summaryrefslogtreecommitdiff
path: root/drivers/dma/ioat/dma_v2.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/dma/ioat/dma_v2.c
Initial import
Diffstat (limited to 'drivers/dma/ioat/dma_v2.c')
-rw-r--r--drivers/dma/ioat/dma_v2.c916
1 files changed, 916 insertions, 0 deletions
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
new file mode 100644
index 000000000..69c7dfcad
--- /dev/null
+++ b/drivers/dma/ioat/dma_v2.c
@@ -0,0 +1,916 @@
+/*
+ * Intel I/OAT DMA Linux driver
+ * Copyright(c) 2004 - 2009 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ */
+
+/*
+ * This driver supports an Intel I/OAT DMA engine (versions >= 2), which
+ * does asynchronous data movement and checksumming operations.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/workqueue.h>
+#include <linux/prefetch.h>
+#include <linux/i7300_idle.h>
+#include "dma.h"
+#include "dma_v2.h"
+#include "registers.h"
+#include "hw.h"
+
+#include "../dmaengine.h"
+
+int ioat_ring_alloc_order = 8;
+module_param(ioat_ring_alloc_order, int, 0644);
+MODULE_PARM_DESC(ioat_ring_alloc_order,
+ "ioat2+: allocate 2^n descriptors per channel"
+ " (default: 8 max: 16)");
+static int ioat_ring_max_alloc_order = IOAT_MAX_ORDER;
+module_param(ioat_ring_max_alloc_order, int, 0644);
+MODULE_PARM_DESC(ioat_ring_max_alloc_order,
+ "ioat2+: upper limit for ring size (default: 16)");
+
+void __ioat2_issue_pending(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+
+ ioat->dmacount += ioat2_ring_pending(ioat);
+ ioat->issued = ioat->head;
+ writew(ioat->dmacount, chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
+ dev_dbg(to_dev(chan),
+ "%s: head: %#x tail: %#x issued: %#x count: %#x\n",
+ __func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
+}
+
+void ioat2_issue_pending(struct dma_chan *c)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+
+ if (ioat2_ring_pending(ioat)) {
+ spin_lock_bh(&ioat->prep_lock);
+ __ioat2_issue_pending(ioat);
+ spin_unlock_bh(&ioat->prep_lock);
+ }
+}
+
+/**
+ * ioat2_update_pending - log pending descriptors
+ * @ioat: ioat2+ channel
+ *
+ * Check if the number of unsubmitted descriptors has exceeded the
+ * watermark. Called with prep_lock held
+ */
+static void ioat2_update_pending(struct ioat2_dma_chan *ioat)
+{
+ if (ioat2_ring_pending(ioat) > ioat_pending_level)
+ __ioat2_issue_pending(ioat);
+}
+
+static void __ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_ring_ent *desc;
+ struct ioat_dma_descriptor *hw;
+
+ if (ioat2_ring_space(ioat) < 1) {
+ dev_err(to_dev(&ioat->base),
+ "Unable to start null desc - ring full\n");
+ return;
+ }
+
+ dev_dbg(to_dev(&ioat->base), "%s: head: %#x tail: %#x issued: %#x\n",
+ __func__, ioat->head, ioat->tail, ioat->issued);
+ desc = ioat2_get_ring_ent(ioat, ioat->head);
+
+ hw = desc->hw;
+ hw->ctl = 0;
+ hw->ctl_f.null = 1;
+ hw->ctl_f.int_en = 1;
+ hw->ctl_f.compl_write = 1;
+ /* set size to non-zero value (channel returns error when size is 0) */
+ hw->size = NULL_DESC_BUFFER_SIZE;
+ hw->src_addr = 0;
+ hw->dst_addr = 0;
+ async_tx_ack(&desc->txd);
+ ioat2_set_chainaddr(ioat, desc->txd.phys);
+ dump_desc_dbg(ioat, desc);
+ wmb();
