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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 13:51:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 13:51:34 -0800
commit007c74e16c1aac9f5c93b372a054f7f11ede8628 (patch)
treebcd838d799379a1289160183674ea485c7dc4154 /kernel
parent009bd55dfcc857d8b00a5bbb17a8db060317af6f (diff)
parente998879d4fb7991856916972168cf27c0d86ed12 (diff)
Merge branch 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb update from Konrad Rzeszutek Wilk: "A generic (but for right now engaged only with AMD SEV) mechanism to adjust a larger size SWIOTLB based on the total memory of the SEV guests which right now require the bounce buffer for interacting with the outside world. Normal knobs (swiotlb=XYZ) still work" * 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma/swiotlb.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 781b9dca197c..7c42df6e6100 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -152,8 +152,6 @@ void swiotlb_set_max_segment(unsigned int val)
max_segment = rounddown(val, PAGE_SIZE);
}
-/* default to 64MB */
-#define IO_TLB_DEFAULT_SIZE (64UL<<20)
unsigned long swiotlb_size_or_default(void)
{
unsigned long size;
@@ -163,6 +161,24 @@ unsigned long swiotlb_size_or_default(void)
return size ? size : (IO_TLB_DEFAULT_SIZE);
}
+void __init swiotlb_adjust_size(unsigned long new_size)
+{
+ unsigned long size;
+
+ /*
+ * If swiotlb parameter has not been specified, give a chance to
+ * architectures such as those supporting memory encryption to
+ * adjust/expand SWIOTLB size for their use.
+ */
+ if (!io_tlb_nslabs) {
+ size = ALIGN(new_size, 1 << IO_TLB_SHIFT);
+ io_tlb_nslabs = size >> IO_TLB_SHIFT;
+ io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+
+ pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20);
+ }
+}
+
void swiotlb_print_info(void)
{
unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;