[PATCH 2/2] scsi: ufs: ufs-pci: Add MCQ support for Intel UFS 4.0 controllers

[sangram kumar yerra]

The Intel UFS 4.0 PCI variant (PCI ID 8086:D335) advertises MCQ
support in its capability register. However, ufshcd_alloc_mcq() also
requires an .op_runtime_config hook to locate the per-queue operation
and runtime (OPR) register blocks, which was not provided by this
variant operations table.

As a result, MCQ initialization fails and ufshcd_add_scsi_host()
prints "MCQ mode is disabled, err=%d\n" before falling back to
legacy single-doorbell (SDB) mode.

Add ufs_intel_mcq_config_resource() to initialize the MCQ
configuration base and add ufs_intel_op_runtime_config() to set up
the OPR register offsets and stride.

Wire both hooks into the variant operations table so MCQ is enabled
when supported by the hardware.

Fixes: 096cd6b7adf2 ("scsi: ufs: ufs-pci: Add support for Intel Nova Lake")
Signed-off-by: sangram kumar yerra <sangram.k.y@xxxxxxxxx>
Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 drivers/ufs/host/ufshcd-pci.c | 39 +++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/ufs/host/ufshcd-pci.c b/drivers/ufs/host/ufshcd-pci.c
index 93bfafc25018..21bb11c724be 100644
--- a/drivers/ufs/host/ufshcd-pci.c
+++ b/drivers/ufs/host/ufshcd-pci.c
@@ -460,6 +460,43 @@ static int ufs_intel_mtl_init(struct ufs_hba *hba)
 	return ufs_intel_common_init(hba);
 }
 
+static int ufs_intel_mcq_config_resource(struct ufs_hba *hba)
+{
+	hba->mcq_base = hba->mmio_base + ufshcd_mcq_queue_cfg_addr(hba);
+
+	return 0;
+}
+
+/*
+ * This Intel UFS4.0 controller maps MCQ doorbell and interrupt-status
+ * registers into the same PCI BAR as the legacy HCI space, at this
+ * fixed offset/stride.
+ */
+#define UFS_INTEL_SQDAO0	0x2800
+#define UFS_INTEL_SQISAO0	0x2814
+#define UFS_INTEL_CQDAO0	0x281C
+#define UFS_INTEL_CQISAO0	0x2824
+#define UFS_INTEL_MCQ_STRIDE	0x30
+
+static int ufs_intel_op_runtime_config(struct ufs_hba *hba)
+{
+	struct ufshcd_mcq_opr_info_t *opr;
+	int i;
+
+	hba->mcq_opr[OPR_SQD].offset  = UFS_INTEL_SQDAO0;
+	hba->mcq_opr[OPR_SQIS].offset = UFS_INTEL_SQISAO0;
+	hba->mcq_opr[OPR_CQD].offset  = UFS_INTEL_CQDAO0;
+	hba->mcq_opr[OPR_CQIS].offset = UFS_INTEL_CQISAO0;
+
+	for (i = 0; i < OPR_MAX; i++) {
+		opr = &hba->mcq_opr[i];
+		opr->stride = UFS_INTEL_MCQ_STRIDE;
+		opr->base = hba->mmio_base + opr->offset;
+	}
+
+	return 0;
+}
+
 static int ufs_qemu_get_hba_mac(struct ufs_hba *hba)
 {
 	return MAX_SUPP_MAC;
@@ -547,6 +584,8 @@ static struct ufs_hba_variant_ops ufs_intel_mtl_hba_vops = {
 	.hce_enable_notify	= ufs_intel_hce_enable_notify,
 	.link_startup_notify	= ufs_intel_link_startup_notify,
 	.pwr_change_notify	= ufs_intel_nvl_pwr_change_notify,
+	.mcq_config_resource	= ufs_intel_mcq_config_resource,
+	.op_runtime_config	= ufs_intel_op_runtime_config,
 	.resume			= ufs_intel_resume,
 	.device_reset		= ufs_intel_device_reset,
 };
-- 
2.34.1