Hi, This v2 of the series is spun out and expanded from my work to add P2PDMA support to DMA map operations[1]. v1 is at [2]. The main changes in v1 are to more carefully define the meaning of the error codes for dma_map_sgtable(). The P2PDMA work requires distinguishing different error conditions in a map_sg operation. dma_map_sgtable() already allows for returning an error code (where as dma_map_sg() is only allowed to return zero) however, it currently only returns -EINVAL when a .map_sg() call returns zero. This series cleans up all .map_sg() implementations to return appropriate error codes. After the cleanup, dma_map_sg() will still return zero, however dma_map_sgtable() will pass the error code from the .map_sg() call. Thanks go to Martn Oliveira for doing a lot of the cleanup of the obscure implementations. The patch set is based off of v5.14-rc2 and a git repo can be found here: https://github.com/sbates130272/linux-p2pmem map_sg_err_cleanup_v2 Thanks, Logan [1] https://lore.kernel.org/linux-block/20210513223203.5542-1-logang@deltatee.com/ [2] https://lore.kernel.org/linux-mips/20210715164544.6827-1-logang@deltatee.com/ -- Changes in v2: - Attempt to define the meanings of the errors returned by dma_map_sgtable() and restrict the valid return codes of .map_sg implementations. (Per Christoph) - Change dma_map_sgtable() to EXPORT_SYMBOL_GPL() (Per Christoph) - Add patches to remove the erroneous setting of sg->dma_address to DMA_MAP_ERROR in a few .map_sg(0 implementations. (Per Christoph). -- Logan Gunthorpe (10): dma-mapping: Allow map_sg() ops to return negative error codes dma-direct: Return appropriate error code from dma_direct_map_sg() iommu: Return full error code from iommu_map_sg[_atomic]() dma-iommu: Return error code from iommu_dma_map_sg() ARM/dma-mapping: don't set failed sg dma_address to DMA_MAPPING_ERROR powerpc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR s390/pci: don't set failed sg dma_address to DMA_MAPPING_ERROR sparc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR x86/amd_gart: don't set failed sg dma_address to DMA_MAPPING_ERROR dma-mapping: Disallow .map_sg operations from returning zero on error Martin Oliveira (11): alpha: return error code from alpha_pci_map_sg() ARM/dma-mapping: return error code from .map_sg() ops ia64/sba_iommu: return error code from sba_map_sg_attrs() MIPS/jazzdma: return error code from jazz_dma_map_sg() powerpc/iommu: return error code from .map_sg() ops s390/pci: return error code from s390_dma_map_sg() sparc/iommu: return error codes from .map_sg() ops parisc: return error code from .map_sg() ops xen: swiotlb: return error code from xen_swiotlb_map_sg() x86/amd_gart: return error code from gart_map_sg() dma-mapping: return error code from dma_dummy_map_sg() arch/alpha/kernel/pci_iommu.c | 10 ++- arch/arm/mm/dma-mapping.c | 26 +++++--- arch/ia64/hp/common/sba_iommu.c | 6 +- arch/mips/jazz/jazzdma.c | 2 +- arch/powerpc/kernel/iommu.c | 6 +- arch/powerpc/platforms/ps3/system-bus.c | 2 +- arch/powerpc/platforms/pseries/vio.c | 5 +- arch/s390/pci/pci_dma.c | 13 ++-- arch/sparc/kernel/iommu.c | 6 +- arch/sparc/kernel/pci_sun4v.c | 6 +- arch/sparc/mm/iommu.c | 2 +- arch/x86/kernel/amd_gart_64.c | 18 +++--- drivers/iommu/dma-iommu.c | 23 +++++-- drivers/iommu/iommu.c | 15 ++--- drivers/parisc/ccio-dma.c | 2 +- drivers/parisc/sba_iommu.c | 2 +- drivers/xen/swiotlb-xen.c | 2 +- include/linux/dma-map-ops.h | 5 +- include/linux/dma-mapping.h | 35 ++-------- include/linux/iommu.h | 22 +++---- kernel/dma/direct.c | 2 +- kernel/dma/dummy.c | 2 +- kernel/dma/mapping.c | 86 ++++++++++++++++++++++--- 23 files changed, 181 insertions(+), 117 deletions(-) base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c -- 2.20.1
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This will be required for returning appropriate error codes when mapping P2PDMA memory. Introduce __dma_map_sg_attrs() which will return the raw error code from the map_sg operation (whether it be negative or zero). Then add a dma_map_sg_attrs() wrapper to convert any negative errors to zero to satisfy the existing calling convention. dma_map_sgtable() defines three error codes that .map_sg implementations are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which is a generic return for cases that are passing DMA_MAPPING_ERROR through. dma_map_sgtable() will convert a zero error return for old map_sg() ops into a -EIO return and return any negative errors as reported. This allows map_sg implementations to start returning multiple negative error codes. Legacy map_sg implementations can continue to return zero until they are all converted. