1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
new file mode 100644
index 000000000..6c7d60c23
--- /dev/null
+++ b/drivers/firmware/efi/fake_mem.c
@@ -0,0 +1,141 @@
+/*
+ * fake_mem.c
+ *
+ * Copyright (C) 2015 FUJITSU LIMITED
+ * Author: Taku Izumi <izumi.taku@jp.fujitsu.com>
+ *
+ * This code introduces new boot option named "efi_fake_mem"
+ * By specifying this parameter, you can add arbitrary attribute to
+ * specific memory range by updating original (firmware provided) EFI
+ * memmap.
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms and conditions of the GNU General Public License,
+ *  version 2, as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ *  more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *  The full GNU General Public License is included in this distribution in
+ *  the file called "COPYING".
+ */
+
+#include <linux/kernel.h>
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/types.h>
+#include <linux/sort.h>
+#include <asm/efi.h>
+
+#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
+
+static struct efi_mem_range fake_mems[EFI_MAX_FAKEMEM];
+static int nr_fake_mem;
+
+static int __init cmp_fake_mem(const void *x1, const void *x2)
+{
+	const struct efi_mem_range *m1 = x1;
+	const struct efi_mem_range *m2 = x2;
+
+	if (m1->range.start < m2->range.start)
+		return -1;
+	if (m1->range.start > m2->range.start)
+		return 1;
+	return 0;
+}
+
+void __init efi_fake_memmap(void)
+{
+	int new_nr_map = efi.memmap.nr_map;
+	efi_memory_desc_t *md;
+	phys_addr_t new_memmap_phy;
+	void *new_memmap;
+	int i;
+
+	if (!nr_fake_mem)
+		return;
+
+	/* count up the number of EFI memory descriptor */
+	for (i = 0; i < nr_fake_mem; i++) {
+		for_each_efi_memory_desc(md) {
+			struct range *r = &fake_mems[i].range;
+
+			new_nr_map += efi_memmap_split_count(md, r);
+		}
+	}
+
+	/* allocate memory for new EFI memmap */
+	new_memmap_phy = efi_memmap_alloc(new_nr_map);
+	if (!new_memmap_phy)
+		return;
+
+	/* create new EFI memmap */
+	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);
+		return;
+	}
+
+	for (i = 0; i < nr_fake_mem; i++)
+		efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);
+
+	/* swap into new EFI memmap */
+	early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);
+
+	efi_memmap_install(new_memmap_phy, new_nr_map);
+
+	/* print new EFI memmap */
+	efi_print_memmap();
+}
+
+static int __init setup_fake_mem(char *p)
+{
+	u64 start = 0, mem_size = 0, attribute = 0;
+	int i;
+
+	if (!p)
+		return -EINVAL;
+
+	while (*p != '\0') {
+		mem_size = memparse(p, &p);
+		if (*p == '@')
+			start = memparse(p+1, &p);
+		else
+			break;
+
+		if (*p == ':')
+			attribute = simple_strtoull(p+1, &p, 0);
+		else
+			break;
+
+		if (nr_fake_mem >= EFI_MAX_FAKEMEM)
+			break;
+
+		fake_mems[nr_fake_mem].range.start = start;
+		fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
+		fake_mems[nr_fake_mem].attribute = attribute;
+		nr_fake_mem++;
+
+		if (*p == ',')
+			p++;
+	}
+
+	sort(fake_mems, nr_fake_mem, sizeof(struct efi_mem_range),
+	     cmp_fake_mem, NULL);
+
+	for (i = 0; i < nr_fake_mem; i++)
+		pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]",
+			fake_mems[i].attribute, fake_mems[i].range.start,
+			fake_mems[i].range.end);
+
+	return *p == '\0' ? 0 : -EINVAL;
+}
+
+early_param("efi_fake_mem", setup_fake_mem);