Work around thinkpad firmware memory layout issues and efi_mem_reserve()

Signed-off-by: Peter Jones <pjones@redhat.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch b/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch
new file mode 100644
index 000000000..037a60c33
--- /dev/null
+++ b/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch
@@ -0,0 +1,61 @@
+From 64ec700cb0b75047ce2ac68cca020e75369cb409 Mon Sep 17 00:00:00 2001
+From: Peter Jones <pjones@redhat.com>
+Date: Wed, 7 Dec 2016 16:19:20 -0500
+Subject: [PATCH 1/4] efi: efi_print_memmap(): Call out invalid entries in the
+ memory map early.
+
+Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
+(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
+Currently the log output for this case (with efi=debug) looks like:
+
+[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |  |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
+
+This is clearly wrong, and also not as informative as it could be.  This
+patch changes it so that if we find obviously invalid memory map
+entries, say so when we're printing the memory map.  It also detects the
+display of the address range calculation overflow, so the new output is:
+
+[    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entry for 0x0 pages at 0x0000000000000000
+[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0x0000000000000000] (0MB)
+
+Signed-off-by: Peter Jones <pjones@redhat.com>
+---
+ arch/x86/platform/efi/efi.c | 18 +++++++++++++++++-
+ 1 file changed, 17 insertions(+), 1 deletion(-)
+
+diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
+index bf99aa7..181c915 100644
+--- a/arch/x86/platform/efi/efi.c
++++ b/arch/x86/platform/efi/efi.c
+@@ -217,11 +217,27 @@ void __init efi_print_memmap(void)
+ 
+ 	for_each_efi_memory_desc(md) {
+ 		char buf[64];
++		bool valid = true;
++		u64 size = (md->num_pages << EFI_PAGE_SHIFT) - 1;
++
++		if (md->num_pages == 0) {
++			size = 0;
++			valid = false;
++		}
++
++		if (md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT)) {
++			size = (u64)-1LL;
++			valid = false;
++		}
++
++		if (!valid)
++			pr_info(FW_BUG "Invalid EFI memory map entry for 0x%llx pages at 0x%016llx\n",
++				md->num_pages, md->phys_addr);
+ 
+ 		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
+ 			i++, efi_md_typeattr_format(buf, sizeof(buf), md),
+ 			md->phys_addr,
+-			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
++			md->phys_addr + size,
+ 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
+ 	}
+ }
+-- 
+2.9.3
+