cryptocop.c

linux内核源码

/* $Id: cryptocop.c,v 1.13 2005/04/21 17:27:55 henriken Exp $
 *
 * Stream co-processor driver for the ETRAX FS
 *
 *    Copyright (C) 2003-2005  Axis Communications AB
 */

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>

#include <linux/list.h>
#include <linux/interrupt.h>

#include <asm/signal.h>
#include <asm/irq.h>

#include <asm/arch/dma.h>
#include <asm/arch/hwregs/dma.h>
#include <asm/arch/hwregs/reg_map.h>
#include <asm/arch/hwregs/reg_rdwr.h>
#include <asm/arch/hwregs/intr_vect_defs.h>

#include <asm/arch/hwregs/strcop.h>
#include <asm/arch/hwregs/strcop_defs.h>
#include <asm/arch/cryptocop.h>



#define DESCR_ALLOC_PAD  (31)

struct cryptocop_dma_desc {
	char *free_buf; /* If non-null will be kfreed in free_cdesc() */
	dma_descr_data *dma_descr;

	unsigned char dma_descr_buf[sizeof(dma_descr_data) + DESCR_ALLOC_PAD];

	unsigned int from_pool:1; /* If 1 'allocated' from the descriptor pool. */
	struct cryptocop_dma_desc *next;
};


struct cryptocop_int_operation{
	void                        *alloc_ptr;
	cryptocop_session_id        sid;

	dma_descr_context           ctx_out;
	dma_descr_context           ctx_in;

	/* DMA descriptors allocated by driver. */
	struct cryptocop_dma_desc   *cdesc_out;
	struct cryptocop_dma_desc   *cdesc_in;

	/* Strcop config to use. */
	cryptocop_3des_mode         tdes_mode;
	cryptocop_csum_type         csum_mode;

	/* DMA descrs provided by consumer. */
	dma_descr_data              *ddesc_out;
	dma_descr_data              *ddesc_in;
};


struct cryptocop_tfrm_ctx {
	cryptocop_tfrm_id tid;
	unsigned int blocklength;

	unsigned int start_ix;

	struct cryptocop_tfrm_cfg *tcfg;
	struct cryptocop_transform_ctx *tctx;

	unsigned char previous_src;
	unsigned char current_src;

	/* Values to use in metadata out. */
	unsigned char hash_conf;
	unsigned char hash_mode;
	unsigned char ciph_conf;
	unsigned char cbcmode;
	unsigned char decrypt;

	unsigned int requires_padding:1;
	unsigned int strict_block_length:1;
	unsigned int active:1;
	unsigned int done:1;
	size_t consumed;
	size_t produced;

	/* Pad (input) descriptors to put in the DMA out list when the transform
	 * output is put on the DMA in list. */
	struct cryptocop_dma_desc *pad_descs;

	struct cryptocop_tfrm_ctx *prev_src;
	struct cryptocop_tfrm_ctx *curr_src;

	/* Mapping to HW. */
	unsigned char unit_no;
};


struct cryptocop_private{
	cryptocop_session_id sid;
	struct cryptocop_private *next;
};

/* Session list. */

struct cryptocop_transform_ctx{
	struct cryptocop_transform_init init;
	unsigned char dec_key[CRYPTOCOP_MAX_KEY_LENGTH];
	unsigned int dec_key_set:1;

	struct cryptocop_transform_ctx *next;
};


struct cryptocop_session{
	cryptocop_session_id sid;

	struct cryptocop_transform_ctx *tfrm_ctx;

	struct cryptocop_session *next;
};

/* Priority levels for jobs sent to the cryptocop.  Checksum operations from
   kernel have highest priority since TCPIP stack processing must not
   be a bottleneck. */
typedef enum {
	cryptocop_prio_kernel_csum = 0,
	cryptocop_prio_kernel = 1,
	cryptocop_prio_user = 2,
	cryptocop_prio_no_prios = 3
} cryptocop_queue_priority;

struct cryptocop_prio_queue{
	struct list_head jobs;
	cryptocop_queue_priority prio;
};

struct cryptocop_prio_job{
	struct list_head node;
	cryptocop_queue_priority prio;

	struct cryptocop_operation *oper;
	struct cryptocop_int_operation *iop;
};

struct ioctl_job_cb_ctx {
	unsigned int processed:1;
};


static struct cryptocop_session *cryptocop_sessions = NULL;
spinlock_t cryptocop_sessions_lock;

/* Next Session ID to assign. */
static cryptocop_session_id next_sid = 1;

/* Pad for checksum. */
static const char csum_zero_pad[1] = {0x00};

