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authorDave Jiang <dave.jiang@intel.com>2015-08-11 17:48:49 +0200
committerVinod Koul <vinod.koul@intel.com>2015-08-17 10:07:30 +0200
commit599d49de7f69cb5a23e913db24e168ba2f09bd05 (patch)
treecce55d57f777b00e12e34f7c96f2e764a15e6547 /drivers/dma/ioat
parentdmaengine: ioatdma: move all the init routines (diff)
downloadlinux-599d49de7f69cb5a23e913db24e168ba2f09bd05.tar.xz
linux-599d49de7f69cb5a23e913db24e168ba2f09bd05.zip
dmaengine: ioatdma: move dma prep functions to single location
Move all DMA descriptor prepping functions to prep.c file. Fixup all broken bits caused by the move. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/ioat')
-rw-r--r--drivers/dma/ioat/Makefile2
-rw-r--r--drivers/dma/ioat/dma.c47
-rw-r--r--drivers/dma/ioat/dma.h81
-rw-r--r--drivers/dma/ioat/dma_v3.c659
-rw-r--r--drivers/dma/ioat/init.c22
-rw-r--r--drivers/dma/ioat/prep.c707
6 files changed, 769 insertions, 749 deletions
diff --git a/drivers/dma/ioat/Makefile b/drivers/dma/ioat/Makefile
index f785f8f42f7d..3a7e66464d0c 100644
--- a/drivers/dma/ioat/Makefile
+++ b/drivers/dma/ioat/Makefile
@@ -1,2 +1,2 @@
obj-$(CONFIG_INTEL_IOATDMA) += ioatdma.o
-ioatdma-y := init.o dma.o dma_v3.o dca.o sysfs.o
+ioatdma-y := init.o dma.o dma_v3.o prep.o dca.o sysfs.o
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 5d78cafdd3f2..e67eda055ea5 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -578,50 +578,3 @@ int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
return -ENOMEM;
}
-
-struct dma_async_tx_descriptor *
-ioat_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 ioatdma_chan *ioat_chan = to_ioat_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 = ioat_xferlen_to_descs(ioat_chan, len);
- if (likely(num_descs) &&
- ioat_check_space_lock(ioat_chan, num_descs) == 0)
- idx = ioat_chan->head;
- else
- return NULL;
- i = 0;
- do {
- size_t copy = min_t(size_t, len, 1 << ioat_chan->xfercap_log);
-
- desc = ioat_get_ring_ent(ioat_chan, 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_chan, 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_chan, desc);
- /* we leave the channel locked to ensure in order submission */
-
- return &desc->txd;
-}
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index d2ffa5775d53..a319befad1a3 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -37,6 +37,14 @@
#define chan_num(ch) ((int)((ch)->reg_base - (ch)->ioat_dma->reg_base) / 0x80)
+/* ioat hardware assumes at least two sources for raid operations */
+#define src_cnt_to_sw(x) ((x) + 2)
+#define src_cnt_to_hw(x) ((x) - 2)
+#define ndest_to_sw(x) ((x) + 1)
+#define ndest_to_hw(x) ((x) - 1)
+#define src16_cnt_to_sw(x) ((x) + 9)
+#define src16_cnt_to_hw(x) ((x) - 9)
+
/*
* workaround for IOAT ver.3.0 null descriptor issue
* (channel returns error when size is 0)
@@ -190,15 +198,22 @@ struct ioat_ring_ent {
struct ioat_sed_ent *sed;
};
+extern const struct sysfs_ops ioat_sysfs_ops;
+extern struct ioat_sysfs_entry ioat_version_attr;
+extern struct ioat_sysfs_entry ioat_cap_attr;
+extern int ioat_pending_level;
+extern int ioat_ring_alloc_order;
+extern struct kobj_type ioat_ktype;
+extern struct kmem_cache *ioat_cache;
+extern int ioat_ring_max_alloc_order;
+extern struct kmem_cache *ioat_sed_cache;
+
static inline struct ioatdma_chan *to_ioat_chan(struct dma_chan *c)
{
return container_of(c, struct ioatdma_chan, dma_chan);
}
-
-
/* wrapper around hardware descriptor format + additional software fields */
-
#ifdef DEBUG
#define set_desc_id(desc, i) ((desc)->id = (i))
#define desc_id(desc) ((desc)->id)
@@ -381,13 +396,10 @@ ioat_set_chainaddr(struct ioatdma_chan *ioat_chan, u64 addr)
ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
}
-irqreturn_t ioat_dma_do_interrupt(int irq, void *data);
-irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data);
-struct ioat_ring_ent **
-ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags);
-void ioat_start_null_desc(struct ioatdma_chan *ioat_chan);
-void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan);
-int ioat_reset_hw(struct ioatdma_chan *ioat_chan);
+/* IOAT Prep functions */
+struct dma_async_tx_descriptor *
+ioat_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 dma_async_tx_descriptor *
ioat_prep_interrupt_lock(struct dma_chan *c, unsigned long flags);
struct dma_async_tx_descriptor *
@@ -412,53 +424,38 @@ struct dma_async_tx_descriptor *
ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
unsigned int src_cnt, size_t len,
enum sum_check_flags *result, unsigned long flags);
+
+/* IOAT Operation functions */
+irqreturn_t ioat_dma_do_interrupt(int irq, void *data);
+irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data);
+struct ioat_ring_ent **
+ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags);
+void ioat_start_null_desc(struct ioatdma_chan *ioat_chan);
+void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan);
+int ioat_reset_hw(struct ioatdma_chan *ioat_chan);
enum dma_status
ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
struct dma_tx_state *txstate);
void ioat_cleanup_event(unsigned long data);
void ioat_timer_event(unsigned long data);
-bool is_bwd_ioat(struct pci_dev *pdev);
-int ioat_probe(struct ioatdma_device *ioat_dma);
-int ioat_register(struct ioatdma_device *ioat_dma);
-int ioat_dma_self_test(struct ioatdma_device *ioat_dma);
-void ioat_dma_remove(struct ioatdma_device *ioat_dma);
-struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase);
-void ioat_init_channel(struct ioatdma_device *ioat_dma,
- struct ioatdma_chan *ioat_chan, int idx);
enum dma_status ioat_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie,
struct dma_tx_state *txstate);
bool ioat_cleanup_preamble(struct ioatdma_chan *ioat_chan,
dma_addr_t *phys_complete);
-void ioat_kobject_add(struct ioatdma_device *ioat_dma, struct kobj_type *type);
-void ioat_kobject_del(struct ioatdma_device *ioat_dma);
-int ioat_dma_setup_interrupts(struct ioatdma_device *ioat_dma);
-void ioat_stop(struct ioatdma_chan *ioat_chan);
-int ioat_dma_probe(struct ioatdma_device *ioat_dma, int dca);
-int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca);
-struct dca_provider *ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase);
int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs);
-int ioat_enumerate_channels(struct ioatdma_device *ioat_dma);
