Messages in this thread | | | Subject | Re: Bug 205201 - overflow of DMA mask and bus mask | From | Christian Zigotzky <> | Date | Thu, 7 Nov 2019 10:53:10 +0100 |
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On 05 November 2019 at 5:28 pm, Christoph Hellwig wrote: > On Tue, Nov 05, 2019 at 08:56:27AM +0100, Christian Zigotzky wrote: >> Hi All, >> >> We still have DMA problems with some PCI devices. Since the PowerPC updates >> 4.21-1 [1] we need to decrease the RAM to 3500MB (mem=3500M) if we want to >> work with our PCI devices. The FSL P5020 and P5040 have these problems >> currently. >> >> Error message: >> >> [ 25.654852] bttv 1000:04:05.0: overflow 0x00000000fe077000+4096 of DMA >> mask ffffffff bus mask df000000 >> >> All 5.x Linux kernels can't initialize a SCSI PCI card anymore so booting >> of a Linux userland isn't possible. >> >> PLEASE check the DMA changes in the PowerPC updates 4.21-1 [1]. The kernel >> 4.20 works with all PCI devices without limitation of RAM. > Can you send me the .config and a dmesg? And in the meantime try the > patch below? > > --- > >From 4d659b7311bd4141fdd3eeeb80fa2d7602ea01d4 Mon Sep 17 00:00:00 2001 > From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > Date: Fri, 18 Oct 2019 13:00:43 +0200 > Subject: dma-direct: check for overflows on 32 bit DMA addresses > > As seen on the new Raspberry Pi 4 and sta2x11's DMA implementation it is > possible for a device configured with 32 bit DMA addresses and a partial > DMA mapping located at the end of the address space to overflow. It > happens when a higher physical address, not DMAable, is translated to > it's DMA counterpart. > > For example the Raspberry Pi 4, configurable up to 4 GB of memory, has > an interconnect capable of addressing the lower 1 GB of physical memory > with a DMA offset of 0xc0000000. It transpires that, any attempt to > translate physical addresses higher than the first GB will result in an > overflow which dma_capable() can't detect as it only checks for > addresses bigger then the maximum allowed DMA address. > > Fix this by verifying in dma_capable() if the DMA address range provided > is at any point lower than the minimum possible DMA address on the bus. > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > --- > include/linux/dma-direct.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h > index adf993a3bd58..6ad9e9ea7564 100644 > --- a/include/linux/dma-direct.h > +++ b/include/linux/dma-direct.h > @@ -3,6 +3,7 @@ > #define _LINUX_DMA_DIRECT_H 1 > > #include <linux/dma-mapping.h> > +#include <linux/memblock.h> /* for min_low_pfn */ > #include <linux/mem_encrypt.h> > > #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA > @@ -27,6 +28,13 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) > if (!dev->dma_mask) > return false; > > +#ifndef CONFIG_ARCH_DMA_ADDR_T_64BIT > + /* Check if DMA address overflowed */ > + if (min(addr, addr + size - 1) < > + __phys_to_dma(dev, (phys_addr_t)(min_low_pfn << PAGE_SHIFT))) > + return false; > +#endif > + > return addr + size - 1 <= > min_not_zero(*dev->dma_mask, dev->bus_dma_mask); > } Hello Christoph,
Thanks a lot for your patch! Unfortunately this patch doesn't solve the issue.
