dmaengine: idxd: Fix max batch size for Intel IAA

>From Intel IAA spec [1], Intel IAA does not support batch processing.

Two batch related default values for IAA are incorrect in current code:
(1) The max batch size of device is set during device initialization,
    that indicates batch is supported. It should be always 0 on IAA.
(2) The max batch size of work queue is set to WQ_DEFAULT_MAX_BATCH (32)
    as the default value regardless of Intel DSA or IAA device during
    work queue setup and cleanup. It should be always 0 on IAA.

Fix the issues by setting the max batch size of device and max batch
size of work queue to 0 on IAA device, that means batch is not
supported.

[1]: https://cdrdv2.intel.com/v1/dl/getContent/721858

Fixes: 23084545db ("dmaengine: idxd: set max_xfer and max_batch for RO device")
Fixes: 92452a72eb ("dmaengine: idxd: set defaults for wq configs")
Fixes: bfe1d56091 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220930201528.18621-2-xiaochen.shen@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/device.c

@@ -390,7 +390,7 @@ static void idxd_wq_disable_cleanup(struct idxd_wq *wq)
 	clear_bit(WQ_FLAG_ATS_DISABLE, &wq->flags);
 	memset(wq->name, 0, WQ_NAME_SIZE);
 	wq->max_xfer_bytes = WQ_DEFAULT_MAX_XFER;
-	wq->max_batch_size = WQ_DEFAULT_MAX_BATCH;
+	idxd_wq_set_max_batch_size(idxd->data->type, wq, WQ_DEFAULT_MAX_BATCH);
 	if (wq->opcap_bmap)
 		bitmap_copy(wq->opcap_bmap, idxd->opcap_bmap, IDXD_MAX_OPCAP_BITS);
 }
@@ -869,7 +869,7 @@ static int idxd_wq_config_write(struct idxd_wq *wq)
 
 	/* bytes 12-15 */
 	wq->wqcfg->max_xfer_shift = ilog2(wq->max_xfer_bytes);
-	wq->wqcfg->max_batch_shift = ilog2(wq->max_batch_size);
+	idxd_wqcfg_set_max_batch_shift(idxd->data->type, wq->wqcfg, ilog2(wq->max_batch_size));
 
 	/* bytes 32-63 */
 	if (idxd->hw.wq_cap.op_config && wq->opcap_bmap) {
@@ -1051,7 +1051,7 @@ static int idxd_wq_load_config(struct idxd_wq *wq)
 	wq->priority = wq->wqcfg->priority;
 
 	wq->max_xfer_bytes = 1ULL << wq->wqcfg->max_xfer_shift;
-	wq->max_batch_size = 1ULL << wq->wqcfg->max_batch_shift;
+	idxd_wq_set_max_batch_size(idxd->data->type, wq, 1U << wq->wqcfg->max_batch_shift);
 
 	for (i = 0; i < WQCFG_STRIDES(idxd); i++) {
 		wqcfg_offset = WQCFG_OFFSET(idxd, wq->id, i);

drivers/dma/idxd/idxd.h

@@ -548,6 +548,38 @@ static inline int idxd_wq_refcount(struct idxd_wq *wq)
 	return wq->client_count;
 };
 
+/*
+ * Intel IAA does not support batch processing.
+ * The max batch size of device, max batch size of wq and
+ * max batch shift of wqcfg should be always 0 on IAA.
+ */
+static inline void idxd_set_max_batch_size(int idxd_type, struct idxd_device *idxd,
+					   u32 max_batch_size)
+{
+	if (idxd_type == IDXD_TYPE_IAX)
+		idxd->max_batch_size = 0;
+	else
+		idxd->max_batch_size = max_batch_size;
+}
+
+static inline void idxd_wq_set_max_batch_size(int idxd_type, struct idxd_wq *wq,
+					      u32 max_batch_size)
+{
+	if (idxd_type == IDXD_TYPE_IAX)
+		wq->max_batch_size = 0;
+	else
+		wq->max_batch_size = max_batch_size;
+}
+
+static inline void idxd_wqcfg_set_max_batch_shift(int idxd_type, union wqcfg *wqcfg,
+						  u32 max_batch_shift)
+{
+	if (idxd_type == IDXD_TYPE_IAX)
+		wqcfg->max_batch_shift = 0;
+	else
+		wqcfg->max_batch_shift = max_batch_shift;
+}
+
 int __must_check __idxd_driver_register(struct idxd_device_driver *idxd_drv,
 					struct module *module, const char *mod_name);
 #define idxd_driver_register(driver) \

drivers/dma/idxd/init.c

@@ -183,7 +183,7 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
 		init_completion(&wq->wq_dead);
 		init_completion(&wq->wq_resurrect);
 		wq->max_xfer_bytes = WQ_DEFAULT_MAX_XFER;
-		wq->max_batch_size = WQ_DEFAULT_MAX_BATCH;
+		idxd_wq_set_max_batch_size(idxd->data->type, wq, WQ_DEFAULT_MAX_BATCH);
 		wq->enqcmds_retries = IDXD_ENQCMDS_RETRIES;
 		wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev));
 		if (!wq->wqcfg) {
@@ -418,7 +418,7 @@ static void idxd_read_caps(struct idxd_device *idxd)
 
 	idxd->max_xfer_bytes = 1ULL << idxd->hw.gen_cap.max_xfer_shift;
 	dev_dbg(dev, "max xfer size: %llu bytes\n", idxd->max_xfer_bytes);
-	idxd->max_batch_size = 1U << idxd->hw.gen_cap.max_batch_shift;
+	idxd_set_max_batch_size(idxd->data->type, idxd, 1U << idxd->hw.gen_cap.max_batch_shift);
 	dev_dbg(dev, "max batch size: %u\n", idxd->max_batch_size);
 	if (idxd->hw.gen_cap.config_en)
 		set_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags);

drivers/dma/idxd/sysfs.c

@@ -1046,7 +1046,7 @@ static ssize_t wq_max_batch_size_store(struct device *dev, struct device_attribu
 	if (batch_size > idxd->max_batch_size)
 		return -EINVAL;
 
-	wq->max_batch_size = (u32)batch_size;
+	idxd_wq_set_max_batch_size(idxd->data->type, wq, (u32)batch_size);
 
 	return count;
 }