-struct dma_async_tx_descriptor *
-ioat_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
- dma_addr_t dma_src, size_t len, unsigned long flags);
void ioat_issue_pending(struct dma_chan *chan);
-int ioat_alloc_chan_resources(struct dma_chan *c);
-void ioat_free_chan_resources(struct dma_chan *c);
-void __ioat_restart_chan(struct ioatdma_chan *ioat_chan);
bool reshape_ring(struct ioatdma_chan *ioat, int order);
void __ioat_issue_pending(struct ioatdma_chan *ioat_chan);
void ioat_timer_event(unsigned long data);
int ioat_quiesce(struct ioatdma_chan *ioat_chan, unsigned long tmo);
int ioat_reset_sync(struct ioatdma_chan *ioat_chan, unsigned long tmo);
+void __ioat_restart_chan(struct ioatdma_chan *ioat_chan);
-extern const struct sysfs_ops ioat_sysfs_ops;
-extern struct ioat_sysfs_entry ioat_version_attr;
-extern struct ioat_sysfs_entry ioat_cap_attr;
-extern int ioat_pending_level;
-extern int ioat_ring_alloc_order;
-extern struct kobj_type ioat_ktype;
-extern struct kmem_cache *ioat_cache;
-extern int ioat_ring_max_alloc_order;
-extern struct kmem_cache *ioat_sed_cache;
-
+/* IOAT Init functions */
+bool is_bwd_ioat(struct pci_dev *pdev);
+void ioat_kobject_add(struct ioatdma_device *ioat_dma, struct kobj_type *type);
+void ioat_kobject_del(struct ioatdma_device *ioat_dma);
+int ioat_dma_setup_interrupts(struct ioatdma_device *ioat_dma);
+void ioat_stop(struct ioatdma_chan *ioat_chan);
+struct dca_provider *ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase);
#endif /* IOATDMA_H */
diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index f6a194a3a463..d0ae8f7c97a6 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -62,107 +62,8 @@
#include "hw.h"
#include "dma.h"
-/* ioat hardware assumes at least two sources for raid operations */
-#define src_cnt_to_sw(x) ((x) + 2)
-#define src_cnt_to_hw(x) ((x) - 2)
-#define ndest_to_sw(x) ((x) + 1)
-#define ndest_to_hw(x) ((x) - 1)
-#define src16_cnt_to_sw(x) ((x) + 9)
-#define src16_cnt_to_hw(x) ((x) - 9)
-
-/* provide a lookup table for setting the source address in the base or
- * extended descriptor of an xor or pq descriptor
- */
-static const u8 xor_idx_to_desc = 0xe0;
-static const u8 xor_idx_to_field[] = { 1, 4, 5, 6, 7, 0, 1, 2 };
-static const u8 pq_idx_to_desc = 0xf8;
-static const u8 pq16_idx_to_desc[] = { 0, 0, 1, 1, 1, 1, 1, 1, 1,
- 2, 2, 2, 2, 2, 2, 2 };
-static const u8 pq_idx_to_field[] = { 1, 4, 5, 0, 1, 2, 4, 5 };
-static const u8 pq16_idx_to_field[] = { 1, 4, 1, 2, 3, 4, 5, 6, 7,
- 0, 1, 2, 3, 4, 5, 6 };
-
static void ioat3_eh(struct ioatdma_chan *ioat_chan);
-static void xor_set_src(struct ioat_raw_descriptor *descs[2],
- dma_addr_t addr, u32 offset, int idx)
-{
- struct ioat_raw_descriptor *raw = descs[xor_idx_to_desc >> idx & 1];
-
- raw->field[xor_idx_to_field[idx]] = addr + offset;
-}
-
-static dma_addr_t pq_get_src(struct ioat_raw_descriptor *descs[2], int idx)
-{
- struct ioat_raw_descriptor *raw = descs[pq_idx_to_desc >> idx & 1];
-
- return raw->field[pq_idx_to_field[idx]];
-}
-
-static dma_addr_t pq16_get_src(struct ioat_raw_descriptor *desc[3], int idx)
-{
- struct ioat_raw_descriptor *raw = desc[pq16_idx_to_desc[idx]];
-
- return raw->field[pq16_idx_to_field[idx]];
-}
-
-static void pq_set_src(struct ioat_raw_descriptor *descs[2],
- dma_addr_t addr, u32 offset, u8 coef, int idx)
-{
- struct ioat_pq_descriptor *pq = (struct ioat_pq_descriptor *) descs[0];
- struct ioat_raw_descriptor *raw = descs[pq_idx_to_desc >> idx & 1];
-
- raw->field[pq_idx_to_field[idx]] = addr + offset;
- pq->coef[idx] = coef;
-}
-
-static void pq16_set_src(struct ioat_raw_descriptor *desc[3],
- dma_addr_t addr, u32 offset, u8 coef, unsigned idx)
-{
- struct ioat_pq_descriptor *pq = (struct ioat_pq_descriptor *)desc[0];
- struct ioat_pq16a_descriptor *pq16 =
- (struct ioat_pq16a_descriptor *)desc[1];
- struct ioat_raw_descriptor *raw = desc[pq16_idx_to_desc[idx]];
-
- raw->field[pq16_idx_to_field[idx]] = addr + offset;
-
- if (idx < 8)
- pq->coef[idx] = coef;
- else
- pq16->coef[idx - 8] = coef;
-}
-
-static struct ioat_sed_ent *
-ioat3_alloc_sed(struct ioatdma_device *ioat_dma, unsigned int hw_pool)
-{
- struct ioat_sed_ent *sed;
- gfp_t flags = __GFP_ZERO | GFP_ATOMIC;
-
- sed = kmem_cache_alloc(ioat_sed_cache, flags);
- if (!sed)
- return NULL;
-
- sed->hw_pool = hw_pool;
- sed->hw = dma_pool_alloc(ioat_dma->sed_hw_pool[hw_pool],
- flags, &sed->dma);
- if (!sed->hw) {
- kmem_cache_free(ioat_sed_cache, sed);
- return NULL;
- }
-
- return sed;
-}
-
-static void
-ioat3_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
-{
- if (!sed)
- return;
-
- dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
- kmem_cache_free(ioat_sed_cache, sed);
-}
-
static bool desc_has_ext(struct ioat_ring_ent *desc)
{
struct ioat_dma_descriptor *hw = desc->hw;
@@ -184,6 +85,16 @@ static bool desc_has_ext(struct ioat_ring_ent *desc)
return false;
}
+static void
+ioat3_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
+{
+ if (!sed)
+ return;
+
+ dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
+ kmem_cache_free(ioat_sed_cache, sed);
+}
+
static u64 ioat3_get_current_completion(struct ioatdma_chan *ioat_chan)
{
u64 phys_complete;
@@ -530,556 +441,6 @@ ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
return dma_cookie_status(c, cookie, txstate);
}
-static struct dma_async_tx_descriptor *
-__ioat_prep_xor_lock(struct dma_chan *c, enum sum_check_flags *result,
- dma_addr_t dest, dma_addr_t *src, unsigned int src_cnt,
- size_t len, unsigned long flags)
-{
- struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
- struct ioat_ring_ent *compl_desc;
- struct ioat_ring_ent *desc;
- struct ioat_ring_ent *ext;
- size_t total_len = len;
- struct ioat_xor_descriptor *xor;
- struct ioat_xor_ext_descriptor *xor_ex = NULL;
- struct ioat_dma_descriptor *hw;
- int num_descs, with_ext, idx, i;
- u32 offset = 0;
- u8 op = result ? IOAT_OP_XOR_VAL : IOAT_OP_XOR;
-
- BUG_ON(src_cnt < 2);
-
- num_descs = ioat_xferlen_to_descs(ioat_chan, len);
- /* we need 2x the number of descriptors to cover greater than 5
- * sources
- */
- if (src_cnt > 5) {
- with_ext = 1;
- num_descs *= 2;
- } else
- with_ext = 0;
-
- /* completion writes from the raid engine may pass completion
- * writes from the legacy engine, so we need one extra null
- * (legacy) descriptor to ensure all completion writes arrive in
- * order.
