1 files changed, 582 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c
new file mode 100644
index 000000000000..de59df970176
--- /dev/null
+++ b/drivers/crypto/ccp/ccp-dev.c
@@ -0,0 +1,582 @@
+/*
+ * AMD Cryptographic Coprocessor (CCP) driver
+ *
+ * Copyright (C) 2013 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/hw_random.h>
+#include <linux/cpu.h>
+#include <asm/cpu_device_id.h>
+#include <linux/ccp.h>
+
+#include "ccp-dev.h"
+
+MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0.0");
+MODULE_DESCRIPTION("AMD Cryptographic Coprocessor driver");
+
+
+static struct ccp_device *ccp_dev;
+static inline struct ccp_device *ccp_get_device(void)
+{
+	return ccp_dev;
+}
+
+static inline void ccp_add_device(struct ccp_device *ccp)
+{
+	ccp_dev = ccp;
+}
+
+static inline void ccp_del_device(struct ccp_device *ccp)
+{
+	ccp_dev = NULL;
+}
+
+/**
+ * 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 = ccp_get_device();
+	unsigned long flags;
+	unsigned int i;
+	int ret;
+
+	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) {
+		ret = -EBUSY;
+		if (cmd->flags & CCP_CMD_MAY_BACKLOG)
+			list_add_tail(&cmd->entry, &ccp->backlog);
+	} 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(struct work_struct *work)
+{
+	struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
+
+	cmd->callback(cmd->data, cmd->ret);
+}
+
+static int ccp_cmd_queue_thread(void *data)
+{
+	struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
+	struct ccp_cmd *cmd;
+
+	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 */
+		INIT_WORK(&cmd->work, ccp_do_cmd_complete);
+		schedule_work(&cmd->work);
+	}
+
+	__set_current_state(TASK_RUNNING);
+
+	return 0;
+}
+
+static 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;
+}
+
+/**
+ * ccp_alloc_struct - allocate and initialize the ccp_device struct
+ *
+ * @dev: device struct of the CCP
+ */
+struct ccp_device *ccp_alloc_struct(struct device *dev)
+{
+	struct ccp_device *ccp;
+
+	ccp = kzalloc(sizeof(*ccp), GFP_KERNEL);
+	if (ccp == NULL) {
+		dev_err(dev, "unable to allocate device struct\n");
+		return NULL;
+	}
+	ccp->dev = dev;
+
+	INIT_LIST_HEAD(&ccp->cmd);
+	INIT_LIST_HEAD(&ccp->backlog);
+
+	spin_lock_init(&ccp->cmd_lock);
+	mutex_init(&ccp->req_mutex);
+	mutex_init(&ccp->ksb_mutex);
+	ccp->ksb_count = KSB_COUNT;
+	ccp->ksb_start = 0;
+
+	return ccp;
+}
+
+/**
+ * ccp_init - initialize the CCP device
+ *
+ * @ccp: ccp_device struct
+ */
+int ccp_init(struct ccp_device *ccp)
+{
+	struct device *dev = ccp->dev;
+	struct ccp_cmd_queue *cmd_q;
+	struct dma_pool *dma_pool;
+	char dma_pool_name[MAX_DMAPOOL_NAME_LEN];
+	unsigned int qmr, qim, i;
+	int ret;
+
+	/* Find available queues */
+	qim = 0;
+	qmr = ioread32(ccp->io_regs + Q_MASK_REG);
+	for (i = 0; i < MAX_HW_QUEUES; i++) {
+		if (!(qmr & (1 << i)))
+			continue;
+
+		/* Allocate a dma pool for this queue */
+		snprintf(dma_pool_name, sizeof(dma_pool_name), "ccp_q%d", i);
+		dma_pool = dma_pool_create(dma_pool_name, dev,
+					   CCP_DMAPOOL_MAX_SIZE,
+					   CCP_DMAPOOL_ALIGN, 0);
+		if (!dma_pool) {
+			dev_err(dev, "unable to allocate dma pool\n");
+			ret = -ENOMEM;
