/* * Intel I/OAT DMA Linux driver * Copyright(c) 2004 - 2007 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. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. * * 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, which does asynchronous * copy operations. */ #include <linux/init.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/interrupt.h> #include <linux/dmaengine.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include "ioatdma.h" #include "ioatdma_registers.h" #include "ioatdma_hw.h" #define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common) #define to_ioatdma_device(dev) container_of(dev, struct ioatdma_device, common) #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) 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)"); /* 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); static struct ioat_desc_sw * ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan); static struct ioat_desc_sw * ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan); static inline struct ioat_dma_chan *ioat_lookup_chan_by_index( struct ioatdma_device *device, int index) { return device->idx[index]; } /** * ioat_dma_do_interrupt - handler used for single vector interrupt mode * @irq: interrupt id * @data: interrupt data */ static irqreturn_t ioat_dma_do_interrupt(int irq, void *data) { struct ioatdma_device *instance = data; struct ioat_dma_chan *ioat_chan; unsigned long attnstatus; int bit; u8 intrctrl; intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET); if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN)) return IRQ_NONE; if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) { writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET); return IRQ_NONE; } attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET); for_each_bit(bit, &attnstatus, BITS_PER_LONG) { ioat_chan = ioat_lookup_chan_by_index(instance, bit); tasklet_schedule(&ioat_chan->cleanup_task); } writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET); return IRQ_HANDLED; } /** * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode * @irq: interrupt id * @data: interrupt data */ static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data) { struct ioat_dma_chan *ioat_chan = data; tasklet_schedule(&ioat_chan->cleanup_task); return IRQ_HANDLED; } static void ioat_dma_cleanup_tasklet(unsigned long data); /** * ioat_dma_enumerate_channels - find and initialize the device's channels * @device: the device to be enumerated */ static int ioat_dma_enumerate_channels(struct ioatdma_device *device) { u8 xfercap_scale; u32 xfercap; int i; struct ioat_dma_chan *ioat_chan; device->common.chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET); xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET); xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale)); for (i = 0; i < device->common.chancnt; i++) { ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL); if (!ioat_chan) { device->common.chancnt = i; break; } ioat_chan->device = device; ioat_chan->reg_base = device->reg_base + (0x80 * (i + 1)); ioat_chan->xfercap = xfercap; ioat_chan->desccount = 0; if (ioat_chan->device->version != IOAT_VER_1_2) { writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE | IOAT_DMA_DCA_ANY_CPU, ioat_chan->reg_base + IOAT_DCACTRL_OFFSET); } spin_lock_init(&ioat_chan->cleanup_lock); spin_lock_init(&ioat_chan->desc_lock); INIT_LIST_HEAD(&ioat_chan->free_desc); INIT_LIST_HEAD(&ioat_chan->used_desc); /* This should be made common somewhere in dmaengine.c */ ioat_chan->common.device = &device->common; list_add_tail(&ioat_chan->common.device_node, &device->common.channels); device->idx[i] = ioat_chan; tasklet_init(&ioat_chan->cleanup_task, ioat_dma_cleanup_tasklet, (unsigned long) ioat_chan); tasklet_disable(&ioat_chan->cleanup_task); } return device->common.chancnt; } /** * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended * descriptors to hw * @chan: DMA channel handle */ static inline void __ioat1_dma_memcpy_issue_pending( struct ioat_dma_chan *ioat_chan) { ioat_chan->pending = 0; writeb(IOAT_CHANCMD_APPEND, ioat_chan->reg_base + IOAT1_CHANCMD_OFFSET); } 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) { spin_lock_bh(&ioat_chan->desc_lock); __ioat1_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); } } static