- */
- if (likely(num_descs) &&
- ioat_check_space_lock(ioat_chan, num_descs+1) == 0)
- idx = ioat_chan->head;
- else
- return NULL;
- i = 0;
- do {
- struct ioat_raw_descriptor *descs[2];
- size_t xfer_size = min_t(size_t,
- len, 1 << ioat_chan->xfercap_log);
- int s;
-
- desc = ioat_get_ring_ent(ioat_chan, idx + i);
- xor = desc->xor;
-
- /* save a branch by unconditionally retrieving the
- * extended descriptor xor_set_src() knows to not write
- * to it in the single descriptor case
- */
- ext = ioat_get_ring_ent(ioat_chan, idx + i + 1);
- xor_ex = ext->xor_ex;
-
- descs[0] = (struct ioat_raw_descriptor *) xor;
- descs[1] = (struct ioat_raw_descriptor *) xor_ex;
- for (s = 0; s < src_cnt; s++)
- xor_set_src(descs, src[s], offset, s);
- xor->size = xfer_size;
- xor->dst_addr = dest + offset;
- xor->ctl = 0;
- xor->ctl_f.op = op;
- xor->ctl_f.src_cnt = src_cnt_to_hw(src_cnt);
-
- len -= xfer_size;
- offset += xfer_size;
- dump_desc_dbg(ioat_chan, desc);
- } while ((i += 1 + with_ext) < num_descs);
-
- /* last xor descriptor carries the unmap parameters and fence bit */
- desc->txd.flags = flags;
- desc->len = total_len;
- if (result)
- desc->result = result;
- xor->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
-
- /* completion descriptor carries interrupt bit */
- compl_desc = ioat_get_ring_ent(ioat_chan, idx + i);
- compl_desc->txd.flags = flags & DMA_PREP_INTERRUPT;
- hw = compl_desc->hw;
- hw->ctl = 0;
- hw->ctl_f.null = 1;
- hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
- hw->ctl_f.compl_write = 1;
- hw->size = NULL_DESC_BUFFER_SIZE;
- dump_desc_dbg(ioat_chan, compl_desc);
-
- /* we leave the channel locked to ensure in order submission */
- return &compl_desc->txd;
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
- unsigned int src_cnt, size_t len, unsigned long flags)
-{
- return __ioat_prep_xor_lock(chan, NULL, dest, src, src_cnt, len, flags);
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_xor_val(struct dma_chan *chan, dma_addr_t *src,
- unsigned int src_cnt, size_t len,
- enum sum_check_flags *result, unsigned long flags)
-{
- /* the cleanup routine only sets bits on validate failure, it
- * does not clear bits on validate success... so clear it here
- */
- *result = 0;
-
- return __ioat_prep_xor_lock(chan, result, src[0], &src[1],
- src_cnt - 1, len, flags);
-}
-
-static void
-dump_pq_desc_dbg(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc,
- struct ioat_ring_ent *ext)
-{
- struct device *dev = to_dev(ioat_chan);
- struct ioat_pq_descriptor *pq = desc->pq;
- struct ioat_pq_ext_descriptor *pq_ex = ext ? ext->pq_ex : NULL;
- struct ioat_raw_descriptor *descs[] = { (void *) pq, (void *) pq_ex };
- int src_cnt = src_cnt_to_sw(pq->ctl_f.src_cnt);
- int i;
-
- dev_dbg(dev, "desc[%d]: (%#llx->%#llx) flags: %#x"
- " sz: %#10.8x ctl: %#x (op: %#x int: %d compl: %d pq: '%s%s'"
- " src_cnt: %d)\n",
- desc_id(desc), (unsigned long long) desc->txd.phys,
- (unsigned long long) (pq_ex ? pq_ex->next : pq->next),
- desc->txd.flags, pq->size, pq->ctl, pq->ctl_f.op, pq->ctl_f.int_en,
- pq->ctl_f.compl_write,
- pq->ctl_f.p_disable ? "" : "p", pq->ctl_f.q_disable ? "" : "q",
- pq->ctl_f.src_cnt);
- for (i = 0; i < src_cnt; i++)
- dev_dbg(dev, "\tsrc[%d]: %#llx coef: %#x\n", i,
- (unsigned long long) pq_get_src(descs, i), pq->coef[i]);
- dev_dbg(dev, "\tP: %#llx\n", pq->p_addr);
- dev_dbg(dev, "\tQ: %#llx\n", pq->q_addr);
- dev_dbg(dev, "\tNEXT: %#llx\n", pq->next);
-}
-
-static void dump_pq16_desc_dbg(struct ioatdma_chan *ioat_chan,
- struct ioat_ring_ent *desc)
-{
- struct device *dev = to_dev(ioat_chan);
- struct ioat_pq_descriptor *pq = desc->pq;
- struct ioat_raw_descriptor *descs[] = { (void *)pq,
- (void *)pq,
- (void *)pq };
- int src_cnt = src16_cnt_to_sw(pq->ctl_f.src_cnt);
- int i;
-
- if (desc->sed) {
- descs[1] = (void *)desc->sed->hw;
- descs[2] = (void *)desc->sed->hw + 64;
- }
-
- dev_dbg(dev, "desc[%d]: (%#llx->%#llx) flags: %#x"
- " sz: %#x ctl: %#x (op: %#x int: %d compl: %d pq: '%s%s'"
- " src_cnt: %d)\n",
- desc_id(desc), (unsigned long long) desc->txd.phys,
- (unsigned long long) pq->next,
- desc->txd.flags, pq->size, pq->ctl,
- pq->ctl_f.op, pq->ctl_f.int_en,
- pq->ctl_f.compl_write,
- pq->ctl_f.p_disable ? "" : "p", pq->ctl_f.q_disable ? "" : "q",
- pq->ctl_f.src_cnt);
- for (i = 0; i < src_cnt; i++) {
- dev_dbg(dev, "\tsrc[%d]: %#llx coef: %#x\n", i,
- (unsigned long long) pq16_get_src(descs, i),
- pq->coef[i]);
- }
- dev_dbg(dev, "\tP: %#llx\n", pq->p_addr);
- dev_dbg(dev, "\tQ: %#llx\n", pq->q_addr);
-}
-
-static struct dma_async_tx_descriptor *
-__ioat_prep_pq_lock(struct dma_chan *c, enum sum_check_flags *result,
- const dma_addr_t *dst, const dma_addr_t *src,
- unsigned int src_cnt, const unsigned char *scf,
- size_t len, unsigned long flags)
-{
- struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
- struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
- struct ioat_ring_ent *compl_desc;
- struct ioat_ring_ent *desc;
- struct ioat_ring_ent *ext;
- size_t total_len = len;
- struct ioat_pq_descriptor *pq;
- struct ioat_pq_ext_descriptor *pq_ex = NULL;
- struct ioat_dma_descriptor *hw;
- u32 offset = 0;
- u8 op = result ? IOAT_OP_PQ_VAL : IOAT_OP_PQ;
- int i, s, idx, with_ext, num_descs;
- int cb32 = (ioat_dma->version < IOAT_VER_3_3) ? 1 : 0;
-
- dev_dbg(to_dev(ioat_chan), "%s\n", __func__);
- /* the engine requires at least two sources (we provide
- * at least 1 implied source in the DMA_PREP_CONTINUE case)
- */
- BUG_ON(src_cnt + dmaf_continue(flags) < 2);
-
- num_descs = ioat_xferlen_to_descs(ioat_chan, len);
- /* we need 2x the number of descriptors to cover greater than 3
- * sources (we need 1 extra source in the q-only continuation
- * case and 3 extra sources in the p+q continuation case.
- */
- if (src_cnt + dmaf_p_disabled_continue(flags) > 3 ||
- (dmaf_continue(flags) && !dmaf_p_disabled_continue(flags))) {
- with_ext = 1;
- num_descs *= 2;
- } else
- with_ext = 0;
-
- /* completion writes from the raid engine may pass completion
- * writes from the legacy engine, so we need one extra null
- * (legacy) descriptor to ensure all completion writes arrive in
- * order.
