iop-adma: P+Q support for iop13xx adma engines

iop33x support is not included because that engine is a bit more awkward
to handle in that it can either be in xor mode or pq mode.  The
dmaengine/async_tx layers currently only comprehend static capabilities.

Note iop13xx does not support hardware PQ continuation so the driver
must handle the DMA_PREP_CONTINUE flag for operations across > 16
sources. From the comment for dma_maxpq:

/* When an engine does not support native continuation we need 3 extra
 * source slots to reuse P and Q with the following coefficients:
 * 1/ {00} * P : remove P from Q', but use it as a source for P'
 * 2/ {01} * Q : use Q to continue Q' calculation
 * 3/ {00} * Q : subtract Q from P' to cancel (2)
 */

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

4 files changed, 381 insertions, 34 deletions

diff --git a/arch/arm/include/asm/hardware/iop3xx-adma.h b/arch/arm/include/asm/hardware/iop3xx-adma.h
index 26eefea02314..1a8c7279a28b 100644
--- a/arch/arm/include/asm/hardware/iop3xx-adma.h
+++ b/arch/arm/include/asm/hardware/iop3xx-adma.h
@@ -187,11 +187,74 @@ union iop3xx_desc {
         void *ptr;
 };
 
+/* No support for p+q operations */
+static inline int
+iop_chan_pq_slot_count(size_t len, int src_cnt, int *slots_per_op)
+{
+        BUG();
+        return 0;
+}
+
+static inline void
+iop_desc_init_pq(struct iop_adma_desc_slot *desc, int src_cnt,
+                  unsigned long flags)
+{
+        BUG();
+}
+
+static inline void
+iop_desc_set_pq_addr(struct iop_adma_desc_slot *desc, dma_addr_t *addr)
+{
+        BUG();
+}
+
+static inline void
+iop_desc_set_pq_src_addr(struct iop_adma_desc_slot *desc, int src_idx,
+                         dma_addr_t addr, unsigned char coef)
+{
+        BUG();
+}
+
+static inline int
+iop_chan_pq_zero_sum_slot_count(size_t len, int src_cnt, int *slots_per_op)
+{
+        BUG();
+        return 0;
+}
+
+static inline void
+iop_desc_init_pq_zero_sum(struct iop_adma_desc_slot *desc, int src_cnt,
+                          unsigned long flags)
+{
+        BUG();
+}
+
+static inline void
+iop_desc_set_pq_zero_sum_byte_count(struct iop_adma_desc_slot *desc, u32 len)
+{
+        BUG();
+}
+
+#define iop_desc_set_pq_zero_sum_src_addr iop_desc_set_pq_src_addr
+
+static inline void
+iop_desc_set_pq_zero_sum_addr(struct iop_adma_desc_slot *desc, int pq_idx,
+                              dma_addr_t *src)
+{
+        BUG();
+}
+
 static inline int iop_adma_get_max_xor(void)
 {
         return 32;
 }
 
+static inline int iop_adma_get_max_pq(void)
+{
+        BUG();
+        return 0;
+}
+
 static inline u32 iop_chan_get_current_descriptor(struct iop_adma_chan *chan)
 {
         int id = chan->device->id;
@@ -332,6 +395,11 @@ static inline int iop_chan_zero_sum_slot_count(size_t len, int src_cnt,
         return slot_cnt;
 }
 
+static inline int iop_desc_is_pq(struct iop_adma_desc_slot *desc)
+{
+        return 0;
+}
+
 static inline u32 iop_desc_get_dest_addr(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan)
 {
@@ -349,6 +417,14 @@ static inline u32 iop_desc_get_dest_addr(struct iop_adma_desc_slot *desc,
         return 0;
 }
 
+
+static inline u32 iop_desc_get_qdest_addr(struct iop_adma_desc_slot *desc,
+                                          struct iop_adma_chan *chan)
+{
+        BUG();
+        return 0;
+}
+
 static inline u32 iop_desc_get_byte_count(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan)
 {
diff --git a/arch/arm/include/asm/hardware/iop_adma.h b/arch/arm/include/asm/hardware/iop_adma.h
index 385c6e8cbbd2..bbe8a0475cad 100644
--- a/arch/arm/include/asm/hardware/iop_adma.h
+++ b/arch/arm/include/asm/hardware/iop_adma.h
@@ -106,6 +106,7 @@ struct iop_adma_desc_slot {
         union {
                 u32 *xor_check_result;
                 u32 *crc32_result;
+                u32 *pq_check_result;
         };
 };
 
diff --git a/arch/arm/mach-iop13xx/include/mach/adma.h b/arch/arm/mach-iop13xx/include/mach/adma.h
index 1cd31df8924d..6d3782d85a9f 100644
--- a/arch/arm/mach-iop13xx/include/mach/adma.h
+++ b/arch/arm/mach-iop13xx/include/mach/adma.h
@@ -150,6 +150,8 @@ static inline int iop_adma_get_max_xor(void)
         return 16;
 }
 