+ ioat->head += 1;
+ __ioat2_issue_pending(ioat);
+}
+
+static void ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
+{
+ spin_lock_bh(&ioat->prep_lock);
+ __ioat2_start_null_desc(ioat);
+ spin_unlock_bh(&ioat->prep_lock);
+}
+
+static void __cleanup(struct ioat2_dma_chan *ioat, dma_addr_t phys_complete)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+ struct dma_async_tx_descriptor *tx;
+ struct ioat_ring_ent *desc;
+ bool seen_current = false;
+ u16 active;
+ int idx = ioat->tail, i;
+
+ dev_dbg(to_dev(chan), "%s: head: %#x tail: %#x issued: %#x\n",
+ __func__, ioat->head, ioat->tail, ioat->issued);
+
+ active = ioat2_ring_active(ioat);
+ for (i = 0; i < active && !seen_current; i++) {
+ smp_read_barrier_depends();
+ prefetch(ioat2_get_ring_ent(ioat, idx + i + 1));
+ desc = ioat2_get_ring_ent(ioat, idx + i);
+ tx = &desc->txd;
+ dump_desc_dbg(ioat, desc);
+ if (tx->cookie) {
+ dma_descriptor_unmap(tx);
+ dma_cookie_complete(tx);
+ if (tx->callback) {
+ tx->callback(tx->callback_param);
+ tx->callback = NULL;
+ }
+ }
+
+ if (tx->phys == phys_complete)
+ seen_current = true;
+ }
+ smp_mb(); /* finish all descriptor reads before incrementing tail */
+ ioat->tail = idx + i;
+ BUG_ON(active && !seen_current); /* no active descs have written a completion? */
+
+ chan->last_completion = phys_complete;
+ if (active - i == 0) {
+ dev_dbg(to_dev(chan), "%s: cancel completion timeout\n",
+ __func__);
+ clear_bit(IOAT_COMPLETION_PENDING, &chan->state);
+ mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
+ }
+}
+
+/**
+ * ioat2_cleanup - clean finished descriptors (advance tail pointer)
+ * @chan: ioat channel to be cleaned up
+ */
+static void ioat2_cleanup(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+ dma_addr_t phys_complete;
+
+ spin_lock_bh(&chan->cleanup_lock);
+ if (ioat_cleanup_preamble(chan, &phys_complete))
+ __cleanup(ioat, phys_complete);
+ spin_unlock_bh(&chan->cleanup_lock);
+}
+
+void ioat2_cleanup_event(unsigned long data)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
+ struct ioat_chan_common *chan = &ioat->base;
+
+ ioat2_cleanup(ioat);
+ if (!test_bit(IOAT_RUN, &chan->state))
+ return;
+ writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
+}
+
+void __ioat2_restart_chan(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+
+ /* set the tail to be re-issued */
+ ioat->issued = ioat->tail;
+ ioat->dmacount = 0;
+ set_bit(IOAT_COMPLETION_PENDING, &chan->state);
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+ dev_dbg(to_dev(chan),
+ "%s: head: %#x tail: %#x issued: %#x count: %#x\n",
+ __func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
+
+ if (ioat2_ring_pending(ioat)) {
+ struct ioat_ring_ent *desc;
+
+ desc = ioat2_get_ring_ent(ioat, ioat->tail);
+ ioat2_set_chainaddr(ioat, desc->txd.phys);
+ __ioat2_issue_pending(ioat);
+ } else
+ __ioat2_start_null_desc(ioat);
+}
+
+int ioat2_quiesce(struct ioat_chan_common *chan, unsigned long tmo)
+{
+ unsigned long end = jiffies + tmo;
+ int err = 0;
+ u32 status;
+
+ status = ioat_chansts(chan);
+ if (is_ioat_active(status) || is_ioat_idle(status))
+ ioat_suspend(chan);
