[PATCH v2] riscv: Call secondary mmu notifier when flushing the tlb

From: Alexandre Ghiti
Date: Thu Mar 28 2024 - 03:38:53 EST


This is required to allow the IOMMU driver to correctly flush its own
TLB.

Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
---

Changes in v2:
- Rebase on top of 6.9-rc1

arch/riscv/mm/tlbflush.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index 893566e004b7..854d984deb07 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -4,6 +4,7 @@
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/hugetlb.h>
+#include <linux/mmu_notifier.h>
#include <asm/sbi.h>
#include <asm/mmu_context.h>

@@ -99,11 +100,19 @@ static void __ipi_flush_tlb_range_asid(void *info)
local_flush_tlb_range_asid(d->start, d->size, d->stride, d->asid);
}

-static void __flush_tlb_range(struct cpumask *cmask, unsigned long asid,
+static inline unsigned long get_mm_asid(struct mm_struct *mm)
+{
+ return (mm && static_branch_unlikely(&use_asid_allocator)) ?
+ atomic_long_read(&mm->context.id) & asid_mask : FLUSH_TLB_NO_ASID;
+}
+
+static void __flush_tlb_range(struct mm_struct *mm,
+ struct cpumask *cmask,
unsigned long start, unsigned long size,
unsigned long stride)
{
struct flush_tlb_range_data ftd;
+ unsigned long asid = get_mm_asid(mm);
bool broadcast;

if (cpumask_empty(cmask))
@@ -137,31 +146,26 @@ static void __flush_tlb_range(struct cpumask *cmask, unsigned long asid,

if (cmask != cpu_online_mask)
put_cpu();
-}

-static inline unsigned long get_mm_asid(struct mm_struct *mm)
-{
- return static_branch_unlikely(&use_asid_allocator) ?
- atomic_long_read(&mm->context.id) & asid_mask : FLUSH_TLB_NO_ASID;
+ if (mm)
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, start + size);
}

void flush_tlb_mm(struct mm_struct *mm)
{
- __flush_tlb_range(mm_cpumask(mm), get_mm_asid(mm),
- 0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
+ __flush_tlb_range(mm, mm_cpumask(mm), 0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
}

void flush_tlb_mm_range(struct mm_struct *mm,
unsigned long start, unsigned long end,
unsigned int page_size)
{
- __flush_tlb_range(mm_cpumask(mm), get_mm_asid(mm),
- start, end - start, page_size);
+ __flush_tlb_range(mm, mm_cpumask(mm), start, end - start, page_size);
}

void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
{
- __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
+ __flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
addr, PAGE_SIZE, PAGE_SIZE);
}

@@ -194,13 +198,13 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
}
}

- __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
+ __flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
start, end - start, stride_size);
}

void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
- __flush_tlb_range((struct cpumask *)cpu_online_mask, FLUSH_TLB_NO_ASID,
+ __flush_tlb_range(NULL, (struct cpumask *)cpu_online_mask,
start, end - start, PAGE_SIZE);
}

@@ -208,7 +212,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
- __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
+ __flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
start, end - start, PMD_SIZE);
}
#endif
@@ -222,7 +226,10 @@ void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
struct mm_struct *mm,
unsigned long uaddr)
{
+ unsigned long start = uaddr & PAGE_MASK;
+
cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
+ mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, start + PAGE_SIZE);
}

void arch_flush_tlb_batched_pending(struct mm_struct *mm)
@@ -232,7 +239,7 @@ void arch_flush_tlb_batched_pending(struct mm_struct *mm)

void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
{
- __flush_tlb_range(&batch->cpumask, FLUSH_TLB_NO_ASID, 0,
- FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
+ __flush_tlb_range(NULL, &batch->cpumask,
+ 0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
cpumask_clear(&batch->cpumask);
}
--
2.39.2