From 9ed68785f7f2b001a6911d64fbd10cfc6fa49b27 Mon Sep 17 00:00:00 2001
From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Date: Tue, 15 Aug 2017 21:13:54 +0300
Subject: [PATCH] ARC: mm: Decouple RAM base address from kernel link address
[Needed for HSDK]
Currently the first page of system (hence RAM base) is assumed to be
@ CONFIG_LINUX_LINK_BASE, where kernel itself is linked.
However is case of HSDK platform, for reasons explained in that patch,
this is not true. kernel needs to be linked @ 0x9000_0000 while DDR
is still wired at 0x8000_0000. To properly account for this 256M of RAM,
we need to introduce a new option and base page frame accountiing off of
it.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: renamed CONFIG_KERNEL_RAM_BASE_ADDRESS => CONFIG_LINUX_RAM_BASE
: simplified changelog]
---
arch/arc/Kconfig | 10 +++++++++-
arch/arc/boot/dts/axc001.dtsi | 2 +-
arch/arc/boot/dts/axc003.dtsi | 2 +-
arch/arc/boot/dts/axc003_idu.dtsi | 2 +-
arch/arc/boot/dts/nsim_hs.dts | 2 +-
arch/arc/include/asm/page.h | 2 +-
arch/arc/mm/cache.c | 2 +-
arch/arc/mm/init.c | 6 +++---
8 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 7db85ab00c522..65b7549e17db3 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -418,7 +418,7 @@ endif # ISA_ARCV2
endmenu # "ARC CPU Configuration"
config LINUX_LINK_BASE
- hex "Linux Link Address"
+ hex "Kernel link address"
default "0x80000000"
help
ARC700 divides the 32 bit phy address space into two equal halves
@@ -431,6 +431,14 @@ config LINUX_LINK_BASE
If you don't know what the above means, leave this setting alone.
This needs to match memory start address specified in Device Tree
+config LINUX_RAM_BASE
+ hex "RAM base address"
+ default LINUX_LINK_BASE
+ help
+ By default Linux is linked at base of RAM. However in some special
+ cases (such as HSDK), Linux can't be linked at start of DDR, hence
+ this option.
+
config HIGHMEM
bool "High Memory Support"
select ARCH_DISCONTIGMEM_ENABLE
diff --git a/arch/arc/boot/dts/axc001.dtsi b/arch/arc/boot/dts/axc001.dtsi
index a380ffa1a4589..fdc266504ada2 100644
--- a/arch/arc/boot/dts/axc001.dtsi
+++ b/arch/arc/boot/dts/axc001.dtsi
@@ -99,7 +99,7 @@ mb_intc: dw-apb-ictl@0xe0012000 {
memory {
device_type = "memory";
- /* CONFIG_KERNEL_RAM_BASE_ADDRESS needs to match low mem start */
+ /* CONFIG_LINUX_RAM_BASE needs to match low mem start */
reg = <0x0 0x80000000 0x0 0x1b000000>; /* (512 - 32) MiB */
};
diff --git a/arch/arc/boot/dts/axc003.dtsi b/arch/arc/boot/dts/axc003.dtsi
index dca7e39409beb..4e6e9f57e790a 100644
--- a/arch/arc/boot/dts/axc003.dtsi
+++ b/arch/arc/boot/dts/axc003.dtsi
@@ -109,7 +109,7 @@ mb_intc: dw-apb-ictl@0xe0012000 {
memory {
device_type = "memory";
- /* CONFIG_KERNEL_RAM_BASE_ADDRESS needs to match low mem start */
+ /* CONFIG_LINUX_RAM_BASE needs to match low mem start */
reg = <0x0 0x80000000 0x0 0x20000000 /* 512 MiB low mem */
0x1 0xc0000000 0x0 0x40000000>; /* 1 GiB highmem */
};
diff --git a/arch/arc/boot/dts/axc003_idu.dtsi b/arch/arc/boot/dts/axc003_idu.dtsi
index 5b56beffc1c51..63954a8b0100e 100644
--- a/arch/arc/boot/dts/axc003_idu.dtsi
+++ b/arch/arc/boot/dts/axc003_idu.dtsi
@@ -115,7 +115,7 @@ mb_intc: dw-apb-ictl@0xe0012000 {
memory {
device_type = "memory";
- /* CONFIG_KERNEL_RAM_BASE_ADDRESS needs to match low mem start */
+ /* CONFIG_LINUX_RAM_BASE needs to match low mem start */
reg = <0x0 0x80000000 0x0 0x20000000 /* 512 MiB low mem */
0x1 0xc0000000 0x0 0x40000000>; /* 1 GiB highmem */
};
diff --git a/arch/arc/boot/dts/nsim_hs.dts b/arch/arc/boot/dts/nsim_hs.dts
index 3772c40c245ec..8d787b251f737 100644
--- a/arch/arc/boot/dts/nsim_hs.dts
+++ b/arch/arc/boot/dts/nsim_hs.dts
@@ -18,7 +18,7 @@ / {
memory {
device_type = "memory";
- /* CONFIG_LINUX_LINK_BASE needs to match low mem start */
+ /* CONFIG_LINUX_RAM_BASE needs to match low mem start */
reg = <0x0 0x80000000 0x0 0x20000000 /* 512 MB low mem */
0x1 0x00000000 0x0 0x40000000>; /* 1 GB highmem */
};
diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 296c3426a6ad3..109baa06831ce 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -85,7 +85,7 @@ typedef pte_t * pgtable_t;
*/
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
-#define ARCH_PFN_OFFSET virt_to_pfn(CONFIG_LINUX_LINK_BASE)
+#define ARCH_PFN_OFFSET virt_to_pfn(CONFIG_LINUX_RAM_BASE)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) (((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index d68d36c159095..eee924dfffa6e 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -1173,7 +1173,7 @@ noinline void __init arc_ioc_setup(void)
write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
/* for now assume kernel base is start of IOC aperture */
- ioc_base = CONFIG_LINUX_LINK_BASE;
+ ioc_base = CONFIG_LINUX_RAM_BASE;
if (ioc_base % mem_sz != 0)
panic("IOC Aperture start must be aligned to the size of the aperture");
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 8c9415ed62804..ba145065c579b 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -26,7 +26,7 @@ pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
EXPORT_SYMBOL(empty_zero_page);
-static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
+static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
static unsigned long low_mem_sz;
#ifdef CONFIG_HIGHMEM
@@ -63,7 +63,7 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
if (!low_mem_sz) {
if (base != low_mem_start)
- panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
+ panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
low_mem_sz = size;
in_use = 1;
@@ -161,7 +161,7 @@ void __init setup_arch_memory(void)
* We can't use the helper free_area_init(zones[]) because it uses
* PAGE_OFFSET to compute the @min_low_pfn which would be wrong
* when our kernel doesn't start at PAGE_OFFSET, i.e.
- * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
+ * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
*/
free_area_init_node(0, /* node-id */
zones_size, /* num pages per zone */
--
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