- */
- if (likely(num_descs) &&
- ioat_check_space_lock(ioat_chan, num_descs + cb32) == 0)
- idx = ioat_chan->head;
- else
- return NULL;
- i = 0;
- do {
- struct ioat_raw_descriptor *descs[2];
- size_t xfer_size = min_t(size_t, len,
- 1 << ioat_chan->xfercap_log);
-
- desc = ioat_get_ring_ent(ioat_chan, idx + i);
- pq = desc->pq;
-
- /* save a branch by unconditionally retrieving the
- * extended descriptor pq_set_src() knows to not write
- * to it in the single descriptor case
- */
- ext = ioat_get_ring_ent(ioat_chan, idx + i + with_ext);
- pq_ex = ext->pq_ex;
-
- descs[0] = (struct ioat_raw_descriptor *) pq;
- descs[1] = (struct ioat_raw_descriptor *) pq_ex;
-
- for (s = 0; s < src_cnt; s++)
- pq_set_src(descs, src[s], offset, scf[s], s);
-
- /* see the comment for dma_maxpq in include/linux/dmaengine.h */
- if (dmaf_p_disabled_continue(flags))
- pq_set_src(descs, dst[1], offset, 1, s++);
- else if (dmaf_continue(flags)) {
- pq_set_src(descs, dst[0], offset, 0, s++);
- pq_set_src(descs, dst[1], offset, 1, s++);
- pq_set_src(descs, dst[1], offset, 0, s++);
- }
- pq->size = xfer_size;
- pq->p_addr = dst[0] + offset;
- pq->q_addr = dst[1] + offset;
- pq->ctl = 0;
- pq->ctl_f.op = op;
- /* we turn on descriptor write back error status */
- if (ioat_dma->cap & IOAT_CAP_DWBES)
- pq->ctl_f.wb_en = result ? 1 : 0;
- pq->ctl_f.src_cnt = src_cnt_to_hw(s);
- pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
- pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
-
- len -= xfer_size;
- offset += xfer_size;
- } while ((i += 1 + with_ext) < num_descs);
-
- /* last pq descriptor carries the unmap parameters and fence bit */
- desc->txd.flags = flags;
- desc->len = total_len;
- if (result)
- desc->result = result;
- pq->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
- dump_pq_desc_dbg(ioat_chan, desc, ext);
-
- if (!cb32) {
- pq->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
- pq->ctl_f.compl_write = 1;
- compl_desc = desc;
- } else {
- /* completion descriptor carries interrupt bit */
- compl_desc = ioat_get_ring_ent(ioat_chan, idx + i);
- compl_desc->txd.flags = flags & DMA_PREP_INTERRUPT;
- hw = compl_desc->hw;
- hw->ctl = 0;
- hw->ctl_f.null = 1;
- hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
- hw->ctl_f.compl_write = 1;
- hw->size = NULL_DESC_BUFFER_SIZE;
- dump_desc_dbg(ioat_chan, compl_desc);
- }
-
-
- /* we leave the channel locked to ensure in order submission */
- return &compl_desc->txd;
-}
-
-static struct dma_async_tx_descriptor *
-__ioat_prep_pq16_lock(struct dma_chan *c, enum sum_check_flags *result,
- const dma_addr_t *dst, const dma_addr_t *src,
- unsigned int src_cnt, const unsigned char *scf,
- size_t len, unsigned long flags)
-{
- struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
- struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
- struct ioat_ring_ent *desc;
- size_t total_len = len;
- struct ioat_pq_descriptor *pq;
- u32 offset = 0;
- u8 op;
- int i, s, idx, num_descs;
-
- /* this function is only called with 9-16 sources */
- op = result ? IOAT_OP_PQ_VAL_16S : IOAT_OP_PQ_16S;
-
- dev_dbg(to_dev(ioat_chan), "%s\n", __func__);
-
- num_descs = ioat_xferlen_to_descs(ioat_chan, len);
-
- /*
- * 16 source pq is only available on cb3.3 and has no completion
- * write hw bug.
- */
- if (num_descs && ioat_check_space_lock(ioat_chan, num_descs) == 0)
- idx = ioat_chan->head;
- else
- return NULL;
-
- i = 0;
-
- do {
- struct ioat_raw_descriptor *descs[4];
- size_t xfer_size = min_t(size_t, len,
- 1 << ioat_chan->xfercap_log);
-
- desc = ioat_get_ring_ent(ioat_chan, idx + i);
- pq = desc->pq;
-
- descs[0] = (struct ioat_raw_descriptor *) pq;
-
- desc->sed = ioat3_alloc_sed(ioat_dma, (src_cnt-2) >> 3);
- if (!desc->sed) {
- dev_err(to_dev(ioat_chan),
- "%s: no free sed entries\n", __func__);
- return NULL;
- }
-
- pq->sed_addr = desc->sed->dma;
- desc->sed->parent = desc;
-
- descs[1] = (struct ioat_raw_descriptor *)desc->sed->hw;
- descs[2] = (void *)descs[1] + 64;
-
- for (s = 0; s < src_cnt; s++)
- pq16_set_src(descs, src[s], offset, scf[s], s);
-
- /* see the comment for dma_maxpq in include/linux/dmaengine.h */
- if (dmaf_p_disabled_continue(flags))
- pq16_set_src(descs, dst[1], offset, 1, s++);
- else if (dmaf_continue(flags)) {
- pq16_set_src(descs, dst[0], offset, 0, s++);
- pq16_set_src(descs, dst[1], offset, 1, s++);
- pq16_set_src(descs, dst[1], offset, 0, s++);
- }
-
- pq->size = xfer_size;
- pq->p_addr = dst[0] + offset;
- pq->q_addr = dst[1] + offset;
- pq->ctl = 0;
- pq->ctl_f.op = op;
- pq->ctl_f.src_cnt = src16_cnt_to_hw(s);
- /* we turn on descriptor write back error status */
- if (ioat_dma->cap & IOAT_CAP_DWBES)
- pq->ctl_f.wb_en = result ? 1 : 0;
- pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
- pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
-
- len -= xfer_size;
- offset += xfer_size;
- } while (++i < num_descs);
-
- /* last pq descriptor carries the unmap parameters and fence bit */
- desc->txd.flags = flags;
- desc->len = total_len;
- if (result)
- desc->result = result;
- pq->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
-
- /* with cb3.3 we should be able to do completion w/o a null desc */
- pq->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
- pq->ctl_f.compl_write = 1;
-
- dump_pq16_desc_dbg(ioat_chan, desc);
-
- /* we leave the channel locked to ensure in order submission */
- return &desc->txd;
-}
-
-static int src_cnt_flags(unsigned int src_cnt, unsigned long flags)
-{
- if (dmaf_p_disabled_continue(flags))
- return src_cnt + 1;
- else if (dmaf_continue(flags))
- return src_cnt + 3;
- else
- return src_cnt;
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_pq(struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
- unsigned int src_cnt, const unsigned char *scf, size_t len,
- unsigned long flags)
-{
- /* specify valid address for disabled result */
- if (flags & DMA_PREP_PQ_DISABLE_P)
- dst[0] = dst[1];
- if (flags & DMA_PREP_PQ_DISABLE_Q)
- dst[1] = dst[0];
-
- /* handle the single source multiply case from the raid6
- * recovery path
- */
- if ((flags & DMA_PREP_PQ_DISABLE_P) && src_cnt == 1) {
- dma_addr_t single_source[2];
- unsigned char single_source_coef[2];
-
- BUG_ON(flags & DMA_PREP_PQ_DISABLE_Q);
- single_source[0] = src[0];
- single_source[1] = src[0];
- single_source_coef[0] = scf[0];
- single_source_coef[1] = 0;
-
- return src_cnt_flags(src_cnt, flags) > 8 ?
- __ioat_prep_pq16_lock(chan, NULL, dst, single_source,
- 2, single_source_coef, len,
- flags) :
- __ioat_prep_pq_lock(chan, NULL, dst, single_source, 2,
- single_source_coef, len, flags);
-
- } else {
- return src_cnt_flags(src_cnt, flags) > 8 ?
- __ioat_prep_pq16_lock(chan, NULL, dst, src, src_cnt,
- scf, len, flags) :
- __ioat_prep_pq_lock(chan, NULL, dst, src, src_cnt,
- scf, len, flags);
- }
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_pq_val(struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src,
- unsigned int src_cnt, const unsigned char *scf, size_t len,
- enum sum_check_flags *pqres, unsigned long flags)
-{
- /* specify valid address for disabled result */
- if (flags & DMA_PREP_PQ_DISABLE_P)
- pq[0] = pq[1];
- if (flags & DMA_PREP_PQ_DISABLE_Q)
- pq[1] = pq[0];
-
- /* the cleanup routine only sets bits on validate failure, it
- * does not clear bits on validate success... so clear it here
- */
- *pqres = 0;
-
- return src_cnt_flags(src_cnt, flags) > 8 ?
- __ioat_prep_pq16_lock(chan, pqres, pq, src, src_cnt, scf, len,
- flags) :
- __ioat_prep_pq_lock(chan, pqres, pq, src, src_cnt, scf, len,
- flags);
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src,
- unsigned int src_cnt, size_t len, unsigned long flags)
-{
- unsigned char scf[src_cnt];
- dma_addr_t pq[2];
-
- memset(scf, 0, src_cnt);
- pq[0] = dst;
- flags |= DMA_PREP_PQ_DISABLE_Q;
- pq[1] = dst; /* specify valid address for disabled result */
-
- return src_cnt_flags(src_cnt, flags) > 8 ?
