[linux-block.git] / drivers / crypto / ccp / ccp-dev.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Cryptographic Coprocessor (CCP) driver
 *
 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
 *
 * Author: Tom Lendacky <thomas.lendacky@amd.com>
 * Author: Gary R Hook <gary.hook@amd.com>
 */

#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hw_random.h>
#include <linux/cpu.h>
#ifdef CONFIG_X86
#include <asm/cpu_device_id.h>
#endif
#include <linux/ccp.h>

#include "ccp-dev.h"

struct ccp_tasklet_data {
	struct completion completion;
	struct ccp_cmd *cmd;
};

/* Human-readable error strings */
#define CCP_MAX_ERROR_CODE	64
static char *ccp_error_codes[] = {
	"",
	"ILLEGAL_ENGINE",
	"ILLEGAL_KEY_ID",
	"ILLEGAL_FUNCTION_TYPE",
	"ILLEGAL_FUNCTION_MODE",
	"ILLEGAL_FUNCTION_ENCRYPT",
	"ILLEGAL_FUNCTION_SIZE",
	"Zlib_MISSING_INIT_EOM",
	"ILLEGAL_FUNCTION_RSVD",
	"ILLEGAL_BUFFER_LENGTH",
	"VLSB_FAULT",
	"ILLEGAL_MEM_ADDR",
	"ILLEGAL_MEM_SEL",
	"ILLEGAL_CONTEXT_ID",
	"ILLEGAL_KEY_ADDR",
	"0xF Reserved",
	"Zlib_ILLEGAL_MULTI_QUEUE",
	"Zlib_ILLEGAL_JOBID_CHANGE",
	"CMD_TIMEOUT",
	"IDMA0_AXI_SLVERR",
	"IDMA0_AXI_DECERR",
	"0x15 Reserved",
	"IDMA1_AXI_SLAVE_FAULT",
	"IDMA1_AIXI_DECERR",
	"0x18 Reserved",
	"ZLIBVHB_AXI_SLVERR",
	"ZLIBVHB_AXI_DECERR",
	"0x1B Reserved",
	"ZLIB_UNEXPECTED_EOM",
	"ZLIB_EXTRA_DATA",
	"ZLIB_BTYPE",
	"ZLIB_UNDEFINED_SYMBOL",
	"ZLIB_UNDEFINED_DISTANCE_S",
	"ZLIB_CODE_LENGTH_SYMBOL",
	"ZLIB _VHB_ILLEGAL_FETCH",
	"ZLIB_UNCOMPRESSED_LEN",
	"ZLIB_LIMIT_REACHED",
	"ZLIB_CHECKSUM_MISMATCH0",
	"ODMA0_AXI_SLVERR",
	"ODMA0_AXI_DECERR",
	"0x28 Reserved",
	"ODMA1_AXI_SLVERR",
	"ODMA1_AXI_DECERR",
};

void ccp_log_error(struct ccp_device *d, unsigned int e)
{
	if (WARN_ON(e >= CCP_MAX_ERROR_CODE))
		return;

	if (e < ARRAY_SIZE(ccp_error_codes))
		dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]);
	else
		dev_err(d->dev, "CCP error %d: Unknown Error\n", e);
}

/* List of CCPs, CCP count, read-write access lock, and access functions
 *
 * Lock structure: get ccp_unit_lock for reading whenever we need to
 * examine the CCP list. While holding it for reading we can acquire
 * the RR lock to update the round-robin next-CCP pointer. The unit lock
 * must be acquired before the RR lock.
 *
 * If the unit-lock is acquired for writing, we have total control over
 * the list, so there's no value in getting the RR lock.
 */
static DEFINE_RWLOCK(ccp_unit_lock);
static LIST_HEAD(ccp_units);

/* Round-robin counter */
static DEFINE_SPINLOCK(ccp_rr_lock);
static struct ccp_device *ccp_rr;

/**
 * ccp_add_device - add a CCP device to the list
 *
 * @ccp: ccp_device struct pointer
 *
 * Put this CCP on the unit list, which makes it available
 * for use.
 *
 * Returns zero if a CCP device is present, -ENODEV otherwise.
 */
void ccp_add_device(struct ccp_device *ccp)
{
	unsigned long flags;

	write_lock_irqsave(&ccp_unit_lock, flags);
	list_add_tail(&ccp->entry, &ccp_units);
	if (!ccp_rr)
		/* We already have the list lock (we're first) so this
		 * pointer can't change on us. Set its initial value.
		 */
		ccp_rr = ccp;
	write_unlock_irqrestore(&ccp_unit_lock, flags);
}

