[PATCH] of/flattree: use callback to setup initrd from /chosen

Jeremy Kerr
2009-12-22T09:39:51Z

At present, the fdt code sets the kernel-wide initrd_start and
initrd_end variables when parsing /chosen. On ARM, we only set these
once the bootmem has been reserved.

This change adds an arch callback to setup the initrd from the device
tree:

void early_init_dt_setup_initrd_arch(unsigned long start,
unsigned long end);

The arch-specific code can then setup the initrd however it likes.

Compiled on powerpc, with CONFIG_BLK_DEV_INITRD=y and =n.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>

---
arch/microblaze/kernel/prom.c | 10 ++++++++++
arch/powerpc/kernel/prom.c | 10 ++++++++++
drivers/of/fdt.c | 15 +++++----------
include/linux/of_fdt.h | 10 ++++++++++
4 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c
index 15853de..4fb5d87 100644
--- a/arch/microblaze/kernel/prom.c
+++ b/arch/microblaze/kernel/prom.c
@@ -101,6 +101,16 @@ void __init early_init_devtree_arch(void)
/* No Microblaze specific code here */
}

+#ifdef CONFIG_BLK_DEV_INITRD
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+ unsigned long end)
+{
+ initrd_start = (unsigned long)__va(start);
+ initrd_end = (unsigned long)__va(end);
+ initrd_below_start_ok = 1;
+}
+#endif
+
/*******
*
* New implementation of the OF "find" APIs, return a refcounted
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 6fea025..236b02c 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -467,6 +467,16 @@ int __init early_init_dt_scan_memory_arch(unsigned long node, const char *uname,
}
#endif /* CONFIG_PPC_PSERIES */

+#ifdef CONFIG_BLK_DEV_INITRD
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+ unsigned long end)
+{
+ initrd_start = (unsigned long)__va(start);
+ initrd_end = (unsigned long)__va(end);
+ initrd_below_start_ok = 1;
+}
+#endif
+
void __init early_reserve_mem(void)
{
u64 base, size;
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 7cb386c..ad0b09a 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -398,28 +398,23 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
*/
void __init early_init_dt_check_for_initrd(unsigned long node)
{
- unsigned long len;
+ unsigned long start, end, len;
__be32 *prop;

pr_debug("Looking for initrd properties... ");

prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
if (prop) {
- initrd_start = (unsigned long)
- __va(of_read_ulong(prop, len/4));
+ start = of_read_ulong(prop, len/4);

prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
if (prop) {
- initrd_end = (unsigned long)
- __va(of_read_ulong(prop, len/4));
- initrd_below_start_ok = 1;
- } else {
- initrd_start = 0;
+ end = of_read_ulong(prop, len/4);
+ early_init_dt_setup_initrd_arch(start, end);
}
}

- pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n",
- initrd_start, initrd_end);
+ pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start, end);
}
#else
inline void early_init_dt_check_for_initrd(unsigned long node)
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 77ae0a4..4aba9a6 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -81,6 +81,16 @@ extern void early_reserve_mem(void);
extern void early_init_devtree_arch(void);
extern u64 dt_mem_next_cell(int s, __be32 **cellp);

+/*
+ * If BLK_DEV_INITRD, the fdt early init code will call this function,
+ * to be provided by the arch code. start and end are specified as
+ * physical addresses.
+ */
+#ifdef CONFIG_BLK_DEV_INITRD
+extern void early_init_dt_setup_initrd_arch(unsigned long start,
+ unsigned long end);
+#endif
+
/* With CONFIG_HAVE_LMB, we can just use the lmb_ functions to add & allocate
* memory; otherwise, the arch has to provide its own functions to do this.
*/