[028/181] efi/fake_mem: arrange for a resource entry per efi_fake_mem instance

Commit Message

Andrew Morton Oct. 13, 2020, 11:49 p.m. UTC

From: Dan Williams <[e-mail]>
Subject: 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.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Dan Williams <[e-mail]>
Acked-by: Ard Biesheuvel <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Ben Skeggs <[e-mail]>
Cc: Brice Goglin <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Dave Jiang <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Ira Weiny <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: Jeff Moyer <[e-mail]>
Cc: Jia He <[e-mail]>
Cc: Joao Martins <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Pavel Tatashin <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Rafael J. Wysocki <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: Vishal Verma <[e-mail]>
Cc: Wei Yang <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Ard Biesheuvel <[e-mail]>
Cc: Bjorn Helgaas <[e-mail]>
Cc: Boris Ostrovsky <[e-mail]>
Cc: Hulk Robot <[e-mail]>
Cc: Jason Yan <[e-mail]>
Cc: "Jérôme Glisse" <[e-mail]>
Cc: Juergen Gross <[e-mail]>
Cc: kernel test robot <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Stefano Stabellini <[e-mail]>
Cc: Vivek Goyal <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 arch/x86/kernel/e820.c              |   16 +++++++++++++++-
 drivers/firmware/efi/x86_fake_mem.c |   12 +++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

Patch

--- a/arch/x86/kernel/e820.c~efi-fake_mem-arrange-for-a-resource-entry-per-efi_fake_mem-instance
+++ a/arch/x86/kernel/e820.c
@@ -305,6 +305,20 @@  static int __init cpcompare(const void *
 	return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 }
 
+static bool e820_nomerge(enum e820_type type)
+{
+	/*
+	 * These types may indicate distinct platform ranges aligned to
+	 * numa node, protection domain, performance domain, or other
+	 * boundaries. Do not merge them.
+	 */
+	if (type == E820_TYPE_PRAM)
+		return true;
+	if (type == E820_TYPE_SOFT_RESERVED)
+		return true;
+	return false;
+}
+
 int __init e820__update_table(struct e820_table *table)
 {
 	struct e820_entry *entries = table->entries;
@@ -380,7 +394,7 @@  int __init e820__update_table(struct e82
 		}
 
 		/* Continue building up new map based on this information: */
-		if (current_type != last_type || current_type == E820_TYPE_PRAM) {
+		if (current_type != last_type || e820_nomerge(current_type)) {
 			if (last_type != 0)	 {
 				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
 				/* Move forward only if the new size was non-zero: */
--- a/drivers/firmware/efi/x86_fake_mem.c~efi-fake_mem-arrange-for-a-resource-entry-per-efi_fake_mem-instance
+++ a/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);
 		}
 	}