+#define iop_adma_get_max_pq iop_adma_get_max_xor
+
 static inline u32 iop_chan_get_current_descriptor(struct iop_adma_chan *chan)
 {
         return __raw_readl(ADMA_ADAR(chan));
@@ -211,7 +213,10 @@ iop_chan_xor_slot_count(size_t len, int src_cnt, int *slots_per_op)
 #define IOP_ADMA_MAX_BYTE_COUNT ADMA_MAX_BYTE_COUNT
 #define IOP_ADMA_ZERO_SUM_MAX_BYTE_COUNT ADMA_MAX_BYTE_COUNT
 #define IOP_ADMA_XOR_MAX_BYTE_COUNT ADMA_MAX_BYTE_COUNT
+#define IOP_ADMA_PQ_MAX_BYTE_COUNT ADMA_MAX_BYTE_COUNT
 #define iop_chan_zero_sum_slot_count(l, s, o) iop_chan_xor_slot_count(l, s, o)
+#define iop_chan_pq_slot_count iop_chan_xor_slot_count
+#define iop_chan_pq_zero_sum_slot_count iop_chan_xor_slot_count
 
 static inline u32 iop_desc_get_dest_addr(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan)
@@ -220,6 +225,13 @@ static inline u32 iop_desc_get_dest_addr(struct iop_adma_desc_slot *desc,
         return hw_desc->dest_addr;
 }
 
+static inline u32 iop_desc_get_qdest_addr(struct iop_adma_desc_slot *desc,
+                                          struct iop_adma_chan *chan)
+{
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
+        return hw_desc->q_dest_addr;
+}
+
 static inline u32 iop_desc_get_byte_count(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan)
 {
@@ -319,6 +331,58 @@ iop_desc_init_zero_sum(struct iop_adma_desc_slot *desc, int src_cnt,
         return 1;
 }
 
+static inline void
+iop_desc_init_pq(struct iop_adma_desc_slot *desc, int src_cnt,
+                  unsigned long flags)
+{
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
+        union {
+                u32 value;
+                struct iop13xx_adma_desc_ctrl field;
+        } u_desc_ctrl;
+
+        u_desc_ctrl.value = 0;
+        u_desc_ctrl.field.src_select = src_cnt - 1;
+        u_desc_ctrl.field.xfer_dir = 3; /* local to internal bus */
+        u_desc_ctrl.field.pq_xfer_en = 1;
+        u_desc_ctrl.field.p_xfer_dis = !!(flags & DMA_PREP_PQ_DISABLE_P);
+        u_desc_ctrl.field.int_en = flags & DMA_PREP_INTERRUPT;
+        hw_desc->desc_ctrl = u_desc_ctrl.value;
+}
+
+static inline int iop_desc_is_pq(struct iop_adma_desc_slot *desc)
+{
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
+        union {
+                u32 value;
+                struct iop13xx_adma_desc_ctrl field;
+        } u_desc_ctrl;
+
+        u_desc_ctrl.value = hw_desc->desc_ctrl;
+        return u_desc_ctrl.field.pq_xfer_en;
+}
+
+static inline void
+iop_desc_init_pq_zero_sum(struct iop_adma_desc_slot *desc, int src_cnt,
+                          unsigned long flags)
+{
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
+        union {
+                u32 value;
+                struct iop13xx_adma_desc_ctrl field;
+        } u_desc_ctrl;
+
+        u_desc_ctrl.value = 0;
+        u_desc_ctrl.field.src_select = src_cnt - 1;
+        u_desc_ctrl.field.xfer_dir = 3; /* local to internal bus */
+        u_desc_ctrl.field.zero_result = 1;
+        u_desc_ctrl.field.status_write_back_en = 1;
+        u_desc_ctrl.field.pq_xfer_en = 1;
+        u_desc_ctrl.field.p_xfer_dis = !!(flags & DMA_PREP_PQ_DISABLE_P);
+        u_desc_ctrl.field.int_en = flags & DMA_PREP_INTERRUPT;
+        hw_desc->desc_ctrl = u_desc_ctrl.value;
+}
+
 static inline void iop_desc_set_byte_count(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan,
                                         u32 byte_count)
@@ -351,6 +415,7 @@ iop_desc_set_zero_sum_byte_count(struct iop_adma_desc_slot *desc, u32 len)
         }
 }
 
