The patch titled
Subject: mm/fork: clear PASID for new mm
has been removed from the -mm tree. Its filename was
mm-fork-clear-pasid-for-new-mm.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Subject: mm/fork: clear PASID for new mm
When a new mm is created, its PASID should be cleared, i.e. the PASID is
initialized to its init state 0 on both ARM and X86.
This patch was part of the series introducing mm->pasid, but got lost
along the way [1]. It still makes sense to have it, because each address
space has a different PASID. And the IOMMU code in
iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be
cleared.
[1] https://lore.kernel.org/linux-iommu/YDgh53AcQHT+T3L0@xxxxxxxxxxxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20210302103837.2562625-1-jean-philippe@xxxxxxxxxx
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 1 +
kernel/fork.c | 8 ++++++++
2 files changed, 9 insertions(+)
--- a/include/linux/mm_types.h~mm-fork-clear-pasid-for-new-mm
+++ a/include/linux/mm_types.h
@@ -23,6 +23,7 @@
#endif
#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
+#define INIT_PASID 0
struct address_space;
struct mem_cgroup;
--- a/kernel/fork.c~mm-fork-clear-pasid-for-new-mm
+++ a/kernel/fork.c
@@ -994,6 +994,13 @@ static void mm_init_owner(struct mm_stru
#endif
}
+static void mm_init_pasid(struct mm_struct *mm)
+{
+#ifdef CONFIG_IOMMU_SUPPORT
+ mm->pasid = INIT_PASID;
+#endif
+}
+
static void mm_init_uprobes_state(struct mm_struct *mm)
{
#ifdef CONFIG_UPROBES
@@ -1024,6 +1031,7 @@ static struct mm_struct *mm_init(struct
mm_init_cpumask(mm);
mm_init_aio(mm);
mm_init_owner(mm, p);
+ mm_init_pasid(mm);
RCU_INIT_POINTER(mm->exe_file, NULL);
mmu_notifier_subscriptions_init(mm);
init_tlb_flush_pending(mm);
_
Patches currently in -mm which might be from fenghua.yu@xxxxxxxxx are
