Tian wrote:
Ralf Baechle wrote:
On Wed, Jun 06, 2007 at 08:38:18AM +0200, Franck Bui-Huu wrote:
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 4975da0..62ef100 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -509,6 +509,14 @@ static void __init resource_init(void)
res->end = end;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+#if defined(CONFIG_LEMOTE_FULONG) && defined(CONFIG_64BIT)
+ /* to keep memory continous, we tell system
0x10000000 - 0x20000000 is reserved
+ * for memory, in fact it is io region, don't
occupy it
+ *
+ * SPARSEMEM?
Definetly yes ! It has been designed for such issue and it should save
you some memory.
A hole of 256MB size in the memory address map will cost 3.5MB with a
64-bit
kernel. The other reason why I don't like this patch is that it drags
platform specific code into the generic MIPS code.
Ralf
we use 16k page，so it's cheaper than that:)
Before I work out sparse memory solution, I think I can drop this
patch and make some trivial fix of the first patch.
Subject: [PATCH] simply ignore the memory hole
Signed-off-by: Songmao Tian <tiansm@xxxxxxxxxx>
---
arch/mips/lemote/lm2e/setup.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)
diff --git a/arch/mips/lemote/lm2e/setup.c
b/arch/mips/lemote/lm2e/setup.c
index 3030518..2498bbf 100644
--- a/arch/mips/lemote/lm2e/setup.c
+++ b/arch/mips/lemote/lm2e/setup.c
@@ -112,7 +112,6 @@ void __init plat_mem_setup(void)
add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);
#ifdef CONFIG_64BIT
if (highmemsize > 0) {
- add_memory_region(0x10000000, 0x10000000, BOOT_MEM_RESERVED);
add_memory_region(0x20000000, highmemsize << 20, BOOT_MEM_RAM);
}
#endif
It seems it's no need to modify code, just config to use
sparse memory will be ok, paging_init can handle the
non-flat-memory situatioins, and i notify the pages drop down as expected.
Subject: [PATCH] use SPARSEMEM to deal with the memory hole of peripheral IO
Signed-off-by: Songmao Tian <tiansm@xxxxxxxxxx>
---
arch/mips/Kconfig | 1 +
arch/mips/configs/fulong_defconfig | 13 +++++++------
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 16f1861..376cbd6 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -957,6 +957,7 @@ config CPU_LOONGSON2
depends on SYS_HAS_CPU_LOONGSON2
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
+ select ARCH_SPARSEMEM_ENABLE
select CPU_SUPPORTS_HIGHMEM
config CPU_MIPS32_R1
diff --git a/arch/mips/configs/fulong_defconfig
b/arch/mips/configs/fulong_defconfig
index cd6563a..92d9772 100644
--- a/arch/mips/configs/fulong_defconfig
+++ b/arch/mips/configs/fulong_defconfig
@@ -1,7 +1,7 @@
#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.22-rc3
-# Wed Jun 6 11:42:13 2007
+# Fri Jun 8 15:09:24 2007
#
CONFIG_MIPS=y
@@ -118,13 +118,14 @@ CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_CPU_SUPPORTS_HIGHMEM=y
CONFIG_SYS_SUPPORTS_HIGHMEM=y
CONFIG_ARCH_FLATMEM_ENABLE=y
+CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_SELECT_MEMORY_MODEL=y
-CONFIG_FLATMEM_MANUAL=y
+# CONFIG_FLATMEM_MANUAL is not set
# CONFIG_DISCONTIGMEM_MANUAL is not set
-# CONFIG_SPARSEMEM_MANUAL is not set
-CONFIG_FLATMEM=y
-CONFIG_FLAT_NODE_MEM_MAP=y
-# CONFIG_SPARSEMEM_STATIC is not set
+CONFIG_SPARSEMEM_MANUAL=y
+CONFIG_SPARSEMEM=y
+CONFIG_HAVE_MEMORY_PRESENT=y
+CONFIG_SPARSEMEM_STATIC=y
CONFIG_SPLIT_PTLOCK_CPUS=4
CONFIG_RESOURCES_64BIT=y
CONFIG_ZONE_DMA_FLAG=0