+#define iop_desc_set_pq_zero_sum_byte_count iop_desc_set_zero_sum_byte_count
 
 static inline void iop_desc_set_dest_addr(struct iop_adma_desc_slot *desc,
                                         struct iop_adma_chan *chan,
@@ -361,6 +426,16 @@ static inline void iop_desc_set_dest_addr(struct iop_adma_desc_slot *desc,
         hw_desc->upper_dest_addr = 0;
 }
 
+static inline void
+iop_desc_set_pq_addr(struct iop_adma_desc_slot *desc, dma_addr_t *addr)
+{
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
+
+        hw_desc->dest_addr = addr[0];
+        hw_desc->q_dest_addr = addr[1];
+        hw_desc->upper_dest_addr = 0;
+}
+
 static inline void iop_desc_set_memcpy_src_addr(struct iop_adma_desc_slot *desc,
                                         dma_addr_t addr)
 {
@@ -389,6 +464,29 @@ static inline void iop_desc_set_xor_src_addr(struct iop_adma_desc_slot *desc,
 }
 
 static inline void
+iop_desc_set_pq_src_addr(struct iop_adma_desc_slot *desc, int src_idx,
+                         dma_addr_t addr, unsigned char coef)
+{
+        int slot_cnt = desc->slot_cnt, slots_per_op = desc->slots_per_op;
+        struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc, *iter;
+        struct iop13xx_adma_src *src;
+        int i = 0;
+
+        do {
+                iter = iop_hw_desc_slot_idx(hw_desc, i);
+                src = &iter->src[src_idx];
+                src->src_addr = addr;
+                src->pq_upper_src_addr = 0;
+                src->pq_dmlt = coef;
+                slot_cnt -= slots_per_op;
+                if (slot_cnt) {
+                        i += slots_per_op;
+                        addr += IOP_ADMA_PQ_MAX_BYTE_COUNT;
+                }
+        } while (slot_cnt);
+}
+
+static inline void
 iop_desc_init_interrupt(struct iop_adma_desc_slot *desc,
         struct iop_adma_chan *chan)
 {
@@ -399,6 +497,15 @@ iop_desc_init_interrupt(struct iop_adma_desc_slot *desc,
 }
 
 #define iop_desc_set_zero_sum_src_addr iop_desc_set_xor_src_addr
+#define iop_desc_set_pq_zero_sum_src_addr iop_desc_set_pq_src_addr
+
+static inline void
+iop_desc_set_pq_zero_sum_addr(struct iop_adma_desc_slot *desc, int pq_idx,
+                              dma_addr_t *src)
+{
+        iop_desc_set_xor_src_addr(desc, pq_idx, src[pq_idx]);
+        iop_desc_set_xor_src_addr(desc, pq_idx+1, src[pq_idx+1]);
+}
 
 static inline void iop_desc_set_next_desc(struct iop_adma_desc_slot *desc,
                                         u32 next_desc_addr)
diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 9c752bd295e1..5a0f4fe2ee6e 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -57,6 +57,80 @@ static void iop_adma_free_slots(struct iop_adma_desc_slot *slot)
         }
 }
 
