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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/fake_mem.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
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.c124
1 files changed, 124 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..6e0f34a38
--- /dev/null
+++ b/drivers/firmware/efi/fake_mem.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+
+#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 "fake_mem.h"
+
+struct efi_mem_range efi_fake_mems[EFI_MAX_FAKEMEM];
+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;
+}
+
+static void __init efi_fake_range(struct efi_mem_range *efi_range)
+{
+ struct efi_memory_map_data data = { 0 };
+ int new_nr_map = efi.memmap.nr_map;
+ efi_memory_desc_t *md;
+ void *new_memmap;
+
+ /* count up the number of EFI memory descriptor */
+ for_each_efi_memory_desc(md)
+ new_nr_map += efi_memmap_split_count(md, &efi_range->range);
+
+ /* allocate memory for new EFI memmap */
+ if (efi_memmap_alloc(new_nr_map, &data) != 0)
+ return;
+
+ /* create new EFI memmap */
+ new_memmap = early_memremap(data.phys_map, data.size);
+ if (!new_memmap) {
+ __efi_memmap_free(data.phys_map, data.size, data.flags);
+ return;
+ }
+
+ efi_memmap_insert(&efi.memmap, new_memmap, efi_range);
+
+ /* swap into new EFI memmap */
+ early_memunmap(new_memmap, data.size);
+
+ efi_memmap_install(&data);
+}
+
+void __init efi_fake_memmap(void)
+{
+ int i;
+
+ if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem)
+ return;
+
+ for (i = 0; i < nr_fake_mem; i++)
+ efi_fake_range(&efi_fake_mems[i]);
+
+ /* 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;
+
+ efi_fake_mems[nr_fake_mem].range.start = start;
+ efi_fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
+ efi_fake_mems[nr_fake_mem].attribute = attribute;
+ nr_fake_mem++;
+
+ if (*p == ',')
+ p++;
+ }
+
+ sort(efi_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]",
+ efi_fake_mems[i].attribute, efi_fake_mems[i].range.start,
+ efi_fake_mems[i].range.end);
+
+ return *p == '\0' ? 0 : -EINVAL;
+}
+
+early_param("efi_fake_mem", setup_fake_mem);