On Wed, Nov 17, 2021 at 06:53:56PM -0800, Vikram Garhwal wrote:
> This is done to get the target path for the overlay nodes which is very useful
> in many cases. For example, Xen hypervisor needs it when applying overlays
> because Xen needs to do further processing of the overlay nodes, e.g. mapping of
> resources(IRQs and IOMMUs) to other VMs, creation of SMMU pagetables, etc.
>
> Signed-off-by: Vikram Garhwal <fnu.vikram@xxxxxxxxxx>
Applied, thanks.
If you can follow up with some testcases for the newly-public
function, that would be most appreciated.
> ---
> libfdt/fdt_overlay.c | 29 +++++++----------------------
> libfdt/libfdt.h | 18 ++++++++++++++++++
> libfdt/version.lds | 1 +
> 3 files changed, 26 insertions(+), 22 deletions(-)
>
> diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
> index d217e79..5c0c398 100644
> --- a/libfdt/fdt_overlay.c
> +++ b/libfdt/fdt_overlay.c
> @@ -40,37 +40,22 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
> return fdt32_to_cpu(*val);
> }
>
> -/**
> - * overlay_get_target - retrieves the offset of a fragment's target
> - * @fdt: Base device tree blob
> - * @fdto: Device tree overlay blob
> - * @fragment: node offset of the fragment in the overlay
> - * @pathp: pointer which receives the path of the target (or NULL)
> - *
> - * overlay_get_target() retrieves the target offset in the base
> - * device tree of a fragment, no matter how the actual targeting is
> - * done (through a phandle or a path)
> - *
> - * returns:
> - * the targeted node offset in the base device tree
> - * Negative error code on error
> - */
> -static int overlay_get_target(const void *fdt, const void *fdto,
> - int fragment, char const **pathp)
> +int fdt_overlay_target_offset(const void *fdt, const void *fdto,
> + int fragment_offset, char const **pathp)
> {
> uint32_t phandle;
> const char *path = NULL;
> int path_len = 0, ret;
>
> /* Try first to do a phandle based lookup */
> - phandle = overlay_get_target_phandle(fdto, fragment);
> + phandle = overlay_get_target_phandle(fdto, fragment_offset);
> if (phandle == (uint32_t)-1)
> return -FDT_ERR_BADPHANDLE;
>
> /* no phandle, try path */
> if (!phandle) {
> /* And then a path based lookup */
> - path = fdt_getprop(fdto, fragment, "target-path", &path_len);
> + path = fdt_getprop(fdto, fragment_offset, "target-path", &path_len);
> if (path)
> ret = fdt_path_offset(fdt, path);
> else
> @@ -636,7 +621,7 @@ static int overlay_merge(void *fdt, void *fdto)
> if (overlay < 0)
> return overlay;
>
> - target = overlay_get_target(fdt, fdto, fragment, NULL);
> + target = fdt_overlay_target_offset(fdt, fdto, fragment, NULL);
> if (target < 0)
> return target;
>
> @@ -779,7 +764,7 @@ static int overlay_symbol_update(void *fdt, void *fdto)
> return -FDT_ERR_BADOVERLAY;
>
> /* get the target of the fragment */
> - ret = overlay_get_target(fdt, fdto, fragment, &target_path);
> + ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
> if (ret < 0)
> return ret;
> target = ret;
> @@ -801,7 +786,7 @@ static int overlay_symbol_update(void *fdt, void *fdto)
>
> if (!target_path) {
> /* again in case setprop_placeholder changed it */
> - ret = overlay_get_target(fdt, fdto, fragment, &target_path);
> + ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
> if (ret < 0)
> return ret;
> target = ret;
> diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
> index 7f117e8..a7f432c 100644
> --- a/libfdt/libfdt.h
> +++ b/libfdt/libfdt.h
> @@ -2116,6 +2116,24 @@ int fdt_del_node(void *fdt, int nodeoffset);
> */
> int fdt_overlay_apply(void *fdt, void *fdto);
>
> +/**
> + * fdt_overlay_target_offset - retrieves the offset of a fragment's target
> + * @fdt: Base device tree blob
> + * @fdto: Device tree overlay blob
> + * @fragment_offset: node offset of the fragment in the overlay
> + * @pathp: pointer which receives the path of the target (or NULL)
> + *
> + * fdt_overlay_target_offset() retrieves the target offset in the base
> + * device tree of a fragment, no matter how the actual targeting is
> + * done (through a phandle or a path)
> + *
> + * returns:
> + * the targeted node offset in the base device tree
> + * Negative error code on error
> + */
> +int fdt_overlay_target_offset(const void *fdt, const void *fdto,
> + int fragment_offset, char const **pathp);
> +
> /**********************************************************************/
> /* Debugging / informational functions */
> /**********************************************************************/
> diff --git a/libfdt/version.lds b/libfdt/version.lds
> index 7ab85f1..cbce5d4 100644
> --- a/libfdt/version.lds
> +++ b/libfdt/version.lds
> @@ -77,6 +77,7 @@ LIBFDT_1.2 {
> fdt_appendprop_addrrange;
> fdt_setprop_inplace_namelen_partial;
> fdt_create_with_flags;
> + fdt_overlay_target_offset;
> local:
> *;
> };
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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