[PATCH v4 01/14] swiotlb: Remove external access to io_tlb_start
From: Claire Chang <hidden>
Date: 2021-02-09 06:23:21
Also in:
linux-devicetree, linux-iommu, lkml, xen-devel
Subsystem:
dma mapping helpers, linux for powerpc (32-bit and 64-bit), the rest, xen hypervisor interface, xen swiotlb subsystem · Maintainers:
Marek Szyprowski, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds, Juergen Gross, Stefano Stabellini
Add a new function, get_swiotlb_start(), and remove external access to io_tlb_start, so we can entirely hide struct swiotlb inside of swiotlb.c in the following patches. Signed-off-by: Claire Chang <redacted> --- arch/powerpc/platforms/pseries/svm.c | 4 ++-- drivers/xen/swiotlb-xen.c | 4 ++-- include/linux/swiotlb.h | 1 + kernel/dma/swiotlb.c | 5 +++++ 4 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
index 7b739cc7a8a9..c10c51d49f3d 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c@@ -55,8 +55,8 @@ void __init svm_swiotlb_init(void) if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false)) return; - if (io_tlb_start) - memblock_free_early(io_tlb_start, + if (vstart) + memblock_free_early(vstart, PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); panic("SVM: Cannot allocate SWIOTLB buffer"); }
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 2b385c1b4a99..91f8c68d1a9b 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c@@ -192,8 +192,8 @@ int __ref xen_swiotlb_init(int verbose, bool early) /* * IO TLB memory already allocated. Just use it. */ - if (io_tlb_start != 0) { - xen_io_tlb_start = phys_to_virt(io_tlb_start); + if (is_swiotlb_active()) { + xen_io_tlb_start = phys_to_virt(get_swiotlb_start()); goto end; }
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index d9c9fc9ca5d2..83200f3b042a 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h@@ -81,6 +81,7 @@ void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); bool is_swiotlb_active(void); +phys_addr_t get_swiotlb_start(void); void __init swiotlb_adjust_size(unsigned long new_size); #else #define swiotlb_force SWIOTLB_NO_FORCE
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 7c42df6e6100..e180211f6ad9 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c@@ -719,6 +719,11 @@ bool is_swiotlb_active(void) return io_tlb_end != 0; } +phys_addr_t get_swiotlb_start(void) +{ + return io_tlb_start; +} + #ifdef CONFIG_DEBUG_FS static int __init swiotlb_create_debugfs(void) --
This can be dropped if Christoph's swiotlb cleanups are landed. https://lore.kernel.org/linux-iommu/20210207160934.2955931-1-hch@lst.de/T/#m7124f29b6076d462101fcff6433295157621da09 (local) 2.30.0.478.g8a0d178c01-goog