Messages in this thread Patch in this message | | | From | Alex Thorlton <> | Subject | [PATCH 1/2] x86: Make E820_X_MAX unconditionally larger than E820MAX | Date | Mon, 5 Dec 2016 11:49:13 -0600 |
| |
It's really not necessary to limit E820_X_MAX to 128 in the non-EFI case. This commit drops E820_X_MAX's dependency on CONFIG_EFI, so that E820_X_MAX is always at least slightly larger than E820MAX.
The real motivation behind this is actually to prevent some issues in the Xen kernel, where the XENMEM_machine_memory_map hypercall can produce an e820 map larger than 128 entries, even on systems where the original e820 table was quite a bit smaller than that, depending on how many IOAPICs are installed on the system.
Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Ingo Molnar <mingo@redhat.com> Cc: Russ Anderson <rja@sgi.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: x86@kernel.org Cc: xen-devel@lists.xenproject.org --- arch/x86/include/asm/e820.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h index 476b574..ec23d8e 100644 --- a/arch/x86/include/asm/e820.h +++ b/arch/x86/include/asm/e820.h @@ -1,13 +1,17 @@ #ifndef _ASM_X86_E820_H #define _ASM_X86_E820_H -#ifdef CONFIG_EFI +/* + * E820_X_MAX is the maximum size of the extended E820 table. The extended + * table may contain up to 3 extra E820 entries per possible NUMA node, so we + * make room for 3 * MAX_NUMNODES possible entries, beyond the standard 128. + * Also note that E820_X_MAX *must* be defined before we include uapi/asm/e820.h. + */ #include <linux/numa.h> #define E820_X_MAX (E820MAX + 3 * MAX_NUMNODES) -#else /* ! CONFIG_EFI */ -#define E820_X_MAX E820MAX -#endif + #include <uapi/asm/e820.h> + #ifndef __ASSEMBLY__ /* see comment in arch/x86/kernel/e820.c */ extern struct e820map *e820; -- 1.8.5.6
| |