From: Yinghai Lu on
lmb_memory_size() will return memory size in lmb.memory.region.
lmb_free_memory_size() will return free memory size in lmb.memory.region.

So We can get exact reseved size in specified range.

Set the size right after initmem_init(), because later bootmem API will
get area above 16M. (except some fallback).

Later after we remove the bootmem, We could call that just before paging_init().

Signed-off-by: Yinghai Lu <yinghai(a)kernel.org>
---
arch/x86/include/asm/e820.h | 2 ++
arch/x86/kernel/e820.c | 17 +++++++++++++++++
arch/x86/kernel/setup.c | 1 +
arch/x86/mm/init_64.c | 7 -------
4 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 6fbd8cd..f59db16 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -118,6 +118,8 @@ extern u64 early_reserve_e820(u64 startt, u64 sizet, u64 align);

void init_lmb_memory(void);
void fill_lmb_memory(void);
+void find_lmb_dma_reserve(void);
+
extern void finish_e820_parsing(void);
extern void e820_reserve_resources(void);
extern void e820_reserve_resources_late(void);
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 12e827b..92c6021 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1103,3 +1103,20 @@ void __init fill_lmb_memory(void)
lmb_analyze();
lmb_dump_all();
}
+
+void __init find_lmb_dma_reserve(void)
+{
+#ifdef CONFIG_X86_64
+ u64 free_size_pfn;
+ u64 mem_size_pfn;
+ /*
+ * need to find out used area below MAX_DMA_PFN
+ * need to use lmb to get free size in [0, MAX_DMA_PFN]
+ * at first, and assume boot_mem will not take below MAX_DMA_PFN
+ */
+ mem_size_pfn = lmb_memory_size(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
+ free_size_pfn = lmb_free_memory_size(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
+ set_dma_reserve(mem_size_pfn - free_size_pfn);
+#endif
+}
+
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e4fe910..c5ec1b8 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1001,6 +1001,7 @@ void __init setup_arch(char **cmdline_p)
#endif

initmem_init(0, max_pfn, acpi, k8);
+ find_lmb_dma_reserve();
#ifndef CONFIG_NO_BOOTMEM
lmb_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
#endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 0d2252c..37c7a82 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -53,8 +53,6 @@
#include <asm/init.h>
#include <linux/bootmem.h>

-static unsigned long dma_reserve __initdata;
-
static int __init parse_direct_gbpages_off(char *arg)
{
direct_gbpages = 0;
@@ -821,11 +819,6 @@ int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,

reserve_bootmem(phys, len, flags);

- if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
- dma_reserve += len / PAGE_SIZE;
- set_dma_reserve(dma_reserve);
- }
-
return 0;
}
#endif
--
1.6.4.2

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