[PATCH v3 08/12] iommu/amd: Define per-IOMMU iopf_queue

[Vasant Hegde <vasant.hegde@amd.com>]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

AMD IOMMU hardware supports PCI Peripheral Paging Request (PPR) using
a PPR log, which is a circular buffer containing requests from downstream
end-point devices.

There is one PPR log per IOMMU instance. Therefore, allocate an iopf_queue
per IOMMU instance during driver initialization, and free the queue during
driver deinitialization.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
---
 drivers/iommu/amd/amd_iommu.h       |  4 +++
 drivers/iommu/amd/amd_iommu_types.h |  4 +++
 drivers/iommu/amd/init.c            |  5 ++++
 drivers/iommu/amd/ppr.c             | 42 +++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 88a6a2321dd5..63ddfbde8d82 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -55,6 +55,10 @@ bool amd_iommu_pasid_supported(void);
 int amd_iommu_gcr3_init(struct iommu_dev_data *dev_data, ioasid_t pasids);
 void amd_iommu_gcr3_uninit(struct iommu_dev_data *dev_data);
 
+/* IOPF */
+int amd_iommu_iopf_init(struct amd_iommu *iommu);
+void amd_iommu_iopf_uninit(struct amd_iommu *iommu);
+
 struct amd_iommu *get_amd_iommu(unsigned int idx);
 u8 amd_iommu_pc_get_max_banks(unsigned int idx);
 bool amd_iommu_pc_supported(void);
diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 20961353460d..d55a564fbd50 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -773,6 +773,10 @@ struct amd_iommu {
 	/* DebugFS Info */
 	struct dentry *debugfs;
 #endif
+
+	/* IOPF support */
+	struct iopf_queue *iopf_queue;
+	unsigned char iopfq_name[32];
 };
 
 static inline struct amd_iommu *dev_to_amd_iommu(struct device *dev)
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 05efab64c86a..80b4d3104b70 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1638,6 +1638,7 @@ static void __init free_iommu_one(struct amd_iommu *iommu)
 	amd_iommu_free_ppr_log(iommu);
 	free_ga_log(iommu);
 	iommu_unmap_mmio_space(iommu);
+	amd_iommu_iopf_uninit(iommu);
 }
 
 static void __init free_iommu_all(void)
@@ -2791,9 +2792,13 @@ static void enable_iommus_v2(void)
 {
 	struct amd_iommu *iommu;
 
+	if (!amd_iommu_gt_ppr_supported())
+		return;
+
 	for_each_iommu(iommu) {
 		amd_iommu_enable_ppr_log(iommu);
 		iommu_enable_gt(iommu);
+		amd_iommu_iopf_init(iommu);
 	}
 }
 
diff --git a/drivers/iommu/amd/ppr.c b/drivers/iommu/amd/ppr.c
index 673fcc30f9dc..9816d7dbcbf0 100644
--- a/drivers/iommu/amd/ppr.c
+++ b/drivers/iommu/amd/ppr.c
@@ -110,3 +110,45 @@ void amd_iommu_poll_ppr_log(struct amd_iommu *iommu)
 		tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);
 	}
 }
+
+/**************************************************************
+ *
+ * IOPF handling stuff
+ */
+
+/* Setup per-IOMMU IOPF queue if not exist. */
+int amd_iommu_iopf_init(struct amd_iommu *iommu)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	raw_spin_lock_irqsave(&iommu->lock, flags);
+
+	if (iommu->iopf_queue)
+		goto out;
+
+	snprintf(iommu->iopfq_name, sizeof(iommu->iopfq_name),
+		 "amdiommu-%#x-iopfq",
+		 PCI_SEG_DEVID_TO_SBDF(iommu->pci_seg->id, iommu->devid));
+
+	iommu->iopf_queue = iopf_queue_alloc(iommu->iopfq_name);
+	if (!iommu->iopf_queue)
+		ret = -ENOMEM;
+
+out:
+	raw_spin_unlock_irqrestore(&iommu->lock, flags);
+	return ret;
+}
+
+/* Destroy per-IOMMU IOPF queue if no longer needed. */
+void amd_iommu_iopf_uninit(struct amd_iommu *iommu)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&iommu->lock, flags);
+
+	iopf_queue_free(iommu->iopf_queue);
+	iommu->iopf_queue = NULL;
+
+	raw_spin_unlock_irqrestore(&iommu->lock, flags);
+}
-- 
2.31.1