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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>