[PATCH 1/2] efi: Add efi_memmap_free() to free EFI memory map

[Yunfeng Ye]

In efi_fake_memmap(), the commit 20b1e22d01a4 ("x86/efi: Don't allocate
memmap through memblock after mm_init()") replace memblock_alloc() with
efi_memmap_alloc(), but there is no matching modification of
memblock_free() when early_memremap() fail.

Fix this by adding efi_memmap_free() to instead of memblock_free().

Fixes: 20b1e22d01a4 ("x86/efi: Don't allocate memmap through memblock after mm_init()")
Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
---
 drivers/firmware/efi/fake_mem.c |  2 +-
 drivers/firmware/efi/memmap.c   | 34 ++++++++++++++++++++++++++++++++++
 include/linux/efi.h             |  1 +
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
index 9501edc..c2f69f6 100644
--- a/drivers/firmware/efi/fake_mem.c
+++ b/drivers/firmware/efi/fake_mem.c
@@ -65,7 +65,7 @@ void __init efi_fake_memmap(void)
 	new_memmap = early_memremap(new_memmap_phy,
 				    efi.memmap.desc_size * new_nr_map);
 	if (!new_memmap) {
-		memblock_free(new_memmap_phy, efi.memmap.desc_size * new_nr_map);
+		efi_memmap_free(new_memmap_phy, new_nr_map);
 		return;
 	}

diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 38b686c..35dc189 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -18,6 +18,11 @@ static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
 	return memblock_phys_alloc(size, SMP_CACHE_BYTES);
 }

+static void __init __efi_memmap_free_early(phys_addr_t addr, unsigned long size)
+{
+	memblock_free(addr, size);
+}
+
 static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
 {
 	unsigned int order = get_order(size);
@@ -29,6 +34,15 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
 	return PFN_PHYS(page_to_pfn(p));
 }

+static void __init __efi_memmap_free_late(phys_addr_t addr, unsigned long size)
+{
+	unsigned int order = get_order(size);
+	struct page *p = pfn_to_page(PHYS_PFN(addr));
+
+	if (p)
+		__free_pages(p, order);
+}
+
 /**
  * efi_memmap_alloc - Allocate memory for the EFI memory map
  * @num_entries: Number of entries in the allocated map.
@@ -50,6 +64,26 @@ phys_addr_t __init efi_memmap_alloc(unsigned int num_entries)
 }

 /**
+ * efi_memmap_free - Free memory for the EFI memory map
+ * @addr: Physical address of the EFI memory map to be freed.
+ * @num_entries: Number of the EFI memory map entries.
+ *
+ * Depending on whether mm_init() has already been invoked or not,
+ * either memblock or "normal" page free is used.
+ */
+void __init efi_memmap_free(phys_addr_t addr, unsigned int num_entries)
+{
+	unsigned long size = num_entries * efi.memmap.desc_size;
+
+	if (slab_is_available()) {
+		__efi_memmap_free_late(addr, size);
+
+		return;
+	}
+	__efi_memmap_free_early(addr, size);
+}
+
+/**
  * __efi_memmap_init - Common code for mapping the EFI memory map
  * @data: EFI memory map data
  * @late: Use early or late mapping function?
diff --git a/include/linux/efi.h b/include/linux/efi.h
index bd38370..8bb741a 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1057,6 +1057,7 @@ static inline efi_status_t efi_query_variable_store(u32 attributes,
 extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);

 extern phys_addr_t __init efi_memmap_alloc(unsigned int num_entries);
+extern void __init efi_memmap_free(phys_addr_t addr, unsigned int num_entries);
 extern int __init efi_memmap_init_early(struct efi_memory_map_data *data);
 extern int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size);
 extern void __init efi_memmap_unmap(void);
-- 
1.8.3.1