diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0104-Add-chip-unique-id-reading-interface.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0104-Add-chip-unique-id-reading-interface.patch | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0104-Add-chip-unique-id-reading-interface.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0104-Add-chip-unique-id-reading-interface.patch new file mode 100644 index 000000000..f366287f1 --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0104-Add-chip-unique-id-reading-interface.patch @@ -0,0 +1,213 @@ +From 61fd1c976a0867deec8607183849969e2d96aef7 Mon Sep 17 00:00:00 2001 +From: Jae Hyun Yoo <jae.hyun.yoo@intel.com> +Date: Fri, 27 Mar 2020 14:42:05 -0700 +Subject: [PATCH] Add chip unique id reading interface + +This commit adds an interface for reading chip unique id value. +Optionally, the id can be encrypted using a dts-supplied hash data. + +Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com> +Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com> +--- + drivers/soc/aspeed/aspeed-bmc-misc.c | 118 ++++++++++++++++++++++++--- + 1 file changed, 105 insertions(+), 13 deletions(-) + +diff --git a/drivers/soc/aspeed/aspeed-bmc-misc.c b/drivers/soc/aspeed/aspeed-bmc-misc.c +index 04d97ab17274..c80b2e71f254 100644 +--- a/drivers/soc/aspeed/aspeed-bmc-misc.c ++++ b/drivers/soc/aspeed/aspeed-bmc-misc.c +@@ -7,15 +7,18 @@ + #include <linux/platform_device.h> + #include <linux/regmap.h> + #include <linux/mfd/syscon.h> ++#include <crypto/hash.h> + + #define DEVICE_NAME "aspeed-bmc-misc" + + struct aspeed_bmc_ctrl { + const char *name; + u32 offset; +- u32 mask; ++ u64 mask; + u32 shift; + bool read_only; ++ u32 reg_width; ++ const char *hash_data; + struct regmap *map; + struct kobj_attribute attr; + }; +@@ -31,6 +34,7 @@ static int aspeed_bmc_misc_parse_dt_child(struct device_node *child, + struct aspeed_bmc_ctrl *ctrl) + { + int rc; ++ u32 mask; + + /* Example child: + * +@@ -38,6 +42,7 @@ static int aspeed_bmc_misc_parse_dt_child(struct device_node *child, + * offset = <0x80>; + * bit-mask = <0x1>; + * bit-shift = <6>; ++ * reg-width = <64>; + * label = "foo"; + * } + */ +@@ -48,9 +53,22 @@ static int aspeed_bmc_misc_parse_dt_child(struct device_node *child, + if (rc < 0) + return rc; + +- rc = of_property_read_u32(child, "bit-mask", &ctrl->mask); +- if (rc < 0) +- return rc; ++ /* optional reg-width, default to 32 */ ++ rc = of_property_read_u32(child, "reg-width", &ctrl->reg_width); ++ if (rc < 0 || ctrl->reg_width != 64) ++ ctrl->reg_width = 32; ++ ++ if (ctrl->reg_width == 32) { ++ rc = of_property_read_u32(child, "bit-mask", &mask); ++ if (rc < 0) ++ return rc; ++ ctrl->mask = mask; ++ } else { ++ rc = of_property_read_u64(child, "bit-mask", &ctrl->mask); ++ if (rc < 0) ++ return rc; ++ } ++ ctrl->mask <<= ctrl->shift; + + rc = of_property_read_u32(child, "bit-shift", &ctrl->shift); + if (rc < 0) +@@ -58,7 +76,9 @@ static int aspeed_bmc_misc_parse_dt_child(struct device_node *child, + + ctrl->read_only = of_property_read_bool(child, "read-only"); + +- ctrl->mask <<= ctrl->shift; ++ /* optional hash_data for obfuscating reads */ ++ if (of_property_read_string(child, "hash-data", &ctrl->hash_data)) ++ ctrl->hash_data = NULL; + + return 0; + } +@@ -88,22 +108,94 @@ static int aspeed_bmc_misc_parse_dt(struct aspeed_bmc_misc *bmc, + return 0; + } + ++#define SHA256_DIGEST_LEN 32 ++static int hmac_sha256(u8 *key, u8 ksize, const char *plaintext, u8 psize, ++ u8 *output) ++{ ++ struct crypto_shash *tfm; ++ struct shash_desc *shash; ++ int ret; ++ ++ if (!ksize) ++ return -EINVAL; ++ ++ tfm = crypto_alloc_shash("hmac(sha256)", 0, 0); ++ if (IS_ERR(tfm)) { ++ return -ENOMEM; ++ } ++ ++ ret = crypto_shash_setkey(tfm, key, ksize); ++ if (ret) ++ goto failed; ++ ++ shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm), GFP_KERNEL); ++ if (!shash) { ++ ret = -ENOMEM; ++ goto failed; ++ } ++ ++ shash->tfm = tfm; ++ ret = crypto_shash_digest(shash, plaintext, psize, output); ++ ++ kfree(shash); ++ ++failed: ++ crypto_free_shash(tfm); ++ return ret; ++} ++ + static ssize_t aspeed_bmc_misc_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) + { + struct aspeed_bmc_ctrl *ctrl; +- unsigned int val; ++ u32 val; ++ u64 val64; + int rc; ++ u8 *binbuf; ++ size_t buf_len; ++ u8 hashbuf[SHA256_DIGEST_LEN]; + + ctrl = container_of(attr, struct aspeed_bmc_ctrl, attr); ++ ++ if (ctrl->reg_width == 32) { ++ rc = regmap_read(ctrl->map, ctrl->offset, &val); ++ if (rc) ++ return rc; ++ val &= (u32)ctrl->mask; ++ val >>= ctrl->shift; ++ ++ return sprintf(buf, "%u\n", val); ++ } + rc = regmap_read(ctrl->map, ctrl->offset, &val); + if (rc) + return rc; ++ val64 = val; ++ rc = regmap_read(ctrl->map, ctrl->offset + sizeof(u32), &val); ++ if (rc) ++ return rc; ++ /* aspeed puts 64-bit regs as L, H in address space */ ++ val64 |= (u64)val << 32; ++ val64 &= ctrl->mask; ++ val64 >>= ctrl->shift; ++ buf_len = sizeof(val64); ++ ++ if (ctrl->hash_data) { ++ rc = hmac_sha256((u8*)&val64, buf_len, ctrl->hash_data, ++ strlen(ctrl->hash_data), hashbuf); ++ if (rc) ++ return rc; ++ buf_len = SHA256_DIGEST_LEN; ++ binbuf = hashbuf; ++ } else { ++ binbuf = (u8*)&val64; ++ buf_len = sizeof(val64); ++ } ++ bin2hex(buf, binbuf, buf_len); ++ buf[buf_len * 2] = '\n'; ++ rc = buf_len * 2 + 1; + +- val &= ctrl->mask; +- val >>= ctrl->shift; ++ return rc; + +- return sprintf(buf, "%u\n", val); + } + + static ssize_t aspeed_bmc_misc_store(struct kobject *kobj, +@@ -114,15 +206,15 @@ static ssize_t aspeed_bmc_misc_store(struct kobject *kobj, + long val; + int rc; + +- rc = kstrtol(buf, 0, &val); +- if (rc) +- return rc; +- + ctrl = container_of(attr, struct aspeed_bmc_ctrl, attr); + + if (ctrl->read_only) + return -EROFS; + ++ rc = kstrtol(buf, 0, &val); ++ if (rc) ++ return rc; ++ + val <<= ctrl->shift; + rc = regmap_update_bits(ctrl->map, ctrl->offset, ctrl->mask, val); + +-- +2.17.1 + |