+			goto e_pool;
+		}
+
+		cmd_q = &ccp->cmd_q[ccp->cmd_q_count];
+		ccp->cmd_q_count++;
+
+		cmd_q->ccp = ccp;
+		cmd_q->id = i;
+		cmd_q->dma_pool = dma_pool;
+
+		/* Reserve 2 KSB regions for the queue */
+		cmd_q->ksb_key = KSB_START + ccp->ksb_start++;
+		cmd_q->ksb_ctx = KSB_START + ccp->ksb_start++;
+		ccp->ksb_count -= 2;
+
+		/* Preset some register values and masks that are queue
+		 * number dependent
+		 */
+		cmd_q->reg_status = ccp->io_regs + CMD_Q_STATUS_BASE +
+				    (CMD_Q_STATUS_INCR * i);
+		cmd_q->reg_int_status = ccp->io_regs + CMD_Q_INT_STATUS_BASE +
+					(CMD_Q_STATUS_INCR * i);
+		cmd_q->int_ok = 1 << (i * 2);
+		cmd_q->int_err = 1 << ((i * 2) + 1);
+
+		cmd_q->free_slots = CMD_Q_DEPTH(ioread32(cmd_q->reg_status));
+
+		init_waitqueue_head(&cmd_q->int_queue);
+
+		/* Build queue interrupt mask (two interrupts per queue) */
+		qim |= cmd_q->int_ok | cmd_q->int_err;
+
+		dev_dbg(dev, "queue #%u available\n", i);
+	}
+	if (ccp->cmd_q_count == 0) {
+		dev_notice(dev, "no command queues available\n");
+		ret = -EIO;
+		goto e_pool;
+	}
+	dev_notice(dev, "%u command queues available\n", ccp->cmd_q_count);
+
+	/* Disable and clear interrupts until ready */
+	iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		cmd_q = &ccp->cmd_q[i];
+
+		ioread32(cmd_q->reg_int_status);
+		ioread32(cmd_q->reg_status);
+	}
+	iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
+
+	/* Request an irq */
+	ret = ccp->get_irq(ccp);
+	if (ret) {
+		dev_err(dev, "unable to allocate an IRQ\n");
+		goto e_pool;
+	}
+
+	/* Initialize the queues used to wait for KSB space and suspend */
+	init_waitqueue_head(&ccp->ksb_queue);
+	init_waitqueue_head(&ccp->suspend_queue);
+
+	/* Create a kthread for each queue */
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		struct task_struct *kthread;
+
+		cmd_q = &ccp->cmd_q[i];
+
+		kthread = kthread_create(ccp_cmd_queue_thread, cmd_q,
+					 "ccp-q%u", cmd_q->id);
+		if (IS_ERR(kthread)) {
+			dev_err(dev, "error creating queue thread (%ld)\n",
+				PTR_ERR(kthread));
+			ret = PTR_ERR(kthread);
+			goto e_kthread;
+		}
+
+		cmd_q->kthread = kthread;
+		wake_up_process(kthread);
+	}
+
+	/* Register the RNG */
+	ccp->hwrng.name = "ccp-rng";
+	ccp->hwrng.read = ccp_trng_read;
+	ret = hwrng_register(&ccp->hwrng);
+	if (ret) {
+		dev_err(dev, "error registering hwrng (%d)\n", ret);
+		goto e_kthread;
+	}
+
+	/* Make the device struct available before enabling interrupts */
+	ccp_add_device(ccp);
+
+	/* Enable interrupts */
+	iowrite32(qim, ccp->io_regs + IRQ_MASK_REG);
+
+	return 0;
+
+e_kthread:
+	for (i = 0; i < ccp->cmd_q_count; i++)
+		if (ccp->cmd_q[i].kthread)
+			kthread_stop(ccp->cmd_q[i].kthread);
+
+	ccp->free_irq(ccp);
+
+e_pool:
+	for (i = 0; i < ccp->cmd_q_count; i++)
+		dma_pool_destroy(ccp->cmd_q[i].dma_pool);
+
+	return ret;
+}
+
+/**
+ * ccp_destroy - tear down the CCP device
+ *
+ * @ccp: ccp_device struct
+ */
+void ccp_destroy(struct ccp_device *ccp)
+{
+	struct ccp_cmd_queue *cmd_q;
+	struct ccp_cmd *cmd;
+	unsigned int qim, i;
+
+	/* Remove general access to the device struct */
+	ccp_del_device(ccp);
+
