactly? Why not just use $fdtcontroladdr for the
kernel? We now keep the U-Boot copy of the .dts files in sync with the
kernel. If you need to modify the DT in U-Boot, for instance by applying
overlays, you can copy that DTB into a better suitable location first:
=> fdt move $fdtcontroladdr $fdt_addr_r
In any case, there shall be only one DT, that one in the U-Boot image. Why
do you need to load another one for the kernel?
Cheers,
Andre
> Signed-off-by: Andrey Skvortsov <andrej.skvort...@gmail.com>
> ---
> board/sunxi/board.c | 120 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 120 insertions(+)
>
> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
> index f321cd58a6..e88bd11a99 100644
> --- a/board/sunxi/board.c
> +++ b/board/sunxi/board.c
> @@ -870,6 +870,125 @@ int board_late_init(void)
> return 0;
> }
>
> +static int cpuidle_dt_fixup_copy_node(ofnode src, int dst_offset, void
> *dst_blob,
> + u32 *count, u32 *phandle)
> +{
> + int offs, len, ret;
> + struct ofprop prop;
> + ofnode subnode;
> +
> + ofnode_for_each_prop(prop, src) {
> + const char *name;
> + const char *val;
> +
> + val = ofprop_get_property(&prop, &name, &len);
> + if (!val)
> + return -EINVAL;
> + if (!strcmp(name, "phandle")) {
> + if (ofnode_device_is_compatible(src, "arm,idle-state"))
> {
> + fdt_setprop_u32(dst_blob, dst_offset, name,
> *phandle);
> + (*phandle)++;
> + (*count)++;
> + } else {
> + log_err("Unexpected phandle node: %s\n", name);
> + return -EINVAL;
> + }
> + } else {
> + ret = fdt_setprop(dst_blob, dst_offset, name, val, len);
> + if (ret < 0)
> + return ret;
> + }
> + }
> +
> + ofnode_for_each_subnode(subnode, src) {
> + const char *name = ofnode_get_name(subnode);
> +
> + if (!name)
> + return -EINVAL;
> + offs = fdt_add_subnode(dst_blob, dst_offset, name);
> + if (offs < 0)
> + return offs;
> + ret = cpuidle_dt_fixup_copy_node(subnode, offs, dst_blob,
> count, phandle);
> + if (ret < 0)
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int cpuidle_dt_fixup(void *blob)
> +{
> + ofnode idle_states_node;
> + ofnode subnode;
> + u32 count, phandle;
> + const struct property *prop;
> + int offs, len, ret;
> +
> + idle_states_node = ofnode_path("/cpus/idle-states");
> + if (!ofnode_valid(idle_states_node)) {
> + log_err("No idle-states node in old fdt, nothing to do");
> + return 0;
> + }
> +
> + /*
> + * Do not proceed if the target dt already has an idle-states node.
> + * In this case assume that the system knows better somehow,
> + * so do not interfere.
> + */
> + if (fdt_path_offset(blob, "/cpus/idle-states") >= 0) {
> + log_err("idle-states node already exists in target");
> + return 0;
> + }
> +
> + offs = fdt_path_offset(blob, "/cpus");
> + if (offs < 0)
> + return offs;
> +
> + offs = fdt_add_subnode(blob, offs, "idle-states");
> + if (offs < 0)
> + return offs;
> +
> + /* copy "/cpus/idle-states" node to destination fdt */
> + ret = fdt_find_max_phandle(blob, &phandle);
> + if (ret < 0)
> + return ret;
> + phandle++;
> + count = 0;
> + ret = cpuidle_dt_fixup_copy_node(idle_states_node, offs, blob, &count,
> &phandle);
> + if (ret < 0)
> + return ret;
> +
> + /* copy "cpu-idle-state" property for all cpus */
> + ofnode_for_each_subnode(subnode, ofnode_path("/cpus")) {
> + char path[32];
> + fdt32_t *value;
> +
> + prop = ofnode_get_property(subnode, "cpu-idle-states", &len);
> + if (!prop)
> + continue;
> +
> + /* find the same node in a new device-tree */
> + ret = ofnode_get_path(subnode, path, sizeof(path));
> + if (ret)
> + return ret;
> +
> + offs = fdt_path_offset(blob, path);
> + if (offs < 0)
> + return offs;
> +
> + /* Allocate space for the list of phandles. */
> + ret = fdt_setprop_placeholder(blob, offs, "cpu-idle-states",
> + count * sizeof(phandle),
> + (void **)&value);
> + if (ret < 0)
> + return ret;
> +
> + /* Fill in the phandles of the idle state nodes. */
> + for (u32 i = 0U; i < count; ++i)
> + value[i] = cpu_to_fdt32(phandle - count + i);
> + }
> + return 0;
> +}
> +
> static void bluetooth_dt_fixup(void *blob)
> {
> /* Some devices ship with a Bluetooth controller default address.
> @@ -914,6 +1033,7 @@ int ft_board_setup(void *blob, struct bd_info *bd)
> setup_environment(blob);
> fdt_fixup_ethernet(blob);
>
> + cpuidle_dt_fixup(blob);
> bluetooth_dt_fixup(blob);
>
> #ifdef CONFIG_VIDEO_DT_SIMPLEFB
