When SWIOTLB_NO_FORCE is used, there should really be no allocations of
io_tlb_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 io_tlb_nslabs
to 1, was to avoid hitting the test for io_tlb_nslabs being 0/not
initialized.
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
kernel/dma/swiotlb.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index c10e855a03bc..526c8321b76f 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -121,12 +121,10 @@ 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;
- io_tlb_nslabs = 1;
- }
return 0;
}
@@ -284,6 +282,9 @@ swiotlb_init(int verbose)
unsigned char *vstart;
unsigned long bytes;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ goto out;
+
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
@@ -302,6 +303,7 @@ swiotlb_init(int verbose)
io_tlb_start = 0;
}
pr_warn("Cannot allocate buffer");
+out:
no_iotlb_memory = true;
}
--
2.25.1
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