inline void __ioat2_dma_memcpy_issue_pending( struct ioat_dma_chan *ioat_chan) { ioat_chan->pending = 0; writew(ioat_chan->dmacount, ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET); } 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) { spin_lock_bh(&ioat_chan->desc_lock); __ioat2_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); } } static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan); struct ioat_desc_sw *first = tx_to_ioat_desc(tx); struct ioat_desc_sw *prev, *new; struct ioat_dma_descriptor *hw; dma_cookie_t cookie; LIST_HEAD(new_chain); u32 copy; size_t len; dma_addr_t src, dst; int orig_ack; unsigned int desc_count = 0; /* src and dest and len are stored in the initial descriptor */ len = first->len; src = first->src; dst = first->dst; orig_ack = first->async_tx.ack; new = first; spin_lock_bh(&ioat_chan->desc_lock); prev = to_ioat_desc(ioat_chan->used_desc.prev); prefetch(prev->hw); do { copy = min_t(size_t, len, ioat_chan->xfercap); new->async_tx.ack = 1; hw = new->hw; hw->size = copy; hw->ctl = 0; hw->src_addr = src; hw->dst_addr = dst; hw->next = 0; /* chain together the physical address list for the HW */ wmb(); prev->hw->next = (u64) new->async_tx.phys; len -= copy; dst += copy; src += copy; list_add_tail(&new->node, &new_chain); desc_count++; prev = new; } while (len && (new = ioat1_dma_get_next_descriptor(ioat_chan))); hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS; if (new->async_tx.callback) { hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN; if (first != new) { /* move callback into to last desc */ new->async_tx.callback = first->async_tx.callback; new->async_tx.callback_param = first->async_tx.callback_param; first->async_tx.callback = NULL; first->async_tx.callback_param = NULL; } } new->tx_cnt = desc_count; new->async_tx.ack = orig_ack; /* client is in control of this ack */ /* store the original values for use in later cleanup */ if (new != first) { new->src = first->src; new->dst = first->dst; new->len = first->len; } /* cookie incr and addition to used_list must be atomic */ cookie = ioat_chan->common.cookie; cookie++; if (cookie < 0) cookie = 1; ioat_chan->common.cookie = new->async_tx.cookie = cookie; /* write address into NextDescriptor field of last desc in chain */ to_ioat_desc(ioat_chan->used_desc.prev)->hw->next = first->async_tx.phys; __list_splice(&new_chain, ioat_chan->used_desc.prev); ioat_chan->dmacount += desc_count; ioat_chan->pending += desc_count; if (ioat_chan->pending >= ioat_pending_level) __ioat1_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); return cookie; } static dma_cookie_t ioat2_tx_submit(struct dma_async_tx_descriptor *tx) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan); struct ioat_desc_sw *first = tx_to_ioat_desc(tx); struct ioat_desc_sw *new; struct ioat_dma_descriptor *hw; dma_cookie_t cookie; u32 copy; size_t len; dma_addr_t src, dst; int orig_ack; unsigned int desc_count = 0; /* src and dest and len are stored in the initial descriptor */ len = first->len; src = first->src; dst = first->dst; orig_ack = first->async_tx.ack; new = first; /* * ioat_chan->desc_lock is still in force in version 2 path * it gets unlocked at end of this function */ do { copy = min_t(size_t, len, ioat_chan->xfercap); new->async_tx.ack = 1; hw = new->hw; hw->size = copy; hw->ctl = 0; hw->src_addr = src; hw->dst_addr = dst; len -= copy; dst += copy; src += copy; desc_count++; } while (len && (new = ioat2_dma_get_next_descriptor(ioat_chan))); hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS; if (new->async_tx.callback) { hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN; if (first != new) { /* move callback into to last desc */ new->async_tx.callback = first->async_tx.callback; new->async_tx.callback_param = first->async_tx.callback_param; first->async_tx.callback = NULL; first->async_tx.callback_param = NULL; } } new->tx_cnt = desc_count; new->async_tx.ack = orig_ack; /* client is in control of this ack */ /* store the original values for use in later cleanup */ if (new != first) { new->src = first->src; new->dst = first->dst; new->len = first->len; } /* cookie incr and addition to used_list must be atomic */ cookie = ioat_chan->common.cookie; cookie++; if (cookie < 0) cookie = 1; ioat_chan->common.cookie = new->async_tx.cookie = cookie; ioat_chan->dmacount += desc_count; ioat_chan->pending += desc_count; if (ioat_chan->pending >= ioat_pending_level) __ioat2_dma_memcpy_issue_pending(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); return cookie; } /** * ioat_dma_alloc_descriptor - allocate and return a sw and hw descriptor pair * @ioat_chan: the channel supplying the memory pool for the descriptors * @flags: allocation flags */ static struct ioat_desc_sw *ioat_dma_alloc_descriptor( struct ioat_dma_chan *ioat_chan, gfp_t flags) { struct ioat_dma_descriptor *desc; struct ioat_desc_sw *desc_sw; struct ioatdma_device *ioatdma_device; dma_addr_t phys; ioatdma_device = to_ioatdma_device(ioat_chan->common.device); desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys); if (unlikely(!desc)) return NULL; desc_sw = kzalloc(sizeof(*desc_sw), flags); if (unlikely(!desc_sw)) { pci_pool_free(ioatdma_device->dma_pool, desc, phys); return NULL; } memset(desc, 0, sizeof(*desc)); dma_async_tx_descriptor_init(&desc_sw->async_tx, &ioat_chan->common); switch (ioat_chan->device->version) { case IOAT_VER_1_2: desc_sw->async_tx.tx_submit = ioat1_tx_submit; break; case IOAT_VER_2_0: desc_sw->async_tx.tx_submit = ioat2_tx_submit; break; } INIT_LIST_HEAD(&desc_sw->async_tx.tx_list); desc_sw->hw = desc; desc_sw->async_tx.phys = phys; return desc_sw; } static int ioat_initial_desc_count = 256; module_param(ioat_initial_desc_count, int, 0644); MODULE_PARM_DESC(ioat_initial_desc_count, "initial descriptors per channel (default: 256)"); /** * ioat2_dma_massage_chan_desc - link the descriptors into a circle * @ioat_chan: the channel to be massaged */ static void ioat2_dma_massage_chan_desc(struct ioat_dma_chan *ioat_chan) { struct ioat_desc_sw *desc, *_desc; /* setup used_desc */ ioat_chan->used_desc.next = ioat_chan->free_desc.next; ioat_chan->used_desc.prev = NULL; /* pull free_desc out of the circle so that every node is a hw * descriptor, but leave it pointing to the list */ ioat_chan->free_desc.prev->next = ioat_chan->free_desc.next; ioat_chan->free_desc.next->prev = ioat_chan->free_desc.prev; /* circle link the hw descriptors */ desc = to_ioat_desc(ioat_chan->free_desc.next); desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys; list_for_each_entry_safe(desc, _desc, ioat_chan->free_desc.next, node) { desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys; } } /** * ioat_dma_alloc_chan_resources - returns the number of allocated descriptors * @chan: the channel to be filled out */ static int ioat_dma_alloc_chan_resources(struct dma_chan *chan) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); struct ioat_desc_sw *desc; u16 chanctrl; u32 chanerr; int i; LIST_HEAD(tmp_list); /* have we already been set up? */ if (!list_empty(&ioat_chan->free_desc)) return ioat_chan->desccount; /* Setup register to interrupt and write completion status on error */ chanctrl = IOAT_CHANCTRL_ERR_INT_EN | IOAT_CHANCTRL_ANY_ERR_ABORT_EN | IOAT_CHANCTRL_ERR_COMPLETION_EN; writew(chanctrl, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET); chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET); if (chanerr) { dev_err(&ioat_chan->device->pdev->dev, "CHANERR = %x, clearing\n", chanerr); writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET); } /* Allocate descriptors */ for (i = 0; i < ioat_initial_desc_count; i++) { desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL); if (!desc) { dev_err(&ioat_chan->device->pdev->dev, "Only %d initial descriptors\n", i); break; } list_add_tail(&desc->node, &tmp_list); } spin_lock_bh(&ioat_chan->desc_lock); ioat_chan->desccount = i; list_splice(&tmp_list, &ioat_chan->free_desc); if (ioat_chan->device->version != IOAT_VER_1_2) ioat2_dma_massage_chan_desc(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); /* allocate a completion writeback area */ /* doing 2 32bit writes to mmio since 1 64b write doesn't work */ ioat_chan->completion_virt = pci_pool_alloc(ioat_chan->device->completion_pool, GFP_KERNEL, &ioat_chan->completion_addr); memset(ioat_chan->completion_virt, 0, sizeof(*ioat_chan->completion_virt)); writel(((u64) ioat_chan->completion_addr) & 