From d7aad5550eca50370e3a1471b46281d03af0699e Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 28 Aug 2020 15:12:10 -0700 Subject: [PATCH] dmaengine: idxd: add support for configurable max wq xfer size Add sysfs attribute max_xfer_size to wq in order to allow the max xfer size configured on a per wq basis. Add support code to configure the valid user input on wq enable. This is a performance tuning parameter. Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/159865265404.29141.3049399618578194052.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul --- Documentation/ABI/stable/sysfs-driver-dma-idxd | 7 +++++ drivers/dma/idxd/device.c | 2 +- drivers/dma/idxd/idxd.h | 1 + drivers/dma/idxd/init.c | 1 + drivers/dma/idxd/sysfs.c | 40 ++++++++++++++++++++++++++ 5 files changed, 50 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd index 1af9c41..452f353 100644 --- a/Documentation/ABI/stable/sysfs-driver-dma-idxd +++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd @@ -170,6 +170,13 @@ Contact: dmaengine@vger.kernel.org Description: The number of entries in this work queue that may be filled via a limited portal. +What: /sys/bus/dsa/devices/wq./max_transfer_size +Date: Aug 28, 2020 +KernelVersion: 5.10.0 +Contact: dmaengine@vger.kernel.org +Description: The max transfer sized for this workqueue. Cannot exceed device + max transfer size. Configurable parameter. + What: /sys/bus/dsa/devices/engine./group_id Date: Oct 25, 2019 KernelVersion: 5.6.0 diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c index 14b4585..b8dbb70 100644 --- a/drivers/dma/idxd/device.c +++ b/drivers/dma/idxd/device.c @@ -529,7 +529,7 @@ static int idxd_wq_config_write(struct idxd_wq *wq) wq->wqcfg.priority = wq->priority; /* bytes 12-15 */ - wq->wqcfg.max_xfer_shift = idxd->hw.gen_cap.max_xfer_shift; + wq->wqcfg.max_xfer_shift = ilog2(wq->max_xfer_bytes); wq->wqcfg.max_batch_shift = idxd->hw.gen_cap.max_batch_shift; dev_dbg(dev, "WQ %d CFGs\n", wq->id); diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index e62b479..81db2a4 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -114,6 +114,7 @@ struct idxd_wq { struct sbitmap_queue sbq; struct dma_chan dma_chan; char name[WQ_NAME_SIZE + 1]; + u64 max_xfer_bytes; }; struct idxd_engine { diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index c7c6197..e5ed575 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -176,6 +176,7 @@ static int idxd_setup_internals(struct idxd_device *idxd) wq->idxd = idxd; mutex_init(&wq->wq_lock); wq->idxd_cdev.minor = -1; + wq->max_xfer_bytes = idxd->max_xfer_bytes; } for (i = 0; i < idxd->max_engines; i++) { diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index dcba609..a3bac72 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1064,6 +1064,45 @@ static ssize_t wq_cdev_minor_show(struct device *dev, static struct device_attribute dev_attr_wq_cdev_minor = __ATTR(cdev_minor, 0444, wq_cdev_minor_show, NULL); +static ssize_t wq_max_transfer_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev); + + return sprintf(buf, "%llu\n", wq->max_xfer_bytes); +} + +static ssize_t wq_max_transfer_size_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev); + struct idxd_device *idxd = wq->idxd; + u64 xfer_size; + int rc; + + if (wq->state != IDXD_WQ_DISABLED) + return -EPERM; + + rc = kstrtou64(buf, 0, &xfer_size); + if (rc < 0) + return -EINVAL; + + if (xfer_size == 0) + return -EINVAL; + + xfer_size = roundup_pow_of_two(xfer_size); + if (xfer_size > idxd->max_xfer_bytes) + return -EINVAL; + + wq->max_xfer_bytes = xfer_size; + + return count; +} + +static struct device_attribute dev_attr_wq_max_transfer_size = + __ATTR(max_transfer_size, 0644, + wq_max_transfer_size_show, wq_max_transfer_size_store); + static struct attribute *idxd_wq_attributes[] = { &dev_attr_wq_clients.attr, &dev_attr_wq_state.attr, @@ -1074,6 +1113,7 @@ static struct attribute *idxd_wq_attributes[] = { &dev_attr_wq_type.attr, &dev_attr_wq_name.attr, &dev_attr_wq_cdev_minor.attr, + &dev_attr_wq_max_transfer_size.attr, NULL, }; -- 2.7.4