[PATCH 2/3] x86: add a is_e820_ram() helper

From: Christoph Hellwig
Date: Wed Mar 25 2015 - 12:06:22 EST


This will allow to deal with persistent memory which needs to be
treated like ram in many, but not all cases.

Based on an earlier patch from Dave Jiang <dave.jiang@xxxxxxxxx>.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/x86/kernel/e820.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 46201de..de088e3 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -48,6 +48,11 @@ unsigned long pci_mem_start = 0xaeedbabe;
EXPORT_SYMBOL(pci_mem_start);
#endif

+static inline bool is_e820_ram(__u32 type)
+{
+ return type == E820_RAM;
+}
+
/*
* This function checks if any part of the range <start,end> is mapped
* with type.
@@ -688,7 +693,7 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
register_nosave_region(pfn, PFN_UP(ei->addr));

pfn = PFN_DOWN(ei->addr + ei->size);
- if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
+ if (!is_e820_ram(ei->type) && ei->type != E820_RESERVED_KERN)
register_nosave_region(PFN_UP(ei->addr), pfn);

if (pfn >= limit_pfn)
@@ -748,7 +753,7 @@ u64 __init early_reserve_e820(u64 size, u64 align)
/*
* Find the highest page frame number we have available
*/
-static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
+static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
{
int i;
unsigned long last_pfn = 0;
@@ -759,7 +764,7 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
unsigned long start_pfn;
unsigned long end_pfn;

- if (ei->type != type)
+ if (!is_e820_ram(ei->type))
continue;

start_pfn = ei->addr >> PAGE_SHIFT;
@@ -784,12 +789,12 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
}
unsigned long __init e820_end_of_ram_pfn(void)
{
- return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
+ return e820_end_pfn(MAX_ARCH_PFN);
}

unsigned long __init e820_end_of_low_ram_pfn(void)
{
- return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
+ return e820_end_pfn(1UL<<(32 - PAGE_SHIFT));
}

static void early_panic(char *msg)
--
1.9.1

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