+	/* Unregister the RNG */
+	hwrng_unregister(&ccp->hwrng);
+
+	/* Stop the queue kthreads */
+	for (i = 0; i < ccp->cmd_q_count; i++)
+		if (ccp->cmd_q[i].kthread)
+			kthread_stop(ccp->cmd_q[i].kthread);
+
+	/* Build queue interrupt mask (two interrupt masks per queue) */
+	qim = 0;
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		cmd_q = &ccp->cmd_q[i];
+		qim |= cmd_q->int_ok | cmd_q->int_err;
+	}
+
+	/* Disable and clear interrupts */
+	iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		cmd_q = &ccp->cmd_q[i];
+
+		ioread32(cmd_q->reg_int_status);
+		ioread32(cmd_q->reg_status);
+	}
+	iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
+
+	ccp->free_irq(ccp);
+
+	for (i = 0; i < ccp->cmd_q_count; i++)
+		dma_pool_destroy(ccp->cmd_q[i].dma_pool);
+
+	/* Flush the cmd and backlog queue */
+	while (!list_empty(&ccp->cmd)) {
+		/* Invoke the callback directly with an error code */
+		cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
+		list_del(&cmd->entry);
+		cmd->callback(cmd->data, -ENODEV);
+	}
+	while (!list_empty(&ccp->backlog)) {
+		/* Invoke the callback directly with an error code */
+		cmd = list_first_entry(&ccp->backlog, struct ccp_cmd, entry);
+		list_del(&cmd->entry);
+		cmd->callback(cmd->data, -ENODEV);
+	}
+}
+
+/**
+ * ccp_irq_handler - handle interrupts generated by the CCP device
+ *
+ * @irq: the irq associated with the interrupt
+ * @data: the data value supplied when the irq was created
+ */
+irqreturn_t ccp_irq_handler(int irq, void *data)
+{
+	struct device *dev = data;
+	struct ccp_device *ccp = dev_get_drvdata(dev);
+	struct ccp_cmd_queue *cmd_q;
+	u32 q_int, status;
+	unsigned int i;
+
+	status = ioread32(ccp->io_regs + IRQ_STATUS_REG);
+
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		cmd_q = &ccp->cmd_q[i];
+
+		q_int = status & (cmd_q->int_ok | cmd_q->int_err);
+		if (q_int) {
+			cmd_q->int_status = status;
+			cmd_q->q_status = ioread32(cmd_q->reg_status);
+			cmd_q->q_int_status = ioread32(cmd_q->reg_int_status);
+
+			/* On error, only save the first error value */
+			if ((q_int & cmd_q->int_err) && !cmd_q->cmd_error)
+				cmd_q->cmd_error = CMD_Q_ERROR(cmd_q->q_status);
+
+			cmd_q->int_rcvd = 1;
+
+			/* Acknowledge the interrupt and wake the kthread */
+			iowrite32(q_int, ccp->io_regs + IRQ_STATUS_REG);
+			wake_up_interruptible(&cmd_q->int_queue);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+#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;
+}
+#endif
+
+static const struct x86_cpu_id ccp_support[] = {
+	{ X86_VENDOR_AMD, 22, },
+};
+
+static int __init ccp_mod_init(void)
+{
+	struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
+
+	if (!x86_match_cpu(ccp_support))
+		return -ENODEV;
+
+	switch (cpuinfo->x86) {
+	case 22:
+		if ((cpuinfo->x86_model < 48) || (cpuinfo->x86_model > 63))
+			return -ENODEV;
+		return ccp_pci_init();
+		break;
+	};
+
+	return -ENODEV;
+}
+
+static void __exit ccp_mod_exit(void)
+{
+	struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
+
+	switch (cpuinfo->x86) {
+	case 22:
+		ccp_pci_exit();
+		break;
+	};
+}
+
+module_init(ccp_mod_init);
+module_exit(ccp_mod_exit);