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iommu/amd: Copy old trans table from old kernel

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Here several things need be done:
- If iommu is pre-enabled in a normal kernel, just disable it and print
  warning.

- If any one of IOMMUs is not pre-enabled in kdump kernel, just continue
  as it does in normal kernel.

- If failed to copy dev table of old kernel, continue to proceed as
  it does in normal kernel.

- Only if all IOMMUs are pre-enabled and copy dev table is done well, free
  the dev table allocated in early_amd_iommu_init() and make amd_iommu_dev_table
  point to the copied one.

- Disable and Re-enable event/cmd buffer,  install the copied DTE table
  to reg, and detect and enable guest vapic.

- Flush all caches

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Baoquan He 2017-08-09 16:33:38 +08:00 committed by Joerg Roedel
parent 45a01c4293
commit 3ac3e5ee5e
1 changed files with 51 additions and 8 deletions
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57
drivers/iommu/amd_iommu_init.c
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@ -37,6 +37,7 @@
#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"
@ -262,6 +263,8 @@ static int amd_iommu_enable_interrupts(void);
static int __init iommu_go_to_state(enum iommu_init_state state);
static void init_device_table_dma(void);
static bool __initdata amd_iommu_pre_enabled = true;
bool translation_pre_enabled(struct amd_iommu *iommu)
{
return (iommu->flags & AMD_IOMMU_FLAG_TRANS_PRE_ENABLED);
@ -857,6 +860,8 @@ static bool copy_device_table(void)
u16 dom_id, dte_v;
gfp_t gfp_flag;
if (!amd_iommu_pre_enabled)
return false;
pr_warn("Translation is already enabled - trying to copy translation structures\n");
for_each_iommu(iommu) {
@ -1496,9 +1501,14 @@ 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);
}
if (amd_iommu_pre_enabled)
amd_iommu_pre_enabled = translation_pre_enabled(iommu);
ret = init_iommu_from_acpi(iommu, h);
if (ret)
@ -1993,8 +2003,7 @@ 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)
{
@ -2130,14 +2139,48 @@ static void early_enable_iommu(struct amd_iommu *iommu)
/*
* This function finally enables all IOMMUs found in the system after
* they have been initialized
* they have been initialized.
*
* Or if in kdump kernel and IOMMUs are all pre-enabled, try to copy
* the old content of device table entries. Not this case or copy failed,
* just continue as normal kernel does.
*/
static void early_enable_iommus(void)
{
struct amd_iommu *iommu;
for_each_iommu(iommu)
if (!copy_device_table()) {
/*
* If come here because of failure in copying device table from old
* kernel with all IOMMUs enabled, print error message and try to
* free allocated old_dev_tbl_cpy.
*/
if (amd_iommu_pre_enabled)
pr_err("Failed to copy DEV table from previous kernel.\n");
if (old_dev_tbl_cpy != NULL)
free_pages((unsigned long)old_dev_tbl_cpy,
get_order(dev_table_size));
for_each_iommu(iommu) {
clear_translation_pre_enabled(iommu);
early_enable_iommu(iommu);
}
} else {
pr_info("Copied DEV table from previous kernel.\n");
free_pages((unsigned long)amd_iommu_dev_table,
get_order(dev_table_size));
amd_iommu_dev_table = old_dev_tbl_cpy;
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))