When SWIOTLB_NO_FORCE is used, there should really be no allocations of
default_nslabs to occur since we are not going to use those slabs. If a
platform was somehow setting swiotlb_no_force and a later call to
swiotlb_init() was to be made we would still be proceeding with
allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce
was set on the kernel command line we would have only allocated 2KB.
This would be inconsistent and the point of initializing default_nslabs
to 1, was intended to allocate the minimum amount of memory possible, so
simply remove that minimal allocation period.
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
Changes in v2:
- rebased against devel/for-linus-5.13
- updated commit message to reflect variable names
kernel/dma/swiotlb.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 539c76beb52e..d20002a61546 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -83,12 +83,10 @@ setup_io_tlb_npages(char *str)
}
if (*str == ',')
++str;
- if (!strcmp(str, "force")) {
+ if (!strcmp(str, "force"))
swiotlb_force = SWIOTLB_FORCE;
- } else if (!strcmp(str, "noforce")) {
+ else if (!strcmp(str, "noforce"))
swiotlb_force = SWIOTLB_NO_FORCE;
- default_nslabs = 1;
- }
return 0;
}
@@ -211,6 +209,9 @@ swiotlb_init(int verbose)
size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
void *tlb;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ return;
+
/* Get IO TLB memory from the low pages */
tlb = memblock_alloc_low(bytes, PAGE_SIZE);
if (!tlb)
--
2.25.1
