crypto: ccp - CCP device driver and interface support
These routines provide the device driver support for the AMD
Cryptographic Coprocessor (CCP).
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c
new file mode 100644
index 0000000..de59df9
--- /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);