Messages in this thread | | | Subject | Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA | From | Kefeng Wang <> | Date | Tue, 11 May 2021 20:35:47 +0800 |
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On 2021/3/8 17:58, Greg KH wrote: > On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote: >> >> >> On 2021/3/7 23:24, Greg KH wrote: >>> On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote: >>>> On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote: >>>>> On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote: >>>>>> Hi Greg. >>>>>> >>>>>> On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote: >>>>>>> On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote: >>>>>>>> Using two distinct DMA zones turned out to be problematic. Here's an >>>>>>>> attempt go back to a saner default. >>>>>>> What problem does this solve? How does this fit into the stable kernel >>>>>>> rules? >>>>>> We changed the way we setup memory zones in arm64 in order to cater for >>>>>> Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory >>>>>> and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate >>>>>> memory that crosses zone boundaries, this broke crashkernel allocations on big >>>>>> machines. This series fixes all this by parsing the HW description and checking >>>>>> for DMA constrained buses. When not found, the unnecessary zone creation is >>>>>> skipped. >>>>> What kernel/commit caused this "breakage"? >>>> 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32 >>> Thanks for the info, all now queued up. >> There is a fix in 5.11. Please consider applying the following commit to >> 5.10.y: >> >> aed5041ef9a3 of: unittest: Fix build on architectures without >> CONFIG_OF_ADDRES > > Thanks, now queued up.
Hi Grep, another commit d78050ee3544 "arm64: Remove arm64_dma32_phys_limit and its uses" should be involved, thanks.
"Prior to this patch, disabling CONFIG_ZONE_DMA32 leads to CMA allocation from the whole RAM as arm64_dma32_phys_limit becomes PHYS_MASK+1." from Catalin, see more from the link https://www.spinics.net/lists/arm-kernel/msg867356.html > > greg k-h > . >
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