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authorKevin Hao <haokexin@gmail.com>2013-12-24 07:12:08 (GMT)
committerScott Wood <scottwood@freescale.com>2014-01-09 23:52:17 (GMT)
commitb27652dd2174df1a7e0a7c5f00d1c8e3ed9287a7 (patch)
treea93bf5700c442d52a2ed86de8d2203f05e78cf23 /arch/powerpc/kernel/prom.c
parent78a235efdc42ff363de81fdbc171385e8b86b69b (diff)
downloadlinux-b27652dd2174df1a7e0a7c5f00d1c8e3ed9287a7.tar.xz
powerpc: introduce early_get_first_memblock_info
For a relocatable kernel since it can be loaded at any place, there is no any relation between the kernel start addr and the memstart_addr. So we can't calculate the memstart_addr from kernel start addr. And also we can't wait to do the relocation after we get the real memstart_addr from device tree because it is so late. So introduce a new function we can use to get the first memblock address and size in a very early stage (before machine_init). Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc/kernel/prom.c')
-rw-r--r--arch/powerpc/kernel/prom.c41
1 files changed, 40 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fa0ad8a..f58c0d3 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -523,6 +523,20 @@ static int __init early_init_dt_scan_memory_ppc(unsigned long node,
return early_init_dt_scan_memory(node, uname, depth, data);
}
+/*
+ * For a relocatable kernel, we need to get the memstart_addr first,
+ * then use it to calculate the virtual kernel start address. This has
+ * to happen at a very early stage (before machine_init). In this case,
+ * we just want to get the memstart_address and would not like to mess the
+ * memblock at this stage. So introduce a variable to skip the memblock_add()
+ * for this reason.
+ */
+#ifdef CONFIG_RELOCATABLE
+static int add_mem_to_memblock = 1;
+#else
+#define add_mem_to_memblock 1
+#endif
+
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
#ifdef CONFIG_PPC64
@@ -543,7 +557,8 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
}
/* Add the chunk to the MEMBLOCK list */
- memblock_add(base, size);
+ if (add_mem_to_memblock)
+ memblock_add(base, size);
}
static void __init early_reserve_mem_dt(void)
@@ -740,6 +755,30 @@ void __init early_init_devtree(void *params)
DBG(" <- early_init_devtree()\n");
}
+#ifdef CONFIG_RELOCATABLE
+/*
+ * This function run before early_init_devtree, so we have to init
+ * initial_boot_params.
+ */
+void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
+{
+ /* Setup flat device-tree pointer */
+ initial_boot_params = params;
+
+ /*
+ * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid
+ * mess the memblock.
+ */
+ add_mem_to_memblock = 0;
+ of_scan_flat_dt(early_init_dt_scan_root, NULL);
+ of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
+ add_mem_to_memblock = 1;
+
+ if (size)
+ *size = first_memblock_size;
+}
+#endif
+
/*******
*
* New implementation of the OF "find" APIs, return a refcounted