+static void
+iop_desc_unmap(struct iop_adma_chan *iop_chan, struct iop_adma_desc_slot *desc)
+{
+        struct dma_async_tx_descriptor *tx = &desc->async_tx;
+        struct iop_adma_desc_slot *unmap = desc->group_head;
+        struct device *dev = &iop_chan->device->pdev->dev;
+        u32 len = unmap->unmap_len;
+        enum dma_ctrl_flags flags = tx->flags;
+        u32 src_cnt;
+        dma_addr_t addr;
+        dma_addr_t dest;
+
+        src_cnt = unmap->unmap_src_cnt;
+        dest = iop_desc_get_dest_addr(unmap, iop_chan);
+        if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+                enum dma_data_direction dir;
+
+                if (src_cnt > 1) /* is xor? */
+                        dir = DMA_BIDIRECTIONAL;
+                else
+                        dir = DMA_FROM_DEVICE;
+
+                dma_unmap_page(dev, dest, len, dir);
+        }
+
+        if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+                while (src_cnt--) {
+                        addr = iop_desc_get_src_addr(unmap, iop_chan, src_cnt);
+                        if (addr == dest)
+                                continue;
+                        dma_unmap_page(dev, addr, len, DMA_TO_DEVICE);
+                }
+        }
+        desc->group_head = NULL;
+}
+
+static void
+iop_desc_unmap_pq(struct iop_adma_chan *iop_chan, struct iop_adma_desc_slot *desc)
+{
+        struct dma_async_tx_descriptor *tx = &desc->async_tx;
+        struct iop_adma_desc_slot *unmap = desc->group_head;
+        struct device *dev = &iop_chan->device->pdev->dev;
+        u32 len = unmap->unmap_len;
+        enum dma_ctrl_flags flags = tx->flags;
+        u32 src_cnt = unmap->unmap_src_cnt;
+        dma_addr_t pdest = iop_desc_get_dest_addr(unmap, iop_chan);
+        dma_addr_t qdest = iop_desc_get_qdest_addr(unmap, iop_chan);
+        int i;
+
+        if (tx->flags & DMA_PREP_CONTINUE)
+                src_cnt -= 3;
+
+        if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP) && !desc->pq_check_result) {
+                dma_unmap_page(dev, pdest, len, DMA_BIDIRECTIONAL);
+                dma_unmap_page(dev, qdest, len, DMA_BIDIRECTIONAL);
+        }
+
+        if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+                dma_addr_t addr;
+
+                for (i = 0; i < src_cnt; i++) {
+                        addr = iop_desc_get_src_addr(unmap, iop_chan, i);
+                        dma_unmap_page(dev, addr, len, DMA_TO_DEVICE);
+                }
+                if (desc->pq_check_result) {
+                        dma_unmap_page(dev, pdest, len, DMA_TO_DEVICE);
+                        dma_unmap_page(dev, qdest, len, DMA_TO_DEVICE);
+                }
+        }
+
+        desc->group_head = NULL;
+}
+
+
 static dma_cookie_t
 iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
         struct iop_adma_chan *iop_chan, dma_cookie_t cookie)
@@ -78,40 +152,10 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
                  * (unmap_single vs unmap_page?)
                  */
                 if (desc->group_head && desc->unmap_len) {
-                        struct iop_adma_desc_slot *unmap = desc->group_head;
-                        struct device *dev =
-                                &iop_chan->device->pdev->dev;
-                        u32 len = unmap->unmap_len;
-                        enum dma_ctrl_flags flags = tx->flags;
-                        u32 src_cnt;
-                        dma_addr_t addr;
-                        dma_addr_t dest;
-
-                        src_cnt = unmap->unmap_src_cnt;
-                        dest = iop_desc_get_dest_addr(unmap, iop_chan);
-                        if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-                                enum dma_data_direction dir;
-
-                                if (src_cnt > 1) /* is xor? */
-                                        dir = DMA_BIDIRECTIONAL;
-                                else
-                                        dir = DMA_FROM_DEVICE;
-
-                                dma_unmap_page(dev, dest, len, dir);
-                        }
-
-                        if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-                                while (src_cnt--) {
-                                        addr = iop_desc_get_src_addr(unmap,
-                                                                     iop_chan,
-                                                                     src_cnt);
-                                        if (addr == dest)
-                                                continue;
-                                        dma_unmap_page(dev, addr, len,
-                                                       DMA_TO_DEVICE);
-                                }
-                        }
-                        desc->group_head = NULL;
+                        if (iop_desc_is_pq(desc))
+                                iop_desc_unmap_pq(iop_chan, desc);
+                        else
+                                iop_desc_unmap(iop_chan, desc);
                 }
         }
 
@@ -702,6 +746,118 @@ iop_adma_prep_dma_xor_val(struct dma_chan *chan, dma_addr_t *dma_src,
         return sw_desc ? &sw_desc->async_tx : NULL;
 }
 
