[PATCH 0/2] Make of_fdt conditionally compile gracefully

[PATCH 0/2] Make of_fdt conditionally compile gracefully

[Grant Likely]

A couple more minor changes for cross-arch device tree support.

g.
---

Grant Likely (2):
      of/flattree: Make unflatten_device_tree() safe to call from any arch
      of/flattree: make of_fdt.h safe to unconditionally include.


 drivers/of/fdt.c       |   15 +++++++++++++++
 include/linux/of_fdt.h |    4 ++++
 2 files changed, 19 insertions(+), 0 deletions(-)

-- 
Signature

[PATCH 1/2] of/flattree: make of_fdt.h safe to unconditionally include.

[Grant Likely]

If CONFIG_OF_FLATTREE is not set, then don't process the body of
linux/of_fdt.h

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

 include/linux/of_fdt.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index a1ca92c..f0fdd1f 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -57,6 +57,7 @@ struct boot_param_header {
 	__be32	dt_struct_size;		/* size of the DT structure block */
 };
 
+#if defined(CONFIG_OF_FLATTREE)
 /* TBD: Temporary export of fdt globals - remove when code fully merged */
 extern int __initdata dt_root_addr_cells;
 extern int __initdata dt_root_size_cells;
@@ -98,6 +99,7 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname,
 /* Other Prototypes */
 extern void unflatten_device_tree(void);
 extern void early_init_devtree(void *);
+#endif /* CONFIG_OF_FLATTREE */
 
 #endif /* __ASSEMBLY__ */
 #endif /* _LINUX_OF_FDT_H */

[PATCH 2/2] of/flattree: Make unflatten_device_tree() safe to call from any arch

[Grant Likely]

This patch makes unflatten_device_tree() safe to call from any arch
setup code with the following changes:
- Make sure initial_boot_params actually points to a device tree blob
  before unflattening
- Make sure the initial_boot_params->magic field is correct
- If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree()
  an empty #define.

This patch also adds some additional debug output to the top of
unflatten_device_tree().

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

 drivers/of/fdt.c       |   15 +++++++++++++++
 include/linux/of_fdt.h |    2 ++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 406757a..5ce7bd5 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -553,6 +553,21 @@ void __init unflatten_device_tree(void)
 
 	pr_debug(" -> unflatten_device_tree()\n");
 
+	if (!initial_boot_params) {
+		pr_debug("No device tree pointer\n");
+		return;
+	}
+
+	pr_debug("Unflattening device tree:\n");
+	pr_debug("magic: %08x\n", be32_to_cpu(initial_boot_params->magic));
+	pr_debug("size: %08x\n", be32_to_cpu(initial_boot_params->totalsize));
+	pr_debug("version: %08x\n", be32_to_cpu(initial_boot_params->version));
+
+	if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
+		pr_err("Invalid device tree blob header\n");
+		return;
+	}
+
 	/* First pass, scan for size */
 	start = ((unsigned long)initial_boot_params) +
 		be32_to_cpu(initial_boot_params->off_dt_struct);
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index f0fdd1f..9d7fd6d 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -99,6 +99,8 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname,
 /* Other Prototypes */
 extern void unflatten_device_tree(void);
 extern void early_init_devtree(void *);
+#else /* CONFIG_OF_FLATTREE */
+#define unflatten_device_tree() do {} while(0)
 #endif /* CONFIG_OF_FLATTREE */
 
 #endif /* __ASSEMBLY__ */

Re: [PATCH 2/2] of/flattree: Make unflatten_device_tree() safe to call from any arch

[Stephen Rothwell]

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Hi Grant,

On Mon, 22 Feb 2010 08:50:59 -0700 Grant Likely <grant.likely@secretlab.ca> wrote:
>
> - If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree()
>   an empty #define.

Any reason not to make this a static inline?

> +#define unflatten_device_tree() do {} while(0)

static inline void unflatten_device_tree(void) {}

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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Re: [PATCH 2/2] of/flattree: Make unflatten_device_tree() safe to call from any arch

[Grant Likely]

On Mon, Feb 22, 2010 at 3:51 PM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> Hi Grant,
>
> On Mon, 22 Feb 2010 08:50:59 -0700 Grant Likely <grant.likely@secretlab.ca> wrote:
>>
>> - If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree()
>>   an empty #define.
>
> Any reason not to make this a static inline?
>
>> +#define unflatten_device_tree() do {} while(0)
>
> static inline void unflatten_device_tree(void) {}

No reason, just wasn't thinking of that.  I've changed this.

g.

>
> --
> Cheers,
> Stephen Rothwell                    sfr@canb.auug.org.au
> http://www.canb.auug.org.au/~sfr/
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH 2/2] of/flattree: Make unflatten_device_tree() safe to call from any arch

[Stephen Rothwell]

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Hi Grant,

On Mon, 22 Feb 2010 16:11:48 -0700 Grant Likely <grant.likely@secretlab.ca> wrote:
>
> No reason, just wasn't thinking of that.  I've changed this.

Thanks.  Andrew Morton says that (unless there is a good reason) we
should program the kernel in C not CPP.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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