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/*
* 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 <soc/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__ */
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