+ while (is_ioat_active(status) || is_ioat_idle(status)) {
+ if (tmo && time_after(jiffies, end)) {
+ err = -ETIMEDOUT;
+ break;
+ }
+ status = ioat_chansts(chan);
+ cpu_relax();
+ }
+
+ return err;
+}
+
+int ioat2_reset_sync(struct ioat_chan_common *chan, unsigned long tmo)
+{
+ unsigned long end = jiffies + tmo;
+ int err = 0;
+
+ ioat_reset(chan);
+ while (ioat_reset_pending(chan)) {
+ if (end && time_after(jiffies, end)) {
+ err = -ETIMEDOUT;
+ break;
+ }
+ cpu_relax();
+ }
+
+ return err;
+}
+
+static void ioat2_restart_channel(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+ dma_addr_t phys_complete;
+
+ ioat2_quiesce(chan, 0);
+ if (ioat_cleanup_preamble(chan, &phys_complete))
+ __cleanup(ioat, phys_complete);
+
+ __ioat2_restart_chan(ioat);
+}
+
+static void check_active(struct ioat2_dma_chan *ioat)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+
+ if (ioat2_ring_active(ioat)) {
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+ return;
+ }
+
+ if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &chan->state))
+ mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
+ else if (ioat->alloc_order > ioat_get_alloc_order()) {
+ /* if the ring is idle, empty, and oversized try to step
+ * down the size
+ */
+ reshape_ring(ioat, ioat->alloc_order - 1);
+
+ /* keep shrinking until we get back to our minimum
+ * default size
+ */
+ if (ioat->alloc_order > ioat_get_alloc_order())
+ mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
+ }
+
+}
+
+void ioat2_timer_event(unsigned long data)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
+ struct ioat_chan_common *chan = &ioat->base;
+ dma_addr_t phys_complete;
+ u64 status;
+
+ status = ioat_chansts(chan);
+
+ /* when halted due to errors check for channel
+ * programming errors before advancing the completion state
+ */
+ if (is_ioat_halted(status)) {
+ u32 chanerr;
+
+ chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+ dev_err(to_dev(chan), "%s: Channel halted (%x)\n",
+ __func__, chanerr);
+ if (test_bit(IOAT_RUN, &chan->state))
+ BUG_ON(is_ioat_bug(chanerr));
+ else /* we never got off the ground */
+ return;
+ }
+
+ /* if we haven't made progress and we have already
+ * acknowledged a pending completion once, then be more
+ * forceful with a restart
+ */
+ spin_lock_bh(&chan->cleanup_lock);
+ if (ioat_cleanup_preamble(chan, &phys_complete))
+ __cleanup(ioat, phys_complete);
+ else if (test_bit(IOAT_COMPLETION_ACK, &chan->state)) {
+ spin_lock_bh(&ioat->prep_lock);
+ ioat2_restart_channel(ioat);
+ spin_unlock_bh(&ioat->prep_lock);
+ spin_unlock_bh(&chan->cleanup_lock);
+ return;
+ } else {
+ set_bit(IOAT_COMPLETION_ACK, &chan->state);
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+ }
+
+
+ if (ioat2_ring_active(ioat))
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+ else {
+ spin_lock_bh(&ioat->prep_lock);
+ check_active(ioat);
+ spin_unlock_bh(&ioat->prep_lock);
+ }
+ spin_unlock_bh(&chan->cleanup_lock);
+}
+
+static int ioat2_reset_hw(struct ioat_chan_common *chan)
+{
+ /* throw away whatever the channel was doing and get it initialized */
+ u32 chanerr;
+
+ ioat2_quiesce(chan, msecs_to_jiffies(100));
+
+ chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+ writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET);
+
+ return ioat2_reset_sync(chan, msecs_to_jiffies(200));
+}
+
+/**
+ * ioat2_enumerate_channels - find and initialize the device's channels
+ * @device: the device to be enumerated
+ */
+int ioat2_enumerate_channels(struct ioatdma_device *device)
+{
+ struct ioat2_dma_chan *ioat;
+ struct device *dev = &device->pdev->dev;
+ struct dma_device *dma = &device->common;
+ u8 xfercap_log;
+ int i;
+
+ INIT_LIST_HEAD(&dma->channels);
+ dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
+ dma->chancnt &= 0x1f; /* bits [4:0] valid */
+ if (dma->chancnt > ARRAY_SIZE(device->idx)) {
+ dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
+ dma->chancnt, ARRAY_SIZE(device->idx));
+ dma->chancnt = ARRAY_SIZE(device->idx);
+ }
+ xfercap_log = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
+ xfercap_log &= 0x1f; /* bits [4:0] valid */
+ if (xfercap_log == 0)
+ return 0;
+ dev_dbg(dev, "%s: xfercap = %d\n", __func__, 1 << xfercap_log);
+
+ /* FIXME which i/oat version is i7300? */
+#ifdef CONFIG_I7300_IDLE_IOAT_CHANNEL
+ if (i7300_idle_platform_probe(NULL, NULL, 1) == 0)
+ dma->chancnt--;
+#endif
+ for (i = 0; i < dma->chancnt; i++) {
+ ioat = devm_kzalloc(dev, sizeof(*ioat), GFP_KERNEL);
+ if (!ioat)
+ break;
+
+ ioat_init_channel(device, &ioat->base, i);
+ ioat->xfercap_log = xfercap_log;
+ spin_lock_init(&ioat->prep_lock);
+ if (device->reset_hw(&ioat->base)) {
+ i = 0;
+ break;
+ }
+ }
+ dma->chancnt = i;
+ return i;
+}
+
+static dma_cookie_t ioat2_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
+{
+ struct dma_chan *c = tx->chan;
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+ struct ioat_chan_common *chan = &ioat->base;
+ dma_cookie_t cookie;
+
+ cookie = dma_cookie_assign(tx);
+ dev_dbg(to_dev(&ioat->base), "%s: cookie: %d\n", __func__, cookie);
+
+ if (!test_and_set_bit(IOAT_CHAN_ACTIVE, &chan->state))
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+ /* make descriptor updates visible before advancing ioat->head,
+ * this is purposefully not smp_wmb() since we are also
+ * publishing the descriptor updates to a dma device
+ */
+ wmb();
+
+ ioat->head += ioat->produce;
+
+ ioat2_update_pending(ioat);
+ spin_unlock_bh(&ioat->prep_lock);
+
+ return cookie;
+}
+
+static struct ioat_ring_ent *ioat2_alloc_ring_ent(struct dma_chan *chan, gfp_t flags)
+{
+ struct ioat_dma_descriptor *hw;
+ struct ioat_ring_ent *desc;
+ struct ioatdma_device *dma;
+ dma_addr_t phys;
+
+ dma = to_ioatdma_device(chan->device);
+ hw = pci_pool_alloc(dma->dma_pool, flags, &phys);
+ if (!hw)
+ return NULL;
+ memset(hw, 0, sizeof(*hw));
+
+ desc = kmem_cache_zalloc(ioat2_cache, flags);
+ if (!desc) {
+ pci_pool_free(dma->dma_pool, hw, phys);
+ return NULL;
+ }
+
+ dma_async_tx_descriptor_init(&desc->txd, chan);
+ desc->txd.tx_submit = ioat2_tx_submit_unlock;
+ desc->hw = hw;
+ desc->txd.phys = phys;
+ return desc;
+}
+
+static void ioat2_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
+{
+ struct ioatdma_device *dma;
+
+ dma = to_ioatdma_device(chan->device);
