[PATCH v2 0/1] libfdt: overlay: make overlay_get_target() public

[PATCH v2 0/1] libfdt: overlay: make overlay_get_target() public

[Vikram Garhwal]

Changes in v2:
v1 -> v2:
    Improve patch subject.
    Rename fdt_overlay_get_target to fdt_overlay_target_offset
    Rename fragment to fragment_offset

Regards,
Vikram

Vikram Garhwal (1):
  libfdt: overlay: make overlay_get_target() public

 libfdt/fdt_overlay.c | 29 +++++++----------------------
 libfdt/libfdt.h      | 18 ++++++++++++++++++
 libfdt/version.lds   |  1 +
 3 files changed, 26 insertions(+), 22 deletions(-)

-- 
2.7.4

[PATCH v2 1/1] libfdt: overlay: make overlay_get_target() public

[Vikram Garhwal]

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-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
---
 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:
 		*;
 };
-- 
2.7.4

Re: [PATCH v2 1/1] libfdt: overlay: make overlay_get_target() public

[David Gibson]

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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-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>

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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Re: [PATCH v2 1/1] libfdt: overlay: make overlay_get_target() public

[Vikram Garhwal]

On Thu, Nov 18, 2021 at 04:26:29PM +1100, David Gibson wrote:
> 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-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> 
> Applied, thanks.
Thanks!
> 
> If you can follow up with some testcases for the newly-public
> function, that would be most appreciated.
Sure, will check the existing test cases and add tests for new public function.

Regards,
Vikram
> 
> > ---
> >  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