--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Export Runtime Configuration Interface Table Version 2 (RCI2)
+ * to sysfs
+ *
+ * Copyright (C) 2019 Dell Inc
+ * by Narendra K <Narendra.K@dell.com>
+ *
+ * System firmware advertises the address of the RCI2 Table via
+ * an EFI Configuration Table entry. This code retrieves the RCI2
+ * table from the address and exports it to sysfs as a binary
+ * attribute 'rci2' under /sys/firmware/efi/tables directory.
+ */
+
+#include <linux/kobject.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/efi.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+#define RCI_SIGNATURE "_RC_"
+
+struct rci2_table_global_hdr {
+ u16 type;
+ u16 resvd0;
+ u16 hdr_len;
+ u8 rci2_sig[4];
+ u16 resvd1;
+ u32 resvd2;
+ u32 resvd3;
+ u8 major_rev;
+ u8 minor_rev;
+ u16 num_of_structs;
+ u32 rci2_len;
+ u16 rci2_chksum;
+} __packed;
+
+static u8 *rci2_base;
+static u32 rci2_table_len;
+unsigned long rci2_table_phys __ro_after_init = EFI_INVALID_TABLE_ADDR;
+
+static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *attr, char *buf,
+ loff_t pos, size_t count)
+{
+ memcpy(buf, attr->private + pos, count);
+ return count;
+}
+
+static BIN_ATTR(rci2, S_IRUSR, raw_table_read, NULL, 0);
+
+static u16 checksum(void)
+{
+ u8 len_is_odd = rci2_table_len % 2;
+ u32 chksum_len = rci2_table_len;
+ u16 *base = (u16 *)rci2_base;
+ u8 buf[2] = {0};
+ u32 offset = 0;
+ u16 chksum = 0;
+
+ if (len_is_odd)
+ chksum_len -= 1;
+
+ while (offset < chksum_len) {
+ chksum += *base;
+ offset += 2;
+ base++;
+ }
+
+ if (len_is_odd) {
+ buf[0] = *(u8 *)base;
+ chksum += *(u16 *)(buf);
+ }
+
+ return chksum;
+}
+
+int __init efi_rci2_sysfs_init(void)
+{
+ struct kobject *tables_kobj;
+ int ret = -ENOMEM;
+
+ rci2_base = memremap(rci2_table_phys,
+ sizeof(struct rci2_table_global_hdr),
+ MEMREMAP_WB);
+ if (!rci2_base) {
+ pr_debug("RCI2 table init failed - could not map RCI2 table\n");
+ goto err;
+ }
+
+ if (strncmp(rci2_base +
+ offsetof(struct rci2_table_global_hdr, rci2_sig),
+ RCI_SIGNATURE, 4)) {
+ pr_debug("RCI2 table init failed - incorrect signature\n");
+ ret = -ENODEV;
+ goto err_unmap;
+ }
+
+ rci2_table_len = *(u32 *)(rci2_base +
+ offsetof(struct rci2_table_global_hdr,
+ rci2_len));
+
+ memunmap(rci2_base);
+
+ if (!rci2_table_len) {
+ pr_debug("RCI2 table init failed - incorrect table length\n");
+ goto err;
+ }
+
+ rci2_base = memremap(rci2_table_phys, rci2_table_len, MEMREMAP_WB);
+ if (!rci2_base) {
+ pr_debug("RCI2 table - could not map RCI2 table\n");
+ goto err;
+ }
+
+ if (checksum() != 0) {
+ pr_debug("RCI2 table - incorrect checksum\n");
+ ret = -ENODEV;
+ goto err_unmap;
+ }
+
+ tables_kobj = kobject_create_and_add("tables", efi_kobj);
+ if (!tables_kobj) {
+ pr_debug("RCI2 table - tables_kobj creation failed\n");
+ goto err_unmap;
+ }
+
+ bin_attr_rci2.size = rci2_table_len;
+ bin_attr_rci2.private = rci2_base;
+ ret = sysfs_create_bin_file(tables_kobj, &bin_attr_rci2);
+ if (ret != 0) {
+ pr_debug("RCI2 table - rci2 sysfs bin file creation failed\n");
+ kobject_del(tables_kobj);
+ kobject_put(tables_kobj);
+ goto err_unmap;
+ }
+
+ return 0;
+
+ err_unmap:
+ memunmap(rci2_base);
+ err:
+ pr_debug("RCI2 table - sysfs initialization failed\n");
+ return ret;
+}
+late_initcall(efi_rci2_sysfs_init);
#define LINUX_EFI_TPM_FINAL_LOG_GUID EFI_GUID(0x1e2ed096, 0x30e2, 0x4254, 0xbd, 0x89, 0x86, 0x3b, 0xbe, 0xf8, 0x23, 0x25)
#define LINUX_EFI_MEMRESERVE_TABLE_GUID EFI_GUID(0x888eb0c6, 0x8ede, 0x4ff5, 0xa8, 0xf0, 0x9a, 0xee, 0x5c, 0xb9, 0x77, 0xc2)
+/* OEM GUIDs */
+#define DELLEMC_EFI_RCI2_TABLE_GUID EFI_GUID(0x2d9f28a2, 0xa886, 0x456a, 0x97, 0xa8, 0xf1, 0x1e, 0xf2, 0x4f, 0xf4, 0x55)
+
typedef struct {
efi_guid_t guid;
u64 table;
};
extern int efi_tpm_final_log_size;
+extern unsigned long rci2_table_phys;
+
/*
* efi_runtime_service() function identifiers.
* "NONE" is used by efi_recover_from_page_fault() to check if the page
projects / mirror_ubuntu-focal-kernel.git / commitdiff