From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M Date: Mon, 25 Nov 2019 08:39:23 +0100 Message-ID: <20191125073923.GA30168@lst.de> References: <20191121072943.GA24024@lst.de> <6eec5c42-019c-a988-fc2a-cb804194683d@xenosoft.de> <20191121180226.GA3852@lst.de> <2fde79cf-875f-94e6-4a1b-f73ebb2e2c32@xenosoft.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <2fde79cf-875f-94e6-4a1b-f73ebb2e2c32@xenosoft.de> Sender: linux-kernel-owner@vger.kernel.org To: Christian Zigotzky Cc: Robin Murphy , linux-arch@vger.kernel.org, darren@stevens-zone.net, mad skateman , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Rob Herring , paulus@samba.org, rtd2@xtra.co.nz, "contact@a-eon.com" , linuxppc-dev , nsaenzjulienne@suse.de, Mike Rapoport List-Id: linux-arch.vger.kernel.org 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. 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, From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 25 Nov 2019 08:39:23 +0100 From: Christoph Hellwig Subject: Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M Message-ID: <20191125073923.GA30168@lst.de> References: <20191121072943.GA24024@lst.de> <6eec5c42-019c-a988-fc2a-cb804194683d@xenosoft.de> <20191121180226.GA3852@lst.de> <2fde79cf-875f-94e6-4a1b-f73ebb2e2c32@xenosoft.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2fde79cf-875f-94e6-4a1b-f73ebb2e2c32@xenosoft.de> To: Christian Zigotzky Cc: Robin Murphy , linux-arch@vger.kernel.org, darren@stevens-zone.net, mad skateman , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Rob Herring , paulus@samba.org, rtd2@xtra.co.nz, "contact@a-eon.com" , linuxppc-dev , nsaenzjulienne@suse.de, Mike Rapoport List-ID: Message-ID: <20191125073923.epQFJOOge20asMYiA69TPhBoLaubEj0sgR_ebPbIKck@z> 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. 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,