diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/crypto/keembay/ocs-aes.c | 1489 |
1 files changed, 1489 insertions, 0 deletions
diff --git a/drivers/crypto/keembay/ocs-aes.c b/drivers/crypto/keembay/ocs-aes.c new file mode 100644 index 000000000..be9f32fc8 --- /dev/null +++ b/drivers/crypto/keembay/ocs-aes.c @@ -0,0 +1,1489 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Intel Keem Bay OCS AES Crypto Driver. + * + * Copyright (C) 2018-2020 Intel Corporation + */ + +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/swab.h> + +#include <asm/byteorder.h> +#include <asm/errno.h> + +#include <crypto/aes.h> +#include <crypto/gcm.h> + +#include "ocs-aes.h" + +#define AES_COMMAND_OFFSET 0x0000 +#define AES_KEY_0_OFFSET 0x0004 +#define AES_KEY_1_OFFSET 0x0008 +#define AES_KEY_2_OFFSET 0x000C +#define AES_KEY_3_OFFSET 0x0010 +#define AES_KEY_4_OFFSET 0x0014 +#define AES_KEY_5_OFFSET 0x0018 +#define AES_KEY_6_OFFSET 0x001C +#define AES_KEY_7_OFFSET 0x0020 +#define AES_IV_0_OFFSET 0x0024 +#define AES_IV_1_OFFSET 0x0028 +#define AES_IV_2_OFFSET 0x002C +#define AES_IV_3_OFFSET 0x0030 +#define AES_ACTIVE_OFFSET 0x0034 +#define AES_STATUS_OFFSET 0x0038 +#define AES_KEY_SIZE_OFFSET 0x0044 +#define AES_IER_OFFSET 0x0048 +#define AES_ISR_OFFSET 0x005C +#define AES_MULTIPURPOSE1_0_OFFSET 0x0200 +#define AES_MULTIPURPOSE1_1_OFFSET 0x0204 +#define AES_MULTIPURPOSE1_2_OFFSET 0x0208 +#define AES_MULTIPURPOSE1_3_OFFSET 0x020C +#define AES_MULTIPURPOSE2_0_OFFSET 0x0220 +#define AES_MULTIPURPOSE2_1_OFFSET 0x0224 +#define AES_MULTIPURPOSE2_2_OFFSET 0x0228 +#define AES_MULTIPURPOSE2_3_OFFSET 0x022C +#define AES_BYTE_ORDER_CFG_OFFSET 0x02C0 +#define AES_TLEN_OFFSET 0x0300 +#define AES_T_MAC_0_OFFSET 0x0304 +#define AES_T_MAC_1_OFFSET 0x0308 +#define AES_T_MAC_2_OFFSET 0x030C +#define AES_T_MAC_3_OFFSET 0x0310 +#define AES_PLEN_OFFSET 0x0314 +#define AES_A_DMA_SRC_ADDR_OFFSET 0x0400 +#define AES_A_DMA_DST_ADDR_OFFSET 0x0404 +#define AES_A_DMA_SRC_SIZE_OFFSET 0x0408 +#define AES_A_DMA_DST_SIZE_OFFSET 0x040C +#define AES_A_DMA_DMA_MODE_OFFSET 0x0410 +#define AES_A_DMA_NEXT_SRC_DESCR_OFFSET 0x0418 +#define AES_A_DMA_NEXT_DST_DESCR_OFFSET 0x041C +#define AES_A_DMA_WHILE_ACTIVE_MODE_OFFSET 0x0420 +#define AES_A_DMA_LOG_OFFSET 0x0424 +#define AES_A_DMA_STATUS_OFFSET 0x0428 +#define AES_A_DMA_PERF_CNTR_OFFSET 0x042C +#define AES_A_DMA_MSI_ISR_OFFSET 0x0480 +#define AES_A_DMA_MSI_IER_OFFSET 0x0484 +#define AES_A_DMA_MSI_MASK_OFFSET 0x0488 +#define AES_A_DMA_INBUFFER_WRITE_FIFO_OFFSET 0x0600 +#define AES_A_DMA_OUTBUFFER_READ_FIFO_OFFSET 0x0700 + +/* + * AES_A_DMA_DMA_MODE register. + * Default: 0x00000000. + * bit[31] ACTIVE + * This bit activates the DMA. When the DMA finishes, it resets + * this bit to zero. + * bit[30:26] Unused by this driver. + * bit[25] SRC_LINK_LIST_EN + * Source link list enable bit. When the linked list is terminated + * this bit is reset by the DMA. + * bit[24] DST_LINK_LIST_EN + * Destination link list enable bit. When the linked list is + * terminated this bit is reset by the DMA. + * bit[23:0] Unused by this driver. + */ +#define AES_A_DMA_DMA_MODE_ACTIVE BIT(31) +#define AES_A_DMA_DMA_MODE_SRC_LINK_LIST_EN BIT(25) +#define AES_A_DMA_DMA_MODE_DST_LINK_LIST_EN BIT(24) + +/* + * AES_ACTIVE register + * default 0x00000000 + * bit[31:10] Reserved + * bit[9] LAST_ADATA + * bit[8] LAST_GCX + * bit[7:2] Reserved + * bit[1] TERMINATION + * bit[0] TRIGGER + */ +#define AES_ACTIVE_LAST_ADATA BIT(9) +#define AES_ACTIVE_LAST_CCM_GCM BIT(8) +#define AES_ACTIVE_TERMINATION BIT(1) +#define AES_ACTIVE_TRIGGER BIT(0) + +#define AES_DISABLE_INT 0x00000000 +#define AES_DMA_CPD_ERR_INT BIT(8) +#define AES_DMA_OUTBUF_RD_ERR_INT BIT(7) +#define AES_DMA_OUTBUF_WR_ERR_INT BIT(6) +#define AES_DMA_INBUF_RD_ERR_INT BIT(5) +#define AES_DMA_INBUF_WR_ERR_INT BIT(4) +#define AES_DMA_BAD_COMP_INT BIT(3) +#define AES_DMA_SAI_INT BIT(2) +#define AES_DMA_SRC_DONE_INT BIT(0) +#define AES_COMPLETE_INT BIT(1) + +#define AES_DMA_MSI_MASK_CLEAR BIT(0) + +#define AES_128_BIT_KEY 0x00000000 +#define AES_256_BIT_KEY BIT(0) + +#define AES_DEACTIVATE_PERF_CNTR 0x00000000 +#define AES_ACTIVATE_PERF_CNTR BIT(0) + +#define AES_MAX_TAG_SIZE_U32 4 + +#define OCS_LL_DMA_FLAG_TERMINATE BIT(31) + +/* + * There is an inconsistency in the documentation. This is documented as a + * 11-bit value, but it is actually 10-bits. + */ +#define AES_DMA_STATUS_INPUT_BUFFER_OCCUPANCY_MASK 0x3FF + +/* + * During CCM decrypt, the OCS block needs to finish processing the ciphertext + * before the tag is written. For 128-bit mode this required delay is 28 OCS + * clock cycles. For 256-bit mode it is 36 OCS clock cycles. + */ +#define CCM_DECRYPT_DELAY_TAG_CLK_COUNT 36UL + +/* + * During CCM decrypt there must be a delay of at least 42 OCS clock cycles + * between setting the TRIGGER bit in AES_ACTIVE and setting the LAST_CCM_GCM + * bit in the same register (as stated in the OCS databook) + */ +#define CCM_DECRYPT_DELAY_LAST_GCX_CLK_COUNT 42UL + +/* See RFC3610 section 2.2 */ +#define L_PRIME_MIN (1) +#define L_PRIME_MAX (7) +/* + * CCM IV format from RFC 3610 section 2.3 + * + * Octet Number Contents + * ------------ --------- + * 0 Flags + * 1 ... 15-L Nonce N + * 16-L ... 