/**
 * ccp_del_device - remove a CCP device from the list
 *
 * @ccp: ccp_device struct pointer
 *
 * Remove this unit from the list of devices. If the next device
 * up for use is this one, adjust the pointer. If this is the last
 * device, NULL the pointer.
 */
void ccp_del_device(struct ccp_device *ccp)
{
	unsigned long flags;

	write_lock_irqsave(&ccp_unit_lock, flags);
	if (ccp_rr == ccp) {
		/* ccp_unit_lock is read/write; any read access
		 * will be suspended while we make changes to the
		 * list and RR pointer.
		 */
		if (list_is_last(&ccp_rr->entry, &ccp_units))
			ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
						  entry);
		else
			ccp_rr = list_next_entry(ccp_rr, entry);
	}
	list_del(&ccp->entry);
	if (list_empty(&ccp_units))
		ccp_rr = NULL;
	write_unlock_irqrestore(&ccp_unit_lock, flags);
}


int ccp_register_rng(struct ccp_device *ccp)
{
	int ret = 0;

	dev_dbg(ccp->dev, "Registering RNG...\n");
	/* Register an RNG */
	ccp->hwrng.name = ccp->rngname;
	ccp->hwrng.read = ccp_trng_read;
	ret = hwrng_register(&ccp->hwrng);
	if (ret)
		dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);

	return ret;
}

void ccp_unregister_rng(struct ccp_device *ccp)
{
	if (ccp->hwrng.name)
		hwrng_unregister(&ccp->hwrng);
}

static struct ccp_device *ccp_get_device(void)
{
	unsigned long flags;
	struct ccp_device *dp = NULL;

	/* We round-robin through the unit list.
	 * The (ccp_rr) pointer refers to the next unit to use.
	 */
	read_lock_irqsave(&ccp_unit_lock, flags);
	if (!list_empty(&ccp_units)) {
		spin_lock(&ccp_rr_lock);
		dp = ccp_rr;
		if (list_is_last(&ccp_rr->entry, &ccp_units))
			ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
						  entry);
		else
			ccp_rr = list_next_entry(ccp_rr, entry);
		spin_unlock(&ccp_rr_lock);
	}
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return dp;
}

/**
 * ccp_present - check if a CCP device is present
 *
 * Returns zero if a CCP device is present, -ENODEV otherwise.
 */
int ccp_present(void)
{
	unsigned long flags;
	int ret;

	read_lock_irqsave(&ccp_unit_lock, flags);
	ret = list_empty(&ccp_units);
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return ret ? -ENODEV : 0;
}
EXPORT_SYMBOL_GPL(ccp_present);

/**
 * ccp_version - get the version of the CCP device
 *
 * Returns the version from the first unit on the list;
 * otherwise a zero if no CCP device is present
 */
unsigned int ccp_version(void)
{
	struct ccp_device *dp;
	unsigned long flags;
	int ret = 0;

	read_lock_irqsave(&ccp_unit_lock, flags);
	if (!list_empty(&ccp_units)) {
		dp = list_first_entry(&ccp_units, struct ccp_device, entry);
		ret = dp->vdata->version;
	}
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(ccp_version);

/**
 * ccp_enqueue_cmd - queue an operation for processing by the CCP
 *
 * @cmd: ccp_cmd struct to be processed
 *
 * Queue a cmd to be processed by the CCP. If queueing the cmd
 * would exceed the defined length of the cmd queue the cmd will
 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
 * result in a return code of -EBUSY.
 *
 * The callback routine specified in the ccp_cmd struct will be
 * called to notify the caller of completion (if the cmd was not
 * backlogged) or advancement out of the backlog. If the cmd has
 * advanced out of the backlog the "err" value of the callback
 * will be -EINPROGRESS. Any other "err" value during callback is
 * the result of the operation.
 *
 * The cmd has been successfully queued if:
 *   the return code is -EINPROGRESS or
 *   the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
 */
int ccp_enqueue_cmd(struct ccp_cmd *cmd)
{
	struct ccp_device *ccp;
	unsigned long flags;
	unsigned int i;
	int ret;

	/* Some commands might need to be sent to a specific device */
	ccp = cmd->ccp ? cmd->ccp : ccp_get_device();

	if (!ccp)
		return -ENODEV;

	/* Caller must supply a callback routine */
	if (!cmd->callback)
		return -EINVAL;

	cmd->ccp = ccp;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	i = ccp->cmd_q_count;

	if (ccp->cmd_count >= MAX_CMD_QLEN) {
		if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
			ret = -EBUSY;
			list_add_tail(&cmd->entry, &ccp->backlog);
		} else {
			ret = -ENOSPC;
		}
	} else {
		ret = -EINPROGRESS;
		ccp->cmd_count++;
		list_add_tail(&cmd->entry, &ccp->cmd);

		/* Find an idle queue */
		if (!ccp->suspending) {
			for (i = 0; i < ccp->cmd_q_count; i++) {
				if (ccp->cmd_q[i].active)
					continue;

				break;
			}
		}
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* If we found an idle queue, wake it up */
	if (i < ccp->cmd_q_count)
		wake_up_process(ccp->cmd_q[i].kthread);

	return ret;
}
EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);

static void ccp_do_cmd_backlog(struct work_struct *work)
{
	struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
	struct ccp_device *ccp = cmd->ccp;
	unsigned long flags;
	unsigned int i;

	cmd->callback(cmd->data, -EINPROGRESS);

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->cmd_count++;
	list_add_tail(&cmd->entry, &ccp->cmd);

