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authorMatt Redfearn2016-03-31 10:05:40 +0100
committerRalf Baechle2016-05-13 14:02:03 +0200
commit5e7c1c918a4433c5dd1844d99f5648e17425fa16 (patch)
treeec338a40b5fabbf17fe7d51eda5e909aed1f0899
parent8c530ea35caef8bc293b56580ab55352f7d86bfc (diff)
MIPS: Introduce plat_get_fdt a platform API to retrieve the FDT
Early access to the kernel command line requires early access to the FDT for platforms which pass the command line within the device tree. There was no common way to retrieve the location of the FDT without incurring side effects, such as plat_mem_setup which, on Malta at least, initializes a bunch of other stuff. This patch adds plat_get_ftd() for IMG platforms. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12988/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/include/asm/bootinfo.h18
-rw-r--r--arch/mips/mti-malta/malta-setup.c7
-rw-r--r--arch/mips/mti-sead3/sead3-setup.c5
3 files changed, 29 insertions, 1 deletions
diff --git a/arch/mips/include/asm/bootinfo.h b/arch/mips/include/asm/bootinfo.h
index b603804caac5..9f67033961a6 100644
--- a/arch/mips/include/asm/bootinfo.h
+++ b/arch/mips/include/asm/bootinfo.h
@@ -144,4 +144,22 @@ static inline void plat_swiotlb_setup(void) {}
#endif /* CONFIG_SWIOTLB */
+#ifdef CONFIG_USE_OF
+/**
+ * plat_get_fdt() - Return a pointer to the platform's device tree blob
+ *
+ * This function provides a platform independent API to get a pointer to the
+ * flattened device tree blob. The interface between bootloader and kernel
+ * is not consistent across platforms so it is necessary to provide this
+ * API such that common startup code can locate the FDT.
+ *
+ * This is used by the KASLR code to get command line arguments and random
+ * seed from the device tree. Any platform wishing to use KASLR should
+ * provide this API and select SYS_SUPPORTS_RELOCATABLE.
+ *
+ * Return: Pointer to the flattened device tree blob.
+ */
+extern void *plat_get_fdt(void);
+#endif /* CONFIG_USE_OF */
+
#endif /* _ASM_BOOTINFO_H */
diff --git a/arch/mips/mti-malta/malta-setup.c b/arch/mips/mti-malta/malta-setup.c
index 4740c82fb97a..33d5ff5069e5 100644
--- a/arch/mips/mti-malta/malta-setup.c
+++ b/arch/mips/mti-malta/malta-setup.c
@@ -248,10 +248,15 @@ static void __init bonito_quirks_setup(void)
#endif
}
+void __init *plat_get_fdt(void)
+{
+ return (void *)__dtb_start;
+}
+
void __init plat_mem_setup(void)
{
unsigned int i;
- void *fdt = __dtb_start;
+ void *fdt = plat_get_fdt();
fdt = malta_dt_shim(fdt);
__dt_setup_arch(fdt);
diff --git a/arch/mips/mti-sead3/sead3-setup.c b/arch/mips/mti-sead3/sead3-setup.c
index e43f4801a245..9f2f9b2b23ce 100644
--- a/arch/mips/mti-sead3/sead3-setup.c
+++ b/arch/mips/mti-sead3/sead3-setup.c
@@ -83,6 +83,11 @@ static void __init parse_memsize_param(void)
}
}
+void __init *plat_get_fdt(void)
+{
+ return (void *)__dtb_start;
+}
+
void __init plat_mem_setup(void)
{
/* allow command line/bootloader env to override memory size in DT */