* [PATCH] arm64: Kconfig: select ZONE_DMA @ 2020-12-17 8:08 Peng Fan (OSS) 2020-12-17 8:44 ` Nicolas Saenz Julienne 0 siblings, 1 reply; 4+ messages in thread From: Peng Fan (OSS) @ 2020-12-17 8:08 UTC (permalink / raw) To: catalin.marinas, will, nsaenzjulienne Cc: Peng Fan, linux-kernel, linux-arm-kernel From: Peng Fan <peng.fan@nxp.com> ZONE_DMA should not be disabled, otherwise arm64_dma_phys_limit is left uninitialized and cause swiotlb have IO TLB above 4GB which might crash some platforms Signed-off-by: Peng Fan <peng.fan@nxp.com> --- Not sure whether need to address code to initialize the variables or force select ZONE_DMA arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 33446269f692..377b391a41d6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -206,6 +206,7 @@ config ARM64 select SWIOTLB select SYSCTL_EXCEPTION_TRACE select THREAD_INFO_IN_TASK + select ZONE_DMA help ARM 64-bit (AArch64) Linux support. -- 2.28.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] arm64: Kconfig: select ZONE_DMA 2020-12-17 8:08 [PATCH] arm64: Kconfig: select ZONE_DMA Peng Fan (OSS) @ 2020-12-17 8:44 ` Nicolas Saenz Julienne 2020-12-17 12:43 ` Catalin Marinas 0 siblings, 1 reply; 4+ messages in thread From: Nicolas Saenz Julienne @ 2020-12-17 8:44 UTC (permalink / raw) To: Peng Fan (OSS), catalin.marinas, will Cc: Peng Fan, linux-kernel, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 1445 bytes --] Hi Peng, sorry for the inconvenience, this is most probably related to these changes: https://lore.kernel.org/linux-arm-kernel/20201119175400.9995-1-nsaenzjulienne@suse.de/ On Thu, 2020-12-17 at 16:08 +0800, Peng Fan (OSS) wrote: > From: Peng Fan <peng.fan@nxp.com> > > ZONE_DMA should not be disabled, otherwise arm64_dma_phys_limit is > left uninitialized and cause swiotlb have IO TLB above 4GB which > might crash some platforms > > Signed-off-by: Peng Fan <peng.fan@nxp.com> > --- > > Not sure whether need to address code to initialize the variables or > force select ZONE_DMA What is the cause for the swiotlb related crashes? I assume it's DMA into an address too high for the bus, but it might be something else. I figure you have a setup with ZONE_DMA32, ZONE_NORMAL and !ZONE_DMA. First of all, I'd suggest you try arm64's defaults (all zones enabled), the series I mention above should fix most of the issues we've had with ZONE_DMA/ZONE_DMA32 in the past. We now parse DT/ACPI and only create two distinct DMA zones if really needed. Otherwise ZONE_DMA spans the whole 32 bit address space. That said, IMO we're not doing the right thing in the !ZONE_DMA && ZONE_DMA32 case, and this should fix it (I didn't test it): - #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) + #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit ? : arm64_dma32_phys_limit) Regards, Nicolas [-- Attachment #1.2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] arm64: Kconfig: select ZONE_DMA 2020-12-17 8:44 ` Nicolas Saenz Julienne @ 2020-12-17 12:43 ` Catalin Marinas 2020-12-17 14:53 ` Nicolas Saenz Julienne 0 siblings, 1 reply; 4+ messages in thread From: Catalin Marinas @ 2020-12-17 12:43 UTC (permalink / raw) To: Nicolas Saenz Julienne Cc: Peng Fan, will, Peng Fan (OSS), linux-arm-kernel, linux-kernel On Thu, Dec 17, 2020 at 09:44:31AM +0100, Nicolas Saenz Julienne wrote: > On Thu, 2020-12-17 at 16:08 +0800, Peng Fan (OSS) wrote: > > From: Peng Fan <peng.fan@nxp.com> > > > > ZONE_DMA should not be disabled, otherwise arm64_dma_phys_limit is > > left uninitialized and cause swiotlb have IO TLB above 4GB which > > might crash some platforms Actually, arm64_dma_phys_limit would be zero-initialised. The ARCH_LOW_ADDRESS_LIMIT becomes ~0UL, hence it covers the whole address