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- include/linux/dma-map-ops.h | 5 ++- include/linux/dma-mapping.h | 35 +++------------ kernel/dma/mapping.c | 85 +++++++++++++++++++++++++++++++++---- 3 files changed, 87 insertions(+), 38 deletions(-) diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 0d53a96a3d64..2f842498c448 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -41,8 +41,9 @@ struct dma_map_ops { size_t size, enum dma_data_direction dir, unsigned long attrs); /* - * map_sg returns 0 on error and a value > 0 on success. - * It should never return a value < 0. + * map_sg should return a negative error code on error. See + * dma_map_sgtable() for a list of appropriate error codes + * and their meanings. */ int (*map_sg)(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 183e7103a66d..daa1e360f0ee 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -110,6 +110,8 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs); dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs); void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, @@ -174,6 +176,11 @@ static inline void dma_unmap_sg_attrs(struct device *dev, unsigned long attrs) { } +static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + return -EOPNOTSUPP; +} static inline dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs) @@ -343,34 +350,6 @@ static inline void dma_sync_single_range_for_device(struct device *dev, return dma_sync_single_for_device(dev, addr + offset, size, dir); } -/** - * dma_map_sgtable - Map the given buffer for DMA - * @dev: The device for which to perform the DMA operation - * @sgt: The sg_table object describing the buffer - * @dir: DMA direction - * @attrs: Optional DMA attributes for the map operation - * - * Maps a buffer described by a scatterlist stored in the given sg_table - * object for the @dir DMA operation by the @dev device. After success the - * ownership for the buffer is transferred to the DMA domain. One has to - * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the - * ownership of the buffer back to the CPU domain before touching the - * buffer by the CPU. - * - * Returns 0 on success or -EINVAL on error during mapping the buffer. - */ -static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, - enum dma_data_direction dir, unsigned long attrs) -{ - int nents; - - nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents <= 0) - return -EINVAL; - sgt->nents = nents; - return 0; -} - /** * dma_unmap_sgtable - Unmap the given buffer for DMA * @dev: The device for which to perform the DMA operation diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 2b06a809d0b9..b8dc8b1cb402 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -177,12 +177,8 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, } EXPORT_SYMBOL(dma_unmap_page_attrs); -/* - * dma_maps_sg_attrs returns 0 on error and > 0 on success. - * It should never return a value < 0. - */ -int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction dir, unsigned long attrs) +static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); int ents; @@ -197,13 +193,86 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else ents = ops->map_sg(dev, sg, nents, dir, attrs); - BUG_ON(ents < 0); - debug_dma_map_sg(dev, sg, nents, ents, dir); + + if (ents > 0) + debug_dma_map_sg(dev, sg, nents, ents, dir); return ents; } + +/** + * dma_map_sg_attrs - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sg: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist passed in the sg argument with + * nents segments for the @dir DMA operation by the @dev device. + * + * Returns the number of mapped entries (which can be less than nents) + * on success. Zero is returned for any error. + * + * dma_unmap_sg_attrs() should be used to unmap the buffer with the + * original sg and original nents (not the value returned by this funciton). + */ +int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + int ret; + + ret = __dma_map_sg_attrs(dev, sg, nents, dir, attrs); + if (ret < 0) + ret = 0; + + return ret; +} EXPORT_SYMBOL(dma_map_sg_attrs); +/** + * dma_map_sgtable - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist stored in the given sg_table + * object for the @dir DMA operation by the @dev device. After success, the + * ownership for the buffer is transferred to the DMA domain. One