+static struct dma_async_tx_descriptor *
+iop_adma_prep_dma_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)
+{
+        struct iop_adma_chan *iop_chan = to_iop_adma_chan(chan);
+        struct iop_adma_desc_slot *sw_desc, *g;
+        int slot_cnt, slots_per_op;
+        int continue_srcs;
+
+        if (unlikely(!len))
+                return NULL;
+        BUG_ON(len > IOP_ADMA_XOR_MAX_BYTE_COUNT);
+
+        dev_dbg(iop_chan->device->common.dev,
+                "%s src_cnt: %d len: %u flags: %lx\n",
+                __func__, src_cnt, len, flags);
+
+        if (dmaf_p_disabled_continue(flags))
+                continue_srcs = 1+src_cnt;
+        else if (dmaf_continue(flags))
+                continue_srcs = 3+src_cnt;
+        else
+                continue_srcs = 0+src_cnt;
+
+        spin_lock_bh(&iop_chan->lock);
+        slot_cnt = iop_chan_pq_slot_count(len, continue_srcs, &slots_per_op);
+        sw_desc = iop_adma_alloc_slots(iop_chan, slot_cnt, slots_per_op);
+        if (sw_desc) {
+                int i;
+
+                g = sw_desc->group_head;
+                iop_desc_set_byte_count(g, iop_chan, len);
+
+                /* even if P is disabled its destination address (bits
+                 * [3:0]) must match Q.  It is ok if P points to an
+                 * invalid address, it won't be written.
+                 */
+                if (flags & DMA_PREP_PQ_DISABLE_P)
+                        dst[0] = dst[1] & 0x7;
+
+                iop_desc_set_pq_addr(g, dst);
+                sw_desc->unmap_src_cnt = src_cnt;
+                sw_desc->unmap_len = len;
+                sw_desc->async_tx.flags = flags;
+                for (i = 0; i < src_cnt; i++)
+                        iop_desc_set_pq_src_addr(g, i, src[i], scf[i]);
+
+                /* if we are continuing a previous operation factor in
+                 * the old p and q values, see the comment for dma_maxpq
+                 * in include/linux/dmaengine.h
+                 */
+                if (dmaf_p_disabled_continue(flags))
+                        iop_desc_set_pq_src_addr(g, i++, dst[1], 1);
+                else if (dmaf_continue(flags)) {
+                        iop_desc_set_pq_src_addr(g, i++, dst[0], 0);
+                        iop_desc_set_pq_src_addr(g, i++, dst[1], 1);
+                        iop_desc_set_pq_src_addr(g, i++, dst[1], 0);
+                }
+                iop_desc_init_pq(g, i, flags);
+        }
+        spin_unlock_bh(&iop_chan->lock);
+
+        return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+static struct dma_async_tx_descriptor *
+iop_adma_prep_dma_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)
+{
+        struct iop_adma_chan *iop_chan = to_iop_adma_chan(chan);
+        struct iop_adma_desc_slot *sw_desc, *g;
+        int slot_cnt, slots_per_op;
+
+        if (unlikely(!len))
+                return NULL;
+        BUG_ON(len > IOP_ADMA_XOR_MAX_BYTE_COUNT);
+
+        dev_dbg(iop_chan->device->common.dev, "%s src_cnt: %d len: %u\n",
+                __func__, src_cnt, len);
+
+        spin_lock_bh(&iop_chan->lock);
+        slot_cnt = iop_chan_pq_zero_sum_slot_count(len, src_cnt + 2, &slots_per_op);
+        sw_desc = iop_adma_alloc_slots(iop_chan, slot_cnt, slots_per_op);
+        if (sw_desc) {
+                /* for validate operations p and q are tagged onto the
+                 * end of the source list
+                 */
+                int pq_idx = src_cnt;
+
+                g = sw_desc->group_head;
+                iop_desc_init_pq_zero_sum(g, src_cnt+2, flags);
+                iop_desc_set_pq_zero_sum_byte_count(g, len);
+                g->pq_check_result = pqres;
+                pr_debug("\t%s: g->pq_check_result: %p\n",
+                        __func__, g->pq_check_result);
+                sw_desc->unmap_src_cnt = src_cnt+2;
+                sw_desc->unmap_len = len;
+                sw_desc->async_tx.flags = flags;
+                while (src_cnt--)
+                        iop_desc_set_pq_zero_sum_src_addr(g, src_cnt,
+                                                          src[src_cnt],
+                                                          scf[src_cnt]);
+                iop_desc_set_pq_zero_sum_addr(g, pq_idx, src);
+        }
+        spin_unlock_bh(&iop_chan->lock);
+
+        return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
 static void iop_adma_free_chan_resources(struct dma_chan *chan)
 {
         struct iop_adma_chan *iop_chan = to_iop_adma_chan(chan);
@@ -1201,6 +1357,13 @@ static int __devinit iop_adma_probe(struct platform_device *pdev)
         if (dma_has_cap(DMA_XOR_VAL, dma_dev->cap_mask))
                 dma_dev->device_prep_dma_xor_val =
                         iop_adma_prep_dma_xor_val;
+        if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
+                dma_set_maxpq(dma_dev, iop_adma_get_max_pq(), 0);
+                dma_dev->device_prep_dma_pq = iop_adma_prep_dma_pq;
+        }
+        if (dma_has_cap(DMA_PQ_VAL, dma_dev->cap_mask))
+                dma_dev->device_prep_dma_pq_val =
+                        iop_adma_prep_dma_pq_val;
         if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask))
                 dma_dev->device_prep_dma_interrupt =
                         iop_adma_prep_dma_interrupt;