- __ioat_prep_pq16_lock(chan, NULL, pq, src, src_cnt, scf, len,
- flags) :
- __ioat_prep_pq_lock(chan, NULL, pq, src, src_cnt, scf, len,
- flags);
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
- unsigned int src_cnt, size_t len,
- enum sum_check_flags *result, unsigned long flags)
-{
- unsigned char scf[src_cnt];
- dma_addr_t pq[2];
-
- /* the cleanup routine only sets bits on validate failure, it
- * does not clear bits on validate success... so clear it here
- */
- *result = 0;
-
- memset(scf, 0, src_cnt);
- pq[0] = src[0];
- flags |= DMA_PREP_PQ_DISABLE_Q;
- pq[1] = pq[0]; /* specify valid address for disabled result */
-
- return src_cnt_flags(src_cnt, flags) > 8 ?
- __ioat_prep_pq16_lock(chan, result, pq, &src[1], src_cnt - 1,
- scf, len, flags) :
- __ioat_prep_pq_lock(chan, result, pq, &src[1], src_cnt - 1,
- scf, len, flags);
-}
-
-struct dma_async_tx_descriptor *
-ioat_prep_interrupt_lock(struct dma_chan *c, unsigned long flags)
-{
- struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
- struct ioat_ring_ent *desc;
- struct ioat_dma_descriptor *hw;
-
- if (ioat_check_space_lock(ioat_chan, 1) == 0)
- desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
- else
- return NULL;
-
- hw = desc->hw;
- hw->ctl = 0;
- hw->ctl_f.null = 1;
- hw->ctl_f.int_en = 1;
- hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
- hw->ctl_f.compl_write = 1;
- hw->size = NULL_DESC_BUFFER_SIZE;
- hw->src_addr = 0;
- hw->dst_addr = 0;
-
- desc->txd.flags = flags;
- desc->len = 1;
-
- dump_desc_dbg(ioat_chan, desc);
-
- /* we leave the channel locked to ensure in order submission */
- return &desc->txd;
-}
-
static int ioat3_irq_reinit(struct ioatdma_device *ioat_dma)
{
struct pci_dev *pdev = ioat_dma->pdev;
diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index de8141c7cd01..6b8fd49cf718 100644
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -110,6 +110,9 @@ MODULE_DEVICE_TABLE(pci, ioat_pci_tbl);
static int ioat_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id);
static void ioat_remove(struct pci_dev *pdev);
+static void
+ioat_init_channel(struct ioatdma_device *ioat_dma,
+ struct ioatdma_chan *ioat_chan, int idx);
static int ioat_dca_enabled = 1;
module_param(ioat_dca_enabled, int, 0644);
@@ -269,7 +272,7 @@ static void ioat_dma_test_callback(void *dma_async_param)
* ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
* @ioat_dma: dma device to be tested
*/
-int ioat_dma_self_test(struct ioatdma_device *ioat_dma)
+static int ioat_dma_self_test(struct ioatdma_device *ioat_dma)
{
int i;
u8 *src;
@@ -453,7 +456,6 @@ err_no_irq:
dev_err(dev, "no usable interrupts\n");
return err;
}
-EXPORT_SYMBOL(ioat_dma_setup_interrupts);
static void ioat_disable_interrupts(struct ioatdma_device *ioat_dma)
{
@@ -461,7 +463,7 @@ static void ioat_disable_interrupts(struct ioatdma_device *ioat_dma)
writeb(0, ioat_dma->reg_base + IOAT_INTRCTRL_OFFSET);
}
-int ioat_probe(struct ioatdma_device *ioat_dma)
+static int ioat_probe(struct ioatdma_device *ioat_dma)
{
int err = -ENODEV;
struct dma_device *dma = &ioat_dma->dma_dev;
@@ -517,7 +519,7 @@ err_dma_pool:
return err;
}
-int ioat_register(struct ioatdma_device *ioat_dma)
+static int ioat_register(struct ioatdma_device *ioat_dma)
{
int err = dma_async_device_register(&ioat_dma->dma_dev);
@@ -530,7 +532,7 @@ int ioat_register(struct ioatdma_device *ioat_dma)
return err;
}
-void ioat_dma_remove(struct ioatdma_device *ioat_dma)
+static void ioat_dma_remove(struct ioatdma_device *ioat_dma)
{
struct dma_device *dma = &ioat_dma->dma_dev;
@@ -550,7 +552,7 @@ void ioat_dma_remove(struct ioatdma_device *ioat_dma)
* ioat_enumerate_channels - find and initialize the device's channels
* @ioat_dma: the ioat dma device to be enumerated
*/
-int ioat_enumerate_channels(struct ioatdma_device *ioat_dma)
+static int ioat_enumerate_channels(struct ioatdma_device *ioat_dma)
{
struct ioatdma_chan *ioat_chan;
struct device *dev = &ioat_dma->pdev->dev;
@@ -593,7 +595,7 @@ int ioat_enumerate_channels(struct ioatdma_device *ioat_dma)
* ioat_free_chan_resources - release all the descriptors
* @chan: the channel to be cleaned
*/
-void ioat_free_chan_resources(struct dma_chan *c)
+static void ioat_free_chan_resources(struct dma_chan *c)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
@@ -646,7 +648,7 @@ void ioat_free_chan_resources(struct dma_chan *c)
/* ioat_alloc_chan_resources - allocate/initialize ioat descriptor ring
* @chan: channel to be initialized
*/
-int ioat_alloc_chan_resources(struct dma_chan *c)
+static int ioat_alloc_chan_resources(struct dma_chan *c)
{
struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
struct ioat_ring_ent **ring;
@@ -712,7 +714,7 @@ int ioat_alloc_chan_resources(struct dma_chan *c)
}
/* common channel initialization */
-void
+static void
ioat_init_channel(struct ioatdma_device *ioat_dma,
struct ioatdma_chan *ioat_chan, int idx)
{
@@ -1048,7 +1050,7 @@ static void ioat3_intr_quirk(struct ioatdma_device *ioat_dma)
}
}
-int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca)
+static int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca)
{
struct pci_dev *pdev = ioat_dma->pdev;
int dca_en = system_has_dca_enabled(pdev);
diff --git a/drivers/dma/ioat/prep.c b/drivers/dma/ioat/prep.c
new file mode 100644
index 000000000000..e323a4036908
--- /dev/null
+++ b/drivers/dma/ioat/prep.c
@@ -0,0 +1,707 @@
+/*
+ * Intel I/OAT DMA Linux driver
+ * Copyright(c) 2004 - 2015 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".
