Provide a service routine to check a physical memory area against the
E820 map. The routine will return false if the complete area is RAM
according to the E820 map and true otherwise.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
arch/x86/xen/setup.c | 23 +++++++++++++++++++++++
arch/x86/xen/xen-ops.h | 1 +
2 files changed, 24 insertions(+)
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 87251b4..99ef82c 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -573,6 +573,29 @@ static unsigned long __init xen_count_remap_pages(unsigned long max_pfn)
return extra;
}
+bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
+{
+ struct e820entry *entry;
+ unsigned mapcnt;
+ phys_addr_t end;
+
+ if (!size)
+ return false;
+
+ end = start + size;
+ entry = xen_e820_map;
+
+ for (mapcnt = 0; mapcnt < xen_e820_map_entries; mapcnt++) {
+ if (entry->type == E820_RAM && entry->addr <= start &&
+ (entry->addr + entry->size) >= end)
+ return false;
+
+ entry++;
+ }
+
+ return true;
+}
+
/*
* Reserve Xen mfn_list.
* See comment above "struct start_info" in <xen/interface/xen.h>
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 9e195c6..c1385b8 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -39,6 +39,7 @@ void xen_reserve_top(void);
void xen_mm_pin_all(void);
void xen_mm_unpin_all(void);
+bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size);
unsigned long __ref xen_chk_extra_mem(unsigned long pfn);
void __init xen_inv_extra_mem(void);
void __init xen_remap_memory(void);
--
2.1.4
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