mmc: cqhci: initialize upper 64 bits of 128-bit task descriptors

Move the task descriptor initialization into cqhci_prep_task_desc().
In addition, make it explicitly initialize all 128 bits of the task
descriptor if the host controller is using 128-bit task descriptors,
rather than relying on the implicit zeroing from dmam_alloc_coherent().

This is needed to prepare for CQHCI inline encryption support, which
requires 128-bit task descriptors and uses the upper 64 bits.

Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Reviewed-and-tested-by: Peng Zhou <peng.zhou@mediatek.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210126001456.382989-4-ebiggers@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/cqhci-core.c

@@ -408,13 +408,15 @@ static void cqhci_disable(struct mmc_host *mmc)
 }
 
 static void cqhci_prep_task_desc(struct mmc_request *mrq,
-					u64 *data, bool intr)
+				 struct cqhci_host *cq_host, int tag)
 {
+	__le64 *task_desc = (__le64 __force *)get_desc(cq_host, tag);
 	u32 req_flags = mrq->data->flags;
+	u64 desc0;
 
-	*data = CQHCI_VALID(1) |
+	desc0 = CQHCI_VALID(1) |
 		CQHCI_END(1) |
-		CQHCI_INT(intr) |
+		CQHCI_INT(1) |
 		CQHCI_ACT(0x5) |
 		CQHCI_FORCED_PROG(!!(req_flags & MMC_DATA_FORCED_PRG)) |
 		CQHCI_DATA_TAG(!!(req_flags & MMC_DATA_DAT_TAG)) |
@@ -425,8 +427,19 @@ static void cqhci_prep_task_desc(struct mmc_request *mrq,
 		CQHCI_BLK_COUNT(mrq->data->blocks) |
 		CQHCI_BLK_ADDR((u64)mrq->data->blk_addr);
 
-	pr_debug("%s: cqhci: tag %d task descriptor 0x%016llx\n",
-		 mmc_hostname(mrq->host), mrq->tag, (unsigned long long)*data);
+	task_desc[0] = cpu_to_le64(desc0);
+
+	if (cq_host->caps & CQHCI_TASK_DESC_SZ_128) {
+		u64 desc1 = 0;
+
+		task_desc[1] = cpu_to_le64(desc1);
+
+		pr_debug("%s: cqhci: tag %d task descriptor 0x%016llx%016llx\n",
+			 mmc_hostname(mrq->host), mrq->tag, desc1, desc0);
+	} else {
+		pr_debug("%s: cqhci: tag %d task descriptor 0x%016llx\n",
+			 mmc_hostname(mrq->host), mrq->tag, desc0);
+	}
 }
 
 static int cqhci_dma_map(struct mmc_host *host, struct mmc_request *mrq)
@@ -567,8 +580,6 @@ static inline int cqhci_tag(struct mmc_request *mrq)
 static int cqhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
 	int err = 0;
-	u64 data = 0;
-	u64 *task_desc = NULL;
 	int tag = cqhci_tag(mrq);
 	struct cqhci_host *cq_host = mmc->cqe_private;
 	unsigned long flags;
@@ -598,9 +609,8 @@ static int cqhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 	}
 
 	if (mrq->data) {
-		task_desc = (__le64 __force *)get_desc(cq_host, tag);
-		cqhci_prep_task_desc(mrq, &data, 1);
-		*task_desc = cpu_to_le64(data);
+		cqhci_prep_task_desc(mrq, cq_host, tag);
+
 		err = cqhci_prep_tran_desc(mrq, cq_host, tag);
 		if (err) {
 			pr_err("%s: cqhci: failed to setup tx desc: %d\n",