diff --git a/Documentation/ABI/stable/sysfs-driver-dma-ioatdma b/Documentation/ABI/stable/sysfs-driver-dma-ioatdma new file mode 100644 index 000000000000..420c1d09e42f --- /dev/null +++ b/Documentation/ABI/stable/sysfs-driver-dma-ioatdma @@ -0,0 +1,30 @@ +What: sys/devices/pciXXXX:XX/0000:XX:XX.X/dma/dmachan/quickdata/cap +Date: December 3, 2009 +KernelVersion: 2.6.32 +Contact: dmaengine@vger.kernel.org +Description: Capabilities the DMA supports.Currently there are DMA_PQ, DMA_PQ_VAL, + DMA_XOR,DMA_XOR_VAL,DMA_INTERRUPT. + +What: sys/devices/pciXXXX:XX/0000:XX:XX.X/dma/dmachan/quickdata/ring_active +Date: December 3, 2009 +KernelVersion: 2.6.32 +Contact: dmaengine@vger.kernel.org +Description: The number of descriptors active in the ring. + +What: sys/devices/pciXXXX:XX/0000:XX:XX.X/dma/dmachan/quickdata/ring_size +Date: December 3, 2009 +KernelVersion: 2.6.32 +Contact: dmaengine@vger.kernel.org +Description: Descriptor ring size, total number of descriptors available. + +What: sys/devices/pciXXXX:XX/0000:XX:XX.X/dma/dmachan/quickdata/version +Date: December 3, 2009 +KernelVersion: 2.6.32 +Contact: dmaengine@vger.kernel.org +Description: Version of ioatdma device. + +What: sys/devices/pciXXXX:XX/0000:XX:XX.X/dma/dmachan/quickdata/intr_coalesce +Date: August 8, 2017 +KernelVersion: 4.14 +Contact: dmaengine@vger.kernel.org +Description: Tune-able interrupt delay value per channel basis. diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c index a371b07a0981..f70cc74032ea 100644 --- a/drivers/dma/ioat/dma.c +++ b/drivers/dma/ioat/dma.c @@ -644,9 +644,13 @@ static void __cleanup(struct ioatdma_chan *ioat_chan, dma_addr_t phys_complete) mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT); } - /* 5 microsecond delay per pending descriptor */ - writew(min((5 * (active - i)), IOAT_INTRDELAY_MASK), - ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET); + /* microsecond delay by sysfs variable per pending descriptor */ + if (ioat_chan->intr_coalesce != ioat_chan->prev_intr_coalesce) { + writew(min((ioat_chan->intr_coalesce * (active - i)), + IOAT_INTRDELAY_MASK), + ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET); + ioat_chan->prev_intr_coalesce = ioat_chan->intr_coalesce; + } } static void ioat_cleanup(struct ioatdma_chan *ioat_chan) diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h index a9bc1a15b0d1..56200eefcf5e 100644 --- a/drivers/dma/ioat/dma.h +++ b/drivers/dma/ioat/dma.h @@ -142,11 +142,14 @@ struct ioatdma_chan { spinlock_t prep_lock; struct ioat_descs descs[2]; int desc_chunks; + int intr_coalesce; + int prev_intr_coalesce; }; struct ioat_sysfs_entry { struct attribute attr; ssize_t (*show)(struct dma_chan *, char *); + ssize_t (*store)(struct dma_chan *, const char *, size_t); }; /** diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c index ed8ed1192775..93e006c3441d 100644 --- a/drivers/dma/ioat/init.c +++ b/drivers/dma/ioat/init.c @@ -39,7 +39,7 @@ MODULE_VERSION(IOAT_DMA_VERSION); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Intel Corporation"); -static struct pci_device_id ioat_pci_tbl[] = { +static const struct pci_device_id ioat_pci_tbl[] = { /* I/OAT v3 platforms */ { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_IOAT_TBG0) }, { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_IOAT_TBG1) }, diff --git a/drivers/dma/ioat/sysfs.c b/drivers/dma/ioat/sysfs.c index cb4a857ee21b..3ac677f29e8f 100644 --- a/drivers/dma/ioat/sysfs.c +++ b/drivers/dma/ioat/sysfs.c @@ -64,8 +64,24 @@ ioat_attr_show(struct kobject *kobj, struct attribute *attr, char *page) return entry->show(&ioat_chan->dma_chan, page); } +static ssize_t +ioat_attr_store(struct kobject *kobj, struct attribute *attr, +const char *page, size_t count) +{ + struct ioat_sysfs_entry *entry; + struct ioatdma_chan *ioat_chan; + + entry = container_of(attr, struct ioat_sysfs_entry, attr); + ioat_chan = container_of(kobj, struct ioatdma_chan, kobj); + + if (!entry->store) + return -EIO; + return entry->store(&ioat_chan->dma_chan, page, count); +} + const struct sysfs_ops ioat_sysfs_ops = { .show = ioat_attr_show, + .store = ioat_attr_store, }; void ioat_kobject_add(struct ioatdma_device *ioat_dma, struct kobj_type *type) @@ -121,11 +137,37 @@ static ssize_t ring_active_show(struct dma_chan *c, char *page) } static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active); +static ssize_t intr_coalesce_show(struct dma_chan *c, char *page) +{ + struct ioatdma_chan *ioat_chan = to_ioat_chan(c); + + return sprintf(page, "%d\n", ioat_chan->intr_coalesce); +} + +static ssize_t intr_coalesce_store(struct dma_chan *c, const char *page, +size_t count) +{ + int intr_coalesce = 0; + struct ioatdma_chan *ioat_chan = to_ioat_chan(c); + + if (sscanf(page, "%du", &intr_coalesce) != -1) { + if ((intr_coalesce < 0) || + (intr_coalesce > IOAT_INTRDELAY_MASK)) + return -EINVAL; + ioat_chan->intr_coalesce = intr_coalesce; + } + + return count; +} + +static struct ioat_sysfs_entry intr_coalesce_attr = __ATTR_RW(intr_coalesce); + static struct attribute *ioat_attrs[] = { &ring_size_attr.attr, &ring_active_attr.attr, &ioat_cap_attr.attr, &ioat_version_attr.attr, + &intr_coalesce_attr.attr, NULL, };