+ pci_pool_free(dma->dma_pool, desc->hw, desc->txd.phys);
+ kmem_cache_free(ioat2_cache, desc);
+}
+
+static struct ioat_ring_ent **ioat2_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
+{
+ struct ioat_ring_ent **ring;
+ int descs = 1 << order;
+ int i;
+
+ if (order > ioat_get_max_alloc_order())
+ return NULL;
+
+ /* allocate the array to hold the software ring */
+ ring = kcalloc(descs, sizeof(*ring), flags);
+ if (!ring)
+ return NULL;
+ for (i = 0; i < descs; i++) {
+ ring[i] = ioat2_alloc_ring_ent(c, flags);
+ if (!ring[i]) {
+ while (i--)
+ ioat2_free_ring_ent(ring[i], c);
+ kfree(ring);
+ return NULL;
+ }
+ set_desc_id(ring[i], i);
+ }
+
+ /* link descs */
+ for (i = 0; i < descs-1; i++) {
+ struct ioat_ring_ent *next = ring[i+1];
+ struct ioat_dma_descriptor *hw = ring[i]->hw;
+
+ hw->next = next->txd.phys;
+ }
+ ring[i]->hw->next = ring[0]->txd.phys;
+
+ return ring;
+}
+
+void ioat2_free_chan_resources(struct dma_chan *c);
+
+/* ioat2_alloc_chan_resources - allocate/initialize ioat2 descriptor ring
+ * @chan: channel to be initialized
+ */
+int ioat2_alloc_chan_resources(struct dma_chan *c)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+ struct ioat_chan_common *chan = &ioat->base;
+ struct ioat_ring_ent **ring;
+ u64 status;
+ int order;
+ int i = 0;
+
+ /* have we already been set up? */
+ if (ioat->ring)
+ return 1 << ioat->alloc_order;
+
+ /* Setup register to interrupt and write completion status on error */
+ writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
+
+ /* allocate a completion writeback area */
+ /* doing 2 32bit writes to mmio since 1 64b write doesn't work */
+ chan->completion = pci_pool_alloc(chan->device->completion_pool,
+ GFP_KERNEL, &chan->completion_dma);
+ if (!chan->completion)
+ return -ENOMEM;
+
+ memset(chan->completion, 0, sizeof(*chan->completion));
+ writel(((u64) chan->completion_dma) & 0x00000000FFFFFFFF,
+ chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
+ writel(((u64) chan->completion_dma) >> 32,
+ chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
+
+ order = ioat_get_alloc_order();
+ ring = ioat2_alloc_ring(c, order, GFP_KERNEL);
+ if (!ring)
+ return -ENOMEM;
+
+ spin_lock_bh(&chan->cleanup_lock);
+ spin_lock_bh(&ioat->prep_lock);
+ ioat->ring = ring;
+ ioat->head = 0;
+ ioat->issued = 0;
+ ioat->tail = 0;
+ ioat->alloc_order = order;
+ set_bit(IOAT_RUN, &chan->state);
+ spin_unlock_bh(&ioat->prep_lock);
+ spin_unlock_bh(&chan->cleanup_lock);
+
+ ioat2_start_null_desc(ioat);
+
+ /* check that we got off the ground */
+ do {
+ udelay(1);
+ status = ioat_chansts(chan);
+ } while (i++ < 20 && !is_ioat_active(status) && !is_ioat_idle(status));
+
+ if (is_ioat_active(status) || is_ioat_idle(status)) {
+ return 1 << ioat->alloc_order;
+ } else {
+ u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+
+ dev_WARN(to_dev(chan),
+ "failed to start channel chanerr: %#x\n", chanerr);
+ ioat2_free_chan_resources(c);
+ return -EFAULT;
+ }
+}
+
+bool reshape_ring(struct ioat2_dma_chan *ioat, int order)
+{
+ /* reshape differs from normal ring allocation in that we want
+ * to allocate a new software ring while only
+ * extending/truncating the hardware ring
