From: Eric Biggers Date: Fri, 10 Jul 2020 07:20:08 +0000 (-0700) Subject: scsi: firmware: qcom_scm: Add support for programming inline crypto keys X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=0f206514749be9988a083ca364b889a7fcff7f78;p=uclinux-h8%2Flinux.git scsi: firmware: qcom_scm: Add support for programming inline crypto keys Add support for the Inline Crypto Engine (ICE) key programming interface that's needed for the ufs-qcom driver to use inline encryption on Snapdragon SoCs. This interface consists of two SCM calls: one to program a key into a keyslot, and one to invalidate a keyslot. Although the UFS specification defines a standard way to do this, on these SoCs the Linux kernel isn't permitted to access the needed crypto configuration registers directly; these SCM calls must be used instead. Link: https://lore.kernel.org/r/20200710072013.177481-2-ebiggers@kernel.org Acked-by: Bjorn Andersson Signed-off-by: Eric Biggers Signed-off-by: Martin K. Petersen --- diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index 0e7233a20f34..1a8eb1b42b1e 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -924,6 +924,107 @@ int qcom_scm_ocmem_unlock(enum qcom_scm_ocmem_client id, u32 offset, u32 size) EXPORT_SYMBOL(qcom_scm_ocmem_unlock); /** + * qcom_scm_ice_available() - Is the ICE key programming interface available? + * + * Return: true iff the SCM calls wrapped by qcom_scm_ice_invalidate_key() and + * qcom_scm_ice_set_key() are available. + */ +bool qcom_scm_ice_available(void) +{ + return __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_INVALIDATE_ICE_KEY) && + __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_CONFIG_SET_ICE_KEY); +} +EXPORT_SYMBOL(qcom_scm_ice_available); + +/** + * qcom_scm_ice_invalidate_key() - Invalidate an inline encryption key + * @index: the keyslot to invalidate + * + * The UFSHCI standard defines a standard way to do this, but it doesn't work on + * these SoCs; only this SCM call does. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_ice_invalidate_key(u32 index) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_INVALIDATE_ICE_KEY, + .arginfo = QCOM_SCM_ARGS(1), + .args[0] = index, + .owner = ARM_SMCCC_OWNER_SIP, + }; + + return qcom_scm_call(__scm->dev, &desc, NULL); +} +EXPORT_SYMBOL(qcom_scm_ice_invalidate_key); + +/** + * qcom_scm_ice_set_key() - Set an inline encryption key + * @index: the keyslot into which to set the key + * @key: the key to program + * @key_size: the size of the key in bytes + * @cipher: the encryption algorithm the key is for + * @data_unit_size: the encryption data unit size, i.e. the size of each + * individual plaintext and ciphertext. Given in 512-byte + * units, e.g. 1 = 512 bytes, 8 = 4096 bytes, etc. + * + * Program a key into a keyslot of Qualcomm ICE (Inline Crypto Engine), where it + * can then be used to encrypt/decrypt UFS I/O requests inline. + * + * The UFSHCI standard defines a standard way to do this, but it doesn't work on + * these SoCs; only this SCM call does. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size, + enum qcom_scm_ice_cipher cipher, u32 data_unit_size) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_CONFIG_SET_ICE_KEY, + .arginfo = QCOM_SCM_ARGS(5, QCOM_SCM_VAL, QCOM_SCM_RW, + QCOM_SCM_VAL, QCOM_SCM_VAL, + QCOM_SCM_VAL), + .args[0] = index, + .args[2] = key_size, + .args[3] = cipher, + .args[4] = data_unit_size, + .owner = ARM_SMCCC_OWNER_SIP, + }; + void *keybuf; + dma_addr_t key_phys; + int ret; + + /* + * 'key' may point to vmalloc()'ed memory, but we need to pass a + * physical address that's been properly flushed. The sanctioned way to + * do this is by using the DMA API. But as is best practice for crypto + * keys, we also must wipe the key after use. This makes kmemdup() + + * dma_map_single() not clearly correct, since the DMA API can use + * bounce buffers. Instead, just use dma_alloc_coherent(). Programming + * keys is normally rare and thus not performance-critical. + */ + + keybuf = dma_alloc_coherent(__scm->dev, key_size, &key_phys, + GFP_KERNEL); + if (!keybuf) + return -ENOMEM; + memcpy(keybuf, key, key_size); + desc.args[1] = key_phys; + + ret = qcom_scm_call(__scm->dev, &desc, NULL); + + memzero_explicit(keybuf, key_size); + + dma_free_coherent(__scm->dev, key_size, keybuf, key_phys); + return ret; +} +EXPORT_SYMBOL(qcom_scm_ice_set_key); + +/** * qcom_scm_hdcp_available() - Check if secure environment supports HDCP. * * Return true if HDCP is supported, false if not. diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h index d9ed670da222..38ea614d29fe 100644 --- a/drivers/firmware/qcom_scm.h +++ b/drivers/firmware/qcom_scm.h @@ -103,6 +103,10 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc, #define QCOM_SCM_OCMEM_LOCK_CMD 0x01 #define QCOM_SCM_OCMEM_UNLOCK_CMD 0x02 +#define QCOM_SCM_SVC_ES 0x10 /* Enterprise Security */ +#define QCOM_SCM_ES_INVALIDATE_ICE_KEY 0x03 +#define QCOM_SCM_ES_CONFIG_SET_ICE_KEY 0x04 + #define QCOM_SCM_SVC_HDCP 0x11 #define QCOM_SCM_HDCP_INVOKE 0x01 diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h index 3d6a24697761..2e1193a3fb5f 100644 --- a/include/linux/qcom_scm.h +++ b/include/linux/qcom_scm.h @@ -44,6 +44,13 @@ enum qcom_scm_sec_dev_id { QCOM_SCM_ICE_DEV_ID = 20, }; +enum qcom_scm_ice_cipher { + QCOM_SCM_ICE_CIPHER_AES_128_XTS = 0, + QCOM_SCM_ICE_CIPHER_AES_128_CBC = 1, + QCOM_SCM_ICE_CIPHER_AES_256_XTS = 3, + QCOM_SCM_ICE_CIPHER_AES_256_CBC = 4, +}; + #define QCOM_SCM_VMID_HLOS 0x3 #define QCOM_SCM_VMID_MSS_MSA 0xF #define QCOM_SCM_VMID_WLAN 0x18 @@ -88,6 +95,12 @@ extern int qcom_scm_ocmem_lock(enum qcom_scm_ocmem_client id, u32 offset, extern int qcom_scm_ocmem_unlock(enum qcom_scm_ocmem_client id, u32 offset, u32 size); +extern bool qcom_scm_ice_available(void); +extern int qcom_scm_ice_invalidate_key(u32 index); +extern int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size, + enum qcom_scm_ice_cipher cipher, + u32 data_unit_size); + extern bool qcom_scm_hdcp_available(void); extern int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp); @@ -138,6 +151,12 @@ static inline int qcom_scm_ocmem_lock(enum qcom_scm_ocmem_client id, u32 offset, static inline int qcom_scm_ocmem_unlock(enum qcom_scm_ocmem_client id, u32 offset, u32 size) { return -ENODEV; } +static inline bool qcom_scm_ice_available(void) { return false; } +static inline int qcom_scm_ice_invalidate_key(u32 index) { return -ENODEV; } +static inline int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size, + enum qcom_scm_ice_cipher cipher, + u32 data_unit_size) { return -ENODEV; } + static inline bool qcom_scm_hdcp_available(void) { return false; } static inline int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp) { return -ENODEV; }