	/* Find an idle queue */
	for (i = 0; i < ccp->cmd_q_count; i++) {
		if (ccp->cmd_q[i].active)
			continue;

		break;
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* If we found an idle queue, wake it up */
	if (i < ccp->cmd_q_count)
		wake_up_process(ccp->cmd_q[i].kthread);
}

static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
{
	struct ccp_device *ccp = cmd_q->ccp;
	struct ccp_cmd *cmd = NULL;
	struct ccp_cmd *backlog = NULL;
	unsigned long flags;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	cmd_q->active = 0;

	if (ccp->suspending) {
		cmd_q->suspended = 1;

		spin_unlock_irqrestore(&ccp->cmd_lock, flags);
		wake_up_interruptible(&ccp->suspend_queue);

		return NULL;
	}

	if (ccp->cmd_count) {
		cmd_q->active = 1;

		cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
		list_del(&cmd->entry);

		ccp->cmd_count--;
	}

	if (!list_empty(&ccp->backlog)) {
		backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
					   entry);
		list_del(&backlog->entry);
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	if (backlog) {
		INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
		schedule_work(&backlog->work);
	}

	return cmd;
}

static void ccp_do_cmd_complete(unsigned long data)
{
	struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
	struct ccp_cmd *cmd = tdata->cmd;

	cmd->callback(cmd->data, cmd->ret);

	complete(&tdata->completion);
}

/**
 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
 *
 * @data: thread-specific data
 */
int ccp_cmd_queue_thread(void *data)
{
	struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
	struct ccp_cmd *cmd;
	struct ccp_tasklet_data tdata;
	struct tasklet_struct tasklet;

	tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);

	set_current_state(TASK_INTERRUPTIBLE);
	while (!kthread_should_stop()) {
		schedule();

		set_current_state(TASK_INTERRUPTIBLE);

		cmd = ccp_dequeue_cmd(cmd_q);
		if (!cmd)
			continue;

		__set_current_state(TASK_RUNNING);

		/* Execute the command */
		cmd->ret = ccp_run_cmd(cmd_q, cmd);

		/* Schedule the completion callback */
		tdata.cmd = cmd;
		init_completion(&tdata.completion);
		tasklet_schedule(&tasklet);
		wait_for_completion(&tdata.completion);
	}

	__set_current_state(TASK_RUNNING);

	return 0;
}

/**
 * ccp_alloc_struct - allocate and initialize the ccp_device struct
 *
 * @dev: device struct of the CCP
 */
struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct ccp_device *ccp;

	ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
	if (!ccp)
		return NULL;
	ccp->dev = dev;
	ccp->sp = sp;
	ccp->axcache = sp->axcache;

	INIT_LIST_HEAD(&ccp->cmd);
	INIT_LIST_HEAD(&ccp->backlog);

	spin_lock_init(&ccp->cmd_lock);
	mutex_init(&ccp->req_mutex);
	mutex_init(&ccp->sb_mutex);
	ccp->sb_count = KSB_COUNT;
	ccp->sb_start = 0;

	/* Initialize the wait queues */
	init_waitqueue_head(&ccp->sb_queue);
	init_waitqueue_head(&ccp->suspend_queue);

	snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
	snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);

	return ccp;
}

int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
	struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
	u32 trng_value;
	int len = min_t(int, sizeof(trng_value), max);

	/* Locking is provided by the caller so we can update device
	 * hwrng-related fields safely
	 */
	trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
	if (!trng_value) {
		/* Zero is returned if not data is available or if a
		 * bad-entropy error is present. Assume an error if
		 * we exceed TRNG_RETRIES reads of zero.
		 */
		if (ccp->hwrng_retries++ > TRNG_RETRIES)
			return -EIO;

		return 0;
	}

	/* Reset the counter and save the rng value */
	ccp->hwrng_retries = 0;
	memcpy(data, &trng_value, len);

	return len;
}

#ifdef CONFIG_PM
bool ccp_queues_suspended(struct ccp_device *ccp)
{
	unsigned int suspended = 0;
	unsigned long flags;
	unsigned int i;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	for (i = 0; i < ccp->cmd_q_count; i++)
		if (ccp->cmd_q[i].suspended)
			suspended++;

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	return ccp->cmd_q_count == suspended;
}

int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
{
	struct ccp_device *ccp = sp->ccp_data;
	unsigned long flags;
	unsigned int i;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->suspending = 1;

	/* Wake all the queue kthreads to prepare for suspend */
	for (i = 0; i < ccp->cmd_q_count; i++)
		wake_up_process(ccp->cmd_q[i].kthread);

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* Wait for all queue kthreads to say they're done */
	while (!ccp_queues_suspended(ccp))
		wait_event_interruptible(ccp->suspend_queue,
					 ccp_queues_suspended(ccp));

	return 0;
}

int ccp_dev_resume(struct sp_device *sp)
{
	struct ccp_device *ccp = sp->ccp_data;
	unsigned long flags;
	unsigned int i;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->suspending = 0;