/* Trash buffer for mem2mem operations. */
#define MEM2MEM_DISCARD_BUF_LENGTH  (512)
static unsigned char mem2mem_discard_buf[MEM2MEM_DISCARD_BUF_LENGTH];

/* Descriptor pool. */
/* FIXME Tweak this value. */
#define CRYPTOCOP_DESCRIPTOR_POOL_SIZE   (100)
static struct cryptocop_dma_desc descr_pool[CRYPTOCOP_DESCRIPTOR_POOL_SIZE];
static struct cryptocop_dma_desc *descr_pool_free_list;
static int descr_pool_no_free;
static spinlock_t descr_pool_lock;

/* Lock to stop cryptocop to start processing of a new operation. The holder
   of this lock MUST call cryptocop_start_job() after it is unlocked. */
spinlock_t cryptocop_process_lock;

static struct cryptocop_prio_queue cryptocop_job_queues[cryptocop_prio_no_prios];
static spinlock_t cryptocop_job_queue_lock;
static struct cryptocop_prio_job *cryptocop_running_job = NULL;
static spinlock_t running_job_lock;

/* The interrupt handler appends completed jobs to this list. The scehduled
 * tasklet removes them upon sending the response to the crypto consumer. */
static struct list_head cryptocop_completed_jobs;
static spinlock_t cryptocop_completed_jobs_lock;

DECLARE_WAIT_QUEUE_HEAD(cryptocop_ioc_process_wq);


/** Local functions. **/

static int cryptocop_open(struct inode *, struct file *);

static int cryptocop_release(struct inode *, struct file *);

static int cryptocop_ioctl(struct inode *inode, struct file *file,
			   unsigned int cmd, unsigned long arg);

static void cryptocop_start_job(void);

static int cryptocop_job_queue_insert(cryptocop_queue_priority prio, struct cryptocop_operation *operation);
static int cryptocop_job_setup(struct cryptocop_prio_job **pj, struct cryptocop_operation *operation);

static int cryptocop_job_queue_init(void);
static void cryptocop_job_queue_close(void);

static int create_md5_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length);

static int create_sha1_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length);

static int transform_ok(struct cryptocop_transform_init *tinit);

static struct cryptocop_session *get_session(cryptocop_session_id sid);

static struct cryptocop_transform_ctx *get_transform_ctx(struct cryptocop_session *sess, cryptocop_tfrm_id tid);

static void delete_internal_operation(struct cryptocop_int_operation *iop);

static void get_aes_decrypt_key(unsigned char *dec_key, const unsigned  char *key, unsigned int keylength);

static int init_stream_coprocessor(void);

static void __exit exit_stream_coprocessor(void);

/*#define LDEBUG*/
#ifdef LDEBUG
#define DEBUG(s) s
#define DEBUG_API(s) s
static void print_cryptocop_operation(struct cryptocop_operation *cop);
static void print_dma_descriptors(struct cryptocop_int_operation *iop);
static void print_strcop_crypto_op(struct strcop_crypto_op *cop);
static void print_lock_status(void);
static void print_user_dma_lists(struct cryptocop_dma_list_operation *dma_op);
#define assert(s) do{if (!(s)) panic(#s);} while(0);
#else
#define DEBUG(s)
#define DEBUG_API(s)
#define assert(s)
#endif


/* Transform constants. */
#define DES_BLOCK_LENGTH   (8)
#define AES_BLOCK_LENGTH   (16)
#define MD5_BLOCK_LENGTH   (64)
#define SHA1_BLOCK_LENGTH  (64)
#define CSUM_BLOCK_LENGTH  (2)
#define MD5_STATE_LENGTH   (16)
#define SHA1_STATE_LENGTH  (20)

/* The device number. */
#define CRYPTOCOP_MAJOR    (254)
#define CRYPTOCOP_MINOR    (0)



const struct file_operations cryptocop_fops = {
	.owner =	THIS_MODULE,
	.open =		cryptocop_open,
	.release =	cryptocop_release,
	.ioctl =	cryptocop_ioctl
};


static void free_cdesc(struct cryptocop_dma_desc *cdesc)
{
	DEBUG(printk("free_cdesc: cdesc 0x%p, from_pool=%d\n", cdesc, cdesc->from_pool));
	kfree(cdesc->free_buf);

	if (cdesc->from_pool) {
		unsigned long int flags;
		spin_lock_irqsave(&descr_pool_lock, flags);
		cdesc->next = descr_pool_free_list;
		descr_pool_free_list = cdesc;
		++descr_pool_no_free;
		spin_unlock_irqrestore(&descr_pool_lock, flags);
	} else {
		kfree(cdesc);
	}
}