has to + * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the + * ownership of the buffer back to the CPU domain before touching the + * buffer by the CPU. + * + * Returns 0 on success or a negative error code on error. The following + * error codes are supported with the given meaning: + * + * -EINVAL - An invalid argument, unaligned access or other error + * in usage. Will not succeed if retried. + * -ENOMEM - Insufficient resources (like memory or IOVA space) to + * complete the mapping. Should succeed if retried later. + * -EIO - Legacy error code with an unknown meaning. eg. this is + * returned if a lower level call returned DMA_MAPPING_ERROR. + */ +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + int nents; + + nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); + if (nents == 0) + return -EIO; + else if (nents < 0) { + if (WARN_ON_ONCE(nents != -EINVAL && nents != -ENOMEM && + nents != -EIO)) + return -EIO; + return nents; + } + + sgt->nents = nents; + return 0; +} +EXPORT_SYMBOL_GPL(dma_map_sgtable); + void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) -- 2.20.1
Now that the map_sg() op expects error codes instead of return zero on error, convert dma_direct_map_sg() to return an error code. Per the documentation for dma_map_sgtable(), -EIO is returned due to an DMA_MAPPING_ERROR with unknown cause. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/direct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f737e3347059..f33ceb68aef2 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -411,7 +411,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, out_unmap: dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); - return 0; + return -EIO; } dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, -- 2.20.1
Convert to ssize_t return code so the return code from __iommu_map() can be returned all the way down through dma_iommu_map_sg(). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Will Deacon <will@kernel.org> --- drivers/iommu/iommu.c | 15 +++++++-------- include/linux/iommu.h | 22 +++++++++++----------- 2 files changed, 18 insertions(+), 19 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 5419c4b9f27a..bf971b4e34aa 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2567,9 +2567,9 @@ size_t iommu_unmap_fast(struct iommu_domain *domain, } EXPORT_SYMBOL_GPL(iommu_unmap_fast); -static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, - struct scatterlist *sg, unsigned int nents, int prot, - gfp_t gfp) +static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot, + gfp_t gfp) { const struct iommu_ops *ops = domain->ops; size_t len = 0, mapped = 0; @@ -2610,19 +2610,18 @@ static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, /* undo mappings already done */ iommu_unmap(domain, iova, mapped); - return 0; - + return ret; } -size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, - struct scatterlist *sg, unsigned int nents, int prot) +ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot) { might_sleep(); return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL); } EXPORT_SYMBOL_GPL(iommu_map_sg); -size_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova, +ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot) { return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 32d448050bf7..9369458ba1bd 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -414,11 +414,11 @@ extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, extern size_t iommu_unmap_fast(struct iommu_domain *domain, unsigned long iova, size_t size, struct iommu_iotlb_gather *iotlb_gather); -extern size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, - struct scatterlist *sg,unsigned int nents, int prot); -extern size_t iommu_map_sg_atomic(struct iommu_domain *domain, - unsigned long iova, struct scatterlist *sg, - unsigned int nents, int prot); +extern ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot); +extern ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, + unsigned long iova, struct scatterlist *sg, + unsigned int nents, int prot); extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova); extern void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token); @@ -679,18 +679,18 @@ static inline size_t iommu_unmap_fast(struct iommu_domain *domain, return 0; } -static inline size_t iommu_map_sg(struct iommu_domain *domain, - unsigned long iova, struct scatterlist *sg, - unsigned int nents, int prot) +static inline ssize_t iommu_map_sg(struct iommu_domain *domain, + unsigned long iova, struct scatterlist *sg, + unsigned int nents, int prot) { - return 0; + return -ENODEV; } -static inline size_t iommu_map_sg_atomic(struct iommu_domain *domain, +static inline ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot) { - return 0; + return -ENODEV; } static inline void iommu_flush_iotlb_all(struct iommu_domain *domain) -- 2.20.1