15 Counter i + * + * Flags = L' = L - 1 + */ +#define L_PRIME_IDX 0 +#define COUNTER_START(lprime) (16 - ((lprime) + 1)) +#define COUNTER_LEN(lprime) ((lprime) + 1) + +enum aes_counter_mode { + AES_CTR_M_NO_INC = 0, + AES_CTR_M_32_INC = 1, + AES_CTR_M_64_INC = 2, + AES_CTR_M_128_INC = 3, +}; + +/** + * struct ocs_dma_linked_list - OCS DMA linked list entry. + * @src_addr: Source address of the data. + * @src_len: Length of data to be fetched. + * @next: Next dma_list to fetch. + * @ll_flags: Flags (Freeze @ terminate) for the DMA engine. + */ +struct ocs_dma_linked_list { + u32 src_addr; + u32 src_len; + u32 next; + u32 ll_flags; +} __packed; + +/* + * Set endianness of inputs and outputs + * AES_BYTE_ORDER_CFG + * default 0x00000000 + * bit [10] - KEY_HI_LO_SWAP + * bit [9] - KEY_HI_SWAP_DWORDS_IN_OCTWORD + * bit [8] - KEY_HI_SWAP_BYTES_IN_DWORD + * bit [7] - KEY_LO_SWAP_DWORDS_IN_OCTWORD + * bit [6] - KEY_LO_SWAP_BYTES_IN_DWORD + * bit [5] - IV_SWAP_DWORDS_IN_OCTWORD + * bit [4] - IV_SWAP_BYTES_IN_DWORD + * bit [3] - DOUT_SWAP_DWORDS_IN_OCTWORD + * bit [2] - DOUT_SWAP_BYTES_IN_DWORD + * bit [1] - DOUT_SWAP_DWORDS_IN_OCTWORD + * bit [0] - DOUT_SWAP_BYTES_IN_DWORD + */ +static inline void aes_a_set_endianness(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(0x7FF, aes_dev->base_reg + AES_BYTE_ORDER_CFG_OFFSET); +} + +/* Trigger AES process start. */ +static inline void aes_a_op_trigger(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_ACTIVE_TRIGGER, aes_dev->base_reg + AES_ACTIVE_OFFSET); +} + +/* Indicate last bulk of data. */ +static inline void aes_a_op_termination(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_ACTIVE_TERMINATION, + aes_dev->base_reg + AES_ACTIVE_OFFSET); +} + +/* + * Set LAST_CCM_GCM in AES_ACTIVE register and clear all other bits. + * + * Called when DMA is programmed to fetch the last batch of data. + * - For AES-CCM it is called for the last batch of Payload data and Ciphertext + * data. + * - For AES-GCM, it is called for the last batch of Plaintext data and + * Ciphertext data. + */ +static inline void aes_a_set_last_gcx(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_ACTIVE_LAST_CCM_GCM, + aes_dev->base_reg + AES_ACTIVE_OFFSET); +} + +/* Wait for LAST_CCM_GCM bit to be unset. */ +static inline void aes_a_wait_last_gcx(const struct ocs_aes_dev *aes_dev) +{ + u32 aes_active_reg; + + do { + aes_active_reg = ioread32(aes_dev->base_reg + + AES_ACTIVE_OFFSET); + } while (aes_active_reg & AES_ACTIVE_LAST_CCM_GCM); +} + +/* Wait for 10 bits of input occupancy. */ +static void aes_a_dma_wait_input_buffer_occupancy(const struct ocs_aes_dev *aes_dev) +{ + u32 reg; + + do { + reg = ioread32(aes_dev->base_reg + AES_A_DMA_STATUS_OFFSET); + } while (reg & AES_DMA_STATUS_INPUT_BUFFER_OCCUPANCY_MASK); +} + + /* + * Set LAST_CCM_GCM and LAST_ADATA bits in AES_ACTIVE register (and clear all + * other bits). + * + * Called when DMA is programmed to fetch the last batch of Associated Data + * (CCM case) or Additional Authenticated Data (GCM case). + */ +static inline void aes_a_set_last_gcx_and_adata(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_ACTIVE_LAST_ADATA | AES_ACTIVE_LAST_CCM_GCM, + aes_dev->base_reg + AES_ACTIVE_OFFSET); +} + +/* Set DMA src and dst transfer size to 0 */ +static inline void aes_a_dma_set_xfer_size_zero(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(0, aes_dev->base_reg + AES_A_DMA_SRC_SIZE_OFFSET); + iowrite32(0, aes_dev->base_reg + AES_A_DMA_DST_SIZE_OFFSET); +} + +/* Activate DMA for zero-byte transfer case. */ +static inline void aes_a_dma_active(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_A_DMA_DMA_MODE_ACTIVE, + aes_dev->base_reg + AES_A_DMA_DMA_MODE_OFFSET); +} + +/* Activate DMA and enable src linked list */ +static inline void aes_a_dma_active_src_ll_en(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_A_DMA_DMA_MODE_ACTIVE | + AES_A_DMA_DMA_MODE_SRC_LINK_LIST_EN, + aes_dev->base_reg + AES_A_DMA_DMA_MODE_OFFSET); +} + +/* Activate DMA and enable dst linked list */ +static inline void aes_a_dma_active_dst_ll_en(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_A_DMA_DMA_MODE_ACTIVE | + AES_A_DMA_DMA_MODE_DST_LINK_LIST_EN, + aes_dev->base_reg + AES_A_DMA_DMA_MODE_OFFSET); +} + +/* Activate DMA and enable src and dst linked lists */ +static inline void aes_a_dma_active_src_dst_ll_en(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(AES_A_DMA_DMA_MODE_ACTIVE | + AES_A_DMA_DMA_MODE_SRC_LINK_LIST_EN | + AES_A_DMA_DMA_MODE_DST_LINK_LIST_EN, + aes_dev->base_reg + AES_A_DMA_DMA_MODE_OFFSET); +} + +/* Reset PERF_CNTR to 0 and activate it */ +static inline void aes_a_dma_reset_and_activate_perf_cntr(const struct ocs_aes_dev *aes_dev) +{ + iowrite32(0x00000000, aes_dev->base_reg + AES_A_DMA_PERF_CNTR_OFFSET); + iowrite32(AES_ACTIVATE_PERF_CNTR, + aes_dev->base_reg + AES_A_DMA_WHILE_ACTIVE_MODE_OFFSET); +} + +/* Wait until PERF_CNTR is > delay, then deactivate it */ +static inline void aes_a_dma_wait_and_deactivate_perf_cntr(const struct ocs_aes_dev *aes_dev, + int delay) +{ + while (ioread32(aes_dev->base_reg + AES_A_DMA_PERF_CNTR_OFFSET) < delay) + ; + iowrite32(AES_DEACTIVATE_PERF_CNTR, + aes_dev->base_reg + AES_A_DMA_WHILE_ACTIVE_MODE_OFFSET); +} + +/* Disable AES and DMA IRQ. */ +static void aes_irq_disable(struct ocs_aes_dev *aes_dev) +{ + u32 isr_val = 0; + + /* Disable interrupts */ + iowrite32(AES_DISABLE_INT, + aes_dev->base_reg + AES_A_DMA_MSI_IER_OFFSET); + iowrite32(AES_DISABLE_INT, aes_dev->base_reg + AES_IER_OFFSET); + + /* Clear any pending interrupt */ + isr_val = ioread32(aes_dev->base_reg + AES_A_DMA_MSI_ISR_OFFSET); + if (isr_val) + iowrite32(isr_val, + aes_dev->base_reg + AES_A_DMA_MSI_ISR_OFFSET); + + isr_val = ioread32(aes_dev->base_reg + AES_A_DMA_MSI_MASK_OFFSET); + if (isr_val) + iowrite32(isr_val, + aes_dev->base_reg + AES_A_DMA_MSI_MASK_OFFSET); + + isr_val = ioread32(aes_dev->base_reg + AES_ISR_OFFSET); + if (isr_val) + iowrite32(isr_val, aes_dev->base_reg + AES_ISR_OFFSET); +} + +/* Enable AES or DMA IRQ. IRQ is disabled once fired. */ +static void aes_irq_enable(struct ocs_aes_dev *aes_dev, u8 irq) +{ + if (irq == AES_COMPLETE_INT) { + /* Ensure DMA error interrupts are enabled */ + iowrite32(AES_DMA_CPD_ERR_INT | + AES_DMA_OUTBUF_RD_ERR_INT | + AES_DMA_OUTBUF_WR_ERR_INT | + AES_DMA_INBUF_RD_ERR_INT | + AES_DMA_INBUF_WR_ERR_INT | + AES_DMA_BAD_COMP_INT | + AES_DMA_SAI_INT, + aes_dev->base_reg + AES_A_DMA_MSI_IER_OFFSET); + /* + * AES_IER + * default 0x00000000 + * bits [31:3] - reserved + * bit [2] - EN_SKS_ERR + * bit [1] - EN_AES_COMPLETE + * bit [0] - reserved + */ + iowrite32(AES_COMPLETE_INT, aes_dev->base_reg + AES_IER_OFFSET); + return; + } + if (irq == AES_DMA_SRC_DONE_INT) { + /* Ensure AES interrupts are disabled */ + iowrite32(AES_DISABLE_INT, aes_dev->base_reg + AES_IER_OFFSET); + /* + * DMA_MSI_IER + * default 0x00000000 + * bits [31:9] - reserved + * bit [8] - CPD_ERR_INT_EN + * bit [7] - OUTBUF_RD_ERR_INT_EN + * bit [6] - OUTBUF_WR_ERR_INT_EN + * bit [5] - INBUF_RD_ERR_INT_EN + * bit [4] - INBUF_WR_ERR_INT_EN + * bit [3] - BAD_COMP_INT_EN + * bit [2] - SAI_INT_EN + * bit [1] - DST_DONE_INT_EN + * bit [0] - SRC_DONE_INT_EN + */ + iowrite32(AES_DMA_CPD_ERR_INT | + AES_DMA_OUTBUF_RD_ERR_INT | + AES_DMA_OUTBUF_WR_ERR_INT | + AES_DMA_INBUF_RD_ERR_INT | + AES_DMA_INBUF_WR_ERR_INT | + AES_DMA_BAD_COMP_INT | + AES_DMA_SAI_INT | + AES_DMA_SRC_DONE_INT, + aes_dev->base_reg + AES_A_DMA_MSI_IER_OFFSET); + } +} + +/* Enable and wait for IRQ (either from OCS AES engine or DMA) */ +static int ocs_aes_irq_enable_and_wait(struct ocs_aes_dev *aes_dev, u8 irq) +{ + int rc; + + reinit_completion(&aes_dev->irq_completion); + aes_irq_enable(aes_dev, irq); + rc = wait_for_completion_interruptible(&aes_dev->irq_completion); + if (rc) + return rc; + + return aes_dev->dma_err_mask ? -EIO : 0; +} + +/* Configure DMA to OCS, linked list mode */ +static inline void dma_to_ocs_aes_ll(struct ocs_aes_dev *aes_dev, + dma_addr_t dma_list) +{ + iowrite32(0, aes_dev->base_reg + AES_A_DMA_SRC_SIZE_OFFSET); + iowrite32(dma_list, + aes_dev->base_reg + AES_A_DMA_NEXT_SRC_DESCR_OFFSET); +} + +/* Configure DMA from OCS, linked list mode */ +static inline void dma_from_ocs_aes_ll(struct ocs_aes_dev *aes_dev, + dma_addr_t dma_list) +{ + iowrite32(0, aes_dev->base_reg + AES_A_DMA_DST_SIZE_OFFSET); + iowrite32(dma_list, + aes_dev->base_reg + AES_A_DMA_NEXT_DST_DESCR_OFFSET); +} + +irqreturn_t ocs_aes_irq_handler(int irq, void *dev_id) +{ + struct ocs_aes_dev *aes_dev = dev_id; + u32 aes_dma_isr; + + /* Read DMA ISR status. */ + aes_dma_isr = ioread32(aes_dev->base_reg + AES_A_DMA_MSI_ISR_OFFSET); + + /* Disable and clear interrupts. */ + aes_irq_disable(aes_dev); + + /* Save DMA error status. */ + aes_dev->dma_err_mask = aes_dma_isr & + (AES_DMA_CPD_ERR_INT | + AES_DMA_OUTBUF_RD_ERR_INT | + AES_DMA_OUTBUF_WR_ERR_INT | + AES_DMA_INBUF_RD_ERR_INT | + AES_DMA_INBUF_WR_ERR_INT | + AES_DMA_BAD_COMP_INT | + AES_DMA_SAI_INT); + + /* Signal IRQ completion. */ + complete(&aes_dev->irq_completion); + + return IRQ_HANDLED; +} + +/** + * ocs_aes_set_key() - Write key into OCS AES hardware. + * @aes_dev: The OCS AES device to write the key to. + * @key_size: The size of the key (in bytes). + * @key: The key to write. + * @cipher: The cipher the key is for. + * + * For AES @key_size must be either 16 or 32. For SM4 @key_size must be 16. + * + * Return: 0 on success, negative error code otherwise. + */ +int ocs_aes_set_key(struct ocs_aes_dev *aes_dev, u32 key_size, const u8 *key, + enum ocs_cipher cipher) +{ + const u32 *key_u32; + u32 val; + int i; + + /* OCS AES supports 128-bit and 256-bit keys only. */ + if (cipher == OCS_AES && !(key_size == 32 || key_size == 16)) { + dev_err(aes_dev->dev, + "%d-bit keys not supported by AES cipher\n", + key_size * 8); + return -EINVAL; + } + /* OCS SM4 supports 128-bit keys only. */ + if (cipher == OCS_SM4 && key_size != 16) { + dev_err(aes_dev->dev, + "%d-bit keys not supported for SM4 cipher\n", + key_size * 8); + return -EINVAL; + } + + if (!key) + return -EINVAL; + + key_u32 = (const u32 *)key; + + /* Write key to AES_KEY[0-7] registers */ + for (i = 0; i < (key_size / sizeof(u32)); i++) { + iowrite32(key_u32[i], + aes_dev->base_reg + AES_KEY_0_OFFSET + + (i * sizeof(u32))); + } + /* + * Write key size + * bits [31:1] - reserved + * bit [0] - AES_KEY_SIZE + * 0 - 128 bit key + * 1 - 256 bit key + */ + val = (key_size == 16) ? AES_128_BIT_KEY : AES_256_BIT_KEY; + iowrite32(val, aes_dev->base_reg + AES_KEY_SIZE_OFFSET); + + return 0; +} + +/* Write AES_COMMAND */ +static inline void set_ocs_aes_command(struct ocs_aes_dev *aes_dev, + enum ocs_cipher cipher, + enum ocs_mode mode, + enum ocs_instruction instruction) +{ + u32 val; + + /* AES_COMMAND + * default 0x000000CC + * bit [14] - CIPHER_SELECT + * 0 - AES + * 1 - SM4 + * bits [11:8] - OCS_AES_MODE + * 0000 - ECB + * 0001 - CBC + * 0010 - CTR + * 0110 - CCM + * 0111 - GCM + * 1001 - CTS + * bits [7:6] - AES_INSTRUCTION + * 00 - ENCRYPT + * 01 - DECRYPT + * 10 - EXPAND + * 11 - BYPASS + * bits [3:2] - CTR_M_BITS + * 00 - No increment + * 01 - Least significant 32 bits are incremented + * 10 - Least significant 64 bits are incremented + * 11 - Full 128 bits are incremented + */ + val = (cipher << 14) | (mode << 8) | (instruction << 6) | + (AES_CTR_M_128_INC << 2); + iowrite32(val, aes_dev->base_reg + AES_COMMAND_OFFSET); +} + +static void ocs_aes_init(struct ocs_aes_dev *aes_dev, + enum ocs_mode mode, + enum ocs_cipher cipher, + enum ocs_instruction instruction) +{ + /* Ensure interrupts are disabled and pending interrupts cleared. */ + aes_irq_disable(aes_dev); + + /* Set endianness recommended by data-sheet. */ + aes_a_set_endianness(aes_dev); + + /* Set AES_COMMAND register. */ + set_ocs_aes_command(aes_dev, cipher, mode, instruction); +} + +/* + * Write the byte length of the last AES/SM4 block of Payload data (without + * zero padding and without the length of the MAC) in register AES_PLEN. + */ +static inline void ocs_aes_write_last_data_blk_len(struct ocs_aes_dev *aes_dev, + u32 size) +{ + u32 val; + + if (size == 0) { + val = 0; + goto exit; + } + + val = size % AES_BLOCK_SIZE; + if (val == 0) + val = AES_BLOCK_SIZE; + +exit: + iowrite32(val, aes_dev->base_reg + AES_PLEN_OFFSET); +} + +/* + * Validate inputs according to mode. + * If OK return 0; else return -EINVAL. + */ +static int ocs_aes_validate_inputs(dma_addr_t src_dma_list, u32 src_size, + const u8 *iv, u32 iv_size, + dma_addr_t aad_dma_list, u32 aad_size, + const u8 *tag, u32 tag_size, + enum ocs_cipher cipher, enum ocs_mode mode, + enum ocs_instruction instruction, + dma_addr_t dst_dma_list) +{ + /* Ensure cipher, mode and instruction are valid. */ + if (!(cipher == OCS_AES || cipher == OCS_SM4)) + return -EINVAL; + + if (mode != OCS_MODE_ECB && mode != OCS_MODE_CBC && + mode != OCS_MODE_CTR && mode != OCS_MODE_CCM && + mode != OCS_MODE_GCM && mode != OCS_MODE_CTS) + return -EINVAL; + + if (instruction != OCS_ENCRYPT && instruction != OCS_DECRYPT && + instruction != OCS_EXPAND && instruction != OCS_BYPASS) + return -EINVAL; + + /* + * When instruction is OCS_BYPASS, OCS simply copies data from source + * to destination using DMA. + * + * AES mode is irrelevant, but both source and destination DMA + * linked-list must be defined. + */ + if (instruction == OCS_BYPASS) { + if (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + return 0; + } + + /* + * For performance reasons switch based on mode to limit unnecessary + * conditionals for each mode + */ + switch (mode) { + case OCS_MODE_ECB: + /* Ensure input length is multiple of block size */ + if (src_size % AES_BLOCK_SIZE != 0) + return -EINVAL; + + /* Ensure source and destination linked lists are created */ + if (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + return 0; + + case OCS_MODE_CBC: + /* Ensure input length is multiple of block size */ + if (src_size % AES_BLOCK_SIZE != 0) + return -EINVAL; + + /* Ensure source and destination linked lists are created */ + if (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* Ensure IV is present and block size in length */ + if (!iv || iv_size != AES_BLOCK_SIZE) + return -EINVAL; + + return 0; + + case OCS_MODE_CTR: + /* Ensure input length of 1 byte or greater */ + if (src_size == 0) + return -EINVAL; + + /* Ensure source and destination linked lists are created */ + if (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* Ensure IV is present and block size in length */ + if (!iv || iv_size != AES_BLOCK_SIZE) + return -EINVAL; + + return 0; + + case OCS_MODE_CTS: + /* Ensure input length >= block size */ + if (src_size < AES_BLOCK_SIZE) + return -EINVAL; + + /* Ensure source and destination linked lists are created */ + if (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* Ensure IV is present and block size in length */ + if (!iv || iv_size != AES_BLOCK_SIZE) + return -EINVAL; + + return 0; + + case OCS_MODE_GCM: + /* Ensure IV is present and GCM_AES_IV_SIZE in length */ + if (!iv || iv_size != GCM_AES_IV_SIZE) + return -EINVAL; + + /* + * If input data present ensure source and destination linked + * lists are created + */ + if (src_size && (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR)) + return -EINVAL; + + /* If aad present ensure aad linked list is created */ + if (aad_size && aad_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* Ensure tag destination is set */ + if (!tag) + return -EINVAL; + + /* Just ensure that tag_size doesn't cause overflows. */ + if (tag_size > (AES_MAX_TAG_SIZE_U32 * sizeof(u32))) + return -EINVAL; + + return 0; + + case OCS_MODE_CCM: + /* Ensure IV is present and block size in length */ + if (!iv || iv_size != AES_BLOCK_SIZE) + return -EINVAL; + + /* 2 <= L <= 8, so 1 <= L' <= 7 */ + if (iv[L_PRIME_IDX] < L_PRIME_MIN || + iv[L_PRIME_IDX] > L_PRIME_MAX) + return -EINVAL; + + /* If aad present ensure aad linked list is created */ + if (aad_size && aad_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* Just ensure that tag_size doesn't cause overflows. */ + if (tag_size > (AES_MAX_TAG_SIZE_U32 * sizeof(u32))) + return -EINVAL; + + if (instruction == OCS_DECRYPT) { + /* + * If input data present ensure source and destination + * linked lists are created + */ + if (src_size && (src_dma_list == DMA_MAPPING_ERROR || + dst_dma_list == DMA_MAPPING_ERROR)) + return -EINVAL; + + /* Ensure input tag is present */ + if (!tag) + return -EINVAL; + + return 