Messages in this thread | | | Subject | Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M | From | Christian Zigotzky <> | Date | Mon, 25 Nov 2019 17:38:33 +0100 |
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On 25 November 2019 at 10:32 am, Mike Rapoport wrote: > On Mon, Nov 25, 2019 at 08:39:23AM +0100, Christoph Hellwig wrote: >> On Sat, Nov 23, 2019 at 12:42:27PM +0100, Christian Zigotzky wrote: >>> Hello Christoph, >>> >>> Please find attached the dmesg of your Git kernel. >> Thanks. It looks like on your platform the swiotlb buffer isn't >> actually addressable based on the bus dma mask limit, which is rather >> interesting. swiotlb_init uses memblock_alloc_low to allocate the >> buffer, and I'll need some help from Mike and the powerpc maintainers >> to figure out how that select where to allocate the buffer from, and >> how we can move it to a lower address. My gut feeling would be to try >> to do what arm64 does and define a new ARCH_LOW_ADDRESS_LIMIT, preferably >> without needing too much arch specific magic. > Presuming the problem is relevant for all CoreNet boards something like > this could work: > > diff --git a/arch/powerpc/include/asm/dma.h b/arch/powerpc/include/asm/dma.h > index 1b4f0254868f..7c6cfeeaff52 100644 > --- a/arch/powerpc/include/asm/dma.h > +++ b/arch/powerpc/include/asm/dma.h > @@ -347,5 +347,11 @@ extern int isa_dma_bridge_buggy; > #define isa_dma_bridge_buggy (0) > #endif > > +#ifdef CONFIG_CORENET_GENERIC > +extern phys_addr_t ppc_dma_phys_limit; > +#define ARCH_LOW_ADDRESS_LIMIT (ppc_dma_phys_limit - 1) > +#endif > + > + > #endif /* __KERNEL__ */ > #endif /* _ASM_POWERPC_DMA_H */ > diff --git a/arch/powerpc/platforms/85xx/common.c b/arch/powerpc/platforms/85xx/common.c > index fe0606439b5a..346b436b6d3f 100644 > --- a/arch/powerpc/platforms/85xx/common.c > +++ b/arch/powerpc/platforms/85xx/common.c > @@ -126,3 +126,7 @@ void __init mpc85xx_qe_par_io_init(void) > } > } > #endif > + > +#ifdef CONFIG_CORENET_GENERIC > +phys_addr_t ppc_dma_phys_limit = 0xffffffffUL; > +#endif > diff --git a/arch/powerpc/platforms/85xx/corenet_generic.c b/arch/powerpc/platforms/85xx/corenet_generic.c > index 7ee2c6628f64..673bcbdc7c75 100644 > --- a/arch/powerpc/platforms/85xx/corenet_generic.c > +++ b/arch/powerpc/platforms/85xx/corenet_generic.c > @@ -64,7 +64,7 @@ void __init corenet_gen_setup_arch(void) > mpc85xx_smp_init(); > > swiotlb_detect_4g(); > - > + ppc_dma_phys_limit = 0x0fffffffUL; > pr_info("%s board\n", ppc_md.name); > > mpc85xx_qe_init(); > >> As a quick hack can you try this patch on top of the tree from Friday? >> >> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >> index f491690d54c6..e3f95c362922 100644 >> --- a/include/linux/memblock.h >> +++ b/include/linux/memblock.h >> @@ -344,7 +344,7 @@ static inline int memblock_get_region_node(const struct memblock_region *r) >> #define MEMBLOCK_LOW_LIMIT 0 >> >> #ifndef ARCH_LOW_ADDRESS_LIMIT >> -#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL >> +#define ARCH_LOW_ADDRESS_LIMIT 0x0fffffffUL >> #endif >> >> phys_addr_t memblock_phys_alloc_range(phys_addr_t size, phys_addr_t align, Hello Mike,
Many thanks for your patch! I will test it tomorrow.
Cheers, Christian
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