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From: Dave Jiang <dave.jiang@intel.com>
To: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	vkoul@kernel.org
Cc: dan.j.williams@intel.com, tony.luck@intel.com,
	jing.lin@intel.com, ashok.raj@intel.com,
	sanjay.k.kumar@intel.com, megha.dey@intel.com,
	jacob.jun.pan@intel.com, yi.l.liu@intel.com, axboe@kernel.dk,
	akpm@linux-foundation.org, tglx@linutronix.de, mingo@redhat.com,
	bp@alien8.de, fenghua.yu@intel.com, hpa@zytor.com
Subject: [PATCH RFC v3 10/14] dmaengine: idxd: add descriptor manipulation routines
Date: Tue, 17 Dec 2019 16:34:00 -0700	[thread overview]
Message-ID: <157662563999.51652.7666173562096628973.stgit@djiang5-desk3.ch.intel.com> (raw)
In-Reply-To: <157662541786.51652.7666763291600764054.stgit@djiang5-desk3.ch.intel.com>

This commit adds helper functions for DSA descriptor allocation, setup,
submission, and free operations.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>

---

idxd_submit_desc() and idxd_alloc_desc() are used in the next patch in the
series.
---
 drivers/dma/idxd/Makefile |    2 -
 drivers/dma/idxd/submit.c |  127 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 128 insertions(+), 1 deletion(-)
 create mode 100644 drivers/dma/idxd/submit.c

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/submit.c b/drivers/dma/idxd/submit.c
new file mode 100644
index 000000000000..2dcd13f9f654
--- /dev/null
+++ b/drivers/dma/idxd/submit.c
@@ -0,0 +1,127 @@
+// 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 <linux/dmaengine.h>
+#include <uapi/linux/idxd.h>
+#include "../dmaengine.h"
+#include "idxd.h"
+#include "registers.h"
+
+static struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, bool nonblock)
+{
+	struct idxd_desc *desc;
+	int idx;
+	struct idxd_device *idxd = wq->idxd;
+
+	if (idxd->state != IDXD_DEV_ENABLED)
+		return ERR_PTR(-EIO);
+
+	if (!nonblock)
+		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 (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);
+}
+
+static int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc,
+			    bool nonblock)
+{
+	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;
+}
+
+static inline void idxd_prep_desc_common(struct idxd_wq *wq,
+					 struct dsa_hw_desc *hw, char opcode,
+					 u64 addr_f1, u64 addr_f2, u64 len,
+					 u64 compl, u32 flags)
+{
+	hw->flags = flags;
+	hw->opcode = opcode;
+	hw->src_addr = addr_f1;
+	hw->dst_addr = addr_f2;
+	hw->xfer_size = len;
+	hw->priv = !!(wq->type == IDXD_WQT_KERNEL);
+	hw->completion_addr = compl;
+
+	/*
+	 * Descriptor completion vectors are 1-8 for MSIX. We will round
+	 * robin through the 8 vectors.
+	 */
+	hw->int_handle = ++wq->vec_ptr;
+	wq->vec_ptr = wq->vec_ptr & 7;
+}
+
+static inline void set_desc_addresses(struct dma_request *req,
+				      u64 *src, u64 *dst)
+{
+		*src = sg_dma_address(&req->sg[0]);
+		*dst = req->pg_dma;
+}
+
+static inline void set_completion_address(struct idxd_desc *desc,
+					  u64 *compl_addr)
+{
+		*compl_addr = desc->compl_dma;
+}


  parent reply	other threads:[~2019-12-17 23:34 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-17 23:32 [PATCH RFC v3 00/14] idxd driver for Intel Data Streaming Accelerator Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 01/14] x86/asm: add iosubmit_cmds512() based on movdir64b CPU instruction Dave Jiang
2020-01-04 14:18   ` Borislav Petkov
2019-12-17 23:33 ` [PATCH RFC v3 02/14] dmaengine: break out channel registration Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 03/14] dmaengine: add new dma device registration Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 04/14] mm: create common code from request allocation based from blk-mq code Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 05/14] dmaengine: add dma_request support functions Dave Jiang
2019-12-27  5:46   ` Vinod Koul
2019-12-17 23:33 ` [PATCH RFC v3 06/14] dmaengine: add dma request submit and completion path support Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 07/14] dmaengine: update dmatest to support dma request Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 08/14] dmaengine: idxd: Init and probe for Intel data accelerators Dave Jiang
2019-12-17 23:33 ` [PATCH RFC v3 09/14] dmaengine: idxd: add configuration component of driver Dave Jiang
2019-12-27  5:50   ` Vinod Koul
2019-12-28 15:20     ` Jiang, Dave
2019-12-17 23:34 ` Dave Jiang [this message]
2019-12-17 23:34 ` [PATCH RFC v3 11/14] dmaengine: idxd: connect idxd to dmaengine subsystem Dave Jiang
2019-12-17 23:34 ` [PATCH RFC v3 12/14] dmaengine: request submit optimization Dave Jiang
2019-12-17 23:34 ` [PATCH RFC v3 13/14] dmaengine: idxd: add char driver to expose submission portal to userland Dave Jiang
2019-12-27  5:58   ` Vinod Koul
2020-01-07 17:45     ` Dave Jiang
2020-01-07 18:17       ` Dave Jiang
2020-01-07 20:18         ` Dave Jiang
2020-01-10  7:59           ` Vinod Koul
2019-12-17 23:34 ` [PATCH RFC v3 14/14] dmaengine: idxd: add sysfs ABI for idxd driver Dave Jiang

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