On Thu, Sep 15, 2016 at 11:03:23PM +0800, Baoquan He wrote:
> Here several things need be done:
> 1) If iommu is pre-enabled in a normal kernel, just disable it and print
> warning.
> 2) If failed to copy dev table of old kernel, continue to proceed as
> it does in normal kernel.
> 3) Re-enable event/cmd buffer and install the new DTE table to reg.
> 4) Flush all caches
>
> Signed-off-by: Baoquan He <b...@redhat.com>
> ---
> drivers/iommu/amd_iommu_init.c | 44
> +++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 41 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
> index ce49641..47a8fc9 100644
> --- a/drivers/iommu/amd_iommu_init.c
> +++ b/drivers/iommu/amd_iommu_init.c
> @@ -34,7 +34,7 @@
> #include <asm/iommu_table.h>
> #include <asm/io_apic.h>
> #include <asm/irq_remapping.h>
> -
> +#include <linux/crash_dump.h>
Please keep that empty line, it is there for readability.
> #include "amd_iommu_proto.h"
> #include "amd_iommu_types.h"
> #include "irq_remapping.h"
> @@ -1344,6 +1344,12 @@ 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) && !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);
> + }
>
> if (translation_pre_enabled(iommu))
> pr_warn("Translation is already enabled - trying to copy
> translation structures\n");
> @@ -1946,9 +1952,41 @@ 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) ) {
Coding style, too many spaces. There is more of that below.
> + is_pre_enabled = true;
> + break;
> + }
> + }
> +
> + if ( !is_pre_enabled) {
> + for_each_iommu(iommu)
> + early_enable_iommu(iommu);
> + } else {
> + 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_feature_disable(iommu, CONTROL_CMDBUF_EN);
> + iommu_feature_disable(iommu,
> CONTROL_EVT_LOG_EN);
Could you move that into new helpers (iommu_disable_command_buffer...)?
> + iommu_enable_command_buffer(iommu);
> + iommu_enable_event_buffer(iommu);
> + iommu_set_device_table(iommu);
> + iommu_flush_all_caches(iommu);
> + }
> + }
> + }
> }
>
> static void enable_iommus_v2(void)
> --
> 2.5.5
>
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