+ *
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/prefetch.h>
+#include "../dmaengine.h"
+#include "registers.h"
+#include "hw.h"
+#include "dma.h"
+
+/* provide a lookup table for setting the source address in the base or
+ * extended descriptor of an xor or pq descriptor
+ */
+static const u8 xor_idx_to_desc = 0xe0;
+static const u8 xor_idx_to_field[] = { 1, 4, 5, 6, 7, 0, 1, 2 };
+static const u8 pq_idx_to_desc = 0xf8;
+static const u8 pq16_idx_to_desc[] = { 0, 0, 1, 1, 1, 1, 1, 1, 1,
+ 2, 2, 2, 2, 2, 2, 2 };
+static const u8 pq_idx_to_field[] = { 1, 4, 5, 0, 1, 2, 4, 5 };
+static const u8 pq16_idx_to_field[] = { 1, 4, 1, 2, 3, 4, 5, 6, 7,
+ 0, 1, 2, 3, 4, 5, 6 };
+
+static void xor_set_src(struct ioat_raw_descriptor *descs[2],
+ dma_addr_t addr, u32 offset, int idx)
+{
+ struct ioat_raw_descriptor *raw = descs[xor_idx_to_desc >> idx & 1];
+
+ raw->field[xor_idx_to_field[idx]] = addr + offset;
+}
+
+static dma_addr_t pq_get_src(struct ioat_raw_descriptor *descs[2], int idx)
+{
+ struct ioat_raw_descriptor *raw = descs[pq_idx_to_desc >> idx & 1];
+
+ return raw->field[pq_idx_to_field[idx]];
+}
+
+static dma_addr_t pq16_get_src(struct ioat_raw_descriptor *desc[3], int idx)
+{
+ struct ioat_raw_descriptor *raw = desc[pq16_idx_to_desc[idx]];
+
+ return raw->field[pq16_idx_to_field[idx]];
+}
+
+static void pq_set_src(struct ioat_raw_descriptor *descs[2],
+ dma_addr_t addr, u32 offset, u8 coef, int idx)
+{
+ struct ioat_pq_descriptor *pq = (struct ioat_pq_descriptor *) descs[0];
+ struct ioat_raw_descriptor *raw = descs[pq_idx_to_desc >> idx & 1];
+
+ raw->field[pq_idx_to_field[idx]] = addr + offset;
+ pq->coef[idx] = coef;
+}
+
+static void pq16_set_src(struct ioat_raw_descriptor *desc[3],
+ dma_addr_t addr, u32 offset, u8 coef, unsigned idx)
+{
+ struct ioat_pq_descriptor *pq = (struct ioat_pq_descriptor *)desc[0];
+ struct ioat_pq16a_descriptor *pq16 =
+ (struct ioat_pq16a_descriptor *)desc[1];
+ struct ioat_raw_descriptor *raw = desc[pq16_idx_to_desc[idx]];
+
+ raw->field[pq16_idx_to_field[idx]] = addr + offset;
+
+ if (idx < 8)
+ pq->coef[idx] = coef;
+ else
+ pq16->coef[idx - 8] = coef;
+}
+
+static struct ioat_sed_ent *
+ioat3_alloc_sed(struct ioatdma_device *ioat_dma, unsigned int hw_pool)
+{
+ struct ioat_sed_ent *sed;
+ gfp_t flags = __GFP_ZERO | GFP_ATOMIC;
+
+ sed = kmem_cache_alloc(ioat_sed_cache, flags);
+ if (!sed)
+ return NULL;
+
+ sed->hw_pool = hw_pool;
+ sed->hw = dma_pool_alloc(ioat_dma->sed_hw_pool[hw_pool],
+ flags, &sed->dma);
+ if (!sed->hw) {
+ kmem_cache_free(ioat_sed_cache, sed);
+ return NULL;
+ }
+
+ return sed;
+}
+
+struct dma_async_tx_descriptor *
+ioat_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 ioatdma_chan *ioat_chan = to_ioat_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 = ioat_xferlen_to_descs(ioat_chan, len);
+ if (likely(num_descs) &&
+ ioat_check_space_lock(ioat_chan, num_descs) == 0)
+ idx = ioat_chan->head;
+ else
+ return NULL;
+ i = 0;
+ do {
+ size_t copy = min_t(size_t, len, 1 << ioat_chan->xfercap_log);
+
+ desc = ioat_get_ring_ent(ioat_chan, 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_chan, 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_chan, desc);
+ /* we leave the channel locked to ensure in order submission */
+
+ return &desc->txd;
+}
+
+
+static struct dma_async_tx_descriptor *
+__ioat_prep_xor_lock(struct dma_chan *c, enum sum_check_flags *result,
+ dma_addr_t dest, dma_addr_t *src, unsigned int src_cnt,
+ size_t len, unsigned long flags)
+{
+ struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
+ struct ioat_ring_ent *compl_desc;
+ struct ioat_ring_ent *desc;
+ struct ioat_ring_ent *ext;
+ size_t total_len = len;
+ struct ioat_xor_descriptor *xor;
+ struct ioat_xor_ext_descriptor *xor_ex = NULL;
+ struct ioat_dma_descriptor *hw;
+ int num_descs, with_ext, idx, i;
+ u32 offset = 0;
+ u8 op = result ? IOAT_OP_XOR_VAL : IOAT_OP_XOR;
+
+ BUG_ON(src_cnt < 2);
+
+ num_descs = ioat_xferlen_to_descs(ioat_chan, len);
+ /* we need 2x the number of descriptors to cover greater than 5
+ * sources
+ */
+ if (src_cnt > 5) {
+ with_ext = 1;
+ num_descs *= 2;
+ } else
+ with_ext = 0;
+
+ /* completion writes from the raid engine may pass completion
+ * writes from the legacy engine, so we need one extra null
+ * (legacy) descriptor to ensure all completion writes arrive in
+ * order.
+ */
+ if (likely(num_descs) &&
+ ioat_check_space_lock(ioat_chan, num_descs+1) == 0)
+ idx = ioat_chan->head;
+ else
+ return NULL;
+ i = 0;
+ do {
+ struct ioat_raw_descriptor *descs[2];
+ size_t xfer_size = min_t(size_t,
+ len, 1 << ioat_chan->xfercap_log);
+ int s;
+
+ desc = ioat_get_ring_ent(ioat_chan, idx + i);
+ xor = desc->xor;
+
+ /* save a branch by unconditionally retrieving the
+ * extended descriptor xor_set_src() knows to not write
+ * to it in the single descriptor case
+ */
+ ext = ioat_get_ring_ent(ioat_chan, idx + i + 1);
+ xor_ex = ext->xor_ex;
+
+ descs[0] = (struct ioat_raw_descriptor *) xor;
+ descs[1] = (struct ioat_raw_descriptor *) xor_ex;
+ for (s = 0; s < src_cnt; s++)
+ xor_set_src(descs, src[s], offset, s);
+ xor->size = xfer_size;
+ xor->dst_addr = dest + offset;
+ xor->ctl = 0;
+ xor->ctl_f.op = op;
+ xor->ctl_f.src_cnt = src_cnt_to_hw(src_cnt);
+
+ len -= xfer_size;
+ offset += xfer_size;
+ dump_desc_dbg(ioat_chan, desc);
+ } while ((i += 1 + with_ext) < num_descs);
+
+ /* last xor descriptor carries the unmap parameters and fence bit */
+ desc->txd.flags = flags;
+ desc->len = total_len;
+ if (result)
+ desc->result = result;
+ xor->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+
+ /* completion descriptor carries interrupt bit */
+ compl_desc = ioat_get_ring_ent(ioat_chan, idx + i);
+ compl_desc->txd.flags = flags & DMA_PREP_INTERRUPT;
+ hw = compl_desc->hw;
+ hw->ctl = 0;
+ hw->ctl_f.null = 1;
+ hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+ hw->ctl_f.compl_write = 1;
+ hw->size = NULL_DESC_BUFFER_SIZE;
+ dump_desc_dbg(ioat_chan, compl_desc);
+
+ /* we leave the channel locked to ensure in order submission */
+ return &compl_desc->txd;
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
+ unsigned int src_cnt, size_t len, unsigned long flags)
+{
+ return __ioat_prep_xor_lock(chan, NULL, dest, src, src_cnt, len, flags);
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_xor_val(struct dma_chan *chan, dma_addr_t *src,
+ unsigned int src_cnt, size_t len,
+ enum sum_check_flags *result, unsigned long flags)
+{
+ /* the cleanup routine only sets bits on validate failure, it
+ * does not clear bits on validate success... so clear it here
+ */
+ *result = 0;
+
+ return __ioat_prep_xor_lock(chan, result, src[0], &src[1],
+ src_cnt - 1, len, flags);
+}
+
+static void
+dump_pq_desc_dbg(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc,
+ struct ioat_ring_ent *ext)
+{
+ struct device *dev = to_dev(ioat_chan);
+ struct ioat_pq_descriptor *pq = desc->pq;
