2024-02-29 09:54:58

by Baolu Lu

Subject: [PATCH 3/3] iommu/vt-d: Remove scalabe mode in domain_context_clear_one()

domain_context_clear_one() only handles the context entry teardown in
legacy mode. Remove the scalable mode check in it to avoid dead code.

Signed-off-by: Lu Baolu <[email protected]>
---
drivers/iommu/intel/iommu.c | 15 +--------------
1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index d682eb6ad4d2..50eb9aed47cc 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2175,9 +2175,6 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8
struct context_entry *context;
u16 did_old;

- if (!iommu)
- return;
-
spin_lock(&iommu->lock);
context = iommu_context_addr(iommu, bus, devfn, 0);
if (!context) {
@@ -2185,14 +2182,7 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8
return;
}

- if (sm_supported(iommu)) {
- if (hw_pass_through && domain_type_is_si(info->domain))
- did_old = FLPT_DEFAULT_DID;
- else
- did_old = domain_id_iommu(info->domain, iommu);
- } else {
- did_old = context_domain_id(context);
- }
+ did_old = context_domain_id(context);

context_clear_entry(context);
__iommu_flush_cache(iommu, context, sizeof(*context));
@@ -2203,9 +2193,6 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8
DMA_CCMD_MASK_NOBIT,
DMA_CCMD_DEVICE_INVL);

- if (sm_supported(iommu))
- qi_flush_pasid_cache(iommu, did_old, QI_PC_ALL_PASIDS, 0);
-
iommu->flush.flush_iotlb(iommu,
did_old,
0,
--
2.34.1

2024-03-04 07:54:12

by Tian, Kevin

Subject: RE: [PATCH 3/3] iommu/vt-d: Remove scalabe mode in domain_context_clear_one()

> From: Lu Baolu <[email protected]>
> Sent: Thursday, February 29, 2024 5:48 PM
>
> @@ -2175,9 +2175,6 @@ static void domain_context_clear_one(struct
> device_domain_info *info, u8 bus, u8
> struct context_entry *context;
> u16 did_old;
>
> - if (!iommu)
> - return;
> -

is this check only relevant to sm mode or should it be removed for
both legacy/sm? If the latter please add a note in the commit msg.

otherwise,

Reviewed-by: Kevin Tian <[email protected]>

2024-03-04 09:45:09

by Baolu Lu

Subject: Re: [PATCH 3/3] iommu/vt-d: Remove scalabe mode in domain_context_clear_one()

On 2024/3/4 15:53, Tian, Kevin wrote:
>> From: Lu Baolu<[email protected]>
>> Sent: Thursday, February 29, 2024 5:48 PM
>>
>> @@ -2175,9 +2175,6 @@ static void domain_context_clear_one(struct
>> device_domain_info *info, u8 bus, u8
>> struct context_entry *context;
>> u16 did_old;
>>
>> - if (!iommu)
>> - return;
>> -
> is this check only relevant to sm mode or should it be removed for
> both legacy/sm? If the latter please add a note in the commit msg.

This kind of check makes no sense. I didn't take it to sm mode. So only
need to remove it in the legacy path.

Anyway, let me update the commit message to reflect this change.

Best regards,
baolu