Messages in this thread | | | Subject | Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA | From | Kefeng Wang <> | Date | Wed, 23 Jun 2021 14:59:59 +0800 |
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Hi Greg,
There are two more patches about the ZONE_DMA[32] changes, especially the second one, both them need be backported, thanks.
791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys() calculation 2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is required
On 2021/5/11 20:35, Kefeng Wang wrote: > > > 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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