+ */
+ struct ioat_chan_common *chan = &ioat->base;
+ struct dma_chan *c = &chan->common;
+ const u32 curr_size = ioat2_ring_size(ioat);
+ const u16 active = ioat2_ring_active(ioat);
+ const u32 new_size = 1 << order;
+ struct ioat_ring_ent **ring;
+ u16 i;
+
+ if (order > ioat_get_max_alloc_order())
+ return false;
+
+ /* double check that we have at least 1 free descriptor */
+ if (active == curr_size)
+ return false;
+
+ /* when shrinking, verify that we can hold the current active
+ * set in the new ring
+ */
+ if (active >= new_size)
+ return false;
+
+ /* allocate the array to hold the software ring */
+ ring = kcalloc(new_size, sizeof(*ring), GFP_NOWAIT);
+ if (!ring)
+ return false;
+
+ /* allocate/trim descriptors as needed */
+ if (new_size > curr_size) {
+ /* copy current descriptors to the new ring */
+ for (i = 0; i < curr_size; i++) {
+ u16 curr_idx = (ioat->tail+i) & (curr_size-1);
+ u16 new_idx = (ioat->tail+i) & (new_size-1);
+
+ ring[new_idx] = ioat->ring[curr_idx];
+ set_desc_id(ring[new_idx], new_idx);
+ }
+
+ /* add new descriptors to the ring */
+ for (i = curr_size; i < new_size; i++) {
+ u16 new_idx = (ioat->tail+i) & (new_size-1);
+
+ ring[new_idx] = ioat2_alloc_ring_ent(c, GFP_NOWAIT);
+ if (!ring[new_idx]) {
+ while (i--) {
+ u16 new_idx = (ioat->tail+i) & (new_size-1);
+
+ ioat2_free_ring_ent(ring[new_idx], c);
+ }
+ kfree(ring);
+ return false;
+ }
+ set_desc_id(ring[new_idx], new_idx);
+ }
+
+ /* hw link new descriptors */
+ for (i = curr_size-1; i < new_size; i++) {
+ u16 new_idx = (ioat->tail+i) & (new_size-1);
+ struct ioat_ring_ent *next = ring[(new_idx+1) & (new_size-1)];
+ struct ioat_dma_descriptor *hw = ring[new_idx]->hw;
+
+ hw->next = next->txd.phys;
+ }
+ } else {
+ struct ioat_dma_descriptor *hw;
+ struct ioat_ring_ent *next;
+
+ /* copy current descriptors to the new ring, dropping the
+ * removed descriptors
+ */
+ for (i = 0; i < new_size; i++) {
+ u16 curr_idx = (ioat->tail+i) & (curr_size-1);
+ u16 new_idx = (ioat->tail+i) & (new_size-1);
+
+ ring[new_idx] = ioat->ring[curr_idx];
+ set_desc_id(ring[new_idx], new_idx);
+ }
+
+ /* free deleted descriptors */
+ for (i = new_size; i < curr_size; i++) {
+ struct ioat_ring_ent *ent;
+
+ ent = ioat2_get_ring_ent(ioat, ioat->tail+i);
+ ioat2_free_ring_ent(ent, c);
+ }
+
+ /* fix up hardware ring */
+ hw = ring[(ioat->tail+new_size-1) & (new_size-1)]->hw;
+ next = ring[(ioat->tail+new_size) & (new_size-1)];
+ hw->next = next->txd.phys;
+ }
+
+ dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
+ __func__, new_size);
+
+ kfree(ioat->ring);
+ ioat->ring = ring;
+ ioat->alloc_order = order;
+
+ return true;
+}
+
+/**
+ * ioat2_check_space_lock - verify space and grab ring producer lock
+ * @ioat: ioat2,3 channel (ring) to operate on
+ * @num_descs: allocation length
+ */
+int ioat2_check_space_lock(struct ioat2_dma_chan *ioat, int num_descs)
+{
+ struct ioat_chan_common *chan = &ioat->base;
+ bool retry;
+
+ retry:
+ spin_lock_bh(&ioat->prep_lock);
+ /* never allow the last descriptor to be consumed, we need at
+ * least one free at all times to allow for on-the-fly ring
+ * resizing.
