Make of_fdt conditionally compile gracefully

PATCH In review Grant Likely 2 participants 6 messages Feb 22, 2010 Device tree

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Grant Likely

author

2010-02-22 15:50 UTC #0 lore raw

cover Make of_fdt conditionally compile gracefully

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 · 1 line

Signature

Grant Likely

author

2010-02-22 15:50 UTC #1 lore raw

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

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-s3s/[email protected]>

---

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

include/linux/of_fdt.h +2 -0

index a1ca92c..f0fdd1f 100644
@@ -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 */

Grant Likely

author

2010-02-22 15:50 UTC #2 lore raw

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

In reply to 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-s3s/[email protected]>

---

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

drivers/of/fdt.c +15 -0

index 406757a..5ce7bd5 100644
@@ -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);

include/linux/of_fdt.h +2 -0

index f0fdd1f..9d7fd6d 100644
@@ -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__ */

Stephen Rothwell

2010-02-22 22:51 UTC #3 lore raw

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

Hi Grant,

Quoted 3 lines · On Mon, 22 Feb 2010 08:50:59 -0700 Grant Likely…

- If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree() an empty #define.

Any reason not to make this a static inline?

Quoted 1 line

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

static inline void unflatten_device_tree(void) {}

Signature · 3 lines

Cheers,
Stephen Rothwell                    [email protected]
http://www.canb.auug.org.au/~sfr/

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Grant Likely

author

2010-02-22 23:11 UTC #4 lore raw

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

Quoted 4 lines · Stephen Rothwell

Hi Grant,
Quoted 1 line · On Mon, 22 Feb 2010 08:50:59 -0700 Grant Likely <[email protected]>…

Quoted 8 lines

Quoted 2 lines
- If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree() an empty #define.
Any reason not to make this a static inline?
Quoted 1 line
+#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.

Quoted 6 lines

--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/

Signature · 2 lines

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

Stephen Rothwell

2010-02-22 23:25 UTC #5 lore raw

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

Hi Grant,

Quoted 2 lines · On Mon, 22 Feb 2010 16:11:48 -0700 Grant Likely…

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.

Signature · 3 lines

Cheers,
Stephen Rothwell                    [email protected]
http://www.canb.auug.org.au/~sfr/

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devicetree-discuss mailing list devicetree-discuss-uLR06cmDAlY/[email protected]
https://lists.ozlabs.org/listinfo/devicetree-discuss