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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/firmware/efi/embedded-firmware.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/embedded-firmware.c')
-rw-r--r--drivers/firmware/efi/embedded-firmware.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/firmware/efi/embedded-firmware.c b/drivers/firmware/efi/embedded-firmware.c
new file mode 100644
index 0000000000..f5be8e2230
--- /dev/null
+++ b/drivers/firmware/efi/embedded-firmware.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for extracting embedded firmware for peripherals from EFI code,
+ *
+ * Copyright (c) 2018 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/dmi.h>
+#include <linux/efi.h>
+#include <linux/efi_embedded_fw.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <crypto/sha2.h>
+
+/* Exported for use by lib/test_firmware.c only */
+LIST_HEAD(efi_embedded_fw_list);
+EXPORT_SYMBOL_NS_GPL(efi_embedded_fw_list, TEST_FIRMWARE);
+bool efi_embedded_fw_checked;
+EXPORT_SYMBOL_NS_GPL(efi_embedded_fw_checked, TEST_FIRMWARE);
+
+static const struct dmi_system_id * const embedded_fw_table[] = {
+#ifdef CONFIG_TOUCHSCREEN_DMI
+ touchscreen_dmi_table,
+#endif
+ NULL
+};
+
+/*
+ * Note the efi_check_for_embedded_firmwares() code currently makes the
+ * following 2 assumptions. This may needs to be revisited if embedded firmware
+ * is found where this is not true:
+ * 1) The firmware is only found in EFI_BOOT_SERVICES_CODE memory segments
+ * 2) The firmware always starts at an offset which is a multiple of 8 bytes
+ */
+static int __init efi_check_md_for_embedded_firmware(
+ efi_memory_desc_t *md, const struct efi_embedded_fw_desc *desc)
+{
+ struct efi_embedded_fw *fw;
+ u8 hash[32];
+ u64 i, size;
+ u8 *map;
+
+ size = md->num_pages << EFI_PAGE_SHIFT;
+ map = memremap(md->phys_addr, size, MEMREMAP_WB);
+ if (!map) {
+ pr_err("Error mapping EFI mem at %#llx\n", md->phys_addr);
+ return -ENOMEM;
+ }
+
+ for (i = 0; (i + desc->length) <= size; i += 8) {
+ if (memcmp(map + i, desc->prefix, EFI_EMBEDDED_FW_PREFIX_LEN))
+ continue;
+
+ sha256(map + i, desc->length, hash);
+ if (memcmp(hash, desc->sha256, 32) == 0)
+ break;
+ }
+ if ((i + desc->length) > size) {
+ memunmap(map);
+ return -ENOENT;
+ }
+
+ pr_info("Found EFI embedded fw '%s'\n", desc->name);
+
+ fw = kmalloc(sizeof(*fw), GFP_KERNEL);
+ if (!fw) {
+ memunmap(map);
+ return -ENOMEM;
+ }
+
+ fw->data = kmemdup(map + i, desc->length, GFP_KERNEL);
+ memunmap(map);
+ if (!fw->data) {
+ kfree(fw);
+ return -ENOMEM;
+ }
+
+ fw->name = desc->name;
+ fw->length = desc->length;
+ list_add(&fw->list, &efi_embedded_fw_list);
+
+ return 0;
+}
+
+void __init efi_check_for_embedded_firmwares(void)
+{
+ const struct efi_embedded_fw_desc *fw_desc;
+ const struct dmi_system_id *dmi_id;
+ efi_memory_desc_t *md;
+ int i, r;
+
+ for (i = 0; embedded_fw_table[i]; i++) {
+ dmi_id = dmi_first_match(embedded_fw_table[i]);
+ if (!dmi_id)
+ continue;
+
+ fw_desc = dmi_id->driver_data;
+
+ /*
+ * In some drivers the struct driver_data contains may contain
+ * other driver specific data after the fw_desc struct; and
+ * the fw_desc struct itself may be empty, skip these.
+ */
+ if (!fw_desc->name)
+ continue;
+
+ for_each_efi_memory_desc(md) {
+ if (md->type != EFI_BOOT_SERVICES_CODE)
+ continue;
+
+ r = efi_check_md_for_embedded_firmware(md, fw_desc);
+ if (r == 0)
+ break;
+ }
+ }
+
+ efi_embedded_fw_checked = true;
+}
+
+int efi_get_embedded_fw(const char *name, const u8 **data, size_t *size)
+{
+ struct efi_embedded_fw *iter, *fw = NULL;
+
+ if (!efi_embedded_fw_checked) {
+ pr_warn("Warning %s called while we did not check for embedded fw\n",
+ __func__);
+ return -ENOENT;
+ }
+
+ list_for_each_entry(iter, &efi_embedded_fw_list, list) {
+ if (strcmp(name, iter->name) == 0) {
+ fw = iter;
+ break;
+ }
+ }
+
+ if (!fw)
+ return -ENOENT;
+
+ *data = fw->data;
+ *size = fw->length;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(efi_get_embedded_fw);