	/* Wake up all the kthreads */
	for (i = 0; i < ccp->cmd_q_count; i++) {
		ccp->cmd_q[i].suspended = 0;
		wake_up_process(ccp->cmd_q[i].kthread);
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	return 0;
}
#endif

int ccp_dev_init(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct ccp_device *ccp;
	int ret;

	ret = -ENOMEM;
	ccp = ccp_alloc_struct(sp);
	if (!ccp)
		goto e_err;
	sp->ccp_data = ccp;

	ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
	if (!ccp->vdata || !ccp->vdata->version) {
		ret = -ENODEV;
		dev_err(dev, "missing driver data\n");
		goto e_err;
	}

	ccp->use_tasklet = sp->use_tasklet;

	ccp->io_regs = sp->io_map + ccp->vdata->offset;
	if (ccp->vdata->setup)
		ccp->vdata->setup(ccp);

	ret = ccp->vdata->perform->init(ccp);
	if (ret)
		goto e_err;

	dev_notice(dev, "ccp enabled\n");

	return 0;

e_err:
	sp->ccp_data = NULL;

	dev_notice(dev, "ccp initialization failed\n");

	return ret;
}

void ccp_dev_destroy(struct sp_device *sp)
{
	struct ccp_device *ccp = sp->ccp_data;

	if (!ccp)
		return;