Return appropriate error codes EINVAL or ENOMEM from iommup_dma_map_sg(). If lower level code returns ENOMEM, then we return it, other errors are coalesced into EINVAL. iommu_dma_map_sg_swiotlb() returns -EIO as its an unknown error from a call that returns DMA_MAPPING_ERROR. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Will Deacon <will@kernel.org> --- drivers/iommu/dma-iommu.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 98ba927aee1a..d9aaed080e68 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -972,7 +972,7 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg, out_unmap: iommu_dma_unmap_sg_swiotlb(dev, sg, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); - return 0; + return -EIO; } /* @@ -993,11 +993,13 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, dma_addr_t iova; size_t iova_len = 0; unsigned long mask = dma_get_seg_boundary(dev); + ssize_t ret; int i; - if (static_branch_unlikely(&iommu_deferred_attach_enabled) && - iommu_deferred_attach(dev, domain)) - return 0; + if (static_branch_unlikely(&iommu_deferred_attach_enabled)) { + ret = iommu_deferred_attach(dev, domain); + goto out; + } if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) iommu_dma_sync_sg_for_device(dev, sg, nents, dir); @@ -1045,14 +1047,17 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, } iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev); - if (!iova) + if (!iova) { + ret = -ENOMEM; goto out_restore_sg; + } /* * We'll leave any physical concatenation to the IOMMU driver's * implementation - it knows better than we do. */ - if (iommu_map_sg_atomic(domain, iova, sg, nents, prot) < iova_len) + ret = iommu_map_sg_atomic(domain, iova, sg, nents, prot); + if (ret < iova_len) goto out_free_iova; return __finalise_sg(dev, sg, nents, iova); @@ -1061,7 +1066,11 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, iommu_dma_free_iova(cookie, iova, iova_len, NULL); out_restore_sg: __invalidate_sg(sg, nents); - return 0; +out: + if (ret == -ENOMEM) + return ret; + else + return -EINVAL; } static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. pci_map_single_1() can fail for different reasons, but since the only supported type of error return is DMA_MAPPING_ERROR, we coalesce those errors into EIO. ENOMEM is returned when no page tables can be allocated. Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> --- arch/alpha/kernel/pci_iommu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c index 35d7b3096d6e..21f9ac101324 100644 --- a/arch/alpha/kernel/pci_iommu.c +++ b/arch/alpha/kernel/pci_iommu.c @@ -649,7 +649,9 @@ static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg, sg->dma_address = pci_map_single_1(pdev, SG_ENT_VIRT_ADDRESS(sg), sg->length, dac_allowed); - return sg->dma_address != DMA_MAPPING_ERROR; + if (sg->dma_address == DMA_MAPPING_ERROR) + return -EIO; + return 1; } start = sg; @@ -685,8 +687,10 @@ static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg, if (out < end) out->dma_length = 0; - if (out - start == 0) + if (out - start == 0) { printk(KERN_WARNING "pci_map_sg failed: no entries?\n"); + return -ENOMEM; + } DBGA("pci_map_sg: %ld entries\n", out - start); return out - start; @@ -699,7 +703,7 @@ static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg, entries. Unmap them now. */ if (out > start) pci_unmap_sg(pdev, start, out - start, dir); - return 0; + return -ENOMEM; } /* Unmap a set of streaming mode DMA translations. Again, cpu read -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. In the case of a DMA_MAPPING_ERROR, -EIO is returned. Otherwise, -ENOMEM or -EINVAL is returned depending on the error from __map_sg_chunk(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> --- arch/arm/mm/dma-mapping.