Export xen_swiotlb for all platforms using xen swiotlb Use xen_swiotlb to determine when vring should use dma APIs to map the ring: when xen_swiotlb is enabled the dma API is required. When it is disabled, it is not required.
Signed-off-by: Peng Fan <peng....@nxp.com> --- V2: This is a modified version from Stefano's patch https://lore.kernel.org/patchwork/patch/1033801/#1222404 Note: This is not to address rpmsg virtio issue, this is to let DomU virtio not using xen swiotlb could use non dma vring on ARM64 platforms. arch/arm/xen/mm.c | 1 + arch/x86/include/asm/xen/swiotlb-xen.h | 2 -- arch/x86/xen/pci-swiotlb-xen.c | 2 -- drivers/virtio/virtio_ring.c | 2 +- drivers/xen/swiotlb-xen.c | 3 +++ include/xen/swiotlb-xen.h | 6 ++++++ include/xen/xen.h | 6 ++++++ 7 files changed, 17 insertions(+), 5 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index d40e9e5fc52b..6a493ea087f0 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -139,6 +139,7 @@ static int __init xen_mm_init(void) struct gnttab_cache_flush cflush; if (!xen_initial_domain()) return 0; + xen_swiotlb = 1; xen_swiotlb_init(1, false); cflush.op = 0; diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h b/arch/x86/include/asm/xen/swiotlb-xen.h index 6b56d0d45d15..bb5ce02b4e20 100644 --- a/arch/x86/include/asm/xen/swiotlb-xen.h +++ b/arch/x86/include/asm/xen/swiotlb-xen.h @@ -3,12 +3,10 @@ #define _ASM_X86_SWIOTLB_XEN_H #ifdef CONFIG_SWIOTLB_XEN -extern int xen_swiotlb; extern int __init pci_xen_swiotlb_detect(void); extern void __init pci_xen_swiotlb_init(void); extern int pci_xen_swiotlb_init_late(void); #else -#define xen_swiotlb (0) static inline int __init pci_xen_swiotlb_detect(void) { return 0; } static inline void __init pci_xen_swiotlb_init(void) { } static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; } diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c index 33293ce01d8d..071fbe0e1a91 100644 --- a/arch/x86/xen/pci-swiotlb-xen.c +++ b/arch/x86/xen/pci-swiotlb-xen.c @@ -18,8 +18,6 @@ #endif #include <linux/export.h> -int xen_swiotlb __read_mostly; - /* * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary * diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a2de775801af..768afd79f67a 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -252,7 +252,7 @@ static bool vring_use_dma_api(struct virtio_device *vdev) * the DMA API if we're a Xen guest, which at least allows * all of the sensible Xen configurations to work correctly. */ - if (xen_domain()) + if (xen_vring_use_dma()) return true; return false; diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index b6d27762c6f8..25747e72e6fe 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -40,6 +40,9 @@ #include <trace/events/swiotlb.h> #define MAX_DMA_BITS 32 + +int xen_swiotlb __read_mostly; + /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h index ffc0d3902b71..235babcde848 100644 --- a/include/xen/swiotlb-xen.h +++ b/include/xen/swiotlb-xen.h @@ -12,4 +12,10 @@ void xen_dma_sync_for_device(dma_addr_t handle, phys_addr_t paddr, size_t size, extern int xen_swiotlb_init(int verbose, bool early); extern const struct dma_map_ops xen_swiotlb_dma_ops; +#ifdef CONFIG_SWIOTLB_XEN +extern int xen_swiotlb; +#else +#define xen_swiotlb (0) +#endif + #endif /* __LINUX_SWIOTLB_XEN_H */ diff --git a/include/xen/xen.h b/include/xen/xen.h index 19a72f591e2b..c51c46f5d739 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -52,4 +52,10 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, extern u64 xen_saved_max_mem_size; #endif +#include <xen/swiotlb-xen.h> +static inline int xen_vring_use_dma(void) +{ + return !!xen_swiotlb; +} + #endif /* _XEN_XEN_H */ -- 2.16.4
