Add support for initrd on ARM arch, in case
mem= boot option change the memory size or the initrd are
not placed in low memory region, we need copy the initrd
to low memory region.
Signed-off-by: yalin wang <yalin.wang2010@xxxxxxxxx>
---
arch/arm/include/asm/fixmap.h | 1 +
arch/arm/kernel/setup.c | 70 +++++++++++++++++++++++++++++++++++++++++++
drivers/of/fdt.c | 2 ++
include/linux/initrd.h | 1 +
init/do_mounts_initrd.c | 2 ++
5 files changed, 76 insertions(+)
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index 58cfe9f..18ad90f 100644
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -10,6 +10,7 @@
enum fixed_addresses {
FIX_EARLYCON_MEM_BASE,
+ FIX_RELOCATE_INITRD,
__end_of_permanent_fixed_addresses,
FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses,
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 20edd34..036473b 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -811,6 +811,75 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
request_resource(&ioport_resource, &lp2);
}
+#if defined(CONFIG_BLK_DEV_INITRD) && defined(CONFIG_MMU)
+/*
+ * Relocate initrd if it is not completely within the linear mapping.
+ * This would be the case if mem= cuts out all or part of it
+ * or the initrd are not in low mem region place.
+ */
+static void __init relocate_initrd(void)
+{
+ phys_addr_t ram_end = memblock_end_of_DRAM();
+ phys_addr_t new_start;
+ phys_addr_t src;
+ unsigned long size, to_free = 0;
+ unsigned long slop, clen, p;
+ void *dest;
+
+ if (initrd_end_phys <= __virt_to_phys(memblock_get_current_limit()))
+ return;
+
+ /*
+ * Any of the original initrd which overlaps the linear map should
+ * be freed after relocating.
+ */
+ if (initrd_start_phys < ram_end)
+ to_free = min(ram_end, initrd_end_phys) - initrd_start_phys;
+
+ size = initrd_end_phys - initrd_start_phys;
+
+ /* initrd needs to be relocated completely inside linear mapping */
+ new_start = memblock_find_in_range(0, 0, size, PAGE_SIZE);
+ if (!new_start)
+ panic("Cannot relocate initrd of size %ld\n", size);
+ memblock_reserve(new_start, size);
+
+ initrd_start = __phys_to_virt(new_start);
+ initrd_end = initrd_start + size;
+
+ pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n",
+ (unsigned long long)initrd_start_phys,
+ (unsigned long long)(initrd_start_phys + size - 1),
+ (unsigned long long)new_start,
+ (unsigned long long)(new_start + size - 1));
+
+ dest = (void *)initrd_start;
+
+ src = initrd_start_phys;
+ while (size) {
+ slop = src & ~PAGE_MASK;
+ clen = min(PAGE_SIZE - slop, size);
+ p = set_fixmap_offset(FIX_RELOCATE_INITRD, src);
+ memcpy(dest, (void *)p, clen);
+ clear_fixmap(FIX_RELOCATE_INITRD);
+ dest += clen;
+ src += clen;
+ size -= clen;
+ }
+
+ if (to_free) {
+ pr_info("Freeing original RAMDISK from [%llx-%llx]\n",
+ (unsigned long long)initrd_start_phys,
+ (unsigned long long)(initrd_start_phys + to_free - 1));
+ memblock_free(initrd_start_phys, to_free);
+ }
+}
+#else
+static inline void __init relocate_initrd(void)
+{
+}
+#endif
+
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
struct screen_info screen_info = {
.orig_video_lines = 30,
@@ -969,6 +1038,7 @@ void __init setup_arch(char **cmdline_p)
arm_memblock_init(mdesc);
paging_init(mdesc);
+ relocate_initrd();
request_standard_resources(mdesc);
if (mdesc->restart)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0749656..3287ecb 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -777,6 +777,8 @@ static void __init early_init_dt_check_for_initrd(unsigned long node)
return;
end = of_read_number(prop, len/4);
+ initrd_start_phys = start;
+ initrd_end_phys = end;
initrd_start = (unsigned long)__va(start);
initrd_end = (unsigned long)__va(end);
initrd_below_start_ok = 1;
diff --git a/include/linux/initrd.h b/include/linux/initrd.h
index 55289d2..0698f37 100644
--- a/include/linux/initrd.h
+++ b/include/linux/initrd.h
@@ -15,6 +15,7 @@ extern int initrd_below_start_ok;
/* free_initrd_mem always gets called with the next two as arguments.. */
extern unsigned long initrd_start, initrd_end;
+extern phys_addr_t initrd_start_phys, initrd_end_phys;
extern void free_initrd_mem(unsigned long, unsigned long);
extern unsigned int real_root_dev;
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index 3e0878e..cb07338 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -21,6 +21,8 @@
#include "do_mounts.h"
unsigned long initrd_start, initrd_end;
+phys_addr_t initrd_start_pyhs __initdata;
+phys_addr_t initrd_end_phys __initdata;
int initrd_below_start_ok;
unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
static int __initdata mount_initrd = 1;
--
1.9.1
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