From e612b4a7db4ae1dd8c2bbe171e10c21723de95b2 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 17 Jul 2015 06:51:28 +0200 Subject: [PATCH] xen: check memory area against e820 map 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 Reviewed-by: David Vrabel Acked-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- 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 87251b4c2e30..99ef82cc4edc 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 diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 2292721b1d10..a4cbb76642d8 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);