x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
memblock_memory_size() will return memory size in memblock.memory.region.
memblock_free_memory_size() will return free memory size in memblock.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@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index d5fd894..0c2b7ef 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1105,3 +1105,19 @@
memblock_analyze();
memblock_dump_all();
}
+
+void __init memblock_find_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 memblock 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 = memblock_x86_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
+ free_size_pfn = memblock_x86_free_memory_in_range(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 a4f0173..924c8f7 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1013,6 +1013,7 @@
#endif
initmem_init(0, max_pfn, acpi, k8);
+ memblock_find_dma_reserve();
#ifndef CONFIG_NO_BOOTMEM
memblock_x86_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
#endif