	ccp->vdata->perform->destroy(ccp);
}
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
63b94509 TL	2	/*
	3	* AMD Cryptographic Coprocessor (CCP) driver
	4	*
68cc652f	5	* Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
63b94509 TL	6	*
63b94509 TL	7	* Author: Tom Lendacky <thomas.lendacky@amd.com>
956ee21a	8	* Author: Gary R Hook <gary.hook@amd.com>
63b94509 TL	9	*/
63b94509 TL	10
63b94509 TL	11	#include <linux/kernel.h>
	12	#include <linux/kthread.h>
	13	#include <linux/sched.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/spinlock.h>
7587c407	16	#include <linux/spinlock_types.h>
553d2374	17	#include <linux/types.h>
63b94509 TL	18	#include <linux/mutex.h>
	19	#include <linux/delay.h>
	20	#include <linux/hw_random.h>
	21	#include <linux/cpu.h>
c4f4b325	22	#ifdef CONFIG_X86
63b94509	23	#include <asm/cpu_device_id.h>
c4f4b325	24	#endif
63b94509 TL	25	#include <linux/ccp.h>
	26
	27	#include "ccp-dev.h"
	28
530abd89 TL	29	struct ccp_tasklet_data {
	30	struct completion completion;
	31	struct ccp_cmd *cmd;
	32	};
	33
81422bad	34	/* Human-readable error strings */
52393d61	35	#define CCP_MAX_ERROR_CODE 64
ff4f44de	36	static char *ccp_error_codes[] = {
81422bad	37	"",
52393d61 HG	38	"ILLEGAL_ENGINE",
	39	"ILLEGAL_KEY_ID",
	40	"ILLEGAL_FUNCTION_TYPE",
	41	"ILLEGAL_FUNCTION_MODE",
	42	"ILLEGAL_FUNCTION_ENCRYPT",
	43	"ILLEGAL_FUNCTION_SIZE",
	44	"Zlib_MISSING_INIT_EOM",
	45	"ILLEGAL_FUNCTION_RSVD",
	46	"ILLEGAL_BUFFER_LENGTH",
	47	"VLSB_FAULT",
	48	"ILLEGAL_MEM_ADDR",
	49	"ILLEGAL_MEM_SEL",
	50	"ILLEGAL_CONTEXT_ID",
	51	"ILLEGAL_KEY_ADDR",
	52	"0xF Reserved",
	53	"Zlib_ILLEGAL_MULTI_QUEUE",
	54	"Zlib_ILLEGAL_JOBID_CHANGE",
	55	"CMD_TIMEOUT",
	56	"IDMA0_AXI_SLVERR",
	57	"IDMA0_AXI_DECERR",
	58	"0x15 Reserved",
	59	"IDMA1_AXI_SLAVE_FAULT",
	60	"IDMA1_AIXI_DECERR",
	61	"0x18 Reserved",
	62	"ZLIBVHB_AXI_SLVERR",
	63	"ZLIBVHB_AXI_DECERR",
	64	"0x1B Reserved",
	65	"ZLIB_UNEXPECTED_EOM",
	66	"ZLIB_EXTRA_DATA",
	67	"ZLIB_BTYPE",
	68	"ZLIB_UNDEFINED_SYMBOL",
	69	"ZLIB_UNDEFINED_DISTANCE_S",
	70	"ZLIB_CODE_LENGTH_SYMBOL",
	71	"ZLIB _VHB_ILLEGAL_FETCH",
	72	"ZLIB_UNCOMPRESSED_LEN",
	73	"ZLIB_LIMIT_REACHED",
	74	"ZLIB_CHECKSUM_MISMATCH0",
	75	"ODMA0_AXI_SLVERR",
	76	"ODMA0_AXI_DECERR",
	77	"0x28 Reserved",
	78	"ODMA1_AXI_SLVERR",
	79	"ODMA1_AXI_DECERR",
81422bad GH	80	};
81422bad GH	81
52393d61	82	void ccp_log_error(struct ccp_device *d, unsigned int e)
81422bad	83	{
52393d61 HG	84	if (WARN_ON(e >= CCP_MAX_ERROR_CODE))
	85	return;
	86
	87	if (e < ARRAY_SIZE(ccp_error_codes))
	88	dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]);
	89	else
	90	dev_err(d->dev, "CCP error %d: Unknown Error\n", e);
81422bad GH	91	}
81422bad GH	92
553d2374 GH	93	/* List of CCPs, CCP count, read-write access lock, and access functions
	94	*
	95	* Lock structure: get ccp_unit_lock for reading whenever we need to
	96	* examine the CCP list. While holding it for reading we can acquire
	97	* the RR lock to update the round-robin next-CCP pointer. The unit lock
	98	* must be acquired before the RR lock.
	99	*
	100	* If the unit-lock is acquired for writing, we have total control over
	101	* the list, so there's no value in getting the RR lock.
	102	*/
	103	static DEFINE_RWLOCK(ccp_unit_lock);
	104	static LIST_HEAD(ccp_units);
	105
	106	/* Round-robin counter */
03a6f290	107	static DEFINE_SPINLOCK(ccp_rr_lock);
553d2374 GH	108	static struct ccp_device *ccp_rr;
553d2374 GH	109
ea0375af GH	110	/**
	111	* ccp_add_device - add a CCP device to the list
	112	*
	113	* @ccp: ccp_device struct pointer
	114	*
553d2374 GH	115	* Put this CCP on the unit list, which makes it available
553d2374 GH	116	* for use.
ea0375af GH	117	*
ea0375af GH	118	* Returns zero if a CCP device is present, -ENODEV otherwise.
553d2374	119	*/
ea0375af	120	void ccp_add_device(struct ccp_device *ccp)
63b94509	121	{
553d2374 GH	122	unsigned long flags;
	123
	124	write_lock_irqsave(&ccp_unit_lock, flags);
	125	list_add_tail(&ccp->entry, &ccp_units);
	126	if (!ccp_rr)
	127	/* We already have the list lock (we're first) so this
	128	* pointer can't change on us. Set its initial value.
	129	*/
	130	ccp_rr = ccp;
	131	write_unlock_irqrestore(&ccp_unit_lock, flags);
63b94509 TL	132	}
63b94509 TL	133
ea0375af GH	134	/**
	135	* ccp_del_device - remove a CCP device from the list
	136	*
	137	* @ccp: ccp_device struct pointer
	138	*
	139	* Remove this unit from the list of devices. If the next device
553d2374 GH	140	* up for use is this one, adjust the pointer. If this is the last
	141	* device, NULL the pointer.
	142	*/
ea0375af	143	void ccp_del_device(struct ccp_device *ccp)
63b94509	144	{
