^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Export Runtime Configuration Interface Table Version 2 (RCI2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * to sysfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (C) 2019 Dell Inc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * by Narendra K <Narendra.K@dell.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * System firmware advertises the address of the RCI2 Table via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * an EFI Configuration Table entry. This code retrieves the RCI2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * table from the address and exports it to sysfs as a binary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * attribute 'rci2' under /sys/firmware/efi/tables directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/kobject.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/efi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #define RCI_SIGNATURE "_RC_"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct rci2_table_global_hdr {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) u16 type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) u16 resvd0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) u16 hdr_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) u8 rci2_sig[4];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) u16 resvd1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) u32 resvd2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) u32 resvd3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) u8 major_rev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) u8 minor_rev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) u16 num_of_structs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) u32 rci2_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) u16 rci2_chksum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) } __packed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static u8 *rci2_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) static u32 rci2_table_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) unsigned long rci2_table_phys __ro_after_init = EFI_INVALID_TABLE_ADDR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) struct bin_attribute *attr, char *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) loff_t pos, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) memcpy(buf, attr->private + pos, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) static BIN_ATTR(rci2, S_IRUSR, raw_table_read, NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static u16 checksum(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) u8 len_is_odd = rci2_table_len % 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) u32 chksum_len = rci2_table_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) u16 *base = (u16 *)rci2_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) u8 buf[2] = {0};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) u32 offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) u16 chksum = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) if (len_is_odd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) chksum_len -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) while (offset < chksum_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) chksum += *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) offset += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) base++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) if (len_is_odd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) buf[0] = *(u8 *)base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) chksum += *(u16 *)(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return chksum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) static int __init efi_rci2_sysfs_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) struct kobject *tables_kobj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) int ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (rci2_table_phys == EFI_INVALID_TABLE_ADDR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) rci2_base = memremap(rci2_table_phys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) sizeof(struct rci2_table_global_hdr),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) MEMREMAP_WB);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (!rci2_base) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) pr_debug("RCI2 table init failed - could not map RCI2 table\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (strncmp(rci2_base +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) offsetof(struct rci2_table_global_hdr, rci2_sig),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) RCI_SIGNATURE, 4)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) pr_debug("RCI2 table init failed - incorrect signature\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) ret = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) goto err_unmap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) rci2_table_len = *(u32 *)(rci2_base +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) offsetof(struct rci2_table_global_hdr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) rci2_len));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) memunmap(rci2_base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if (!rci2_table_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) pr_debug("RCI2 table init failed - incorrect table length\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) rci2_base = memremap(rci2_table_phys, rci2_table_len, MEMREMAP_WB);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (!rci2_base) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) pr_debug("RCI2 table - could not map RCI2 table\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (checksum() != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) pr_debug("RCI2 table - incorrect checksum\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) ret = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) goto err_unmap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) tables_kobj = kobject_create_and_add("tables", efi_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) if (!tables_kobj) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) pr_debug("RCI2 table - tables_kobj creation failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) goto err_unmap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) bin_attr_rci2.size = rci2_table_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) bin_attr_rci2.private = rci2_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) ret = sysfs_create_bin_file(tables_kobj, &bin_attr_rci2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (ret != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) pr_debug("RCI2 table - rci2 sysfs bin file creation failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) kobject_del(tables_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) kobject_put(tables_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) goto err_unmap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) err_unmap:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) memunmap(rci2_base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) pr_debug("RCI2 table - sysfs initialization failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) late_initcall(efi_rci2_sysfs_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags