diff options
Diffstat (limited to 'drivers/crypto/ccp/ccp-dev.c')
-rw-r--r-- | drivers/crypto/ccp/ccp-dev.c | 471 |
1 files changed, 148 insertions, 323 deletions
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c index 861bacc1b..4dbc18727 100644 --- a/drivers/crypto/ccp/ccp-dev.c +++ b/drivers/crypto/ccp/ccp-dev.c @@ -1,7 +1,7 @@ /* * AMD Cryptographic Coprocessor (CCP) driver * - * Copyright (C) 2013 Advanced Micro Devices, Inc. + * Copyright (C) 2013,2016 Advanced Micro Devices, Inc. * * Author: Tom Lendacky <thomas.lendacky@amd.com> * @@ -16,6 +16,8 @@ #include <linux/sched.h> #include <linux/interrupt.h> #include <linux/spinlock.h> +#include <linux/rwlock_types.h> +#include <linux/types.h> #include <linux/mutex.h> #include <linux/delay.h> #include <linux/hw_random.h> @@ -37,20 +39,107 @@ struct ccp_tasklet_data { struct ccp_cmd *cmd; }; -static struct ccp_device *ccp_dev; -static inline struct ccp_device *ccp_get_device(void) +/* 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; + +/* Ever-increasing value to produce unique unit numbers */ +static atomic_t ccp_unit_ordinal; +unsigned int ccp_increment_unit_ordinal(void) { - return ccp_dev; + return atomic_inc_return(&ccp_unit_ordinal); } -static inline void ccp_add_device(struct ccp_device *ccp) +/** + * 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) { - ccp_dev = 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); } -static inline void ccp_del_device(struct ccp_device *ccp) +/** + * 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) { - ccp_dev = NULL; + 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); +} + +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; } /** @@ -60,14 +149,41 @@ static inline void ccp_del_device(struct ccp_device *ccp) */ int ccp_present(void) { - if (ccp_get_device()) - return 0; + unsigned long flags; + int ret; - return -ENODEV; + 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 @@ -221,7 +337,12 @@ static void ccp_do_cmd_complete(unsigned long data) complete(&tdata->completion); } -static int ccp_cmd_queue_thread(void *data) +/** + * 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; @@ -257,35 +378,6 @@ static int ccp_cmd_queue_thread(void *data) 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 * @@ -309,253 +401,11 @@ struct ccp_device *ccp_alloc_struct(struct device *dev) 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; + ccp->ord = ccp_increment_unit_ordinal(); + snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", ccp->ord); + snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", ccp->ord); -#ifdef CONFIG_ARM64 - /* For arm64 set the recommended queue cache settings */ - iowrite32(ccp->axcache, ccp->io_regs + CMD_Q_CACHE_BASE + - (CMD_Q_CACHE_INC * i)); -#endif - - 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; + return ccp; } #ifdef CONFIG_PM @@ -577,41 +427,22 @@ bool ccp_queues_suspended(struct ccp_device *ccp) } #endif -#ifdef CONFIG_X86 -static const struct x86_cpu_id ccp_support[] = { - { X86_VENDOR_AMD, 22, }, - { }, -}; -#endif - static int __init ccp_mod_init(void) { #ifdef CONFIG_X86 - struct cpuinfo_x86 *cpuinfo = &boot_cpu_data; int ret; - if (!x86_match_cpu(ccp_support)) - return -ENODEV; - - switch (cpuinfo->x86) { - case 22: - if ((cpuinfo->x86_model < 48) || (cpuinfo->x86_model > 63)) - return -ENODEV; - - ret = ccp_pci_init(); - if (ret) - return ret; - - /* Don't leave the driver loaded if init failed */ - if (!ccp_get_device()) { - ccp_pci_exit(); - return -ENODEV; - } - - return 0; + ret = ccp_pci_init(); + if (ret) + return ret; - break; + /* Don't leave the driver loaded if init failed */ + if (ccp_present() != 0) { + ccp_pci_exit(); + return -ENODEV; } + + return 0; #endif #ifdef CONFIG_ARM64 @@ -622,7 +453,7 @@ static int __init ccp_mod_init(void) return ret; /* Don't leave the driver loaded if init failed */ - if (!ccp_get_device()) { + if (ccp_present() != 0) { ccp_platform_exit(); return -ENODEV; } @@ -636,13 +467,7 @@ static int __init ccp_mod_init(void) static void __exit ccp_mod_exit(void) { #ifdef CONFIG_X86 - struct cpuinfo_x86 *cpuinfo = &boot_cpu_data; - - switch (cpuinfo->x86) { - case 22: - ccp_pci_exit(); - break; - } + ccp_pci_exit(); #endif #ifdef CONFIG_ARM64 |