On Thu, 4 Jun 2026 14:09:59 +0530
"Aneesh Kumar K.V (Arm)" [off-list ref] wrote:
quoted hunk ↗ jump to hunk
SWIOTLB_FORCE has no remaining in-tree users. Forced bouncing is now
controlled through the swiotlb=force command line option via
swiotlb_force_bounce.
Remove the unused flag and simplify the force_bounce initialization.
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
include/linux/swiotlb.h | 1 -
kernel/dma/swiotlb.c | 3 +--
2 files changed, 1 insertion(+), 3 deletions(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 526f82e9da45..af88ca7182f4 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -15,7 +15,6 @@ struct page;
struct scatterlist;
#define SWIOTLB_VERBOSE (1 << 0) /* verbose initialization */
-#define SWIOTLB_FORCE (1 << 1) /* force bounce buffering */
#define SWIOTLB_ANY (1 << 2) /* allow any memory for the buffer */
These constants are kernel-internal, so let's not leave a hole in the
bitmask... I mean, what about changing SWIOTLB_ANY to (1 << 1) after
you remove SWIOTLB_FORCE?
Other than that, LGTM.
I consider this whole series a big step towards saner handling of
encrypted/decrypted memory for DMA buffers. Thank you for your effort!
Petr T
quoted hunk ↗ jump to hunk
/*
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index e4bd8c9eaeda..81cc4928e949 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -400,8 +400,7 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
if (swiotlb_force_disable)
return;
- io_tlb_default_mem.force_bounce =
- swiotlb_force_bounce || (flags & SWIOTLB_FORCE);
+ io_tlb_default_mem.force_bounce = swiotlb_force_bounce;
#ifdef CONFIG_SWIOTLB_DYNAMIC
if (!remap)