+ */
+ if (likely(ioat2_ring_space(ioat) > num_descs)) {
+ dev_dbg(to_dev(chan), "%s: num_descs: %d (%x:%x:%x)\n",
+ __func__, num_descs, ioat->head, ioat->tail, ioat->issued);
+ ioat->produce = num_descs;
+ return 0; /* with ioat->prep_lock held */
+ }
+ retry = test_and_set_bit(IOAT_RESHAPE_PENDING, &chan->state);
+ spin_unlock_bh(&ioat->prep_lock);
+
+ /* is another cpu already trying to expand the ring? */
+ if (retry)
+ goto retry;
+
+ spin_lock_bh(&chan->cleanup_lock);
+ spin_lock_bh(&ioat->prep_lock);
+ retry = reshape_ring(ioat, ioat->alloc_order + 1);
+ clear_bit(IOAT_RESHAPE_PENDING, &chan->state);
+ spin_unlock_bh(&ioat->prep_lock);
+ spin_unlock_bh(&chan->cleanup_lock);
+
+ /* if we were able to expand the ring retry the allocation */
+ if (retry)
+ goto retry;
+
+ if (printk_ratelimit())
+ dev_dbg(to_dev(chan), "%s: ring full! num_descs: %d (%x:%x:%x)\n",
+ __func__, num_descs, ioat->head, ioat->tail, ioat->issued);
+
+ /* progress reclaim in the allocation failure case we may be
+ * called under bh_disabled so we need to trigger the timer
+ * event directly
+ */
+ if (time_is_before_jiffies(chan->timer.expires)
+ && timer_pending(&chan->timer)) {
+ struct ioatdma_device *device = chan->device;
+
+ mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+ device->timer_fn((unsigned long) &chan->common);
+ }
+
+ return -ENOMEM;
+}
+
+struct dma_async_tx_descriptor *
+ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
+ dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+ struct ioat_dma_descriptor *hw;
+ struct ioat_ring_ent *desc;
+ dma_addr_t dst = dma_dest;
+ dma_addr_t src = dma_src;
+ size_t total_len = len;
+ int num_descs, idx, i;
+
+ num_descs = ioat2_xferlen_to_descs(ioat, len);
+ if (likely(num_descs) && ioat2_check_space_lock(ioat, num_descs) == 0)
+ idx = ioat->head;
+ else
+ return NULL;
+ i = 0;
+ do {
+ size_t copy = min_t(size_t, len, 1 << ioat->xfercap_log);
+
+ desc = ioat2_get_ring_ent(ioat, idx + i);
+ hw = desc->hw;
+
+ hw->size = copy;
+ hw->ctl = 0;
+ hw->src_addr = src;
+ hw->dst_addr = dst;
+
+ len -= copy;
+ dst += copy;
+ src += copy;
+ dump_desc_dbg(ioat, desc);
+ } while (++i < num_descs);
+
+ desc->txd.flags = flags;
+ desc->len = total_len;
+ hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+ hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+ hw->ctl_f.compl_write = 1;
+ dump_desc_dbg(ioat, desc);
+ /* we leave the channel locked to ensure in order submission */
+
+ return &desc->txd;
+}
+
+/**
+ * ioat2_free_chan_resources - release all the descriptors
+ * @chan: the channel to be cleaned
+ */
+void ioat2_free_chan_resources(struct dma_chan *c)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+ struct ioat_chan_common *chan = &ioat->base;
+ struct ioatdma_device *device = chan->device;
+ struct ioat_ring_ent *desc;
+ const u16 total_descs = 1 << ioat->alloc_order;
+ int descs;
+ int i;
+
+ /* Before freeing channel resources first check
+ * if they have been previously allocated for this channel.
