[PATCH v5 1/9] swiotlb: bail out of swiotlb_init_late() if swiotlb is already allocated
Petr Tesarik
petrtesarik at huaweicloud.com
Mon Jul 24 05:12:37 PDT 2023
From: Petr Tesarik <petr.tesarik.ext at huawei.com>
If swiotlb is allocated, immediately return 0, so callers do not have to
check io_tlb_default_mem.nslabs explicitly.
Signed-off-by: Petr Tesarik <petr.tesarik.ext at huawei.com>
---
arch/arm/xen/mm.c | 10 ++++------
arch/x86/kernel/pci-dma.c | 12 ++++++------
kernel/dma/swiotlb.c | 3 +++
3 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 3d826c0b5fee..882cd70c7a2f 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -125,12 +125,10 @@ static int __init xen_mm_init(void)
return 0;
/* we can work with the default swiotlb */
- if (!io_tlb_default_mem.nslabs) {
- rc = swiotlb_init_late(swiotlb_size_or_default(),
- xen_swiotlb_gfp(), NULL);
- if (rc < 0)
- return rc;
- }
+ rc = swiotlb_init_late(swiotlb_size_or_default(),
+ xen_swiotlb_gfp(), NULL);
+ if (rc < 0)
+ return rc;
cflush.op = 0;
cflush.a.dev_bus_addr = 0;
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index de6be0a3965e..08988b0a1c91 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -86,16 +86,16 @@ static void __init pci_xen_swiotlb_init(void)
int pci_xen_swiotlb_init_late(void)
{
+ int rc;
+
if (dma_ops == &xen_swiotlb_dma_ops)
return 0;
/* we can work with the default swiotlb */
- if (!io_tlb_default_mem.nslabs) {
- int rc = swiotlb_init_late(swiotlb_size_or_default(),
- GFP_KERNEL, xen_swiotlb_fixup);
- if (rc < 0)
- return rc;
- }
+ rc = swiotlb_init_late(swiotlb_size_or_default(),
+ GFP_KERNEL, xen_swiotlb_fixup);
+ if (rc < 0)
+ return rc;
/* XXX: this switches the dma ops under live devices! */
dma_ops = &xen_swiotlb_dma_ops;
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 2b83e3ad9dca..66fc8ec9ae45 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -384,6 +384,9 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask,
bool retried = false;
int rc = 0;
+ if (io_tlb_default_mem.nslabs)
+ return 0;
+
if (swiotlb_force_disable)
return 0;
--
2.25.1
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