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Diffstat (limited to 'drivers/crypto/caam/qi.h')
| -rw-r--r-- | drivers/crypto/caam/qi.h | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/crypto/caam/qi.h b/drivers/crypto/caam/qi.h new file mode 100644 index 0000000..0c2e68b --- /dev/null +++ b/drivers/crypto/caam/qi.h @@ -0,0 +1,204 @@ +/* + * Public definitions for the CAAM/QI (Queue Interface) backend. + * + * Copyright 2013-2016 Freescale Semiconductor, Inc. + * Copyright 2016-2017 NXP + */ + +#ifndef __QI_H__ +#define __QI_H__ + +#include <linux/fsl_qman.h> +#include "compat.h" +#include "desc.h" +#include "desc_constr.h" + +/* + * CAAM hardware constructs a job descriptor which points to a shared descriptor + * (as pointed by context_a of to-CAAM FQ). + * When the job descriptor is executed by DECO, the whole job descriptor + * together with shared descriptor gets loaded in DECO buffer, which is + * 64 words (each 32-bit) long. + * + * The job descriptor constructed by CAAM hardware has the following layout: + * + * HEADER (1 word) + * Shdesc ptr (1 or 2 words) + * SEQ_OUT_PTR (1 word) + * Out ptr (1 or 2 words) + * Out length (1 word) + * SEQ_IN_PTR (1 word) + * In ptr (1 or 2 words) + * In length (1 word) + * + * The shdesc ptr is used to fetch shared descriptor contents into DECO buffer. + * + * Apart from shdesc contents, the total number of words that get loaded in DECO + * buffer are '8' or '11'. The remaining words in DECO buffer can be used for + * storing shared descriptor. + */ +#define MAX_SDLEN ((CAAM_DESC_BYTES_MAX - DESC_JOB_IO_LEN) / CAAM_CMD_SZ) + +/* Length of a single buffer in the QI driver memory cache */ +#define CAAM_QI_MEMCACHE_SIZE 768 + +extern bool caam_congested __read_mostly; + +/* + * This is the request structure the driver application should fill while + * submitting a job to driver. + */ +struct caam_drv_req; + +/* + * caam_qi_cbk - application's callback function invoked by the driver when the + * request has been successfully processed. + * @drv_req: original request that was submitted + * @status: completion status of request (0 - success, non-zero - error code) + */ +typedef void (*caam_qi_cbk)(struct caam_drv_req *drv_req, u32 status); + +enum optype { + ENCRYPT, + DECRYPT, + GIVENCRYPT, + NUM_OP +}; + +/** + * caam_drv_ctx - CAAM/QI backend driver context + * + * The jobs are processed by the driver against a driver context. + * With every cryptographic context, a driver context is attached. + * The driver context contains data for private use by driver. + * For the applications, this is an opaque structure. + * + * @prehdr: preheader placed before shrd desc + * @sh_desc: shared descriptor + * @context_a: shared descriptor dma address + * @req_fq: to-CAAM request frame queue + * @rsp_fq: from-CAAM response frame queue + * @cpu: cpu on which to receive CAAM response + * @op_type: operation type + * @qidev: device pointer for CAAM/QI backend + */ +struct caam_drv_ctx { + u32 prehdr[2]; + u32 sh_desc[MAX_SDLEN]; + dma_addr_t context_a; + struct qman_fq *req_fq; + struct qman_fq *rsp_fq; + int cpu; + enum optype op_type; + struct device *qidev; +} ____cacheline_aligned; + +/** + * caam_drv_req - The request structure the driver application should fill while + * submitting a job to driver. + * @fd_sgt: QMan S/G pointing to output (fd_sgt[0]) and input (fd_sgt[1]) + * buffers. + * @cbk: callback function to invoke when job is completed + * @app_ctx: arbitrary context attached with request by the application + * + * The fields mentioned below should not be used by application. + * These are for private use by driver. + * + * @hdr__: linked list header to maintain list of outstanding requests to CAAM + * @hwaddr: DMA address for the S/G table. + */ +struct caam_drv_req { + struct qm_sg_entry fd_sgt[2]; + struct caam_drv_ctx *drv_ctx; + caam_qi_cbk cbk; + void *app_ctx; +} ____cacheline_aligned; + +/** + * caam_drv_ctx_init - Initialise a CAAM/QI driver context + * + * A CAAM/QI driver context must be attached with each cryptographic context. + * This function allocates memory for CAAM/QI context and returns a handle to + * the application. This handle must be submitted along with each enqueue + * request to the driver by the application. + * + * @cpu: CPU where the application prefers to the driver to receive CAAM + * responses. The request completion callback would be issued from this + * CPU. + * @sh_desc: shared descriptor pointer to be attached with CAAM/QI driver + * context. + * + * Returns a driver context on success or negative error code on failure. + */ +struct caam_drv_ctx *caam_drv_ctx_init(struct device *qidev, int *cpu, + u32 *sh_desc); + +/** + * caam_qi_enqueue - Submit a request to QI backend driver. + * + * The request structure must be properly filled as described above. + * + * @qidev: device pointer for QI backend + * @req: CAAM QI request structure + * + * Returns 0 on success or negative error code on failure. + */ +int caam_qi_enqueue(struct device *qidev, struct caam_drv_req *req); + +/** + * caam_drv_ctx_busy - Check if there are too many jobs pending with CAAM + * or too many CAAM responses are pending to be processed. + * @drv_ctx: driver context for which job is to be submitted + * + * Returns caam congestion status 'true/false' + */ +bool caam_drv_ctx_busy(struct caam_drv_ctx *drv_ctx); + +/** + * caam_drv_ctx_update - Update QI driver context + * + * Invoked when shared descriptor is required to be change in driver context. + * + * @drv_ctx: driver context to be updated + * @sh_desc: new shared descriptor pointer to be updated in QI driver context + * + * Returns 0 on success or negative error code on failure. + */ +int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc); + +/** + * caam_drv_ctx_rel - Release a QI driver context + * @drv_ctx: context to be released + */ +void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx); + +int caam_qi_init(struct platform_device *pdev); +int caam_qi_shutdown(struct device *dev); + +/** + * qi_cache_alloc - Allocate buffers from CAAM-QI cache + * + * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) needs data which has + * to be allocated on the hotpath. Instead of using malloc, one can use the + * services of the CAAM QI memory cache (backed by kmem_cache). The buffers + * will have a size of 256B, which is sufficient for hosting 16 SG entries. + * + * @flags: flags that would be used for the equivalent malloc(..) call + * + * Returns a pointer to a retrieved buffer on success or NULL on failure. + */ +void *qi_cache_alloc(gfp_t flags); + +/** + * qi_cache_free - Frees buffers allocated from CAAM-QI cache + * + * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) no longer needs + * the buffer previously allocated by a qi_cache_alloc call. + * No checking is being done, the call is a passthrough call to + * kmem_cache_free(...) + * + * @obj: object previously allocated using qi_cache_alloc() + */ +void qi_cache_free(void *obj); + +#endif /* __QI_H__ */ |