diff options
Diffstat (limited to 'drivers/dma/ioat_dma.c')
| -rw-r--r-- | drivers/dma/ioat_dma.c | 267 |
1 files changed, 262 insertions, 5 deletions
diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c index 171cad6..da57296 100644 --- a/drivers/dma/ioat_dma.c +++ b/drivers/dma/ioat_dma.c @@ -32,6 +32,7 @@ #include <linux/dmaengine.h> #include <linux/delay.h> #include <linux/dma-mapping.h> +#include <linux/workqueue.h> #include "ioatdma.h" #include "ioatdma_registers.h" #include "ioatdma_hw.h" @@ -41,11 +42,17 @@ #define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node) #define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, async_tx) +#define chan_num(ch) ((int)((ch)->reg_base - (ch)->device->reg_base) / 0x80) static int ioat_pending_level = 4; module_param(ioat_pending_level, int, 0644); MODULE_PARM_DESC(ioat_pending_level, "high-water mark for pushing ioat descriptors (default: 4)"); +#define RESET_DELAY msecs_to_jiffies(100) +#define WATCHDOG_DELAY round_jiffies(msecs_to_jiffies(2000)) +static void ioat_dma_chan_reset_part2(struct work_struct *work); +static void ioat_dma_chan_watchdog(struct work_struct *work); + /* internal functions */ static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan); static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan); @@ -137,6 +144,7 @@ static int ioat_dma_enumerate_channels(struct ioatdma_device *device) ioat_chan->reg_base = device->reg_base + (0x80 * (i + 1)); ioat_chan->xfercap = xfercap; ioat_chan->desccount = 0; + INIT_DELAYED_WORK(&ioat_chan->work, ioat_dma_chan_reset_part2); if (ioat_chan->device->version != IOAT_VER_1_2) { writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE | IOAT_DMA_DCA_ANY_CPU, @@ -175,7 +183,7 @@ static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); - if (ioat_chan->pending != 0) { + if (ioat_chan->pending > 0) { spin_lock_bh(&ioat_chan->desc_lock); __ioat1_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); @@ -194,13 +202,228 @@ static void ioat2_dma_memcpy_issue_pending(struct dma_chan *chan) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); - if (ioat_chan->pending != 0) { + if (ioat_chan->pending > 0) { spin_lock_bh(&ioat_chan->desc_lock); __ioat2_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); } } + +/** + * ioat_dma_chan_reset_part2 - reinit the channel after a reset + */ +static void ioat_dma_chan_reset_part2(struct work_struct *work) +{ + struct ioat_dma_chan *ioat_chan = + container_of(work, struct ioat_dma_chan, work.work); + struct ioat_desc_sw *desc; + + spin_lock_bh(&ioat_chan->cleanup_lock); + spin_lock_bh(&ioat_chan->desc_lock); + + ioat_chan->completion_virt->low = 0; + ioat_chan->completion_virt->high = 0; + ioat_chan->pending = 0; + + /* + * count the descriptors waiting, and be sure to do it + * right for both the CB1 line and the CB2 ring + */ + ioat_chan->dmacount = 0; + if (ioat_chan->used_desc.prev) { + desc = to_ioat_desc(ioat_chan->used_desc.prev); + do { + ioat_chan->dmacount++; + desc = to_ioat_desc(desc->node.next); + } while (&desc->node != ioat_chan->used_desc.next); + } + + /* + * write the new starting descriptor address + * this puts channel engine into ARMED state + */ + desc = to_ioat_desc(ioat_chan->used_desc.prev); + switch (ioat_chan->device->version) { + case IOAT_VER_1_2: + writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF, + ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW); + writel(((u64) desc->async_tx.phys) >> 32, + ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH); + + writeb(IOAT_CHANCMD_START, ioat_chan->reg_base + + IOAT_CHANCMD_OFFSET(ioat_chan->device->version)); + break; + case IOAT_VER_2_0: + writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF, + ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW); + writel(((u64) desc->async_tx.phys) >> 32, + ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH); + + /* tell the engine