553d2374 GH	145	unsigned long flags;
	146
	147	write_lock_irqsave(&ccp_unit_lock, flags);
	148	if (ccp_rr == ccp) {
	149	/* ccp_unit_lock is read/write; any read access
	150	* will be suspended while we make changes to the
	151	* list and RR pointer.
	152	*/
	153	if (list_is_last(&ccp_rr->entry, &ccp_units))
	154	ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
	155	entry);
	156	else
	157	ccp_rr = list_next_entry(ccp_rr, entry);
	158	}
	159	list_del(&ccp->entry);
	160	if (list_empty(&ccp_units))
	161	ccp_rr = NULL;
	162	write_unlock_irqrestore(&ccp_unit_lock, flags);
	163	}
	164
084935b2 GH	165
	166
	167	int ccp_register_rng(struct ccp_device *ccp)
	168	{
	169	int ret = 0;
	170
	171	dev_dbg(ccp->dev, "Registering RNG...\n");
	172	/* Register an RNG */
	173	ccp->hwrng.name = ccp->rngname;
	174	ccp->hwrng.read = ccp_trng_read;
	175	ret = hwrng_register(&ccp->hwrng);
	176	if (ret)
	177	dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
	178
	179	return ret;
	180	}
	181
	182	void ccp_unregister_rng(struct ccp_device *ccp)
	183	{
	184	if (ccp->hwrng.name)
	185	hwrng_unregister(&ccp->hwrng);
	186	}
	187
553d2374 GH	188	static struct ccp_device *ccp_get_device(void)
	189	{
	190	unsigned long flags;
	191	struct ccp_device *dp = NULL;
	192
	193	/* We round-robin through the unit list.
	194	* The (ccp_rr) pointer refers to the next unit to use.
	195	*/
	196	read_lock_irqsave(&ccp_unit_lock, flags);
	197	if (!list_empty(&ccp_units)) {
03a6f290	198	spin_lock(&ccp_rr_lock);
553d2374 GH	199	dp = ccp_rr;
	200	if (list_is_last(&ccp_rr->entry, &ccp_units))
	201	ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
	202	entry);
	203	else
	204	ccp_rr = list_next_entry(ccp_rr, entry);
03a6f290	205	spin_unlock(&ccp_rr_lock);
553d2374 GH	206	}
	207	read_unlock_irqrestore(&ccp_unit_lock, flags);
	208
	209	return dp;
63b94509 TL	210	}
63b94509 TL	211
c9f21cb6 TL	212	/**
	213	* ccp_present - check if a CCP device is present
	214	*
	215	* Returns zero if a CCP device is present, -ENODEV otherwise.
	216	*/
	217	int ccp_present(void)
	218	{
553d2374 GH	219	unsigned long flags;
553d2374 GH	220	int ret;
c9f21cb6	221
553d2374 GH	222	read_lock_irqsave(&ccp_unit_lock, flags);
	223	ret = list_empty(&ccp_units);
	224	read_unlock_irqrestore(&ccp_unit_lock, flags);
	225
	226	return ret ? -ENODEV : 0;
c9f21cb6 TL	227	}
	228	EXPORT_SYMBOL_GPL(ccp_present);
	229
c7019c4d GH	230	/**
	231	* ccp_version - get the version of the CCP device
	232	*
	233	* Returns the version from the first unit on the list;
	234	* otherwise a zero if no CCP device is present
	235	*/
	236	unsigned int ccp_version(void)
	237	{
	238	struct ccp_device *dp;
	239	unsigned long flags;
	240	int ret = 0;
	241
	242	read_lock_irqsave(&ccp_unit_lock, flags);
	243	if (!list_empty(&ccp_units)) {
	244	dp = list_first_entry(&ccp_units, struct ccp_device, entry);
	245	ret = dp->vdata->version;
	246	}
	247	read_unlock_irqrestore(&ccp_unit_lock, flags);
	248
	249	return ret;
	250	}
	251	EXPORT_SYMBOL_GPL(ccp_version);
	252
63b94509 TL	253	/**
	254	* ccp_enqueue_cmd - queue an operation for processing by the CCP
	255	*
	256	* @cmd: ccp_cmd struct to be processed
	257	*
	258	* Queue a cmd to be processed by the CCP. If queueing the cmd
	259	* would exceed the defined length of the cmd queue the cmd will
	260	* only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
	261	* result in a return code of -EBUSY.
	262	*
	263	* The callback routine specified in the ccp_cmd struct will be
	264	* called to notify the caller of completion (if the cmd was not
	265	* backlogged) or advancement out of the backlog. If the cmd has
	266	* advanced out of the backlog the "err" value of the callback
	267	* will be -EINPROGRESS. Any other "err" value during callback is
	268	* the result of the operation.
	269	*
	270	* The cmd has been successfully queued if:
	271	* the return code is -EINPROGRESS or
	272	* the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
	273	*/
	274	int ccp_enqueue_cmd(struct ccp_cmd *cmd)
	275	{
7c468447	276	struct ccp_device *ccp;
63b94509 TL	277	unsigned long flags;
	278	unsigned int i;
	279	int ret;
	280
7c468447 GH	281	/* Some commands might need to be sent to a specific device */
	282	ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
	283
63b94509 TL	284	if (!ccp)
	285	return -ENODEV;
	286
	287	/* Caller must supply a callback routine */
	288	if (!cmd->callback)
	289	return -EINVAL;
	290
	291	cmd->ccp = ccp;
	292
	293	spin_lock_irqsave(&ccp->cmd_lock, flags);
	294
	295	i = ccp->cmd_q_count;
	296
	297	if (ccp->cmd_count >= MAX_CMD_QLEN) {
cfba73d2 GBY	298	if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
cfba73d2 GBY	299	ret = -EBUSY;
63b94509	300	list_add_tail(&cmd->entry, &ccp->backlog);
cfba73d2 GBY	301	} else {
	302	ret = -ENOSPC;
	303	}
63b94509 TL	304	} else {
	305	ret = -EINPROGRESS;
	306	ccp->cmd_count++;
	307	list_add_tail(&cmd->entry, &ccp->cmd);
	308
	309	/* Find an idle queue */
	310	if (!ccp->suspending) {
	311	for (i = 0; i < ccp->cmd_q_count; i++) {
	312	if (ccp->cmd_q[i].active)
	313	continue;
	314
	315	break;
	316	}
	317	}
	318	}
	319
	320	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
	321
	322	/* If we found an idle queue, wake it up */
	323	if (i < ccp->cmd_q_count)
	324	wake_up_process(ccp->cmd_q[i].kthread);
	325
	326	return ret;
	327	}
	328	EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
	329
	330	static void ccp_do_cmd_backlog(struct work_struct *work)
	331	{
	332	struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
	333	struct ccp_device *ccp = cmd->ccp;
	334	unsigned long flags;
	335	unsigned int i;
	336
	337	cmd->callback(cmd->data, -EINPROGRESS);
	338
	339	spin_lock_irqsave(&ccp->cmd_lock, flags);
	340
	341	ccp->cmd_count++;
	342	list_add_tail(&cmd->entry, &ccp->cmd);
	343
	344	/* Find an idle queue */
	345	for (i = 0; i < ccp->cmd_q_count; i++) {
	346	if (ccp->cmd_q[i].active)
	347	continue;
	348
	349	break;
	350	}
	351
	352	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
	353
	354	/* If we found an idle queue, wake it up */
	355	if (i < ccp->cmd_q_count)
	356	wake_up_process(ccp->cmd_q[i].kthread);
	357	}
	358
	359	static struct ccp_cmd ccp_dequeue_cmd(struct ccp_cmd_queue cmd_q)
	360	{
	361	struct ccp_device *ccp = cmd_q->ccp;
	362	struct ccp_cmd *cmd = NULL;
	363	struct ccp_cmd *backlog = NULL;
	364	unsigned long flags;
	365
	366	spin_lock_irqsave(&ccp->cmd_lock, flags);
	367
368	cmd_q->active = 0;
369
370	if (ccp->suspending) {
371	cmd_q->suspended = 1;
372
373	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
374	wake_up_interruptible(&ccp->suspend_queue);
375
376	return NULL;
377	}
378
379	if (ccp->cmd_count) {
380	cmd_q->active = 1;
381
382	cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
383	list_del(&cmd->entry);
384
385	ccp->cmd_count--;
386	}
387
388	if (!list_empty(&ccp->backlog)) {
389	backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
390	entry);
391	list_del(&backlog->entry);
392	}
393
394	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
395
396	if (backlog) {
397	INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
398	schedule_work(&backlog->work);
399	}
400
401	return cmd;
402	}
403
530abd89	404	static void ccp_do_cmd_complete(unsigned long data)
63b94509	405	{
530abd89 TL	406	struct ccp_tasklet_data tdata = (struct ccp_tasklet_data )data;
530abd89 TL	407	struct ccp_cmd *cmd = tdata->cmd;
63b94509 TL	408
63b94509 TL	409	cmd->callback(cmd->data, cmd->ret);
77af0ae4	410
530abd89	411	complete(&tdata->completion);
63b94509 TL	412	}
63b94509 TL	413
ea0375af GH	414	/**
	415	* ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
	416	*
	417	* @data: thread-specific data
	418	*/
	419	int ccp_cmd_queue_thread(void *data)
63b94509 TL	420	{
	421	struct ccp_cmd_queue cmd_q = (struct ccp_cmd_queue )data;
	422	struct ccp_cmd *cmd;
530abd89 TL	423	struct ccp_tasklet_data tdata;
	424	struct tasklet_struct tasklet;
	425
	426	tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
63b94509 TL	427
	428	set_current_state(TASK_INTERRUPTIBLE);
	429	while (!kthread_should_stop()) {
	430	schedule();
	431
	432	set_current_state(TASK_INTERRUPTIBLE);
	433
	434	cmd = ccp_dequeue_cmd(cmd_q);
	435	if (!cmd)
	436	continue;
	437
	438	__set_current_state(TASK_RUNNING);
	439
	440	/* Execute the command */
	441	cmd->ret = ccp_run_cmd(cmd_q, cmd);
	442
	443	/* Schedule the completion callback */
530abd89 TL	444	tdata.cmd = cmd;
	445	init_completion(&tdata.completion);
	446	tasklet_schedule(&tasklet);
	447	wait_for_completion(&tdata.completion);
63b94509 TL	448	}
	449
	450	__set_current_state(TASK_RUNNING);
	451
	452	return 0;
	453	}
	454
63b94509 TL	455	/**
	456	* ccp_alloc_struct - allocate and initialize the ccp_device struct
	457	*
	458	* @dev: device struct of the CCP
	459	*/
720419f0	460	struct ccp_device ccp_alloc_struct(struct sp_device sp)
63b94509	461	{
720419f0	462	struct device *dev = sp->dev;
63b94509 TL	463	struct ccp_device *ccp;
63b94509 TL	464
be03a3a0	465	ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
8db88467	466	if (!ccp)
63b94509	467	return NULL;
63b94509	468	ccp->dev = dev;
720419f0 BS	469	ccp->sp = sp;
720419f0 BS	470	ccp->axcache = sp->axcache;
63b94509 TL	471
