From: Jason Gunthorpe <[email protected]>
Linus suggested that the kconfig here is confusing:
https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/
Let's break it into three kconfigs controlling distinct things:
- CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional
fields for the IOMMU. Currently only PASID, but later patches store
a struct iommu_mm_data *
- CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit
for keeping track of the ENQCMD instruction. x86 will select this if
IOMMU_SVA is enabled
- IOMMU_SVA controls if the IOMMU core compiles in the SVA support code
for iommu driver use and the IOMMU exported API
This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID
Signed-off-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Tina Zhang <[email protected]>
---
arch/Kconfig | 5 +++++
arch/x86/Kconfig | 1 +
arch/x86/kernel/traps.c | 2 +-
drivers/iommu/Kconfig | 1 +
include/linux/iommu.h | 2 +-
include/linux/mm_types.h | 2 +-
include/linux/sched.h | 2 +-
kernel/fork.c | 2 +-
mm/Kconfig | 3 +++
mm/init-mm.c | 2 +-
10 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index f4b210ab0612..3e49f862670e 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -301,6 +301,11 @@ config ARCH_HAS_DMA_CLEAR_UNCACHED
config ARCH_HAS_CPU_FINALIZE_INIT
bool
+# The architecture has a per-task state that includes the mm's PASID
+config ARCH_HAS_CPU_PASID
+ bool
+ select IOMMU_MM_DATA
+
# Select if arch init_task must go in the __init_task_data section
config ARCH_TASK_STRUCT_ON_STACK
bool
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3762f41bb092..68a2ec36a46e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -71,6 +71,7 @@ config X86
select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
select ARCH_HAS_CPU_FINALIZE_INIT
+ select ARCH_HAS_CPU_PASID if IOMMU_SVA
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c876f1d36a81..2b62dbb3396a 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -565,7 +565,7 @@ static bool fixup_iopl_exception(struct pt_regs *regs)
*/
static bool try_fixup_enqcmd_gp(void)
{
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_ARCH_HAS_CPU_PASID
u32 pasid;
/*
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 7673bb82945b..9a29d742617e 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -160,6 +160,7 @@ config IOMMU_DMA
# Shared Virtual Addressing
config IOMMU_SVA
+ select IOMMU_MM_DATA
bool
config FSL_PAMU
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ec289c1016f5..f16cca7899ec 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1336,7 +1336,7 @@ static inline bool tegra_dev_iommu_get_stream_id(struct device *dev, u32 *stream
return false;
}
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_IOMMU_MM_DATA
static inline void mm_pasid_init(struct mm_struct *mm)
{
mm->pasid = IOMMU_PASID_INVALID;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 957ce38768b2..41f248608dd9 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -938,7 +938,7 @@ struct mm_struct {
#endif
struct work_struct async_put_work;
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_IOMMU_MM_DATA
u32 pasid;
#endif
#ifdef CONFIG_KSM
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 292c31697248..70888a36677b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -954,7 +954,7 @@ struct task_struct {
/* Recursion prevention for eventfd_signal() */
unsigned in_eventfd:1;
#endif
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_ARCH_HAS_CPU_PASID
unsigned pasid_activated:1;
#endif
#ifdef CONFIG_CPU_SUP_INTEL
diff --git a/kernel/fork.c b/kernel/fork.c
index 10917c3e1f03..43fd9bc1a522 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1179,7 +1179,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
tsk->use_memdelay = 0;
#endif
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_ARCH_HAS_CPU_PASID
tsk->pasid_activated = 0;
#endif
diff --git a/mm/Kconfig b/mm/Kconfig
index 89971a894b60..0143f4d905c9 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1270,6 +1270,9 @@ config LOCK_MM_AND_FIND_VMA
bool
depends on !STACK_GROWSUP
+config IOMMU_MM_DATA
+ bool
+
source "mm/damon/Kconfig"
endmenu
diff --git a/mm/init-mm.c b/mm/init-mm.c
index cfd367822cdd..c52dc2740a3d 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -44,7 +44,7 @@ struct mm_struct init_mm = {
#endif
.user_ns = &init_user_ns,
.cpu_bitmap = CPU_BITS_NONE,
-#ifdef CONFIG_IOMMU_SVA
+#ifdef CONFIG_IOMMU_MM_DATA
.pasid = IOMMU_PASID_INVALID,
#endif
INIT_MM_CONTEXT(init_mm)
--
2.17.1
On Tue, Nov 28, 2023 at 10:16:35AM +0800, Tina Zhang wrote:
> From: Jason Gunthorpe <[email protected]>
>
> Linus suggested that the kconfig here is confusing:
>
> https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/
>
> Let's break it into three kconfigs controlling distinct things:
>
> - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional
> fields for the IOMMU. Currently only PASID, but later patches store
> a struct iommu_mm_data *
>
> - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit
> for keeping track of the ENQCMD instruction. x86 will select this if
> IOMMU_SVA is enabled
>
> - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code
> for iommu driver use and the IOMMU exported API
>
> This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID
>
> Signed-off-by: Jason Gunthorpe <[email protected]>
> Signed-off-by: Tina Zhang <[email protected]>
> ---
> arch/Kconfig | 5 +++++
> arch/x86/Kconfig | 1 +
> arch/x86/kernel/traps.c | 2 +-
> drivers/iommu/Kconfig | 1 +
> include/linux/iommu.h | 2 +-
> include/linux/mm_types.h | 2 +-
> include/linux/sched.h | 2 +-
> kernel/fork.c | 2 +-
> mm/Kconfig | 3 +++
> mm/init-mm.c | 2 +-
> 10 files changed, 16 insertions(+), 6 deletions(-)
Try again, you need to cc the mm list and the x86 list
Jason