From: Vasant Hegde <vasant.hegde@amd.com>
Date: Wed, 6 Jul 2022 17:07:55 +0530
Subject: iommu/amd: Introduce per PCI segment irq_lookup_table
Git-commit: 333e581bcdffc09e6c6c95a0c24bfc66b3b4dcfd
Patch-mainline: v6.0-rc1
References: bsc#1205701

This will replace global irq lookup table (irq_lookup_table).

Co-developed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20220706113825.25582-6-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/amd/amd_iommu_types.h |  6 ++++++
 drivers/iommu/amd/init.c            | 27 +++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index d0ee78c656ff..cfb5f0e44186 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -565,6 +565,12 @@ struct amd_iommu_pci_seg {
 	 * device id.
 	 */
 	struct amd_iommu **rlookup_table;
+
+	/*
+	 * This table is used to find the irq remapping table for a given
+	 * device id quickly.
+	 */
+	struct irq_remap_table **irq_lookup_table;
 };
 
 /*
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 35863ba9f86e..e05d792c57cf 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -684,6 +684,26 @@ static inline void free_rlookup_table(struct amd_iommu_pci_seg *pci_seg)
 	pci_seg->rlookup_table = NULL;
 }
 
+static inline int __init alloc_irq_lookup_table(struct amd_iommu_pci_seg *pci_seg)
+{
+	pci_seg->irq_lookup_table = (void *)__get_free_pages(
+					     GFP_KERNEL | __GFP_ZERO,
+					     get_order(rlookup_table_size));
+	kmemleak_alloc(pci_seg->irq_lookup_table,
+		       rlookup_table_size, 1, GFP_KERNEL);
+	if (pci_seg->irq_lookup_table == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static inline void free_irq_lookup_table(struct amd_iommu_pci_seg *pci_seg)
+{
+	kmemleak_free(pci_seg->irq_lookup_table);
+	free_pages((unsigned long)pci_seg->irq_lookup_table,
+		   get_order(rlookup_table_size));
+	pci_seg->irq_lookup_table = NULL;
+}
 
 /*
  * Allocates the command buffer. This buffer is per AMD IOMMU. We can
@@ -1535,6 +1555,7 @@ static void __init free_pci_segments(void)
 
 	for_each_pci_segment_safe(pci_seg, next) {
 		list_del(&pci_seg->list);
+		free_irq_lookup_table(pci_seg);
 		free_rlookup_table(pci_seg);
 		free_dev_table(pci_seg);
 		kfree(pci_seg);
@@ -2900,6 +2921,7 @@ static int __init early_amd_iommu_init(void)
 		amd_iommu_irq_remap = check_ioapic_information();
 
 	if (amd_iommu_irq_remap) {
+		struct amd_iommu_pci_seg *pci_seg;
 		/*
 		 * Interrupt remapping enabled, create kmem_cache for the
 		 * remapping tables.
@@ -2916,6 +2938,11 @@ static int __init early_amd_iommu_init(void)
 		if (!amd_iommu_irq_cache)
 			goto out;
 
+		for_each_pci_segment(pci_seg) {
+			if (alloc_irq_lookup_table(pci_seg))
+				goto out;
+		}
+
 		irq_lookup_table = (void *)__get_free_pages(
 				GFP_KERNEL | __GFP_ZERO,
 				get_order(rlookup_table_size));