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authorGary R Hook <gary.hook@amd.com>2016-03-01 13:49:04 -0600
committerHerbert Xu <herbert@gondor.apana.org.au>2016-03-11 21:19:07 +0800
commit553d2374db0bb3f48bbd29bef7ba2a4d1a3f325d (patch)
tree1a32958d7359b5e46f7e7f613ac180e88eb8a0df /drivers/crypto/ccp/ccp-dev.c
parent3f19ce2054541a6c663c8a5fcf52e7baa1c6c5f5 (diff)
downloadlinux-553d2374db0bb3f48bbd29bef7ba2a4d1a3f325d.tar.gz
crypto: ccp - Support for multiple CCPs
Enable management of >1 CCPs in a system. Each device will get a unique identifier, as well as uniquely named resources. Treat each CCP as an orthogonal unit and register resources individually. Signed-off-by: Gary R Hook <gary.hook@amd.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/ccp/ccp-dev.c')
-rw-r--r--drivers/crypto/ccp/ccp-dev.c113
1 files changed, 100 insertions, 13 deletions
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c
index 725c59016a36..dd71e673a109 100644
--- a/drivers/crypto/ccp/ccp-dev.c
+++ b/drivers/crypto/ccp/ccp-dev.c
@@ -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 +39,96 @@ 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_RWLOCK(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);
}
+/*
+ * Put this CCP on the unit list, which makes it available
+ * for use.
+ */
static inline 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);
}
+/* 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.
+ */
static inline 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)) {
+ write_lock_irqsave(&ccp_rr_lock, flags);
+ 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);
+ write_unlock_irqrestore(&ccp_rr_lock, flags);
+ }
+ read_unlock_irqrestore(&ccp_unit_lock, flags);
+
+ return dp;
}
/**
@@ -60,10 +138,14 @@ 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);
@@ -309,6 +391,10 @@ struct ccp_device *ccp_alloc_struct(struct device *dev)
ccp->ksb_count = KSB_COUNT;
ccp->ksb_start = 0;
+ 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);
+
return ccp;
}
@@ -334,7 +420,8 @@ int ccp_init(struct ccp_device *ccp)
continue;
/* Allocate a dma pool for this queue */
- snprintf(dma_pool_name, sizeof(dma_pool_name), "ccp_q%d", i);
+ snprintf(dma_pool_name, sizeof(dma_pool_name), "%s_q%d",
+ ccp->name, i);
dma_pool = dma_pool_create(dma_pool_name, dev,
CCP_DMAPOOL_MAX_SIZE,
CCP_DMAPOOL_ALIGN, 0);
@@ -416,7 +503,7 @@ int ccp_init(struct ccp_device *ccp)
cmd_q = &ccp->cmd_q[i];
kthread = kthread_create(ccp_cmd_queue_thread, cmd_q,
- "ccp-q%u", cmd_q->id);
+ "%s-q%u", ccp->name, cmd_q->id);
if (IS_ERR(kthread)) {
dev_err(dev, "error creating queue thread (%ld)\n",
PTR_ERR(kthread));
@@ -429,7 +516,7 @@ int ccp_init(struct ccp_device *ccp)
}
/* Register the RNG */
- ccp->hwrng.name = "ccp-rng";
+ ccp->hwrng.name = ccp->rngname;
ccp->hwrng.read = ccp_trng_read;
ret = hwrng_register(&ccp->hwrng);
if (ret) {
@@ -587,7 +674,7 @@ 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_pci_exit();
return -ENODEV;
}
@@ -603,7 +690,7 @@ 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;
}