[PATCH v2 09/37] iommu/amd: Introduce per PCI segment unity map list

[Vasant Hegde via iommu <iommu@lists.linux-foundation.org>]

Newer AMD systems can support multiple PCI segments. In order to support
multiple PCI segments IVMD table in IVRS structure is enhanced to
include pci segment id. Update ivmd_header structure to include "pci_seg".

Also introduce per PCI segment unity map list. It will replace global
amd_iommu_unity_map list.

Note that we have used "reserved" field in IVMD table to include "pci_seg
id" which was set to zero. It will take care of backward compatibility
(new kernel will work fine on older systems).

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>
---
 drivers/iommu/amd/amd_iommu_types.h | 13 +++++++------
 drivers/iommu/amd/init.c            | 30 +++++++++++++++++++----------
 drivers/iommu/amd/iommu.c           |  8 +++++++-
 3 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index f9776f188e36..c4c9c35e2bf7 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -579,6 +579,13 @@ struct amd_iommu_pci_seg {
 	 * More than one device can share the same requestor id.
 	 */
 	u16 *alias_table;
+
+	/*
+	 * A list of required unity mappings we find in ACPI. It is not locked
+	 * because as runtime it is only read. It is created at ACPI table
+	 * parsing time.
+	 */
+	struct list_head unity_map;
 };
 
 /*
@@ -805,12 +812,6 @@ struct unity_map_entry {
 	int prot;
 };
 
-/*
- * List of all unity mappings. It is not locked because as runtime it is only
- * read. It is created at ACPI table parsing time.
- */
-extern struct list_head amd_iommu_unity_map;
-
 /*
  * Data structures for device handling
  */
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index fe31de6e764c..d613e20ea013 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -142,7 +142,8 @@ struct ivmd_header {
 	u16 length;
 	u16 devid;
 	u16 aux;
-	u64 resv;
+	u16 pci_seg;
+	u8  resv[6];
 	u64 range_start;
 	u64 range_length;
 } __attribute__((packed));
@@ -162,8 +163,6 @@ static int amd_iommu_target_ivhd_type;
 
 u16 amd_iommu_last_bdf;			/* largest PCI device id we have
 					   to handle */
-LIST_HEAD(amd_iommu_unity_map);		/* a list of required unity mappings
-					   we find in ACPI */
 
 LIST_HEAD(amd_iommu_pci_seg_list);	/* list of all PCI segments */
 LIST_HEAD(amd_iommu_list);		/* list of all AMD IOMMUs in the
@@ -1562,6 +1561,7 @@ static struct amd_iommu_pci_seg *__init alloc_pci_segment(u16 id)
 
 	pci_seg->id = id;
 	init_llist_head(&pci_seg->dev_data_list);
+	INIT_LIST_HEAD(&pci_seg->unity_map);
 	list_add_tail(&pci_seg->list, &amd_iommu_pci_seg_list);
 
 	if (alloc_dev_table(pci_seg))
@@ -2397,10 +2397,13 @@ static int iommu_init_irq(struct amd_iommu *iommu)
 static void __init free_unity_maps(void)
 {
 	struct unity_map_entry *entry, *next;
+	struct amd_iommu_pci_seg *p, *pci_seg;
 
-	list_for_each_entry_safe(entry, next, &amd_iommu_unity_map, list) {
-		list_del(&entry->list);
-		kfree(entry);
+	for_each_pci_segment_safe(pci_seg, p) {
+		list_for_each_entry_safe(entry, next, &pci_seg->unity_map, list) {
+			list_del(&entry->list);
+			kfree(entry);
+		}
 	}
 }
 
@@ -2408,8 +2411,13 @@ static void __init free_unity_maps(void)
 static int __init init_unity_map_range(struct ivmd_header *m)
 {
 	struct unity_map_entry *e = NULL;
+	struct amd_iommu_pci_seg *pci_seg;
 	char *s;
 
+	pci_seg = get_pci_segment(m->pci_seg);
+	if (pci_seg == NULL)
+		return -ENOMEM;
+
 	e = kzalloc(sizeof(*e), GFP_KERNEL);
 	if (e == NULL)
 		return -ENOMEM;
@@ -2447,14 +2455,16 @@ static int __init init_unity_map_range(struct ivmd_header *m)
 	if (m->flags & IVMD_FLAG_EXCL_RANGE)
 		e->prot = (IVMD_FLAG_IW | IVMD_FLAG_IR) >> 1;
 
-	DUMP_printk("%s devid_start: %02x:%02x.%x devid_end: %02x:%02x.%x"
-		    " range_start: %016llx range_end: %016llx flags: %x\n", s,
+	DUMP_printk("%s devid_start: %04x:%02x:%02x.%x devid_end: "
+		    "%04x:%02x:%02x.%x range_start: %016llx range_end: %016llx"
+		    " flags: %x\n", s, m->pci_seg,
 		    PCI_BUS_NUM(e->devid_start), PCI_SLOT(e->devid_start),
-		    PCI_FUNC(e->devid_start), PCI_BUS_NUM(e->devid_end),
+		    PCI_FUNC(e->devid_start), m->pci_seg,
+		    PCI_BUS_NUM(e->devid_end),
 		    PCI_SLOT(e->devid_end), PCI_FUNC(e->devid_end),
 		    e->address_start, e->address_end, m->flags);
 
-	list_add_tail(&e->list, &amd_iommu_unity_map);
+	list_add_tail(&e->list, &pci_seg->unity_map);
 
 	return 0;
 }
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index c6058b6f2538..0f500b1a3885 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2242,13 +2242,19 @@ static void amd_iommu_get_resv_regions(struct device *dev,
 {
 	struct iommu_resv_region *region;
 	struct unity_map_entry *entry;
+	struct amd_iommu *iommu;
+	struct amd_iommu_pci_seg *pci_seg;
 	int devid;
 
 	devid = get_device_id(dev);
 	if (devid < 0)
 		return;
+	iommu = rlookup_amd_iommu(dev);
+	if (!iommu)
+		return;
+	pci_seg = iommu->pci_seg;
 
-	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+	list_for_each_entry(entry, &pci_seg->unity_map, list) {
 		int type, prot = 0;
 		size_t length;
 
-- 
2.27.0

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