0x00000000FFFFFFFF, ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW); writel(((u64) ioat_chan->completion_addr) >> 32, ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH); tasklet_enable(&ioat_chan->cleanup_task); ioat_dma_start_null_desc(ioat_chan); /* give chain to dma device */ return ioat_chan->desccount; } /** * ioat_dma_free_chan_resources - release all the descriptors * @chan: the channel to be cleaned */ static void ioat_dma_free_chan_resources(struct dma_chan *chan) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); struct ioatdma_device *ioatdma_device = to_ioatdma_device(chan->device); struct ioat_desc_sw *desc, *_desc; int in_use_descs = 0; tasklet_disable(&ioat_chan->cleanup_task); ioat_dma_memcpy_cleanup(ioat_chan); /* Delay 100ms after reset to allow internal DMA logic to quiesce * before removing DMA descriptor resources. */ writeb(IOAT_CHANCMD_RESET, ioat_chan->reg_base + IOAT_CHANCMD_OFFSET(ioat_chan->device->version)); mdelay(100); spin_lock_bh(&ioat_chan->desc_lock); switch (ioat_chan->device->version) { case IOAT_VER_1_2: list_for_each_entry_safe(desc, _desc, &ioat_chan->used_desc, node) { in_use_descs++; list_del(&desc->node); pci_pool_free(ioatdma_device->dma_pool, desc->hw, desc->async_tx.phys); kfree(desc); } list_for_each_entry_safe(desc, _desc, &ioat_chan->free_desc, node) { list_del(&desc->node); pci_pool_free(ioatdma_device->dma_pool, desc->hw, desc->async_tx.phys); kfree(desc); } break; case IOAT_VER_2_0: list_for_each_entry_safe(desc, _desc, ioat_chan->free_desc.next, node) { list_del(&desc->node); pci_pool_free(ioatdma_device->dma_pool, desc->hw, desc->async_tx.phys); kfree(desc); } desc = to_ioat_desc(ioat_chan->free_desc.next); pci_pool_free(ioatdma_device->dma_pool, desc->hw, desc->async_tx.phys); kfree(desc); INIT_LIST_HEAD(&ioat_chan->free_desc); INIT_LIST_HEAD(&ioat_chan->used_desc); break; } spin_unlock_bh(&ioat_chan->desc_lock); pci_pool_free(ioatdma_device->completion_pool, ioat_chan->completion_virt, ioat_chan->completion_addr); /* one is ok since we left it on there on purpose */ if (in_use_descs > 1) dev_err(&ioat_chan->device->pdev->dev, "Freeing %d in use descriptors!\n", in_use_descs - 1); ioat_chan->last_completion = ioat_chan->completion_addr = 0; ioat_chan->pending = 0; ioat_chan->dmacount = 0; } /** * ioat_dma_get_next_descriptor - return the next available descriptor * @ioat_chan: IOAT DMA channel handle * * Gets the next descriptor from the chain, and must be called with the * channel's desc_lock held. Allocates more descriptors if the channel * has run out. */ static struct ioat_desc_sw * ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan) { struct ioat_desc_sw *new; if (!list_empty(&ioat_chan->free_desc)) { new = to_ioat_desc(ioat_chan->free_desc.next); list_del(&new->node); } else { /* try to get another desc */ new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC); if (!new) { dev_err(&ioat_chan->device->pdev->dev, "alloc failed\n"); return NULL; } } prefetch(new->hw); return new; } static struct ioat_desc_sw * ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan) { struct ioat_desc_sw *new; /* * used.prev points to where to start processing * used.next points to next free descriptor * if used.prev == NULL, there are none waiting to be processed * if used.next == used.prev.prev, there is only one free descriptor, * and we need to use it to as a noop descriptor before * linking in a new set of descriptors, since the device * has probably already read the pointer to it */ if (ioat_chan->used_desc.prev && ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) { struct ioat_desc_sw *desc; struct ioat_desc_sw *noop_desc; int i; /* set up the noop descriptor */ noop_desc = to_ioat_desc(ioat_chan->used_desc.next); noop_desc->hw->size = 0; noop_desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL; noop_desc->hw->src_addr = 0; noop_desc->hw->dst_addr = 0; ioat_chan->used_desc.next = ioat_chan->used_desc.next->next; ioat_chan->pending++; ioat_chan->dmacount++; /* try to get a few more descriptors */ for (i = 16; i; i--) { desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC); if (!desc) { dev_err(&ioat_chan->device->pdev->dev, "alloc