+ struct ioat_pq_ext_descriptor *pq_ex = ext ? ext->pq_ex : NULL;
+ struct ioat_raw_descriptor *descs[] = { (void *) pq, (void *) pq_ex };
+ int src_cnt = src_cnt_to_sw(pq->ctl_f.src_cnt);
+ int i;
+
+ dev_dbg(dev, "desc[%d]: (%#llx->%#llx) flags: %#x"
+ " sz: %#10.8x ctl: %#x (op: %#x int: %d compl: %d pq: '%s%s'"
+ " src_cnt: %d)\n",
+ desc_id(desc), (unsigned long long) desc->txd.phys,
+ (unsigned long long) (pq_ex ? pq_ex->next : pq->next),
+ desc->txd.flags, pq->size, pq->ctl, pq->ctl_f.op,
+ pq->ctl_f.int_en, pq->ctl_f.compl_write,
+ pq->ctl_f.p_disable ? "" : "p", pq->ctl_f.q_disable ? "" : "q",
+ pq->ctl_f.src_cnt);
+ for (i = 0; i < src_cnt; i++)
+ dev_dbg(dev, "\tsrc[%d]: %#llx coef: %#x\n", i,
+ (unsigned long long) pq_get_src(descs, i), pq->coef[i]);
+ dev_dbg(dev, "\tP: %#llx\n", pq->p_addr);
+ dev_dbg(dev, "\tQ: %#llx\n", pq->q_addr);
+ dev_dbg(dev, "\tNEXT: %#llx\n", pq->next);
+}
+
+static void dump_pq16_desc_dbg(struct ioatdma_chan *ioat_chan,
+ struct ioat_ring_ent *desc)
+{
+ struct device *dev = to_dev(ioat_chan);
+ struct ioat_pq_descriptor *pq = desc->pq;
+ struct ioat_raw_descriptor *descs[] = { (void *)pq,
+ (void *)pq,
+ (void *)pq };
+ int src_cnt = src16_cnt_to_sw(pq->ctl_f.src_cnt);
+ int i;
+
+ if (desc->sed) {
+ descs[1] = (void *)desc->sed->hw;
+ descs[2] = (void *)desc->sed->hw + 64;
+ }
+
+ dev_dbg(dev, "desc[%d]: (%#llx->%#llx) flags: %#x"
+ " sz: %#x ctl: %#x (op: %#x int: %d compl: %d pq: '%s%s'"
+ " src_cnt: %d)\n",
+ desc_id(desc), (unsigned long long) desc->txd.phys,
+ (unsigned long long) pq->next,
+ desc->txd.flags, pq->size, pq->ctl,
+ pq->ctl_f.op, pq->ctl_f.int_en,
+ pq->ctl_f.compl_write,
+ pq->ctl_f.p_disable ? "" : "p", pq->ctl_f.q_disable ? "" : "q",
+ pq->ctl_f.src_cnt);
+ for (i = 0; i < src_cnt; i++) {
+ dev_dbg(dev, "\tsrc[%d]: %#llx coef: %#x\n", i,
+ (unsigned long long) pq16_get_src(descs, i),
+ pq->coef[i]);
+ }
+ dev_dbg(dev, "\tP: %#llx\n", pq->p_addr);
+ dev_dbg(dev, "\tQ: %#llx\n", pq->q_addr);
+}
+
+static struct dma_async_tx_descriptor *
+__ioat_prep_pq_lock(struct dma_chan *c, enum sum_check_flags *result,
+ const dma_addr_t *dst, const dma_addr_t *src,
+ unsigned int src_cnt, const unsigned char *scf,
+ size_t len, unsigned long flags)
+{
+ struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
+ struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
+ struct ioat_ring_ent *compl_desc;
+ struct ioat_ring_ent *desc;
+ struct ioat_ring_ent *ext;
+ size_t total_len = len;
+ struct ioat_pq_descriptor *pq;
+ struct ioat_pq_ext_descriptor *pq_ex = NULL;
+ struct ioat_dma_descriptor *hw;
+ u32 offset = 0;
+ u8 op = result ? IOAT_OP_PQ_VAL : IOAT_OP_PQ;
+ int i, s, idx, with_ext, num_descs;
+ int cb32 = (ioat_dma->version < IOAT_VER_3_3) ? 1 : 0;
+
+ dev_dbg(to_dev(ioat_chan), "%s\n", __func__);
+ /* the engine requires at least two sources (we provide
+ * at least 1 implied source in the DMA_PREP_CONTINUE case)
+ */
+ BUG_ON(src_cnt + dmaf_continue(flags) < 2);
+
+ num_descs = ioat_xferlen_to_descs(ioat_chan, len);
+ /* we need 2x the number of descriptors to cover greater than 3
+ * sources (we need 1 extra source in the q-only continuation
+ * case and 3 extra sources in the p+q continuation case.
+ */
+ if (src_cnt + dmaf_p_disabled_continue(flags) > 3 ||
+ (dmaf_continue(flags) && !dmaf_p_disabled_continue(flags))) {
+ with_ext = 1;
+ num_descs *= 2;
+ } else
+ with_ext = 0;
+
+ /* completion writes from the raid engine may pass completion
+ * writes from the legacy engine, so we need one extra null
+ * (legacy) descriptor to ensure all completion writes arrive in
+ * order.
+ */
+ if (likely(num_descs) &&
+ ioat_check_space_lock(ioat_chan, num_descs + cb32) == 0)
+ idx = ioat_chan->head;
+ else
+ return NULL;
+ i = 0;
+ do {
+ struct ioat_raw_descriptor *descs[2];
+ size_t xfer_size = min_t(size_t, len,
+ 1 << ioat_chan->xfercap_log);
+
+ desc = ioat_get_ring_ent(ioat_chan, idx + i);
+ pq = desc->pq;
+
+ /* save a branch by unconditionally retrieving the
+ * extended descriptor pq_set_src() knows to not write
+ * to it in the single descriptor case
+ */
+ ext = ioat_get_ring_ent(ioat_chan, idx + i + with_ext);
+ pq_ex = ext->pq_ex;
+
+ descs[0] = (struct ioat_raw_descriptor *) pq;
+ descs[1] = (struct ioat_raw_descriptor *) pq_ex;
+
+ for (s = 0; s < src_cnt; s++)
+ pq_set_src(descs, src[s], offset, scf[s], s);
+
+ /* see the comment for dma_maxpq in include/linux/dmaengine.h */
+ if (dmaf_p_disabled_continue(flags))
+ pq_set_src(descs, dst[1], offset, 1, s++);
+ else if (dmaf_continue(flags)) {
+ pq_set_src(descs, dst[0], offset, 0, s++);
+ pq_set_src(descs, dst[1], offset, 1, s++);
+ pq_set_src(descs, dst[1], offset, 0, s++);
+ }
+ pq->size = xfer_size;
+ pq->p_addr = dst[0] + offset;
+ pq->q_addr = dst[1] + offset;
+ pq->ctl = 0;
+ pq->ctl_f.op = op;
+ /* we turn on descriptor write back error status */
+ if (ioat_dma->cap & IOAT_CAP_DWBES)
+ pq->ctl_f.wb_en = result ? 1 : 0;
+ pq->ctl_f.src_cnt = src_cnt_to_hw(s);
+ pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
+ pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
+
+ len -= xfer_size;
+ offset += xfer_size;
+ } while ((i += 1 + with_ext) < num_descs);
+
+ /* last pq descriptor carries the unmap parameters and fence bit */
+ desc->txd.flags = flags;
+ desc->len = total_len;
+ if (result)
+ desc->result = result;
+ pq->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+ dump_pq_desc_dbg(ioat_chan, desc, ext);
+
+ if (!cb32) {
+ pq->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+ pq->ctl_f.compl_write = 1;
+ compl_desc = desc;
+ } else {
+ /* completion descriptor carries interrupt bit */
+ compl_desc = ioat_get_ring_ent(ioat_chan, idx + i);
+ compl_desc->txd.flags = flags & DMA_PREP_INTERRUPT;
+ hw = compl_desc->hw;
+ hw->ctl = 0;
+ hw->ctl_f.null = 1;
+ hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+ hw->ctl_f.compl_write = 1;
+ hw->size = NULL_DESC_BUFFER_SIZE;
+ dump_desc_dbg(ioat_chan, compl_desc);
+ }
+
+
+ /* we leave the channel locked to ensure in order submission */
+ return &compl_desc->txd;
+}
+
+static struct dma_async_tx_descriptor *
+__ioat_prep_pq16_lock(struct dma_chan *c, enum sum_check_flags *result,
+ const dma_addr_t *dst, const dma_addr_t *src,
+ unsigned int src_cnt, const unsigned char *scf,
+ size_t len, unsigned long flags)
+{
+ struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
+ struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
+ struct ioat_ring_ent *desc;
+ size_t total_len = len;
+ struct ioat_pq_descriptor *pq;
+ u32 offset = 0;
+ u8 op;
+ int i, s, idx, num_descs;
+
+ /* this function is only called with 9-16 sources */
+ op = result ? IOAT_OP_PQ_VAL_16S : IOAT_OP_PQ_16S;
+
+ dev_dbg(to_dev(ioat_chan), "%s\n", __func__);
+
+ num_descs = ioat_xferlen_to_descs(ioat_chan, len);
+
+ /*
+ * 16 source pq is only available on cb3.3 and has no completion
+ * write hw bug.
