On 09/20/16 at 02:40pm, Joerg Roedel wrote:
> 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 <bhe at 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.
Thanks, will change.
>
> > #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.
Will change.
>
> > + 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...)?
Yes, sure, will do.
>
> > + 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
> >
