The IVRS ACPI table specifies maximum address sizes for I/O virtual addresses that can be handled by the IOMMUs in the system. Parse that data from the IVRS header so that it can be considered in limiting the I/O aperture.
Based on prior work by Marius Hillenbrand. Link: https://www.amd.com/system/files/TechDocs/48882_IOMMU_3.05_PUB.pdf Signed-off-by: Sebastian Ott <seb...@amazon.de> --- drivers/iommu/amd_iommu.c | 1 + drivers/iommu/amd_iommu_init.c | 26 ++++++++++++++++++++++++++ drivers/iommu/amd_iommu_types.h | 3 +++ 3 files changed, 30 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 2883ac389abb..fb4a44550c4a 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -88,6 +88,7 @@ const struct iommu_ops amd_iommu_ops; static ATOMIC_NOTIFIER_HEAD(ppr_notifier); int amd_iommu_max_glx_val = -1; +u8 amd_iommu_ivrs_va_size; /* * general struct to manage commands send to an IOMMU diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 5b81fd16f5fa..3b07218e7000 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -11,6 +11,7 @@ #include <linux/pci.h> #include <linux/acpi.h> #include <linux/list.h> +#include <linux/bitfield.h> #include <linux/bitmap.h> #include <linux/slab.h> #include <linux/syscore_ops.h> @@ -41,6 +42,7 @@ * definitions for the ACPI scanning code */ #define IVRS_HEADER_LENGTH 48 +#define IVRS_HEADER_IVINFO_OFFSET 36 #define ACPI_IVHD_TYPE_MAX_SUPPORTED 0x40 #define ACPI_IVMD_TYPE_ALL 0x20 @@ -2492,6 +2494,27 @@ static void __init free_dma_resources(void) free_unity_maps(); } +static void __init get_ivrs_ivinfo(struct acpi_table_header *ivrs) +{ + u32 *ivinfo = (u32 *)((u8 *)ivrs + IVRS_HEADER_IVINFO_OFFSET); + u8 va_size = FIELD_GET(GENMASK(21, 15), *ivinfo); + u8 valid_va_sizes[] = {32, 40, 48, 64}; + int i; + + for (i = 0; i < ARRAY_SIZE(valid_va_sizes); i++) { + if (va_size == valid_va_sizes[i]) { + amd_iommu_ivrs_va_size = va_size; + break; + } + } + + if (!amd_iommu_ivrs_va_size) { + pr_warn("Invalid virtual address size %u in IVRS header, use most restrictive %u\n", + va_size, valid_va_sizes[0]); + amd_iommu_ivrs_va_size = valid_va_sizes[0]; + } +} + /* * This is the hardware init function for AMD IOMMU in the system. * This function is called either from amd_iommu_init or from the interrupt @@ -2546,6 +2569,9 @@ static int __init early_amd_iommu_init(void) if (ret) goto out; + get_ivrs_ivinfo(ivrs_base); + DUMP_printk("IVRS vasize=%d\n", amd_iommu_ivrs_va_size); + amd_iommu_target_ivhd_type = get_highest_supported_ivhd_type(ivrs_base); DUMP_printk("Using IVHD type %#x\n", amd_iommu_target_ivhd_type); diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index 7a8fdec138bd..8141b2874170 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -755,6 +755,9 @@ extern bool amd_iommu_force_isolation; /* Max levels of glxval supported */ extern int amd_iommu_max_glx_val; +/* Maximum virtual address size supported */ +extern u8 amd_iommu_ivrs_va_size; + /* * This function flushes all internal caches of * the IOMMU used by this driver. -- 2.17.1 Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
