Messages in this thread Patch in this message | | | Date | Mon, 25 Nov 2019 11:32:00 +0200 | From | Mike Rapoport <> | Subject | Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M |
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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,
-- Sincerely yours, Mike.
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