space. > > Signed-off-by: Peng Fan <peng.fan@nxp.com> > > --- > > > > Not sure whether need to address code to initialize the variables or > > force select ZONE_DMA > > What is the cause for the swiotlb related crashes? I assume it's DMA into an > address too high for the bus, but it might be something else. I think that's the case, swiotlb is not within the low 32-bit of the address space. > I figure you have a setup with ZONE_DMA32, ZONE_NORMAL and !ZONE_DMA. > > First of all, I'd suggest you try arm64's defaults (all zones enabled), the > series I mention above should fix most of the issues we've had with > ZONE_DMA/ZONE_DMA32 in the past. We now parse DT/ACPI and only create two > distinct DMA zones if really needed. Otherwise ZONE_DMA spans the whole 32 bit > address space. > > That said, IMO we're not doing the right thing in the !ZONE_DMA && ZONE_DMA32 > case, and this should fix it (I didn't test it): > > - #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) > + #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit ? : arm64_dma32_phys_limit) Does this limit need to be inclusive? -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] arm64: Kconfig: select ZONE_DMA 2020-12-17 12:43 ` Catalin Marinas @ 2020-12-17 14:53 ` Nicolas Saenz Julienne 0 siblings, 0 replies; 4+ messages in thread From: Nicolas Saenz Julienne @ 2020-12-17 14:53 UTC (permalink / raw) To: Catalin Marinas Cc: Peng Fan, will, Peng Fan (OSS), linux-arm-kernel, linux-kernel [-- Attachment #1.1: Type: text/plain, Size: 1888 bytes --] On Thu, 2020-12-17 at 12:43 +0000, Catalin Marinas wrote: > On Thu, Dec 17, 2020 at 09:44:31AM +0100, Nicolas Saenz Julienne wrote: > > On Thu, 2020-12-17 at 16:08 +0800, Peng Fan (OSS) wrote: > > > From: Peng Fan <peng.fan@nxp.com> > > > > > > ZONE_DMA should not be disabled, otherwise arm64_dma_phys_limit is > > > left uninitialized and cause swiotlb have IO TLB above 4GB which > > > might crash some platforms > > Actually, arm64_dma_phys_limit would be zero-initialised. The > ARCH_LOW_ADDRESS_LIMIT becomes ~0UL, hence it covers the whole address > space. > > > > Signed-off-by: Peng Fan <peng.fan@nxp.com> > > > --- > > > > > > Not sure whether need to address code to initialize the variables or > > > force select ZONE_DMA > > > > What is the cause for the swiotlb related crashes? I assume it's DMA into an > > address too high for the bus, but it might be something else. > > I think that's the case, swiotlb is not within the low 32-bit of the > address space. > > > I figure you have a setup with ZONE_DMA32, ZONE_NORMAL and !ZONE_DMA. > > > > First of all, I'd suggest you try arm64's defaults (all zones enabled), the > > series I mention above should fix most of the issues we've had with > > ZONE_DMA/ZONE_DMA32 in the past. We now parse DT/ACPI and only create two > > distinct DMA zones if really needed. Otherwise ZONE_DMA spans the whole 32 bit > > address space. > > > > That said, IMO we're not doing the right thing in the !ZONE_DMA && ZONE_DMA32 > > case, and this should fix it (I didn't test it): > > > > - #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) > > + #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit ? : arm64_dma32_phys_limit) > > Does this limit need to be inclusive? Yes, I'm missing a '- 1'. I'll send a fix if there is no further push back/comments. Regards, Nicolas [-- Attachment #1.2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-12-17 14:55 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-12-17 8:08 [PATCH] arm64: Kconfig: select ZONE_DMA Peng Fan (OSS) 2020-12-17 8:44 ` Nicolas Saenz Julienne 2020-12-17 12:43 ` Catalin Marinas 2020-12-17 14:53 ` Nicolas Saenz Julienne
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