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authorDave Jiang <dave.jiang@intel.com>2020-01-22 02:44:17 +0300
committerVinod Koul <vkoul@kernel.org>2020-01-24 08:48:45 +0300
commitd1dfe5b8ac644a0ffccfe7af22abed7c80b34702 (patch)
treed617491597045d9cda8dad3ed4c20a2b1f53cb02 /drivers/dma
parentb131ad593884cb3decc4950f807af2faffc05a3c (diff)
downloadlinux-d1dfe5b8ac644a0ffccfe7af22abed7c80b34702.tar.xz
dmaengine: idxd: add descriptor manipulation routines
This commit adds helper functions for DSA descriptor allocation, submission, and free operations. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/157965025757.73301.12692876585357550065.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/idxd/Makefile2
-rw-r--r--drivers/dma/idxd/idxd.h10
-rw-r--r--drivers/dma/idxd/submit.c91
3 files changed, 102 insertions, 1 deletions
diff --git a/drivers/dma/idxd/Makefile b/drivers/dma/idxd/Makefile
index a552560a03dc..50eca12015e2 100644
--- a/drivers/dma/idxd/Makefile
+++ b/drivers/dma/idxd/Makefile
@@ -1,2 +1,2 @@
obj-$(CONFIG_INTEL_IDXD) += idxd.o
-idxd-y := init.o irq.o device.o sysfs.o
+idxd-y := init.o irq.o device.o sysfs.o submit.o
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 909926aefd3e..d369b75468e3 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -68,6 +68,11 @@ enum idxd_wq_type {
#define WQ_NAME_SIZE 1024
#define WQ_TYPE_SIZE 10
+enum idxd_op_type {
+ IDXD_OP_BLOCK = 0,
+ IDXD_OP_NONBLOCK = 1,
+};
+
struct idxd_wq {
void __iomem *dportal;
struct device conf_dev;
@@ -246,4 +251,9 @@ int idxd_wq_disable(struct idxd_wq *wq);
int idxd_wq_map_portal(struct idxd_wq *wq);
void idxd_wq_unmap_portal(struct idxd_wq *wq);
+/* submission */
+int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc);
+struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype);
+void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc);
+
#endif
diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
new file mode 100644
index 000000000000..a405f06990e3
--- /dev/null
+++ b/drivers/dma/idxd/submit.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <uapi/linux/idxd.h>
+#include "idxd.h"
+#include "registers.h"
+
+struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
+{
+ struct idxd_desc *desc;
+ int idx;
+ struct idxd_device *idxd = wq->idxd;
+
+ if (idxd->state != IDXD_DEV_ENABLED)
+ return ERR_PTR(-EIO);
+
+ if (optype == IDXD_OP_BLOCK)
+ percpu_down_read(&wq->submit_lock);
+ else if (!percpu_down_read_trylock(&wq->submit_lock))
+ return ERR_PTR(-EBUSY);
+
+ if (!atomic_add_unless(&wq->dq_count, 1, wq->size)) {
+ int rc;
+
+ if (optype == IDXD_OP_NONBLOCK) {
+ percpu_up_read(&wq->submit_lock);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ percpu_up_read(&wq->submit_lock);
+ percpu_down_write(&wq->submit_lock);
+ rc = wait_event_interruptible(wq->submit_waitq,
+ atomic_add_unless(&wq->dq_count,
+ 1, wq->size) ||
+ idxd->state != IDXD_DEV_ENABLED);
+ percpu_up_write(&wq->submit_lock);
+ if (rc < 0)
+ return ERR_PTR(-EINTR);
+ if (idxd->state != IDXD_DEV_ENABLED)
+ return ERR_PTR(-EIO);
+ } else {
+ percpu_up_read(&wq->submit_lock);
+ }
+
+ idx = sbitmap_get(&wq->sbmap, 0, false);
+ if (idx < 0) {
+ atomic_dec(&wq->dq_count);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ desc = wq->descs[idx];
+ memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
+ memset(desc->completion, 0, sizeof(struct dsa_completion_record));
+ return desc;
+}
+
+void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
+{
+ atomic_dec(&wq->dq_count);
+
+ sbitmap_clear_bit(&wq->sbmap, desc->id);
+ wake_up(&wq->submit_waitq);
+}
+
+int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
+{
+ struct idxd_device *idxd = wq->idxd;
+ int vec = desc->hw->int_handle;
+
+ if (idxd->state != IDXD_DEV_ENABLED)
+ return -EIO;
+
+ /*
+ * The wmb() flushes writes to coherent DMA data before possibly
+ * triggering a DMA read. The wmb() is necessary even on UP because
+ * the recipient is a device.
+ */
+ wmb();
+ iosubmit_cmds512(wq->dportal, desc->hw, 1);
+
+ /*
+ * Pending the descriptor to the lockless list for the irq_entry
+ * that we designated the descriptor to.
+ */
+ llist_add(&desc->llnode, &idxd->irq_entries[vec].pending_llist);
+
+ return 0;
+}