failed\n"); break; } list_add_tail(&desc->node, ioat_chan->used_desc.next); desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys; to_ioat_desc(desc->node.prev)->hw->next = desc->async_tx.phys; ioat_chan->desccount++; } ioat_chan->used_desc.next = noop_desc->node.next; } new = to_ioat_desc(ioat_chan->used_desc.next); prefetch(new); ioat_chan->used_desc.next = new->node.next; if (ioat_chan->used_desc.prev == NULL) ioat_chan->used_desc.prev = &new->node; prefetch(new->hw); return new; } static struct ioat_desc_sw *ioat_dma_get_next_descriptor( struct ioat_dma_chan *ioat_chan) { if (!ioat_chan) return NULL; switch (ioat_chan->device->version) { case IOAT_VER_1_2: return ioat1_dma_get_next_descriptor(ioat_chan); break; case IOAT_VER_2_0: return ioat2_dma_get_next_descriptor(ioat_chan); break; } return NULL; } static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy( struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src, size_t len, unsigned long flags) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); struct ioat_desc_sw *new; spin_lock_bh(&ioat_chan->desc_lock); new = ioat_dma_get_next_descriptor(ioat_chan); spin_unlock_bh(&ioat_chan->desc_lock); if (new) { new->len = len; new->dst = dma_dest; new->src = dma_src; return &new->async_tx; } else return NULL; } static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy( struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src, size_t len, unsigned long flags) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); struct ioat_desc_sw *new; spin_lock_bh(&ioat_chan->desc_lock); new = ioat2_dma_get_next_descriptor(ioat_chan); /* * leave ioat_chan->desc_lock set in ioat 2 path * it will get unlocked at end of tx_submit */ if (new) { new->len = len; new->dst = dma_dest; new->src = dma_src; return &new->async_tx; } else return NULL; } static void ioat_dma_cleanup_tasklet(unsigned long data) { struct ioat_dma_chan *chan = (void *)data; ioat_dma_memcpy_cleanup(chan); writew(IOAT_CHANCTRL_INT_DISABLE, chan->reg_base + IOAT_CHANCTRL_OFFSET); } /** * ioat_dma_memcpy_cleanup - cleanup up finished descriptors * @chan: ioat channel to be cleaned up */ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan) { unsigned long phys_complete; struct ioat_desc_sw *desc, *_desc; dma_cookie_t cookie = 0; unsigned long desc_phys; struct ioat_desc_sw *latest_desc; prefetch(ioat_chan->completion_virt); if (!spin_trylock_bh(&ioat_chan->cleanup_lock)) return; /* The completion writeback can happen at any time, so reads by the driver need to be atomic operations The descriptor physical addresses are limited to 32-bits when the CPU can only do a 32-bit mov */ #if (BITS_PER_LONG == 64) phys_complete = ioat_chan->completion_virt->full & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR; #else phys_complete = ioat_chan->completion_virt->low & IOAT_LOW_COMPLETION_MASK; #endif if ((ioat_chan->completion_virt->full & IOAT_CHANSTS_DMA_TRANSFER_STATUS) == IOAT_CHANSTS_DMA_TRANSFER_STATUS_HALTED) { dev_err(&ioat_chan->device->pdev->dev, "Channel halted, chanerr = %x\n", readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET)); /* TODO do something to salvage the situation */ } if (phys_complete == ioat_chan->last_completion) { spin_unlock_bh(&ioat_chan->cleanup_lock); return; } cookie = 0; spin_lock_bh(&ioat_chan->desc_lock); switch (ioat_chan->device->version) { case IOAT_VER_1_2: list_for_each_entry_safe(desc, _desc, &ioat_chan->used_desc, node) { /* * Incoming DMA requests may use multiple descriptors, * due to exceeding xfercap, perhaps. If so, only the * last one will have a cookie, and require unmapping. */ if (desc->async_tx.cookie) { cookie = desc->async_tx.cookie; /* * yes we are unmapping both _page and _single * alloc'd regions with unmap_page. Is this * *really* that bad? */ pci_unmap_page(ioat_chan->device->pdev, pci_unmap_addr(desc, dst), pci_unmap_len(desc, len), PCI_DMA_FROMDEVICE); pci_unmap_page(ioat_chan->device->pdev, pci_unmap_addr(desc, src), pci_unmap_len(desc, len), PCI_DMA_TODEVICE); if (desc->async_tx.callback) { desc->async_tx.callback(desc->async_tx.callback_param); desc->async_tx.callback = NULL; } } if (desc->async_tx.phys != phys_complete) { /* * a completed entry, but not the last, so clean * up if the client is done with the descriptor */ if (desc->async_tx.ack) { list_del(&desc->node); list_add_tail(&desc->node, &ioat_chan->free_desc); } else desc->async_tx.cookie = 0; } else { /* * last used desc. Do not remove, so we can * append from it, but don't look at it next * time, either */ desc->async_tx.cookie = 0; /* TODO check status bits? */ break; } } break; case IOAT_VER_2_0: /* has some other thread has already cleaned up? */ if (ioat_chan->used_desc.prev == NULL) break; /* work backwards to find latest finished desc */ desc = to_ioat_desc(ioat_chan->used_desc.next); latest_desc = NULL; do { desc = to_ioat_desc(desc->node.prev); desc_phys = (unsigned long)desc->async_tx.phys & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR; if (desc_phys == phys_complete) { latest_desc = desc; break; } } while (&desc->node != ioat_chan->used_desc.prev); if (latest_desc != NULL) { /* work forwards to clear finished descriptors */ for (desc = to_ioat_desc(ioat_chan->used_desc.prev); &desc->node != latest_desc->node.next && &desc->node != ioat_chan->used_desc.next; desc = to_ioat_desc(desc->node.next)) { if (desc->async_tx.cookie) { cookie = desc->async_tx.cookie; desc->async_tx.cookie = 0; pci_unmap_page(ioat_chan->device->pdev, pci_unmap_addr(desc, dst), pci_unmap_len(desc, len), PCI_DMA_FROMDEVICE); pci_unmap_page(ioat_chan->device->pdev, pci_unmap_addr(desc, src), pci_unmap_len(desc, len), PCI_DMA_TODEVICE); if (desc->async_tx.callback) { desc->async_tx.callback(desc->async_tx.callback_param); desc->async_tx.callback = NULL; } } } /* move used.prev up beyond those that are finished */ if (&desc->node == ioat_chan->used_desc.next) ioat_chan->used_desc.prev = NULL; else ioat_chan->used_desc.prev = &desc->node; } break; } spin_unlock_bh(&ioat_chan->desc_lock); ioat_chan->last_completion = phys_complete; if (cookie != 0) ioat_chan->completed_cookie = cookie; spin_unlock_bh(&ioat_chan->cleanup_lock); } static void ioat_dma_dependency_added(struct dma_chan *chan) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); spin_lock_bh(&ioat_chan->desc_lock); if (ioat_chan->pending == 0) { spin_unlock_bh(&ioat_chan->desc_lock); ioat_dma_memcpy_cleanup(ioat_chan); } else spin_unlock_bh(&ioat_chan->desc_lock); } /** * ioat_dma_is_complete - poll the status of a IOAT DMA transaction * @chan: IOAT DMA channel handle * @cookie: DMA transaction identifier * @done: if not %NULL, updated with last completed transaction * @used: if not %NULL, updated with last used transaction */ static enum dma_status ioat_dma_is_complete(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *done, dma_cookie_t *used) { struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan); dma_cookie_t last_used; dma_cookie_t last_complete; enum dma_status ret; last_used = chan->cookie; last_complete = ioat_chan->completed_cookie; if (done) *done = last_complete; if (used) *used = last_used; ret = dma_async_is_complete(cookie, last_complete, last_used); if (ret == DMA_SUCCESS) return ret; ioat_dma_memcpy_cleanup(ioat_chan); last_used = chan->cookie; last_complete = ioat_chan->completed_cookie; if (done) *done = last_complete; if (used) *used = last_used; return dma_async_is_complete(cookie, last_complete, last_used); } static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan) { struct ioat_desc_sw *desc; spin_lock_bh(&ioat_chan->desc_lock); desc = ioat_dma_get_next_descriptor(ioat_chan); desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL | IOAT_DMA_DESCRIPTOR_CTL_INT_GN | IOAT_DMA_DESCRIPTOR_CTL_CP_STS; desc->hw->size = 0; desc->hw->src_addr = 0; desc->hw->dst_addr = 0; desc->async_tx.ack = 1; switch (ioat_chan->device->version) { case IOAT_VER_1_2: desc->hw->next = 0; list_add_tail(&desc->node, &ioat_chan->used_desc); 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); ioat_chan->dmacount++; __ioat2_dma_memcpy_issue_pending(ioat_chan); break; } spin_unlock_bh(&ioat_chan->desc_lock); } /* * Perform a IOAT transaction to verify the HW works. */ #define IOAT_TEST_SIZE 2000 static void ioat_dma_test_callback(void *dma_async_param) { printk(KERN_ERR "ioatdma: ioat_dma_test_callback(%p)\n", dma_async_param); } /** * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works. * @device: device to be tested */ static int ioat_dma_self_test(struct ioatdma_device *device) { int i; u8 *src; u8 *dest; struct dma_chan *dma_chan; struct dma_async_tx_descriptor *tx; dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; int err = 0; src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL); if (!src) return -ENOMEM; dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL); if (!dest) { kfree(src); return -ENOMEM; } /* Fill in src buffer */ for (i = 0; i < IOAT_TEST_SIZE; i++) src[i] = (u8)i; /* Start copy, using first DMA channel */ dma_chan = container_of(device->common.channels.next, struct dma_chan, device_node); if (device->common.device_alloc_chan_resources(dma_chan) < 1) { dev_err(&device->pdev->dev, "selftest cannot allocate chan resource\n"); err = -ENODEV; goto out; } dma_src = dma_map_single(dma_chan->device->dev, src, IOAT_TEST_SIZE, DMA_TO_DEVICE); dma_dest = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE); tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src, IOAT_TEST_SIZE, 0); if (!tx) { dev_err(&device->pdev->dev, "Self-test prep failed, disabling\n"); err = -ENODEV; goto free_resources; } async_tx_ack(tx); tx->callback = ioat_dma_test_callback; tx->callback_param = (void *)0x8086; cookie = tx->tx_submit(tx); if (cookie < 0) { dev_err(&device->pdev->dev, "Self-test setup failed, disabling\n"); err = -ENODEV; goto free_resources; } device->common.device_issue_pending(dma_chan); msleep(1); if (device->common.device_is_tx_complete(dma_chan, cookie, NULL, NULL) != DMA_SUCCESS) { dev_err(&device->pdev->dev, "Self-test copy timed out, disabling\n"); err = -ENODEV; goto free_resources; } if (memcmp(src, dest, IOAT_TEST_SIZE)) { dev_err(&device->pdev->dev, "Self-test copy failed compare, disabling\n"); err = -ENODEV; goto free_resources; } free_resources: device->common.device_free_chan_resources(dma_chan); out: kfree(src); kfree(dest); return err; } static char ioat_interrupt_style[32] = "msix"; module_param_string(ioat_interrupt_style, ioat_interrupt_style, sizeof(ioat_interrupt_style), 0644); MODULE_PARM_DESC(ioat_interrupt_style, "set ioat interrupt style: msix (default), " "msix-single-vector, msi, intx)"); /** * ioat_dma_setup_interrupts - setup interrupt handler * @device: ioat device */ static int ioat_dma_setup_interrupts(struct ioatdma_device *device) { struct ioat_dma_chan *ioat_chan; int err, i, j, msixcnt; u8 intrctrl = 0; if (!strcmp(ioat_interrupt_style, "msix")) goto msix; if (!strcmp(ioat_interrupt_style, "msix-single-vector")) goto msix_single_vector; if (!strcmp(ioat_interrupt_style, "msi")) goto msi; if (!strcmp(ioat_interrupt_style, "intx")) goto intx; dev_err(&device->pdev->dev, "invalid ioat_interrupt_style %s\n", ioat_interrupt_style); goto err_no_irq; msix: /* The number of MSI-X vectors should equal the number of channels */ msixcnt = device->common.chancnt; for (i = 0; i < msixcnt; i++) device->msix_entries[i].entry = i; err = pci_enable_msix(device->pdev, device->msix_entries, msixcnt); if (err < 0) goto msi; if (err > 0) goto msix_single_vector; for (i = 0; i < msixcnt; i++) { ioat_chan = ioat_lookup_chan_by_index(device, i); err = request_irq(device->msix_entries[i].vector, ioat_dma_do_interrupt_msix, 0, "ioat-msix", ioat_chan); if (err) { for (j = 0; j < i; j++) { ioat_chan = ioat_lookup_chan_by_index(device, j); free_irq(device->msix_entries[j].vector, ioat_chan); } goto msix_single_vector; } } intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL; device->irq_mode = msix_multi_vector; goto done; msix_single_vector: device->msix_entries[0].entry = 0; err = pci_enable_msix(device->pdev, device->msix_entries, 1); if (err) goto msi; err = request_irq(device->msix_entries[0].vector, ioat_dma_do_interrupt, 0, "ioat-msix", device); if (err) { pci_disable_msix(device->pdev); goto msi; } device->irq_mode = msix_single_vector; goto done; msi: err = pci_enable_msi(device->pdev); if (err) goto intx; err = request_irq(device->pdev->irq, ioat_dma_do_interrupt, 0, "ioat-msi", device); if (err) { pci_disable_msi(device->pdev); goto intx; } /* * CB 1.2 devices need a bit set in configuration space to enable MSI */ if (device->version == IOAT_VER_1_2) { u32 dmactrl; pci_read_config_dword(device->pdev, IOAT_PCI_DMACTRL_OFFSET, &dmactrl); dmactrl |= IOAT_PCI_DMACTRL_MSI_EN; pci_write_config_dword(device->pdev, IOAT_PCI_DMACTRL_OFFSET, dmactrl); } device->irq_mode = msi; goto done; intx: err = request_irq(device->pdev->irq, ioat_dma_do_interrupt, IRQF_SHARED, "ioat-intx", device); if (err) goto err_no_irq; device->irq_mode = intx; done: intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN; writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET); return 0; err_no_irq: /* Disable all interrupt generation */ writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET); dev_err(&device->pdev->dev, "no usable interrupts\n"); device->irq_mode = none; return -1; } /** * ioat_dma_remove_interrupts - remove whatever interrupts were set * @device: ioat device */ static void ioat_dma_remove_interrupts(struct ioatdma_device *device) { struct ioat_dma_chan *ioat_chan; int i; /* Disable all interrupt generation */ writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET); switch (device->irq_mode) { case msix_multi_vector: for (i = 0; i < device->common.chancnt; i++) { ioat_chan = ioat_lookup_chan_by_index(device, i); free_irq(device->msix_entries[i].vector, ioat_chan); } pci_disable_msix(device->pdev); break; case msix_single_vector: free_irq(device->msix_entries[0].vector, device); pci_disable_msix(device->pdev); break; case msi: free_irq(device->pdev->irq, device); pci_disable_msi(device->pdev); break; case intx: free_irq(device->pdev->irq, device); break; case none: dev_warn(&device->pdev->dev, "call to %s without interrupts setup\n", __func__); } device->irq_mode = none; } struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev, void __iomem *iobase) { int err; struct ioatdma_device *device; device = kzalloc(sizeof(*device), GFP_KERNEL); if (!device) { err = -ENOMEM; goto err_kzalloc; } device->pdev = pdev; device->reg_base = iobase; device->version = readb(device->reg_base + IOAT_VER_OFFSET); /* DMA coherent memory pool for DMA descriptor allocations */ device->dma_pool = pci_pool_create("dma_desc_pool", pdev, sizeof(struct ioat_dma_descriptor), 64, 0); if (!device->dma_pool) { err = -ENOMEM; goto err_dma_pool; } device->completion_pool = pci_pool_create("completion_pool", pdev, sizeof(u64), SMP_CACHE_BYTES, SMP_CACHE_BYTES); if (!device->completion_pool) { err = -ENOMEM; goto err_completion_pool; } INIT_LIST_HEAD(&device->common.channels); ioat_dma_enumerate_channels(device); device->common.device_alloc_chan_resources = ioat_dma_alloc_chan_resources; device->common.device_free_chan_resources = ioat_dma_free_chan_resources; device->common.dev = &pdev->dev; dma_cap_set(DMA_MEMCPY, device->common.cap_mask); device->common.device_is_tx_complete = ioat_dma_is_complete; device->common.device_dependency_added = ioat_dma_dependency_added; switch (device->version) { case IOAT_VER_1_2: device->common.device_prep_dma_memcpy = ioat1_dma_prep_memcpy; device->common.device_issue_pending = ioat1_dma_memcpy_issue_pending; break; case IOAT_VER_2_0: device->common.device_prep_dma_memcpy = ioat2_dma_prep_memcpy; device->common.device_issue_pending = ioat2_dma_memcpy_issue_pending; break; } dev_err(&device->pdev->dev, "Intel(R) I/OAT DMA Engine found," " %d channels, device version 0x%02x, driver version %s\n", device->common.chancnt, device->version, IOAT_DMA_VERSION); err = ioat_dma_setup_interrupts(device); if (err) goto err_setup_interrupts; err = ioat_dma_self_test(device); if (err) goto err_self_test; dma_async_device_register(&device->common); return device; err_self_test: ioat_dma_remove_interrupts(device); err_setup_interrupts: pci_pool_destroy(device->completion_pool); err_completion_pool: pci_pool_destroy(device->dma_pool); err_dma_pool: kfree(device); err_kzalloc: dev_err(&pdev->dev, "Intel(R) I/OAT DMA Engine initialization failed\n"); return NULL; } void ioat_dma_remove(struct ioatdma_device *device) { struct dma_chan *chan, *_chan; struct ioat_dma_chan *ioat_chan; ioat_dma_remove_interrupts(device); dma_async_device_unregister(&device->common); pci_pool_destroy(device->dma_pool); pci_pool_destroy(device->completion_pool); iounmap(device->reg_base); pci_release_regions(device->pdev); pci_disable_device(device->pdev); list_for_each_entry_safe(chan, _chan, &device->common.channels, device_node) { ioat_chan = to_ioat_chan(chan); list_del(&chan->device_node); kfree(ioat_chan); } kfree(device); }