scsi: ufs: pci: Add support MCQ for QEMU-based UFS

Recently, ufs-mcq feature has been introduced to QEMU hw/ufs device [1].
This patch adds MCQ support for upstream QEMU UFS PCI controller.  This
patch provides mandatory vops callbacks to make UFS controller work
properly on MCQ mode.  Operation and Runtime Config register stride is
fixed to 48bytes which is implemented by qemu.

[1] https://lore.kernel.org/qemu-devel/cover.1716876237.git.jeuk20.kim@samsung.com/

Signed-off-by: Minwoo Im <minwoo.im@samsung.com>
Link: https://lore.kernel.org/r/20240531212244.1593535-2-minwoo.im@samsung.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufs-mcq.c

@@ -18,6 +18,7 @@
 #include <linux/iopoll.h>
 
 #define MAX_QUEUE_SUP GENMASK(7, 0)
+#define QCFGPTR GENMASK(23, 16)
 #define UFS_MCQ_MIN_RW_QUEUES 2
 #define UFS_MCQ_MIN_READ_QUEUES 0
 #define UFS_MCQ_MIN_POLL_QUEUES 0
@@ -116,6 +117,19 @@ struct ufs_hw_queue *ufshcd_mcq_req_to_hwq(struct ufs_hba *hba,
 	return &hba->uhq[hwq];
 }
 
+/**
+ * ufshcd_mcq_queue_cfg_addr - get an start address of the MCQ Queue Config
+ * Registers.
+ * @hba: per adapter instance
+ *
+ * Return: Start address of MCQ Queue Config Registers in HCI
+ */
+unsigned int ufshcd_mcq_queue_cfg_addr(struct ufs_hba *hba)
+{
+	return FIELD_GET(QCFGPTR, hba->mcq_capabilities) * 0x200;
+}
+EXPORT_SYMBOL_GPL(ufshcd_mcq_queue_cfg_addr);
+
 /**
  * ufshcd_mcq_decide_queue_depth - decide the queue depth
  * @hba: per adapter instance

drivers/ufs/host/ufshcd-pci.c

@@ -20,6 +20,8 @@
 #include <linux/acpi.h>
 #include <linux/gpio/consumer.h>
 
+#define MAX_SUPP_MAC 64
+
 struct ufs_host {
 	void (*late_init)(struct ufs_hba *hba);
 };
@@ -446,6 +448,49 @@ static int ufs_intel_mtl_init(struct ufs_hba *hba)
 	return ufs_intel_common_init(hba);
 }
 
+static int ufs_qemu_get_hba_mac(struct ufs_hba *hba)
+{
+	return MAX_SUPP_MAC;
+}
+
+static int ufs_qemu_mcq_config_resource(struct ufs_hba *hba)
+{
+	hba->mcq_base = hba->mmio_base + ufshcd_mcq_queue_cfg_addr(hba);
+
+	return 0;
+}
+
+static int ufs_qemu_op_runtime_config(struct ufs_hba *hba)
+{
+	struct ufshcd_mcq_opr_info_t *opr;
+	int i;
+
+	u32 sqdao = ufsmcq_readl(hba, ufshcd_mcq_cfg_offset(REG_SQDAO, 0));
+	u32 sqisao = ufsmcq_readl(hba, ufshcd_mcq_cfg_offset(REG_SQISAO, 0));
+	u32 cqdao = ufsmcq_readl(hba, ufshcd_mcq_cfg_offset(REG_CQDAO, 0));
+	u32 cqisao = ufsmcq_readl(hba, ufshcd_mcq_cfg_offset(REG_CQISAO, 0));
+
+	hba->mcq_opr[OPR_SQD].offset = sqdao;
+	hba->mcq_opr[OPR_SQIS].offset = sqisao;
+	hba->mcq_opr[OPR_CQD].offset = cqdao;
+	hba->mcq_opr[OPR_CQIS].offset = cqisao;
+
+	for (i = 0; i < OPR_MAX; i++) {
+		opr = &hba->mcq_opr[i];
+		opr->stride = 48;
+		opr->base = hba->mmio_base + opr->offset;
+	}
+
+	return 0;
+}
+
+static struct ufs_hba_variant_ops ufs_qemu_hba_vops = {
+	.name                   = "qemu-pci",
+	.get_hba_mac		= ufs_qemu_get_hba_mac,
+	.mcq_config_resource	= ufs_qemu_mcq_config_resource,
+	.op_runtime_config	= ufs_qemu_op_runtime_config,
+};
+
 static struct ufs_hba_variant_ops ufs_intel_cnl_hba_vops = {
 	.name                   = "intel-pci",
 	.init			= ufs_intel_common_init,
@@ -591,7 +636,8 @@ static const struct dev_pm_ops ufshcd_pci_pm_ops = {
 };
 
 static const struct pci_device_id ufshcd_pci_tbl[] = {
-	{ PCI_VENDOR_ID_REDHAT, 0x0013, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+	{ PCI_VENDOR_ID_REDHAT, 0x0013, PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		(kernel_ulong_t)&ufs_qemu_hba_vops },
 	{ PCI_VENDOR_ID_SAMSUNG, 0xC00C, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
 	{ PCI_VDEVICE(INTEL, 0x9DFA), (kernel_ulong_t)&ufs_intel_cnl_hba_vops },
 	{ PCI_VDEVICE(INTEL, 0x4B41), (kernel_ulong_t)&ufs_intel_ehl_hba_vops },

include/ufs/ufshcd.h

@@ -1278,6 +1278,7 @@ void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val);
 void ufshcd_hba_stop(struct ufs_hba *hba);
 void ufshcd_schedule_eh_work(struct ufs_hba *hba);
 void ufshcd_mcq_config_mac(struct ufs_hba *hba, u32 max_active_cmds);
+unsigned int ufshcd_mcq_queue_cfg_addr(struct ufs_hba *hba);
 u32 ufshcd_mcq_read_cqis(struct ufs_hba *hba, int i);
 void ufshcd_mcq_write_cqis(struct ufs_hba *hba, u32 val, int i);
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,