[PATCH v3 1/7] of/fdt: make memblock minimum physical address arch configurable

Ard Biesheuvel ard.biesheuvel at linaro.org
Mon Nov 16 03:23:12 PST 2015

By default, early_init_dt_add_memory_arch() ignores memory below
the base of the kernel image since it won't be addressable via the
linear mapping. However, this is not appropriate anymore once we
decouple the kernel text mapping from the linear mapping, so archs
may want to drop the low limit entirely. So allow the minimum to be
overridden by setting MIN_MEMBLOCK_ADDR.

Acked-by: Mark Rutland <mark.rutland at arm.com>
Acked-by: Rob Herring <robh at kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
 drivers/of/fdt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index d2430298a309..0455564f8cbc 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -971,13 +971,16 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 #define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
-	const u64 phys_offset = __pa(PAGE_OFFSET);
+	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
 	if (!PAGE_ALIGNED(base)) {
 		if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {

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