summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/efi/fake_mem.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/firmware/efi/fake_mem.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/fake_mem.c')
-rw-r--r--drivers/firmware/efi/fake_mem.c141
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);