+ */
+ if (!ioat->ring)
+ return;
+
+ ioat_stop(chan);
+ device->reset_hw(chan);
+
+ spin_lock_bh(&chan->cleanup_lock);
+ spin_lock_bh(&ioat->prep_lock);
+ descs = ioat2_ring_space(ioat);
+ dev_dbg(to_dev(chan), "freeing %d idle descriptors\n", descs);
+ for (i = 0; i < descs; i++) {
+ desc = ioat2_get_ring_ent(ioat, ioat->head + i);
+ ioat2_free_ring_ent(desc, c);
+ }
+
+ if (descs < total_descs)
+ dev_err(to_dev(chan), "Freeing %d in use descriptors!\n",
+ total_descs - descs);
+
+ for (i = 0; i < total_descs - descs; i++) {
+ desc = ioat2_get_ring_ent(ioat, ioat->tail + i);
+ dump_desc_dbg(ioat, desc);
+ ioat2_free_ring_ent(desc, c);
+ }
+
+ kfree(ioat->ring);
+ ioat->ring = NULL;
+ ioat->alloc_order = 0;
+ pci_pool_free(device->completion_pool, chan->completion,
+ chan->completion_dma);
+ spin_unlock_bh(&ioat->prep_lock);
+ spin_unlock_bh(&chan->cleanup_lock);
+
+ chan->last_completion = 0;
+ chan->completion_dma = 0;
+ ioat->dmacount = 0;
+}
+
+static ssize_t ring_size_show(struct dma_chan *c, char *page)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+
+ return sprintf(page, "%d\n", (1 << ioat->alloc_order) & ~1);
+}
+static struct ioat_sysfs_entry ring_size_attr = __ATTR_RO(ring_size);
+
+static ssize_t ring_active_show(struct dma_chan *c, char *page)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+
+ /* ...taken outside the lock, no need to be precise */
+ return sprintf(page, "%d\n", ioat2_ring_active(ioat));
+}
+static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active);
+
+static struct attribute *ioat2_attrs[] = {
+ &ring_size_attr.attr,
+ &ring_active_attr.attr,
+ &ioat_cap_attr.attr,
+ &ioat_version_attr.attr,
+ NULL,
+};
+
+struct kobj_type ioat2_ktype = {
+ .sysfs_ops = &ioat_sysfs_ops,
+ .default_attrs = ioat2_attrs,
+};
+
+int ioat2_dma_probe(struct ioatdma_device *device, int dca)
+{
+ struct pci_dev *pdev = device->pdev;
+ struct dma_device *dma;
+ struct dma_chan *c;
+ struct ioat_chan_common *chan;
+ int err;
+
+ device->enumerate_channels = ioat2_enumerate_channels;
+ device->reset_hw = ioat2_reset_hw;
+ device->cleanup_fn = ioat2_cleanup_event;
+ device->timer_fn = ioat2_timer_event;
+ device->self_test = ioat_dma_self_test;
+ dma = &device->common;
+ dma->device_prep_dma_memcpy = ioat2_dma_prep_memcpy_lock;
+ dma->device_issue_pending = ioat2_issue_pending;
+ dma->device_alloc_chan_resources = ioat2_alloc_chan_resources;
+ dma->device_free_chan_resources = ioat2_free_chan_resources;
+ dma->device_tx_status = ioat_dma_tx_status;
+
+ err = ioat_probe(device);
+ if (err)
+ return err;
+
+ list_for_each_entry(c, &dma->channels, device_node) {
+ chan = to_chan_common(c);
+ writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE | IOAT_DMA_DCA_ANY_CPU,
+ chan->reg_base + IOAT_DCACTRL_OFFSET);
+ }
+
+ err = ioat_register(device);
+ if (err)
+ return err;
+
+ ioat_kobject_add(device, &ioat2_ktype);
+
+ if (dca)
+ device->dca = ioat2_dca_init(pdev, device->reg_base);
+
+ return err;
+}