efi/fake_mem: arrange for a resource entry per efi_fake_mem instance

In preparation for attaching a platform device per iomem resource teach
the efi_fake_mem code to create an e820 entry per instance.  Similar to
E820_TYPE_PRAM, bypass merging resource when the e820 map is sanitized.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Link: https://lkml.kernel.org/r/159643096068.4062302.11590041070221681669.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/firmware/efi/x86_fake_mem.c b/drivers/firmware/efi/x86_fake_mem.c
index e5d6d5a1b240..0bafcc1bb0f6 100644
--- a/drivers/firmware/efi/x86_fake_mem.c
+++ b/drivers/firmware/efi/x86_fake_mem.c
@@ -38,7 +38,7 @@ void __init efi_fake_memmap_early(void)
 		m_start = mem->range.start;
 		m_end = mem->range.end;
 		for_each_efi_memory_desc(md) {
-			u64 start, end;
+			u64 start, end, size;
 
 			if (md->type != EFI_CONVENTIONAL_MEMORY)
 				continue;
@@ -58,11 +58,17 @@ void __init efi_fake_memmap_early(void)
 			 */
 			start = max(start, m_start);
 			end = min(end, m_end);
+			size = end - start + 1;
 
 			if (end <= start)
 				continue;
-			e820__range_update(start, end - start + 1, E820_TYPE_RAM,
-					E820_TYPE_SOFT_RESERVED);
+
+			/*
+			 * Ensure each efi_fake_mem instance results in
+			 * a unique e820 resource
+			 */
+			e820__range_remove(start, size, E820_TYPE_RAM, 1);
+			e820__range_add(start, size, E820_TYPE_SOFT_RESERVED);
 			e820__update_table(e820_table);
 		}
 	}