forked from Minki/linux
996f545fbb
User-space use mappable BOs notably for fences, and expects that a value update by the GPU will be immediatly visible through the user-space mapping. ARM has a property that may prevent this from happening though: memory can be mapped multiple times only if the different mappings share the same caching properties. However all the lowmem memory is already identity-mapped into the kernel with cache enabled, so when user-space requests an uncached mapping, we actually get an "undefined caching policy" one and this has strange side-effects described on Freedesktop bug 86690. To prevent this from happening, allow user-space to explicitly specify which objects should be coherent, and create such objects with the TTM_PL_FLAG_UNCACHED flag. This will make TTM allocate memory using the DMA API, which will fix the identify mapping and allow us to safely map the objects to user-space uncached. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Lucas Stach <dev@lynxeye.de> Signed-off-by: Ben Skeggs <bskeggs@redhat.com> |
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
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| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
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| target | ||
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| uapi | ||
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| Kbuild | ||