+ */
+ if (num_descs && ioat_check_space_lock(ioat_chan, num_descs) == 0)
+ idx = ioat_chan->head;
+ else
+ return NULL;
+
+ i = 0;
+
+ do {
+ struct ioat_raw_descriptor *descs[4];
+ size_t xfer_size = min_t(size_t, len,
+ 1 << ioat_chan->xfercap_log);
+
+ desc = ioat_get_ring_ent(ioat_chan, idx + i);
+ pq = desc->pq;
+
+ descs[0] = (struct ioat_raw_descriptor *) pq;
+
+ desc->sed = ioat3_alloc_sed(ioat_dma, (src_cnt-2) >> 3);
+ if (!desc->sed) {
+ dev_err(to_dev(ioat_chan),
+ "%s: no free sed entries\n", __func__);
+ return NULL;
+ }
+
+ pq->sed_addr = desc->sed->dma;
+ desc->sed->parent = desc;
+
+ descs[1] = (struct ioat_raw_descriptor *)desc->sed->hw;
+ descs[2] = (void *)descs[1] + 64;
+
+ for (s = 0; s < src_cnt; s++)
+ pq16_set_src(descs, src[s], offset, scf[s], s);
+
+ /* see the comment for dma_maxpq in include/linux/dmaengine.h */
+ if (dmaf_p_disabled_continue(flags))
+ pq16_set_src(descs, dst[1], offset, 1, s++);
+ else if (dmaf_continue(flags)) {
+ pq16_set_src(descs, dst[0], offset, 0, s++);
+ pq16_set_src(descs, dst[1], offset, 1, s++);
+ pq16_set_src(descs, dst[1], offset, 0, s++);
+ }
+
+ pq->size = xfer_size;
+ pq->p_addr = dst[0] + offset;
+ pq->q_addr = dst[1] + offset;
+ pq->ctl = 0;
+ pq->ctl_f.op = op;
+ pq->ctl_f.src_cnt = src16_cnt_to_hw(s);
+ /* we turn on descriptor write back error status */
+ if (ioat_dma->cap & IOAT_CAP_DWBES)
+ pq->ctl_f.wb_en = result ? 1 : 0;
+ pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
+ pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
+
+ len -= xfer_size;
+ offset += xfer_size;
+ } while (++i < num_descs);
+
+ /* last pq descriptor carries the unmap parameters and fence bit */
+ desc->txd.flags = flags;
+ desc->len = total_len;
+ if (result)
+ desc->result = result;
+ pq->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+
+ /* with cb3.3 we should be able to do completion w/o a null desc */
+ pq->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+ pq->ctl_f.compl_write = 1;
+
+ dump_pq16_desc_dbg(ioat_chan, desc);
+
+ /* we leave the channel locked to ensure in order submission */
+ return &desc->txd;
+}
+
+static int src_cnt_flags(unsigned int src_cnt, unsigned long flags)
+{
+ if (dmaf_p_disabled_continue(flags))
+ return src_cnt + 1;
+ else if (dmaf_continue(flags))
+ return src_cnt + 3;
+ else
+ return src_cnt;
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_pq(struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
+ unsigned int src_cnt, const unsigned char *scf, size_t len,
+ unsigned long flags)
+{
+ /* specify valid address for disabled result */
+ if (flags & DMA_PREP_PQ_DISABLE_P)
+ dst[0] = dst[1];
+ if (flags & DMA_PREP_PQ_DISABLE_Q)
+ dst[1] = dst[0];
+
+ /* handle the single source multiply case from the raid6
+ * recovery path
+ */
+ if ((flags & DMA_PREP_PQ_DISABLE_P) && src_cnt == 1) {
+ dma_addr_t single_source[2];
+ unsigned char single_source_coef[2];
+
+ BUG_ON(flags & DMA_PREP_PQ_DISABLE_Q);
+ single_source[0] = src[0];
+ single_source[1] = src[0];
+ single_source_coef[0] = scf[0];
+ single_source_coef[1] = 0;
+
+ return src_cnt_flags(src_cnt, flags) > 8 ?
+ __ioat_prep_pq16_lock(chan, NULL, dst, single_source,
+ 2, single_source_coef, len,
+ flags) :
+ __ioat_prep_pq_lock(chan, NULL, dst, single_source, 2,
+ single_source_coef, len, flags);
+
+ } else {
+ return src_cnt_flags(src_cnt, flags) > 8 ?
+ __ioat_prep_pq16_lock(chan, NULL, dst, src, src_cnt,
+ scf, len, flags) :
+ __ioat_prep_pq_lock(chan, NULL, dst, src, src_cnt,
+ scf, len, flags);
+ }
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_pq_val(struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src,
+ unsigned int src_cnt, const unsigned char *scf, size_t len,
+ enum sum_check_flags *pqres, unsigned long flags)
+{
+ /* specify valid address for disabled result */
+ if (flags & DMA_PREP_PQ_DISABLE_P)
+ pq[0] = pq[1];
+ if (flags & DMA_PREP_PQ_DISABLE_Q)
+ pq[1] = pq[0];
+
+ /* the cleanup routine only sets bits on validate failure, it
+ * does not clear bits on validate success... so clear it here
+ */
+ *pqres = 0;
+
+ return src_cnt_flags(src_cnt, flags) > 8 ?
+ __ioat_prep_pq16_lock(chan, pqres, pq, src, src_cnt, scf, len,
+ flags) :
+ __ioat_prep_pq_lock(chan, pqres, pq, src, src_cnt, scf, len,
+ flags);
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src,
+ unsigned int src_cnt, size_t len, unsigned long flags)
+{
+ unsigned char scf[src_cnt];
+ dma_addr_t pq[2];
+
+ memset(scf, 0, src_cnt);
+ pq[0] = dst;
+ flags |= DMA_PREP_PQ_DISABLE_Q;
+ pq[1] = dst; /* specify valid address for disabled result */
+
+ return src_cnt_flags(src_cnt, flags) > 8 ?
+ __ioat_prep_pq16_lock(chan, NULL, pq, src, src_cnt, scf, len,
+ flags) :
+ __ioat_prep_pq_lock(chan, NULL, pq, src, src_cnt, scf, len,
+ flags);
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
+ unsigned int src_cnt, size_t len,
+ enum sum_check_flags *result, unsigned long flags)
+{
+ unsigned char scf[src_cnt];
+ dma_addr_t pq[2];
+
+ /* the cleanup routine only sets bits on validate failure, it
+ * does not clear bits on validate success... so clear it here
+ */
+ *result = 0;
+
+ memset(scf, 0, src_cnt);
+ pq[0] = src[0];
+ flags |= DMA_PREP_PQ_DISABLE_Q;
+ pq[1] = pq[0]; /* specify valid address for disabled result */
+
+ return src_cnt_flags(src_cnt, flags) > 8 ?
+ __ioat_prep_pq16_lock(chan, result, pq, &src[1], src_cnt - 1,
+ scf, len, flags) :
+ __ioat_prep_pq_lock(chan, result, pq, &src[1], src_cnt - 1,
+ scf, len, flags);
+}
+
+struct dma_async_tx_descriptor *
+ioat_prep_interrupt_lock(struct dma_chan *c, unsigned long flags)
+{
+ struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
+ struct ioat_ring_ent *desc;
+ struct ioat_dma_descriptor *hw;
+
+ if (ioat_check_space_lock(ioat_chan, 1) == 0)
+ desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
+ else
+ return NULL;
+
+ hw = desc->hw;
+ hw->ctl = 0;
+ hw->ctl_f.null = 1;
+ hw->ctl_f.int_en = 1;
+ hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+ hw->ctl_f.compl_write = 1;
+ hw->size = NULL_DESC_BUFFER_SIZE;
+ hw->src_addr = 0;
+ hw->dst_addr = 0;
+
+ desc->txd.flags = flags;
+ desc->len = 1;
+
+ dump_desc_dbg(ioat_chan, desc);
+
+ /* we leave the channel locked to ensure in order submission */
+ return &desc->txd;
+}
+