This is a note to let you know that I've just added the patch titled parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-dma-api-return-error-instead-of-bug_on-for-dma-ops-on-non-dma-devs.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 33f9e02495d15a061f0c94ef46f5103a2d0c20f3 Mon Sep 17 00:00:00 2001 From: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Date: Mon, 3 Jul 2017 10:38:05 +0200 Subject: parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs From: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> commit 33f9e02495d15a061f0c94ef46f5103a2d0c20f3 upstream. Enabling parport pc driver on a B2600 (and probably other 64bit PARISC systems) produced following BUG: CPU: 0 PID: 1 Comm: swapper Not tainted 4.12.0-rc5-30198-g1132d5e #156 task: 000000009e050000 task.stack: 000000009e04c000 YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI PSW: 00001000000001101111111100001111 Not tainted r00-03 000000ff0806ff0f 000000009e04c990 0000000040871b78 000000009e04cac0 r04-07 0000000040c14de0 ffffffffffffffff 000000009e07f098 000000009d82d200 r08-11 000000009d82d210 0000000000000378 0000000000000000 0000000040c345e0 r12-15 0000000000000005 0000000040c345e0 0000000000000000 0000000040c9d5e0 r16-19 0000000040c345e0 00000000f00001c4 00000000f00001bc 0000000000000061 r20-23 000000009e04ce28 0000000000000010 0000000000000010 0000000040b89e40 r24-27 0000000000000003 0000000000ffffff 000000009d82d210 0000000040c14de0 r28-31 0000000000000000 000000009e04ca90 000000009e04cb40 0000000000000000 sr00-03 0000000000000000 0000000000000000 0000000000000000 0000000000000000 sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000404aece0 00000000404aece4 IIR: 03ffe01f ISR: 0000000010340000 IOR: 000001781304cac8 CPU: 0 CR30: 000000009e04c000 CR31: 00000000e2976de2 ORIG_R28: 0000000000000200 IAOQ[0]: sba_dma_supported+0x80/0xd0 IAOQ[1]: sba_dma_supported+0x84/0xd0 RP(r2): parport_pc_probe_port+0x178/0x1200 Cause is a call to dma_coerce_mask_and_coherenet in parport_pc_probe_port, which PARISC DMA API doesn't handle very nicely. This commit gives back DMA_ERROR_CODE for DMA API calls, if device isn't capable of DMA transaction. Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/parisc/include/asm/dma-mapping.h | 11 +++++++---- drivers/parisc/ccio-dma.c | 12 ++++++++++++ drivers/parisc/dino.c | 5 ++++- drivers/parisc/lba_pci.c | 6 ++++-- drivers/parisc/sba_iommu.c | 14 ++++++++++++++ 5 files changed, 41 insertions(+), 7 deletions(-) --- a/arch/parisc/include/asm/dma-mapping.h +++ b/arch/parisc/include/asm/dma-mapping.h @@ -39,6 +39,8 @@ struct hppa_dma_ops { ** flush/purge and allocate "regular" cacheable pages for everything. */ +#define DMA_ERROR_CODE (~(dma_addr_t)0) + #ifdef CONFIG_PA11 extern struct hppa_dma_ops pcxl_dma_ops; extern struct hppa_dma_ops pcx_dma_ops; @@ -209,12 +211,13 @@ parisc_walk_tree(struct device *dev) break; } } - BUG_ON(!dev->platform_data); return dev->platform_data; } - -#define GET_IOC(dev) (HBA_DATA(parisc_walk_tree(dev))->iommu) - + +#define GET_IOC(dev) ({ \ + void *__pdata = parisc_walk_tree(dev); \ + __pdata ? HBA_DATA(__pdata)->iommu : NULL; \ +}) #ifdef CONFIG_IOMMU_CCIO struct parisc_device; --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -743,6 +743,8 @@ ccio_map_single(struct device *dev, void BUG_ON(!dev); ioc = GET_IOC(dev); + if (!ioc) + return DMA_ERROR_CODE; BUG_ON(size <= 0); @@ -807,6 +809,10 @@ ccio_unmap_single(struct device *dev, dm BUG_ON(!dev); ioc = GET_IOC(dev); + if (!ioc) { + WARN_ON(!ioc); + return; + } DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long)iova, size); @@ -910,6 +916,8 @@ ccio_map_sg(struct device *dev, struct s BUG_ON(!dev); ioc = GET_IOC(dev); + if (!ioc) + return 0; DBG_RUN_SG("%s() START %d entries\n", __func__, nents); @@ -982,6 +990,10 @@ ccio_unmap_sg(struct device *dev, struct BUG_ON(!dev); ioc = GET_IOC(dev); + if (!ioc) { + WARN_ON(!ioc); + return; + } DBG_RUN_SG("%s() START %d entries, %08lx,%x\n", __func__, nents, sg_virt_addr(sglist), sglist->length); --- a/drivers/parisc/dino.c +++ b/drivers/parisc/dino.c @@ -154,7 +154,10 @@ struct dino_device }; /* Looks nice and keeps the compiler happy */ -#define DINO_DEV(d) ((struct dino_device *) d) +#define DINO_DEV(d) ({ \ + void *__pdata = d; \ + BUG_ON(!__pdata); \ + (struct dino_device *)__pdata; }) /* --- a/drivers/parisc/lba_pci.c +++ b/drivers/parisc/lba_pci.c @@ -111,8 +111,10 @@ static u32 lba_t32; /* Looks nice and keeps the compiler happy */ -#define LBA_DEV(d) ((struct lba_device *) (d)) - +#define LBA_DEV(d) ({ \ + void *__pdata = d; \ + BUG_ON(!__pdata); \ + (struct lba_device *)__pdata; }) /* ** Only allow 8 subsidiary busses per LBA --- a/drivers/parisc/sba_iommu.c +++ b/drivers/parisc/sba_iommu.c @@ -691,6 +691,8 @@ static int sba_dma_supported( struct dev return 0; ioc = GET_IOC(dev); + if (!ioc) + return 0; /* * check if mask is >= than the current max IO Virt Address @@ -722,6 +724,8 @@ sba_map_single(struct device *dev, void int pide; ioc = GET_IOC(dev); + if (!ioc) + return DMA_ERROR_CODE; /* save offset bits */ offset = ((dma_addr_t) (long) addr) & ~IOVP_MASK; @@ -803,6 +807,10 @@ sba_unmap_single(struct device *dev, dma DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long) iova, size); ioc = GET_IOC(dev); + if (!ioc) { + WARN_ON(!ioc); + return; + } offset = iova & ~IOVP_MASK; iova ^= offset; /* clear offset bits */ size += offset; @@ -942,6 +950,8 @@ sba_map_sg(struct device *dev, struct sc DBG_RUN_SG("%s() START %d entries\n", __func__, nents); ioc = GET_IOC(dev); + if (!ioc) + return 0; /* Fast path single entry scatterlists. */ if (nents == 1) { @@ -1028,6 +1038,10 @@ sba_unmap_sg(struct device *dev, struct __func__, nents, sg_virt_addr(sglist), sglist->length); ioc = GET_IOC(dev); + if (!ioc) { + WARN_ON(!ioc); + return; + } #ifdef SBA_COLLECT_STATS ioc->usg_calls++; Patches currently in stable-queue which might be from tsbogend@xxxxxxxxxxxxxxxx are queue-3.18/parisc-dma-api-return-error-instead-of-bug_on-for-dma-ops-on-non-dma-devs.patch