to go with what's left to be done */ + writew(ioat_chan->dmacount, + ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET); + + break; + } + dev_err(&ioat_chan->device->pdev->dev, + "chan%d reset - %d descs waiting, %d total desc\n", + chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount); + + spin_unlock_bh(&ioat_chan->desc_lock); + spin_unlock_bh(&ioat_chan->cleanup_lock); +} + +/** + * ioat_dma_reset_channel - restart a channel + * @ioat_chan: IOAT DMA channel handle + */ +static void ioat_dma_reset_channel(struct ioat_dma_chan *ioat_chan) +{ + u32 chansts, chanerr; + + if (!ioat_chan->used_desc.prev) + return; + + chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET); + chansts = (ioat_chan->completion_virt->low + & IOAT_CHANSTS_DMA_TRANSFER_STATUS); + if (chanerr) { + dev_err(&ioat_chan->device->pdev->dev, + "chan%d, CHANSTS = 0x%08x CHANERR = 0x%04x, clearing\n", + chan_num(ioat_chan), chansts, chanerr); + writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET); + } + + /* + * whack it upside the head with a reset + * and wait for things to settle out. + * force the pending count to a really big negative + * to make sure no one forces an issue_pending + * while we're waiting. + */ + + spin_lock_bh(&ioat_chan->desc_lock); + ioat_chan->pending = INT_MIN; + writeb(IOAT_CHANCMD_RESET, + ioat_chan->reg_base + + IOAT_CHANCMD_OFFSET(ioat_chan->device->version)); + spin_unlock_bh(&ioat_chan->desc_lock); + + /* schedule the 2nd half instead of sleeping a long time */ + schedule_delayed_work(&ioat_chan->work, RESET_DELAY); +} + +/** + * ioat_dma_chan_watchdog - watch for stuck channels + */ +static void ioat_dma_chan_watchdog(struct work_struct *work) +{ + struct ioatdma_device *device = + container_of(work, struct ioatdma_device, work.work); + struct ioat_dma_chan *ioat_chan; + int i; + + union { + u64 full; + struct { + u32 low; + u32 high; + }; + } completion_hw; + unsigned long compl_desc_addr_hw; + + for (i = 0; i < device->common.chancnt; i++) { + ioat_chan = ioat_lookup_chan_by_index(device, i); + + if (ioat_chan->device->version == IOAT_VER_1_2 + /* have we started processing anything yet */ + && ioat_chan->last_completion + /* have we completed any since last watchdog cycle? */ + && (ioat_chan->last_completion == + ioat_chan->watchdog_completion) + /* has TCP stuck on one cookie since last watchdog? */ + && (ioat_chan->watchdog_tcp_cookie == + ioat_chan->watchdog_last_tcp_cookie) + && (ioat_chan->watchdog_tcp_cookie != + ioat_chan->completed_cookie) + /* is there something in the chain to be processed? */ + /* CB1 chain always has at least the last one processed */ + && (ioat_chan->used_desc.prev != ioat_chan->used_desc.next) + && ioat_chan->pending == 0) { + + /* + * check CHANSTS register for completed + * descriptor address. + * if it is different than completion writeback, + * it is not zero + * and it has changed since the last watchdog + * we can assume that channel + * is still working correctly + * and the problem is in completion writeback. + * update completion writeback + * with actual CHANSTS value + * else + * try resetting the channel + */ + + completion_hw.low = readl(ioat_chan->reg_base + + IOAT_CHANSTS_OFFSET_LOW(ioat_chan->device->version)); + completion_hw.high = readl(ioat_chan->reg_base + + IOAT_CHANSTS_OFFSET_HIGH(ioat_chan->device->version)); +#if (BITS_PER_LONG == 64) + compl_desc_addr_hw = + completion_hw.full + & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR; +#else + compl_desc_addr_hw = + completion_hw.low & IOAT_LOW_COMPLETION_MASK; +#endif + + if ((compl_desc_addr_hw != 0) + && (compl_desc_addr_hw != ioat_chan->watchdog_completion) + && (compl_desc_addr_hw != ioat_chan->last_compl_desc_addr_hw)) { + ioat_chan->last_compl_desc_addr_hw = compl_desc_addr_hw; + ioat_chan->completion_virt->low = completion_hw.low; + ioat_chan->completion_virt->high = completion_hw.high; + } else { + ioat_dma_reset_channel(ioat_chan); + ioat_chan->watchdog_completion = 0; + ioat_chan->last_compl_desc_addr_hw = 0; + } + + /* + * for version 2.0 if there are descriptors yet to be processed + * and the last completed hasn't changed since the last watchdog + * if they haven't hit the pending level + * issue the pending to push them through + * else + * try resetting the channel + */ + } else if (ioat_chan->device->version == IOAT_VER_2_0 + && ioat_chan->used_desc.prev + && ioat_chan->last_completion + && ioat_chan->last_completion == ioat_chan->watchdog_completion) { + + if (ioat_chan->pending < ioat_pending_level) + ioat2_dma_memcpy_issue_pending(&ioat_chan->common); + else { + ioat_dma_reset_channel(ioat_chan); + ioat_chan->watchdog_completion = 0; + } + } else { + ioat_chan->last_compl_desc_addr_hw = 0; + ioat_chan->watchdog_completion + = ioat_chan->last_completion; + } + + ioat_chan->watchdog_last_tcp_cookie = + ioat_chan->watchdog_tcp_cookie; + } + + schedule_delayed_work(&device->work, WATCHDOG_DELAY); +} + static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan); @@ -586,6 +809,10 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan) ioat_chan->last_completion = ioat_chan->completion_addr = 0; ioat_chan->pending = 0; ioat_chan->dmacount = 0; + ioat_chan->watchdog_completion = 0; + ioat_chan->last_compl_desc_addr_hw = 0; + ioat_chan->watchdog_tcp_cookie = + ioat_chan->watchdog_last_tcp_cookie = 0; } /** @@ -717,8 +944,12 @@ static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy( new->src = dma_src; new->async_tx.flags = flags; return &new->async_tx; - } else + } else { + dev_err(&ioat_chan->device->pdev->dev, + "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n", + chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount); return NULL; + } } static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy( @@ -745,8 +976,13 @@ static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy( new->src = dma_src; new->async_tx.flags = flags; return &new->async_tx; - } else + } else { + spin_unlock_bh(&ioat_chan->desc_lock); + dev_err(&ioat_chan->device->pdev->dev, + "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n", + chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount); return NULL; + } } static void ioat_dma_cleanup_tasklet(unsigned long data) @@ -821,11 +1057,25 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan) if (phys_complete == ioat_chan->last_completion) { spin_unlock_bh(&ioat_chan->cleanup_lock); + /* + * perhaps we're stuck so hard that the watchdog can't go off? + * try to catch it after 2 seconds + */ + if (time_after(jiffies, + ioat_chan->last_completion_time + HZ*WATCHDOG_DELAY)) { + ioat_dma_chan_watchdog(&(ioat_chan->device->work.work)); + ioat_chan->last_completion_time = jiffies; + } return; } + ioat_chan->last_completion_time = jiffies; cookie = 0; - spin_lock_bh(&ioat_chan->desc_lock); + if (!spin_trylock_bh(&ioat_chan->desc_lock)) { + spin_unlock_bh(&ioat_chan->cleanup_lock); + return; + } + switch (ioat_chan->device->version) { case IOAT_VER_1_2: list_for_each_entry_safe(desc, _desc, @@ -942,6 +1192,7 @@ static enum dma_status ioat_dma_is_complete(struct dma_chan *chan, last_used = chan->cookie; last_complete = ioat_chan->completed_cookie; + ioat_chan->watchdog_tcp_cookie = cookie; if (done) *done = last_complete; @@ -1332,6 +1583,10 @@ struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev, dma_async_device_register(&device->common); + INIT_DELAYED_WORK(&device->work, ioat_dma_chan_watchdog); + schedule_delayed_work(&device->work, + WATCHDOG_DELAY); + return device; err_self_test: @@ -1364,6 +1619,8 @@ void ioat_dma_remove(struct ioatdma_device *device) pci_release_regions(device->pdev); pci_disable_device(device->pdev); + cancel_delayed_work(&device->work); + list_for_each_entry_safe(chan, _chan, &device->common.channels, device_node) { ioat_chan = to_ioat_chan(chan); |