[PATCH v7 38/70] cxl: Remove vma linked list walk

Liam Howlett
2022-04-04T14:39:59Z

Use the VMA iterator instead. This requires a little restructuring
of the surrounding code to hoist the mm to the caller. That turns
cxl_prefault_one() into a trivial function, so call cxl_fault_segment()
directly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
---
drivers/misc/cxl/fault.c | 45 ++++++++++++++--------------------------
1 file changed, 15 insertions(+), 30 deletions(-)

diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
index 60c829113299..2c64f55cf01f 100644
--- a/drivers/misc/cxl/fault.c
+++ b/drivers/misc/cxl/fault.c
@@ -280,22 +280,6 @@ void cxl_handle_fault(struct work_struct *fault_work)
mmput(mm);
}

-static void cxl_prefault_one(struct cxl_context *ctx, u64 ea)
-{
- struct mm_struct *mm;
-
- mm = get_mem_context(ctx);
- if (mm == NULL) {
- pr_devel("cxl_prefault_one unable to get mm %i\n",
- pid_nr(ctx->pid));
- return;
- }
-
- cxl_fault_segment(ctx, mm, ea);
-
- mmput(mm);
-}
-
static u64 next_segment(u64 ea, u64 vsid)
{
if (vsid & SLB_VSID_B_1T)
@@ -306,23 +290,16 @@ static u64 next_segment(u64 ea, u64 vsid)
return ea + 1;
}

-static void cxl_prefault_vma(struct cxl_context *ctx)
+static void cxl_prefault_vma(struct cxl_context *ctx, struct mm_struct *mm)
{
u64 ea, last_esid = 0;
struct copro_slb slb;
+ VMA_ITERATOR(vmi, mm, 0);
struct vm_area_struct *vma;
int rc;
- struct mm_struct *mm;
-
- mm = get_mem_context(ctx);
- if (mm == NULL) {
- pr_devel("cxl_prefault_vm unable to get mm %i\n",
- pid_nr(ctx->pid));
- return;
- }

mmap_read_lock(mm);
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ for_each_vma(vmi, vma) {
for (ea = vma->vm_start; ea < vma->vm_end;
ea = next_segment(ea, slb.vsid)) {
rc = copro_calculate_slb(mm, ea, &slb);
@@ -337,20 +314,28 @@ static void cxl_prefault_vma(struct cxl_context *ctx)
}
}
mmap_read_unlock(mm);
-
- mmput(mm);
}

void cxl_prefault(struct cxl_context *ctx, u64 wed)
{
+ struct mm_struct *mm = get_mem_context(ctx);
+
+ if (mm == NULL) {
+ pr_devel("cxl_prefault unable to get mm %i\n",
+ pid_nr(ctx->pid));
+ return;
+ }
+
switch (ctx->afu->prefault_mode) {
case CXL_PREFAULT_WED:
- cxl_prefault_one(ctx, wed);
+ cxl_fault_segment(ctx, mm, wed);
break;
case CXL_PREFAULT_ALL:
- cxl_prefault_vma(ctx);
+ cxl_prefault_vma(ctx, mm);
break;
default:
break;
}
+
+ mmput(mm);
}
--
2.34.1