static struct cryptocop_dma_desc *alloc_cdesc(int alloc_flag)
{
	int use_pool = (alloc_flag & GFP_ATOMIC) ? 1 : 0;
	struct cryptocop_dma_desc *cdesc;

	if (use_pool) {
		unsigned long int flags;
		spin_lock_irqsave(&descr_pool_lock, flags);
		if (!descr_pool_free_list) {
			spin_unlock_irqrestore(&descr_pool_lock, flags);
			DEBUG_API(printk("alloc_cdesc: pool is empty\n"));
			return NULL;
		}
		cdesc = descr_pool_free_list;
		descr_pool_free_list = descr_pool_free_list->next;
		--descr_pool_no_free;
		spin_unlock_irqrestore(&descr_pool_lock, flags);
		cdesc->from_pool = 1;
	} else {
		cdesc = kmalloc(sizeof(struct cryptocop_dma_desc), alloc_flag);
		if (!cdesc) {
			DEBUG_API(printk("alloc_cdesc: kmalloc\n"));
			return NULL;
		}
		cdesc->from_pool = 0;
	}
	cdesc->dma_descr = (dma_descr_data*)(((unsigned long int)cdesc + offsetof(struct cryptocop_dma_desc, dma_descr_buf) + DESCR_ALLOC_PAD) & ~0x0000001F);

	cdesc->next = NULL;

	cdesc->free_buf = NULL;
	cdesc->dma_descr->out_eop = 0;
	cdesc->dma_descr->in_eop = 0;
	cdesc->dma_descr->intr = 0;
	cdesc->dma_descr->eol = 0;
	cdesc->dma_descr->wait = 0;
	cdesc->dma_descr->buf = NULL;
	cdesc->dma_descr->after = NULL;

	DEBUG_API(printk("alloc_cdesc: return 0x%p, cdesc->dma_descr=0x%p, from_pool=%d\n", cdesc, cdesc->dma_descr, cdesc->from_pool));
	return cdesc;
}


static void setup_descr_chain(struct cryptocop_dma_desc *cd)
{
	DEBUG(printk("setup_descr_chain: entering\n"));
	while (cd) {
		if (cd->next) {
			cd->dma_descr->next = (dma_descr_data*)virt_to_phys(cd->next->dma_descr);
		} else {
			cd->dma_descr->next = NULL;
		}
		cd = cd->next;
	}
	DEBUG(printk("setup_descr_chain: exit\n"));
}


/* Create a pad descriptor for the transform.
 * Return -1 for error, 0 if pad created. */
static int create_pad_descriptor(struct cryptocop_tfrm_ctx *tc, struct cryptocop_dma_desc **pad_desc, int alloc_flag)
{
	struct cryptocop_dma_desc        *cdesc = NULL;
	int                              error = 0;
	struct strcop_meta_out           mo = {
		.ciphsel = src_none,
		.hashsel = src_none,
		.csumsel = src_none
	};
	char                             *pad;
	size_t                           plen;

	DEBUG(printk("create_pad_descriptor: start.\n"));
	/* Setup pad descriptor. */

	DEBUG(printk("create_pad_descriptor: setting up padding.\n"));
	cdesc = alloc_cdesc(alloc_flag);
	if (!cdesc){
		DEBUG_API(printk("create_pad_descriptor: alloc pad desc\n"));
		goto error_cleanup;
	}
	switch (tc->unit_no) {
	case src_md5:
		error = create_md5_pad(alloc_flag, tc->consumed, &pad, &plen);
		if (error){
			DEBUG_API(printk("create_pad_descriptor: create_md5_pad_failed\n"));
			goto error_cleanup;
		}
		cdesc->free_buf = pad;
		mo.hashsel = src_dma;
		mo.hashconf = tc->hash_conf;
		mo.hashmode = tc->hash_mode;
		break;
	case src_sha1:
		error = create_sha1_pad(alloc_flag, tc->consumed, &pad, &plen);
		if (error){
			DEBUG_API(printk("create_pad_descriptor: create_sha1_pad_failed\n"));
			goto error_cleanup;
		}
		cdesc->free_buf = pad;
		mo.hashsel = src_dma;
		mo.hashconf = tc->hash_conf;
		mo.hashmode = tc->hash_mode;
		break;
	case src_csum:
		if (tc->consumed % tc->blocklength){
			pad = (char*)csum_zero_pad;
			plen = 1;
		} else {
			pad = (char*)cdesc; /* Use any pointer. */
			plen = 0;
		}
		mo.csumsel = src_dma;
		break;
	}