Here several things need be done: - If iommu is pre-enabled in a normal kernel, just disable it and print warning. - If failed to copy dev table of old kernel, continue to proceed as it does in normal kernel. - Disable and Re-enable event/cmd buffer, and install the copied DTE table to reg. - Flush all caches Signed-off-by: Baoquan He <bhe at redhat.com> --- drivers/iommu/amd_iommu_init.c | 51 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 44 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index d4200e8..bc214fa 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -36,6 +36,7 @@ #include <asm/io_apic.h> #include <asm/irq_remapping.h> +#include <linux/crash_dump.h> #include "amd_iommu_proto.h" #include "amd_iommu_types.h" #include "irq_remapping.h" @@ -1481,9 +1482,12 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h) iommu->int_enabled = false; init_translation_status(iommu); - - if (translation_pre_enabled(iommu)) - pr_warn("Translation is already enabled - trying to copy translation structures\n"); + if (translation_pre_enabled(iommu) && !is_kdump_kernel()) { + iommu_disable(iommu); + clear_translation_pre_enabled(iommu); + pr_warn("Translation was enabled for IOMMU:%d but we are not in kdump mode\n", + iommu->index); + } ret = init_iommu_from_acpi(iommu, h); if (ret) @@ -1975,8 +1979,7 @@ static int __init init_memory_definitions(struct acpi_table_header *table) } /* - * Init the device table to not allow DMA access for devices and - * suppress all page faults + * Init the device table to not allow DMA access for devices */ static void init_device_table_dma(void) { @@ -2117,9 +2120,43 @@ static void early_enable_iommu(struct amd_iommu *iommu) static void early_enable_iommus(void) { struct amd_iommu *iommu; + bool is_pre_enabled = false; - for_each_iommu(iommu) - early_enable_iommu(iommu); + for_each_iommu(iommu) { + if (translation_pre_enabled(iommu)) { + is_pre_enabled = true; + break; + } + } + + if (!is_pre_enabled) { + for_each_iommu(iommu) + early_enable_iommu(iommu); + } else { + pr_warn("Translation is already enabled - trying to copy translation structures\n"); + if (copy_dev_tables()) { + pr_err("Failed to copy DEV table from previous kernel.\n"); + /* + * If failed to copy dev tables from old kernel, continue to proceed + * as it does in normal kernel. + */ + for_each_iommu(iommu) { + clear_translation_pre_enabled(iommu); + early_enable_iommu(iommu); + } + } else { + pr_info("Copied DEV table from previous kernel.\n"); + for_each_iommu(iommu) { + iommu_disable_command_buffer(iommu); + iommu_disable_event_buffer(iommu); + iommu_enable_command_buffer(iommu); + iommu_enable_event_buffer(iommu); + iommu_enable_ga(iommu); + iommu_set_device_table(iommu); + iommu_flush_all_caches(iommu); + } + } + } #ifdef CONFIG_IRQ_REMAP if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir)) -- 2.5.5