	472	INIT_LIST_HEAD(&ccp->cmd);
	473	INIT_LIST_HEAD(&ccp->backlog);
	474
	475	spin_lock_init(&ccp->cmd_lock);
	476	mutex_init(&ccp->req_mutex);
956ee21a GH	477	mutex_init(&ccp->sb_mutex);
	478	ccp->sb_count = KSB_COUNT;
	479	ccp->sb_start = 0;
63b94509	480
103600ab GH	481	/* Initialize the wait queues */
	482	init_waitqueue_head(&ccp->sb_queue);
	483	init_waitqueue_head(&ccp->suspend_queue);
	484
720419f0 BS	485	snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
720419f0 BS	486	snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);
553d2374	487
63b94509 TL	488	return ccp;
	489	}
	490
8256e683 GH	491	int ccp_trng_read(struct hwrng rng, void data, size_t max, bool wait)
	492	{
	493	struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
	494	u32 trng_value;
	495	int len = min_t(int, sizeof(trng_value), max);
	496
	497	/* Locking is provided by the caller so we can update device
	498	* hwrng-related fields safely
	499	*/
	500	trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
	501	if (!trng_value) {
	502	/* Zero is returned if not data is available or if a
	503	* bad-entropy error is present. Assume an error if
	504	* we exceed TRNG_RETRIES reads of zero.
	505	*/
	506	if (ccp->hwrng_retries++ > TRNG_RETRIES)
	507	return -EIO;
	508
	509	return 0;
	510	}
	511
	512	/* Reset the counter and save the rng value */
	513	ccp->hwrng_retries = 0;
	514	memcpy(data, &trng_value, len);
	515
	516	return len;
	517	}
	518
63b94509 TL	519	#ifdef CONFIG_PM
	520	bool ccp_queues_suspended(struct ccp_device *ccp)
	521	{
	522	unsigned int suspended = 0;
	523	unsigned long flags;
	524	unsigned int i;
	525
	526	spin_lock_irqsave(&ccp->cmd_lock, flags);
	527
	528	for (i = 0; i < ccp->cmd_q_count; i++)
	529	if (ccp->cmd_q[i].suspended)
	530	suspended++;
	531
	532	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
	533
	534	return ccp->cmd_q_count == suspended;
	535	}
970e8303	536
720419f0	537	int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
970e8303	538	{
720419f0	539	struct ccp_device *ccp = sp->ccp_data;
970e8303 BS	540	unsigned long flags;
	541	unsigned int i;
	542
	543	spin_lock_irqsave(&ccp->cmd_lock, flags);
	544
	545	ccp->suspending = 1;
	546
	547	/* Wake all the queue kthreads to prepare for suspend */
	548	for (i = 0; i < ccp->cmd_q_count; i++)
	549	wake_up_process(ccp->cmd_q[i].kthread);
	550
	551	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
	552
	553	/* Wait for all queue kthreads to say they're done */
	554	while (!ccp_queues_suspended(ccp))
	555	wait_event_interruptible(ccp->suspend_queue,
	556	ccp_queues_suspended(ccp));
	557
	558	return 0;
	559	}
	560
720419f0	561	int ccp_dev_resume(struct sp_device *sp)
970e8303	562	{
720419f0	563	struct ccp_device *ccp = sp->ccp_data;
970e8303 BS	564	unsigned long flags;
	565	unsigned int i;
	566
	567	spin_lock_irqsave(&ccp->cmd_lock, flags);
	568
	569	ccp->suspending = 0;
	570
	571	/* Wake up all the kthreads */
	572	for (i = 0; i < ccp->cmd_q_count; i++) {
	573	ccp->cmd_q[i].suspended = 0;
	574	wake_up_process(ccp->cmd_q[i].kthread);
	575	}
	576
	577	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
	578
	579	return 0;
	580	}
63b94509 TL	581	#endif
63b94509 TL	582
720419f0	583	int ccp_dev_init(struct sp_device *sp)
970e8303	584	{
720419f0 BS	585	struct device *dev = sp->dev;
	586	struct ccp_device *ccp;
	587	int ret;
970e8303	588
720419f0 BS	589	ret = -ENOMEM;
720419f0 BS	590	ccp = ccp_alloc_struct(sp);
970e8303	591	if (!ccp)
720419f0 BS	592	goto e_err;
	593	sp->ccp_data = ccp;
	594
	595	ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
	596	if (!ccp->vdata \|\| !ccp->vdata->version) {
	597	ret = -ENODEV;
	598	dev_err(dev, "missing driver data\n");
	599	goto e_err;
	600	}
970e8303	601
f4d18d65	602	ccp->use_tasklet = sp->use_tasklet;
970e8303	603
720419f0 BS	604	ccp->io_regs = sp->io_map + ccp->vdata->offset;
	605	if (ccp->vdata->setup)
	606	ccp->vdata->setup(ccp);
63b94509	607
720419f0	608	ret = ccp->vdata->perform->init(ccp);
3f19ce20	609	if (ret)
720419f0	610	goto e_err;
db34cf91	611
720419f0	612	dev_notice(dev, "ccp enabled\n");
3f19ce20 GH	613
3f19ce20 GH	614	return 0;
c4f4b325	615
720419f0 BS	616	e_err:
720419f0 BS	617	sp->ccp_data = NULL;
c4f4b325	618
720419f0	619	dev_notice(dev, "ccp initialization failed\n");
63b94509	620
720419f0	621	return ret;
63b94509 TL	622	}
63b94509 TL	623
720419f0	624	void ccp_dev_destroy(struct sp_device *sp)
63b94509	625	{
720419f0	626	struct ccp_device *ccp = sp->ccp_data;
c4f4b325	627
720419f0 BS	628	if (!ccp)
720419f0 BS	629	return;
63b94509	630
720419f0 BS	631	ccp->vdata->perform->destroy(ccp);
720419f0 BS	632	}