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| author | Stefano Stabellini <stefano.stabellini@xilinx.com> | 2021-03-19 13:01:40 -0700 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2021-04-23 11:33:50 +0200 |
| commit | f5079a9a2a31607a2343e544e9182ce35b030578 (patch) | |
| tree | 845187f971beecc8c97874a6789a4661e3951056 /include/xen | |
| parent | a929e124060c448b367f56b28a0c118876147b1f (diff) | |
| download | lwn-f5079a9a2a31607a2343e544e9182ce35b030578.tar.gz lwn-f5079a9a2a31607a2343e544e9182ce35b030578.zip | |
xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped
Newer Xen versions expose two Xen feature flags to tell us if the domain
is directly mapped or not. Only when a domain is directly mapped it
makes sense to enable swiotlb-xen on ARM.
Introduce a function on ARM to check the new Xen feature flags and also
to deal with the legacy case. Call the function xen_swiotlb_detect.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'include/xen')
| -rw-r--r-- | include/xen/arm/swiotlb-xen.h | 7 | ||||
| -rw-r--r-- | include/xen/interface/features.h | 14 | ||||
| -rw-r--r-- | include/xen/swiotlb-xen.h | 1 |
3 files changed, 22 insertions, 0 deletions
diff --git a/include/xen/arm/swiotlb-xen.h b/include/xen/arm/swiotlb-xen.h new file mode 100644 index 000000000000..2994fe6031a0 --- /dev/null +++ b/include/xen/arm/swiotlb-xen.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM_SWIOTLB_XEN_H +#define _ASM_ARM_SWIOTLB_XEN_H + +extern int xen_swiotlb_detect(void); + +#endif /* _ASM_ARM_SWIOTLB_XEN_H */ diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h index 6d1384abfbdf..5a7bdefa06a8 100644 --- a/include/xen/interface/features.h +++ b/include/xen/interface/features.h @@ -83,6 +83,20 @@ */ #define XENFEAT_linux_rsdp_unrestricted 15 +/* + * A direct-mapped (or 1:1 mapped) domain is a domain for which its + * local pages have gfn == mfn. If a domain is direct-mapped, + * XENFEAT_direct_mapped is set; otherwise XENFEAT_not_direct_mapped + * is set. + * + * If neither flag is set (e.g. older Xen releases) the assumptions are: + * - not auto_translated domains (x86 only) are always direct-mapped + * - on x86, auto_translated domains are not direct-mapped + * - on ARM, Dom0 is direct-mapped, DomUs are not + */ +#define XENFEAT_not_direct_mapped 16 +#define XENFEAT_direct_mapped 17 + #define XENFEAT_NR_SUBMAPS 1 #endif /* __XEN_PUBLIC_FEATURES_H__ */ diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h index d5eaf9d682b8..dbc4a4b785f6 100644 --- a/include/xen/swiotlb-xen.h +++ b/include/xen/swiotlb-xen.h @@ -3,6 +3,7 @@ #define __LINUX_SWIOTLB_XEN_H #include <linux/swiotlb.h> +#include <asm/xen/swiotlb-xen.h> void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir); |