From: Adrian Huang
Commit 387caf0b759a ("iommu/amd: Treat per-device exclusion
ranges as r/w unity-mapped regions") accidentally overwrites
the 'flags' field in IVMD (struct ivmd_header) when the I/O
virtualization memory definition is associated with the
exclusion range entry. This leads to the corrupted IVMD table
(incorrect checksum). The kdump kernel reports the invalid checksum:
ACPI BIOS Warning (bug): Incorrect checksum in table [IVRS] - 0x5C, should be
0x60 (20200717/tbprint-177)
AMD-Vi: [Firmware Bug]: IVRS invalid checksum
Fix the above-mentioned issue by modifying the 'struct unity_map_entry'
member instead of the IVMD header.
Cleanup: The *exclusion_range* functions are not used anymore, so
get rid of them.
Fixes: 387caf0b759a ("iommu/amd: Treat per-device exclusion ranges as r/w
unity-mapped regions")
Reported-and-tested-by: Baoquan He
Signed-off-by: Adrian Huang
Cc: Jerry Snitselaar
---
drivers/iommu/amd/init.c | 56 +++-
1 file changed, 10 insertions(+), 46 deletions(-)
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 445a08d23fed..1ba6b4cc56e8 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1103,25 +1103,6 @@ static int __init add_early_maps(void)
return 0;
}
-/*
- * Reads the device exclusion range from ACPI and initializes the IOMMU with
- * it
- */
-static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
-{
- if (!(m->flags & IVMD_FLAG_EXCL_RANGE))
- return;
-
- /*
-* Treat per-device exclusion ranges as r/w unity-mapped regions
-* since some buggy BIOSes might lead to the overwritten exclusion
-* range (exclusion_start and exclusion_length members). This
-* happens when there are multiple exclusion ranges (IVMD entries)
-* defined in ACPI table.
-*/
- m->flags = (IVMD_FLAG_IW | IVMD_FLAG_IR | IVMD_FLAG_UNITY_MAP);
-}
-
/*
* Takes a pointer to an AMD IOMMU entry in the ACPI table and
* initializes the hardware and our data structures with it.
@@ -2073,30 +2054,6 @@ static void __init free_unity_maps(void)
}
}
-/* called when we find an exclusion range definition in ACPI */
-static int __init init_exclusion_range(struct ivmd_header *m)
-{
- int i;
-
- switch (m->type) {
- case ACPI_IVMD_TYPE:
- set_device_exclusion_range(m->devid, m);
- break;
- case ACPI_IVMD_TYPE_ALL:
- for (i = 0; i <= amd_iommu_last_bdf; ++i)
- set_device_exclusion_range(i, m);
- break;
- case ACPI_IVMD_TYPE_RANGE:
- for (i = m->devid; i <= m->aux; ++i)
- set_device_exclusion_range(i, m);
- break;
- default:
- break;
- }
-
- return 0;
-}
-
/* called for unity map ACPI definition */
static int __init init_unity_map_range(struct ivmd_header *m)
{
@@ -2107,9 +2064,6 @@ static int __init init_unity_map_range(struct ivmd_header
*m)
if (e == NULL)
return -ENOMEM;
- if (m->flags & IVMD_FLAG_EXCL_RANGE)
- init_exclusion_range(m);
-
switch (m->type) {
default:
kfree(e);
@@ -2133,6 +2087,16 @@ static int __init init_unity_map_range(struct
ivmd_header *m)
e->address_end = e->address_start + PAGE_ALIGN(m->range_length);
e->prot = m->flags >> 1;
+ /*
+* Treat per-device exclusion ranges as r/w unity-mapped regions
+* since some buggy BIOSes might lead to the overwritten exclusion
+* range (exclusion_start and exclusion_length members). This
+* happens when there are multiple exclusion ranges (IVMD entries)
+* defined in ACPI table.
+*/
+ 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,
PCI_BUS_NUM(e->devid_start), PCI_SLOT(e->devid_start),
--
2.17.1
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