Error messages:
[ 6.041163] bttv: driver version 0.9.19 loaded [ 6.041167] bttv: using 8 buffers with 2080k (520 pages) each for capture [ 6.041559] bttv: Bt8xx card found (0) [ 6.041609] bttv: 0: Bt878 (rev 17) at 1000:04:05.0, irq: 19, latency: 128, mmio: 0xc20001000 [ 6.041622] bttv: 0: using: Typhoon TView RDS + FM Stereo / KNC1 TV Station RDS [card=53,insmod option] [ 6.042216] bttv: 0: tuner type=5 [ 6.111994] bttv: 0: audio absent, no audio device found! [ 6.176425] bttv: 0: Setting PLL: 28636363 => 35468950 (needs up to 100ms) [ 6.200005] bttv: PLL set ok [ 6.209351] bttv: 0: registered device video0 [ 6.211576] bttv: 0: registered device vbi0 [ 6.214897] bttv: 0: registered device radio0 [ 114.218806] bttv 1000:04:05.0: overflow 0x00000000ff507000+4096 of DMA mask ffffffff bus mask df000000 [ 114.218848] Modules linked in: rfcomm bnep tuner_simple tuner_types tea5767 tuner tda7432 tvaudio msp3400 bttv tea575x tveeprom videobuf_dma_sg videobuf_core rc_core videodev mc btusb btrtl btbcm btintel bluetooth uio_pdrv_genirq uio ecdh_generic ecc [ 114.219012] [c0000001ecddf720] [80000000008ff6e8] .buffer_prepare+0x150/0x268 [bttv] [ 114.219029] [c0000001ecddf860] [80000000008fff6c] .bttv_qbuf+0x50/0x64 [bttv]
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Trace:
[ 462.783184] Call Trace: [ 462.783187] [c0000001c6c67420] [c0000000000b3358] .report_addr+0xb8/0xc0 (unreliable) [ 462.783192] [c0000001c6c67490] [c0000000000b351c] .dma_direct_map_page+0xf0/0x128 [ 462.783195] [c0000001c6c67530] [c0000000000b35b0] .dma_direct_map_sg+0x5c/0xac [ 462.783205] [c0000001c6c675e0] [8000000000862e88] .__videobuf_iolock+0x660/0x6d8 [videobuf_dma_sg] [ 462.783220] [c0000001c6c676b0] [8000000000854274] .videobuf_iolock+0x98/0xb4 [videobuf_core] [ 462.783271] [c0000001c6c67720] [80000000008686e8] .buffer_prepare+0x150/0x268 [bttv] [ 462.783276] [c0000001c6c677c0] [8000000000854afc] .videobuf_qbuf+0x2b8/0x428 [videobuf_core] [ 462.783288] [c0000001c6c67860] [8000000000868f6c] .bttv_qbuf+0x50/0x64 [bttv] [ 462.783383] [c0000001c6c678e0] [80000000007bf208] .v4l_qbuf+0x54/0x60 [videodev] [ 462.783402] [c0000001c6c67970] [80000000007c1eac] .__video_do_ioctl+0x30c/0x3f8 [videodev] [ 462.783421] [c0000001c6c67a80] [80000000007c3c08] .video_usercopy+0x18c/0x3dc [videodev] [ 462.783440] [c0000001c6c67c00] [80000000007bb14c] .v4l2_ioctl+0x60/0x78 [videodev] [ 462.783460] [c0000001c6c67c90] [80000000007d3c48] .v4l2_compat_ioctl32+0x9b4/0x1850 [videodev] [ 462.783468] [c0000001c6c67d70] [c0000000001ad9cc] .__se_compat_sys_ioctl+0x284/0x127c [ 462.783473] [c0000001c6c67e20] [c00000000000067c] system_call+0x60/0x6c [ 462.783475] Instruction dump: [ 462.783477] 40fe0044 60000000 892255d0 2f890000 40fe0020 3c82ffc5 39200001 60000000 [ 462.783483] 38842029 992255d0 485ad0d9 60000000 <0fe00000> 38210070 e8010010 7c0803a6 [ 462.783490] ---[ end trace b677d4a00458e277 ]---
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dmesg fsl p5040: https://bugzilla.kernel.org/attachment.cgi?id=285813
Kernel 5.4-rc6 config for the Cyrus+ board and for the QEMU ppce500 board (CPU: P5040 and P5020): https://bugzilla.kernel.org/attachment.cgi?id=285815
Bug report: https://bugzilla.kernel.org/show_bug.cgi?id=205201
Thanks for your help,
Christian
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