Re: [PATCH v2 11/37] iommu/amd: Introduce per PCI segment device table size

[Joerg Roedel]

On Mon, Apr 25, 2022 at 05:03:49PM +0530, Vasant Hegde wrote:
> + /* Size of the device table */
> + u32 dev_table_size;

Same here and with all other size indicators. If they are always going
to have their maximum value anyways, we can drop them.

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[PATCH v2 11/37] iommu/amd: Introduce per PCI segment device table size

[Vasant Hegde via iommu]

With multiple pci segment support, number of BDF supported by each
segment may differ. Hence introduce per segment device table size
which depends on last_bdf. This will replace global
"device_table_size" variable.

Co-developed-by: Suravee Suthikulpanit 
Signed-off-by: Suravee Suthikulpanit 
Signed-off-by: Vasant Hegde 
---
 drivers/iommu/amd/amd_iommu_types.h |  3 +++
 drivers/iommu/amd/init.c| 18 ++
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h 
b/drivers/iommu/amd/amd_iommu_types.h
index e39e7db54e69..aa666d0723ba 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -547,6 +547,9 @@ struct amd_iommu_pci_seg {
/* Largest PCI device id we expect translation requests for */
u16 last_bdf;
 
+   /* Size of the device table */
+   u32 dev_table_size;
+
/*
 * device table virtual address
 *
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 71f39551a83a..f8da686182b5 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -414,6 +414,7 @@ static void iommu_set_cwwb_range(struct amd_iommu *iommu)
 static void iommu_set_device_table(struct amd_iommu *iommu)
 {
u64 entry;
+   u32 dev_table_size = iommu->pci_seg->dev_table_size;
 
BUG_ON(iommu->mmio_base == NULL);
 
@@ -651,7 +652,7 @@ static int __init find_last_devid_acpi(struct 
acpi_table_header *table, u16 pci_
 static inline int __init alloc_dev_table(struct amd_iommu_pci_seg *pci_seg)
 {
pci_seg->dev_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO | 
GFP_DMA32,
- 
get_order(dev_table_size));
+ 
get_order(pci_seg->dev_table_size));
if (!pci_seg->dev_table)
return -ENOMEM;
 
@@ -661,7 +662,7 @@ static inline int __init alloc_dev_table(struct 
amd_iommu_pci_seg *pci_seg)
 static inline void free_dev_table(struct amd_iommu_pci_seg *pci_seg)
 {
free_pages((unsigned long)pci_seg->dev_table,
-   get_order(dev_table_size));
+   get_order(pci_seg->dev_table_size));
pci_seg->dev_table = NULL;
 }
 
@@ -1034,7 +1035,7 @@ static bool __copy_device_table(struct amd_iommu *iommu)
entry = (((u64) hi) << 32) + lo;
 
old_devtb_size = ((entry & ~PAGE_MASK) + 1) << 12;
-   if (old_devtb_size != dev_table_size) {
+   if (old_devtb_size != pci_seg->dev_table_size) {
pr_err("The device table size of IOMMU:%d is not expected!\n",
iommu->index);
return false;
@@ -1053,15 +1054,15 @@ static bool __copy_device_table(struct amd_iommu *iommu)
}
old_devtb = (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT) && 
is_kdump_kernel())
? (__force void *)ioremap_encrypted(old_devtb_phys,
-   dev_table_size)
-   : memremap(old_devtb_phys, dev_table_size, MEMREMAP_WB);
+   pci_seg->dev_table_size)
+   : memremap(old_devtb_phys, pci_seg->dev_table_size, 
MEMREMAP_WB);
 
if (!old_devtb)
return false;
 
gfp_flag = GFP_KERNEL | __GFP_ZERO | GFP_DMA32;
pci_seg->old_dev_tbl_cpy = (void *)__get_free_pages(gfp_flag,
-   get_order(dev_table_size));
+   
get_order(pci_seg->dev_table_size));
if (pci_seg->old_dev_tbl_cpy == NULL) {
pr_err("Failed to allocate memory for copying old device 
table!\n");
memunmap(old_devtb);
@@ -1580,6 +1581,7 @@ static struct amd_iommu_pci_seg *__init 
alloc_pci_segment(u16 id,
 
pci_seg->last_bdf = last_bdf;
DUMP_printk("PCI segment : 0x%0x, last bdf : 0x%04x\n", id, last_bdf);
+   pci_seg->dev_table_size = tbl_size(DEV_TABLE_ENTRY_SIZE);
 
pci_seg->id = id;
init_llist_head(_seg->dev_data_list);
@@ -2675,7 +2677,7 @@ static void early_enable_iommus(void)
for_each_pci_segment(pci_seg) {
if (pci_seg->old_dev_tbl_cpy != NULL) {
free_pages((unsigned 
long)pci_seg->old_dev_tbl_cpy,
-   get_order(dev_table_size));
+   
get_order(pci_seg->dev_table_size));
pci_seg->old_dev_tbl_cpy = NULL;
}
}
@@ -2689,7 +2691,7 @@ static void early_enable_iommus(void)
 
for_each_pci_segment(pci_seg) {
free_pages((unsigned long)pci_seg->dev_table,
-  get_order(dev_table_size));
+