From: Adrian Huang ahuang12@lenovo.com
[ Upstream commit 0bbe4ced53e36786eafc2ecbf9a1761f55b4a82e ]
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 bhe@redhat.com Signed-off-by: Adrian Huang ahuang12@lenovo.com Cc: Jerry Snitselaar jsnitsel@redhat.com Link: https://lore.kernel.org/r/20200926102602.19177-1-adrianhuang0701@gmail.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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 bf45f8e2c7edd..016e35d3d6c86 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -1110,25 +1110,6 @@ 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. @@ -2080,30 +2061,6 @@ 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) { @@ -2114,9 +2071,6 @@ 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); @@ -2140,6 +2094,16 @@ 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),