0; + } + + /* Instruction == OCS_ENCRYPT */ + + /* + * Destination linked list always required (for tag even if no + * input data) + */ + if (dst_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + /* If input data present ensure src linked list is created */ + if (src_size && src_dma_list == DMA_MAPPING_ERROR) + return -EINVAL; + + return 0; + + default: + return -EINVAL; + } +} + +/** + * ocs_aes_op() - Perform AES/SM4 operation. + * @aes_dev: The OCS AES device to use. + * @mode: The mode to use (ECB, CBC, CTR, or CTS). + * @cipher: The cipher to use (AES or SM4). + * @instruction: The instruction to perform (encrypt or decrypt). + * @dst_dma_list: The OCS DMA list mapping output memory. + * @src_dma_list: The OCS DMA list mapping input payload data. + * @src_size: The amount of data mapped by @src_dma_list. + * @iv: The IV vector. + * @iv_size: The size (in bytes) of @iv. + * + * Return: 0 on success, negative error code otherwise. + */ +int ocs_aes_op(struct ocs_aes_dev *aes_dev, + enum ocs_mode mode, + enum ocs_cipher cipher, + enum ocs_instruction instruction, + dma_addr_t dst_dma_list, + dma_addr_t src_dma_list, + u32 src_size, + u8 *iv, + u32 iv_size) +{ + u32 *iv32; + int rc; + + rc = ocs_aes_validate_inputs(src_dma_list, src_size, iv, iv_size, 0, 0, + NULL, 0, cipher, mode, instruction, + dst_dma_list); + if (rc) + return rc; + /* + * ocs_aes_validate_inputs() is a generic check, now ensure mode is not + * GCM or CCM. + */ + if (mode == OCS_MODE_GCM || mode == OCS_MODE_CCM) + return -EINVAL; + + /* Cast IV to u32 array. */ + iv32 = (u32 *)iv; + + ocs_aes_init(aes_dev, mode, cipher, instruction); + + if (mode == OCS_MODE_CTS) { + /* Write the byte length of the last data block to engine. */ + ocs_aes_write_last_data_blk_len(aes_dev, src_size); + } + + /* ECB is the only mode that doesn't use IV. */ + if (mode != OCS_MODE_ECB) { + iowrite32(iv32[0], aes_dev->base_reg + AES_IV_0_OFFSET); + iowrite32(iv32[1], aes_dev->base_reg + AES_IV_1_OFFSET); + iowrite32(iv32[2], aes_dev->base_reg + AES_IV_2_OFFSET); + iowrite32(iv32[3], aes_dev->base_reg + AES_IV_3_OFFSET); + } + + /* Set AES_ACTIVE.TRIGGER to start the operation. */ + aes_a_op_trigger(aes_dev); + + /* Configure and activate input / output DMA. */ + dma_to_ocs_aes_ll(aes_dev, src_dma_list); + dma_from_ocs_aes_ll(aes_dev, dst_dma_list); + aes_a_dma_active_src_dst_ll_en(aes_dev); + + if (mode == OCS_MODE_CTS) { + /* + * For CTS mode, instruct engine to activate ciphertext + * stealing if last block of data is incomplete. + */ + aes_a_set_last_gcx(aes_dev); + } else { + /* For all other modes, just write the 'termination' bit. */ + aes_a_op_termination(aes_dev); + } + + /* Wait for engine to complete processing. */ + rc = ocs_aes_irq_enable_and_wait(aes_dev, AES_COMPLETE_INT); + if (rc) + return rc; + + if (mode == OCS_MODE_CTR) { + /* Read back IV for streaming mode */ + iv32[0] = ioread32(aes_dev->base_reg + AES_IV_0_OFFSET); + iv32[1] = ioread32(aes_dev->base_reg + AES_IV_1_OFFSET); + iv32[2] = ioread32(aes_dev->base_reg + AES_IV_2_OFFSET); + iv32[3] = ioread32(aes_dev->base_reg + AES_IV_3_OFFSET); + } + + return 0; +} + +/* Compute and write J0 to engine registers. */ +static void ocs_aes_gcm_write_j0(const struct ocs_aes_dev *aes_dev, + const u8 *iv) +{ + const u32 *j0 = (u32 *)iv; + + /* + * IV must be 12 bytes; Other sizes not supported as Linux crypto API + * does only expects/allows 12 byte IV for GCM + */ + iowrite32(0x00000001, aes_dev->base_reg + AES_IV_0_OFFSET); + iowrite32(__swab32(j0[2]), aes_dev->base_reg + AES_IV_1_OFFSET); + iowrite32(__swab32(j0[1]), aes_dev->base_reg + AES_IV_2_OFFSET); + iowrite32(__swab32(j0[0]), aes_dev->base_reg + AES_IV_3_OFFSET); +} + +/* Read GCM tag from engine registers. */ +static inline void ocs_aes_gcm_read_tag(struct ocs_aes_dev *aes_dev, + u8 *tag, u32 tag_size) +{ + u32 tag_u32[AES_MAX_TAG_SIZE_U32]; + + /* + * The Authentication Tag T is stored in Little Endian order in the + * registers with the most significant bytes stored from AES_T_MAC[3] + * downward. + */ + tag_u32[0] = __swab32(ioread32(aes_dev->base_reg + AES_T_MAC_3_OFFSET)); + tag_u32[1] = __swab32(ioread32(aes_dev->base_reg + AES_T_MAC_2_OFFSET)); + tag_u32[2] = __swab32(ioread32(aes_dev->base_reg + AES_T_MAC_1_OFFSET)); + tag_u32[3] = __swab32(ioread32(aes_dev->base_reg + AES_T_MAC_0_OFFSET)); + + memcpy(tag, tag_u32, tag_size); +} + +/** + * ocs_aes_gcm_op() - Perform GCM operation. + * @aes_dev: The OCS AES device to use. + * @cipher: The Cipher to use (AES or SM4). + * @instruction: The instruction to perform (encrypt or decrypt). + * @dst_dma_list: The OCS DMA list mapping output memory. + * @src_dma_list: The OCS DMA list mapping input payload data. + * @src_size: The amount of data mapped by @src_dma_list. + * @iv: The input IV vector. + * @aad_dma_list: The OCS DMA list mapping input AAD data. + * @aad_size: The amount of data mapped by @aad_dma_list. + * @out_tag: Where to store computed tag. + * @tag_size: The size (in bytes) of @out_tag. + * + * Return: 0 on success, negative error code otherwise. + */ +int ocs_aes_gcm_op(struct ocs_aes_dev *aes_dev, + enum ocs_cipher cipher, + enum ocs_instruction instruction, + dma_addr_t dst_dma_list, + dma_addr_t src_dma_list, + u32 src_size, + const u8 *iv, + dma_addr_t aad_dma_list, + u32 aad_size, + u8 *out_tag, + u32 tag_size) +{ + u64 bit_len; + u32 val; + int rc; + + rc = ocs_aes_validate_inputs(src_dma_list, src_size, iv, + GCM_AES_IV_SIZE, aad_dma_list, + aad_size, out_tag, tag_size, cipher, + OCS_MODE_GCM, instruction, + dst_dma_list); + if (rc) + return rc; + + ocs_aes_init(aes_dev, OCS_MODE_GCM, cipher, instruction); + + /* Compute and write J0 to OCS HW. */ + ocs_aes_gcm_write_j0(aes_dev, iv); + + /* Write out_tag byte length */ + iowrite32(tag_size, aes_dev->base_reg + AES_TLEN_OFFSET); + + /* Write the byte length of the last plaintext / ciphertext block. */ + ocs_aes_write_last_data_blk_len(aes_dev, src_size); + + /* Write ciphertext bit length */ + bit_len = (u64)src_size * 8; + val = bit_len & 0xFFFFFFFF; + iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_0_OFFSET); + val = bit_len >> 32; + iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_1_OFFSET); + + /* Write aad bit length */ + bit_len = (u64)aad_size * 8; + val = bit_len & 0xFFFFFFFF; + iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_2_OFFSET); + val = bit_len >> 32; + iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_3_OFFSET); + + /* Set AES_ACTIVE.TRIGGER to start the operation. */ + aes_a_op_trigger(aes_dev); + + /* Process AAD. */ + if (aad_size) { + /* If aad present, configure DMA to feed it to the engine. */ + dma_to_ocs_aes_ll(aes_dev, aad_dma_list); + aes_a_dma_active_src_ll_en(aes_dev); + + /* Instructs engine to pad last block of aad, if needed. */ + aes_a_set_last_gcx_and_adata(aes_dev); + + /* Wait for DMA transfer to complete. */ + rc = ocs_aes_irq_enable_and_wait(aes_dev, AES_DMA_SRC_DONE_INT); + if (rc) + return rc; + } else { + aes_a_set_last_gcx_and_adata(aes_dev); + } + + /* Wait until adata (if present) has been processed. */ + aes_a_wait_last_gcx(aes_dev); + aes_a_dma_wait_input_buffer_occupancy(aes_dev); + + /* Now process payload. */ + if (src_size) { + /* Configure and activate DMA for both input and output data. */ + dma_to_ocs_aes_ll(aes_dev, src_dma_list); + dma_from_ocs_aes_ll(aes_dev, dst_dma_list); + aes_a_dma_active_src_dst_ll_en(aes_dev); + } else { + aes_a_dma_set_xfer_size_zero(aes_dev); + aes_a_dma_active(aes_dev); + } + + /* Instruct AES/SMA4 engine payload processing is over. */ + aes_a_set_last_gcx(aes_dev); + + /* Wait for OCS AES engine to complete processing. */ + rc = ocs_aes_irq_enable_and_wait(aes_dev, AES_COMPLETE_INT); + if (rc) + return rc; + + ocs_aes_gcm_read_tag(aes_dev, out_tag, tag_size); + + return 0; +} + +/* Write encrypted tag to AES/SM4 engine. */ +static void ocs_aes_ccm_write_encrypted_tag(struct ocs_aes_dev *aes_dev, + const u8 *in_tag, u32 tag_size) +{ + int i; + + /* Ensure DMA input buffer is empty */ + aes_a_dma_wait_input_buffer_occupancy(aes_dev); + + /* + * During CCM decrypt, the OCS block needs to finish processing the + * ciphertext before the tag is written. So delay needed after DMA has + * completed writing the ciphertext + */ + aes_a_dma_reset_and_activate_perf_cntr(aes_dev); + aes_a_dma_wait_and_deactivate_perf_cntr(aes_dev, + CCM_DECRYPT_DELAY_TAG_CLK_COUNT); + + /* Write encrypted tag to AES/SM4 engine. */ + for (i = 0; i < tag_size; i++) { + iowrite8(in_tag[i], aes_dev->base_reg + + AES_A_DMA_INBUFFER_WRITE_FIFO_OFFSET); + } +} + +/* + * Write B0 CCM block to OCS AES HW. + * + * Note: B0 format is documented in NIST Special Publication 800-38C + * https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38c.pdf + * (see Section A.2.1) + */ +static int ocs_aes_ccm_write_b0(const struct ocs_aes_dev *aes_dev, + const u8 *iv, u32 adata_size, u32 tag_size, + u32 cryptlen) +{ + u8 b0[16]; /* CCM B0 block is 16 bytes long. */ + int i, q; + + /* Initialize B0 to 0. */ + memset(b0, 0, sizeof(b0)); + + /* + * B0[0] is the 'Flags Octet' and has the following structure: + * bit 7: Reserved + * bit 6: Adata flag + * bit 5-3: t value encoded as (t-2)/2 + * bit 2-0: q value encoded as q - 1 + */ + /* If there is AAD data, set the Adata flag. */ + if (adata_size) + b0[0] |= BIT(6); + /* + * t denotes the octet length of T. + * t can only be an element of { 4, 6, 8, 10, 12, 14, 16} and is + * encoded as (t - 2) / 2 + */ + b0[0] |= (((tag_size - 2) / 2) & 0x7) << 3; + /* + * q is the octet length of Q. + * q can only be an element of {2, 3, 4, 5, 6, 7, 8} and is encoded as + * q - 1 == iv[0] & 0x7; + */ + b0[0] |= iv[0] & 0x7; + /* + * Copy the Nonce N from IV to B0; N is located in iv[1]..iv[15 - q] + * and must be copied to b0[1]..b0[15-q]. + * q == (iv[0] & 0x7) + 1 + */ + q = (iv[0] & 0x7) + 1; + for (i = 1; i <= 15 - q; i++) + b0[i] = iv[i]; + /* + * The rest of B0 must contain Q, i.e., the message length. + * Q is encoded in q octets, in big-endian order, so to write it, we + * start from the end of B0 and we move backward. + */ + i = sizeof(b0) - 1; + while (q) { + b0[i] = cryptlen & 0xff; + cryptlen >>= 8; + i--; + q--; + } + /* + * If cryptlen is not zero at this point, it means that its original + * value was too big. + */ + if (cryptlen) + return -EOVERFLOW; + /* Now write B0 to OCS AES input buffer. */ + for (i = 0; i < sizeof(b0); i++) + iowrite8(b0[i], aes_dev->base_reg + + AES_A_DMA_INBUFFER_WRITE_FIFO_OFFSET); + return 0; +} + +/* + * Write adata length to OCS AES HW. + * + * Note: adata len encoding is documented in NIST Special Publication 800-38C + * https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38c.pdf + * (see Section A.2.2) + */ +static void ocs_aes_ccm_write_adata_len(const struct ocs_aes_dev *aes_dev, + u64 adata_len) +{ + u8 enc_a[10]; /* Maximum encoded size: 10 octets. */ + int i, len; + + /* + * adata_len ('a') is encoded as follows: + * If 0 < a < 2^16 - 2^8 ==> 'a' encoded as [a]16, i.e., two octets + * (big endian). + * If 2^16 - 2^8 ≤ a < 2^32 ==> 'a' encoded as 0xff || 0xfe || [a]32, + * i.e., six octets (big endian). + * If 2^32 ≤ a < 2^64 ==> 'a' encoded as 0xff || 0xff || [a]64, + * i.e., ten octets (big endian). + */ + if (adata_len < 65280) { + len = 2; + *(__be16 *)enc_a = cpu_to_be16(adata_len); + } else if (adata_len <= 0xFFFFFFFF) { + len = 6; + *(__be16 *)enc_a = cpu_to_be16(0xfffe); + *(__be32 *)&enc_a[2] = cpu_to_be32(adata_len); + } else { /* adata_len >= 2^32 */ + len = 10; + *(__be16 *)enc_a = cpu_to_be16(0xffff); + *(__be64 *)&enc_a[2] = cpu_to_be64(adata_len); + } + for (i = 0; i < len; i++) + iowrite8(enc_a[i], + aes_dev->base_reg + + AES_A_DMA_INBUFFER_WRITE_FIFO_OFFSET); +} + +static int ocs_aes_ccm_do_adata(struct ocs_aes_dev *aes_dev, + dma_addr_t adata_dma_list, u32 adata_size) +{ + int rc; + + if (!adata_size) { + /* Since no aad the LAST_GCX bit can be set now */ + aes_a_set_last_gcx_and_adata(aes_dev); + goto exit; + } + + /* Adata case. */ + + /* + * Form the encoding of the Associated data length and write it + * to the AES/SM4 input buffer. + */ + ocs_aes_ccm_write_adata_len(aes_dev, adata_size); + + /* Configure the AES/SM4 DMA to fetch the Associated Data */ + dma_to_ocs_aes_ll(aes_dev, adata_dma_list); + + /* Activate DMA to fetch Associated data. */ + aes_a_dma_active_src_ll_en(aes_dev); + + /* Set LAST_GCX and LAST_ADATA in AES ACTIVE register. */ + aes_a_set_last_gcx_and_adata(aes_dev); + + /* Wait for DMA transfer to complete. */ + rc = ocs_aes_irq_enable_and_wait(aes_dev, AES_DMA_SRC_DONE_INT); + if (rc) + return rc; + +exit: + /* Wait until adata (if present) has been processed. */ + aes_a_wait_last_gcx(aes_dev); + aes_a_dma_wait_input_buffer_occupancy(aes_dev); + + return 0; +} + +static int ocs_aes_ccm_encrypt_do_payload(struct ocs_aes_dev *aes_dev, + dma_addr_t dst_dma_list, + dma_addr_t src_dma_list, + u32 src_size) +{ + if (src_size) { + /* + * Configure and activate DMA for both input and output + * data. + */ + dma_to_ocs_aes_ll(aes_dev, src_dma_list); + dma_from_ocs_aes_ll(aes_dev, dst_dma_list); + aes_a_dma_active_src_dst_ll_en(aes_dev); + } else { + /* Configure and activate DMA for output data only. */ + dma_from_ocs_aes_ll(aes_dev, dst_dma_list); + aes_a_dma_active_dst_ll_en(aes_dev); + } + + /* + * Set the LAST GCX bit in AES_ACTIVE Register to instruct + * AES/SM4 engine to pad the last block of data. + */ + aes_a_set_last_gcx(aes_dev); + + /* We are done, wait for IRQ and return. */ + return ocs_aes_irq_enable_and_wait(aes_dev, AES_COMPLETE_INT); +} + +static int ocs_aes_ccm_decrypt_do_payload(struct ocs_aes_dev *aes_dev, + dma_addr_t dst_dma_list, + dma_addr_t src_dma_list, + u32 src_size) +{ + if (!src_size) { + /* Let engine process 0-length input. */ + aes_a_dma_set_xfer_size_zero(aes_dev); + aes_a_dma_active(aes_dev); + aes_a_set_last_gcx(aes_dev); + + return 0; + } + + /* + * Configure and activate DMA for both input and output + * data. + */ + dma_to_ocs_aes_ll(aes_dev, src_dma_list); + dma_from_ocs_aes_ll(aes_dev, dst_dma_list); + aes_a_dma_active_src_dst_ll_en(aes_dev); + /* + * Set the LAST GCX bit in AES_ACTIVE Register; this allows the + * AES/SM4 engine to differentiate between encrypted data and + * encrypted MAC. + */ + aes_a_set_last_gcx(aes_dev); + /* + * Enable DMA DONE interrupt; once DMA transfer is over, + * interrupt handler will process the MAC/tag. + */ + return ocs_aes_irq_enable_and_wait(aes_dev, AES_DMA_SRC_DONE_INT); +} + +/* + * Compare Tag to Yr. + * + * Only used at the end of CCM decrypt. If tag == yr, message authentication + * has succeeded. + */ +static inline int ccm_compare_tag_to_yr(struct ocs_aes_dev *aes_dev, + u8 tag_size_bytes) +{ + u32 tag[AES_MAX_TAG_SIZE_U32]; + u32 yr[AES_MAX_TAG_SIZE_U32]; + u8 i; + + /* Read Tag and Yr from AES registers. */ + for (i = 0; i < AES_MAX_TAG_SIZE_U32; i++) { + tag[i] = ioread32(aes_dev->base_reg + + AES_T_MAC_0_OFFSET + (i * sizeof(u32))); + yr[i] = ioread32(aes_dev->base_reg + + AES_MULTIPURPOSE2_0_OFFSET + + (i * sizeof(u32))); + } + + return memcmp(tag, yr, tag_size_bytes) ? -EBADMSG : 0; +} + +/** + * ocs_aes_ccm_op() - Perform CCM operation. + * @aes_dev: The OCS AES device to use. + * @cipher: The Cipher to use (AES or SM4). + * @instruction: The instruction to perform (encrypt or decrypt). + * @dst_dma_list: The OCS DMA list mapping output memory. + * @src_dma_list: The OCS DMA list mapping input payload data. + * @src_size: The amount of data mapped by @src_dma_list. + * @iv: The input IV vector. + * @adata_dma_list: The OCS DMA list mapping input A-data. + * @adata_size: The amount of data mapped by @adata_dma_list. + * @in_tag: Input tag. + * @tag_size: The size (in bytes) of @in_tag. + * + * Note: for encrypt the tag is appended to the ciphertext (in the memory + * mapped by @dst_dma_list). + * + * Return: 0 on success, negative error code otherwise. + */ +int ocs_aes_ccm_op(struct ocs_aes_dev *aes_dev, + enum ocs_cipher cipher, + enum ocs_instruction instruction, + dma_addr_t dst_dma_list, + dma_addr_t src_dma_list, + u32 src_size, + u8 *iv, + dma_addr_t adata_dma_list, + u32 adata_size, + u8 *in_tag, + u32 tag_size) +{ + u32 *iv_32; + u8 lprime; + int rc; + + rc = ocs_aes_validate_inputs(src_dma_list, src_size, iv, + AES_BLOCK_SIZE, adata_dma_list, adata_size, + in_tag, tag_size, cipher, OCS_MODE_CCM, + instruction, dst_dma_list); + if (rc) + return rc; + + ocs_aes_init(aes_dev, OCS_MODE_CCM, cipher, instruction); + + /* + * Note: rfc 3610 and NIST 800-38C require counter of zero to encrypt + * auth tag so ensure this is the case + */ + lprime = iv[L_PRIME_IDX]; + memset(&iv[COUNTER_START(lprime)], 0, COUNTER_LEN(lprime)); + + /* + * Nonce is already converted to ctr0 before being passed into this + * function as iv. + */ + iv_32 = (u32 *)iv; + iowrite32(__swab32(iv_32[0]), + aes_dev->base_reg + AES_MULTIPURPOSE1_3_OFFSET); + iowrite32(__swab32(iv_32[1]), + aes_dev->base_reg + AES_MULTIPURPOSE1_2_OFFSET); + iowrite32(__swab32(iv_32[2]), + aes_dev->base_reg + AES_MULTIPURPOSE1_1_OFFSET); + iowrite32(__swab32(iv_32[3]), + aes_dev->base_reg + AES_MULTIPURPOSE1_0_OFFSET); + + /* Write MAC/tag length in register AES_TLEN */ + iowrite32(tag_size, aes_dev->base_reg + AES_TLEN_OFFSET); + /* + * Write the byte length of the last AES/SM4 block of Payload data + * (without zero padding and without the length of the MAC) in register + * AES_PLEN. + */ + ocs_aes_write_last_data_blk_len(aes_dev, src_size); + + /* Set AES_ACTIVE.TRIGGER to start the operation. */ + aes_a_op_trigger(aes_dev); + + aes_a_dma_reset_and_activate_perf_cntr(aes_dev); + + /* Form block B0 and write it to the AES/SM4 input buffer. */ + rc = ocs_aes_ccm_write_b0(aes_dev, iv, adata_size, tag_size, src_size); + if (rc) + return rc; + /* + * Ensure there has been at least CCM_DECRYPT_DELAY_LAST_GCX_CLK_COUNT + * clock cycles since TRIGGER bit was set + */ + aes_a_dma_wait_and_deactivate_perf_cntr(aes_dev, + CCM_DECRYPT_DELAY_LAST_GCX_CLK_COUNT); + + /* Process Adata. */ + ocs_aes_ccm_do_adata(aes_dev, adata_dma_list, adata_size); + + /* For Encrypt case we just process the payload and return. */ + if (instruction == OCS_ENCRYPT) { + return ocs_aes_ccm_encrypt_do_payload(aes_dev, dst_dma_list, + src_dma_list, src_size); + } + /* For Decypt we need to process the payload and then the tag. */ + rc = ocs_aes_ccm_decrypt_do_payload(aes_dev, dst_dma_list, + src_dma_list, src_size); + if (rc) + return rc; + + /* Process MAC/tag directly: feed tag to engine and wait for IRQ. */ + ocs_aes_ccm_write_encrypted_tag(aes_dev, in_tag, tag_size); + rc = ocs_aes_irq_enable_and_wait(aes_dev, AES_COMPLETE_INT); + if (rc) + return rc; + + return ccm_compare_tag_to_yr(aes_dev, tag_size); +} + +/** + * ocs_create_linked_list_from_sg() - Create OCS DMA linked list from SG list. + * @aes_dev: The OCS AES device the list will be created for. + * @sg: The SG list OCS DMA linked list will be created from. When + * passed to this function, @sg must have been already mapped + * with dma_map_sg(). + * @sg_dma_count: The number of DMA-mapped entries in @sg. This must be the + * value returned by dma_map_sg() when @sg was mapped. + * @dll_desc: The OCS DMA dma_list to use to store information about the + * created linked list. + * @data_size: The size of the data (from the SG list) to be mapped into the + * OCS DMA linked list. + * @data_offset: The offset (within the SG list) of the data to be mapped. + * + * Return: 0 on success, negative error code otherwise. + */ +int ocs_create_linked_list_from_sg(const struct ocs_aes_dev *aes_dev, + struct scatterlist *sg, + int sg_dma_count, + struct ocs_dll_desc *dll_desc, + size_t data_size, size_t data_offset) +{ + struct ocs_dma_linked_list *ll = NULL; + struct scatterlist *sg_tmp; + unsigned int tmp; + int dma_nents; + int i; + + if (!dll_desc || !sg || !aes_dev) + return -EINVAL; + + /* Default values for when no ddl_desc is created. */ + dll_desc->vaddr = NULL; + dll_desc->dma_addr = DMA_MAPPING_ERROR; + dll_desc->size = 0; + + if (data_size == 0) + return 0; + + /* Loop over sg_list until we reach entry at specified offset. */ + while (data_offset >= sg_dma_len(sg)) { + data_offset -= sg_dma_len(sg); + sg_dma_count--; + sg = sg_next(sg); + /* If we reach the end of the list, offset was invalid. */ + if (!sg || sg_dma_count == 0) + return -EINVAL; + } + + /* Compute number of DMA-mapped SG entries to add into OCS DMA list. */ + dma_nents = 0; + tmp = 0; + sg_tmp = sg; + while (tmp < data_offset + data_size) { + /* If we reach the end of the list, data_size was invalid. */ + if (!sg_tmp) + return -EINVAL; + tmp += sg_dma_len(sg_tmp); + dma_nents++; + sg_tmp = sg_next(sg_tmp); + } + if (dma_nents > sg_dma_count) + return -EINVAL; + + /* Allocate the DMA list, one entry for each SG entry. */ + dll_desc->size = sizeof(struct ocs_dma_linked_list) * dma_nents; + dll_desc->vaddr = dma_alloc_coherent(aes_dev->dev, dll_desc->size, + &dll_desc->dma_addr, GFP_KERNEL); + if (!dll_desc->vaddr) + return -ENOMEM; + + /* Populate DMA linked list entries. */ + ll = dll_desc->vaddr; + for (i = 0; i < dma_nents; i++, sg = sg_next(sg)) { + ll[i].src_addr = sg_dma_address(sg) + data_offset; + ll[i].src_len = (sg_dma_len(sg) - data_offset) < data_size ? + (sg_dma_len(sg) - data_offset) : data_size; + data_offset = 0; + data_size -= ll[i].src_len; + /* Current element points to the DMA address of the next one. */ + ll[i].next = dll_desc->dma_addr + (sizeof(*ll) * (i + 1)); + ll[i].ll_flags = 0; + } + /* Terminate last element. */ + ll[i - 1].next = 0; + ll[i - 1].ll_flags = OCS_LL_DMA_FLAG_TERMINATE; + + return 0; +} |