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index c4b8df2ad328..113b9cb3701b 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -980,7 +980,7 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, { const struct dma_map_ops *ops = get_dma_ops(dev); struct scatterlist *s; - int i, j; + int i, j, ret; for_each_sg(sg, s, nents, i) { #ifdef CONFIG_NEED_SG_DMA_LENGTH @@ -988,15 +988,17 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, #endif s->dma_address = ops->map_page(dev, sg_page(s), s->offset, s->length, dir, attrs); - if (dma_mapping_error(dev, s->dma_address)) + if (dma_mapping_error(dev, s->dma_address)) { + ret = -EIO; goto bad_mapping; + } } return nents; bad_mapping: for_each_sg(sg, s, i, j) ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); - return 0; + return ret; } /** @@ -1622,7 +1624,7 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, bool is_coherent) { struct scatterlist *s = sg, *dma = sg, *start = sg; - int i, count = 0; + int i, count = 0, ret; unsigned int offset = s->offset; unsigned int size = s->offset + s->length; unsigned int max = dma_get_max_seg_size(dev); @@ -1634,8 +1636,10 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, s->dma_length = 0; if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) { - if (__map_sg_chunk(dev, start, size, &dma->dma_address, - dir, attrs, is_coherent) < 0) + ret = __map_sg_chunk(dev, start, size, + &dma->dma_address, dir, attrs, + is_coherent); + if (ret < 0) goto bad_mapping; dma->dma_address += offset; @@ -1648,8 +1652,9 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, } size += s->length; } - if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs, - is_coherent) < 0) + ret = __map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs, + is_coherent); + if (ret < 0) goto bad_mapping; dma->dma_address += offset; @@ -1660,7 +1665,9 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, bad_mapping: for_each_sg(sg, s, count, i) __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s)); - return 0; + if (ret == -ENOMEM) + return ret; + return -EINVAL; } /** -- 2.20.1
Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> --- arch/arm/mm/dma-mapping.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 113b9cb3701b..4b61541853ea 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1632,7 +1632,6 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents, for (i = 1; i < nents; i++) { s = sg_next(s); - s->dma_address = DMA_MAPPING_ERROR; s->dma_length = 0; if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) { -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. In the case of a dma_mapping_error() return -EIO as the actual cause is opaque here. sba_coalesce_chunks() may only presently fail if sba_alloc_range() fails, which in turn only fails if the iommu is out of mapping resources, hence a -ENOMEM is used in that case. Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> --- arch/ia64/hp/common/sba_iommu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c index 9148ddbf02e5..430c166b68cd 100644 --- a/arch/ia64/hp/common/sba_iommu.c +++ b/arch/ia64/hp/common/sba_iommu.c @@ -1458,8 +1458,8 @@ static int sba_map_sg_attrs(struct device *dev, struct scatterlist *sglist, sglist->dma_length = sglist->length; sglist->dma_address = sba_map_page(dev, sg_page(sglist), sglist->offset, sglist->length, dir, attrs); - if (dma_mapping_error(dev, sglist->dma_address)) - return 0; + if(dma_mapping_error(dev, sglist->dma_address)) + return -EIO; return 1; } @@ -1486,7 +1486,7 @@ static int sba_map_sg_attrs(struct device *dev, struct scatterlist *sglist, coalesced = sba_coalesce_chunks(ioc, dev, sglist, nents); if (coalesced < 0) { sba_unmap_sg_attrs(dev, sglist, nents, dir, attrs); - return 0; + return -ENOMEM; } /* -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. vdma_alloc() may fail for different reasons, but since it only supports indicating an error via a return of DMA_MAPPING_ERROR, we coalesce the different reasons into -EIO as is documented on dma_map_sgtable(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> --- arch/mips/jazz/jazzdma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/jazz/jazzdma.c b/arch/mips/jazz/jazzdma.c index 461457b28982..eabddb89d221 100644 --- a/arch/mips/jazz/jazzdma.c +++ b/arch/mips/jazz/jazzdma.c @@ -552,7 +552,7 @@ static int jazz_dma_map_sg(struct device *dev, struct scatterlist *sglist, dir); sg->dma_address = vdma_alloc(sg_phys(sg), sg->length); if (sg->dma_address == DMA_MAPPING_ERROR) - return 0; + return -EIO; sg_dma_len(sg) = sg->length; } -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. Propagate the error up if vio_dma_iommu_map_sg() fails. ppc_iommu_map_sg() may fail either because of iommu_range_alloc() or because of tbl->it_ops->set(). The former only supports returning an error with DMA_MAPPING_ERROR and an examination of the latter indicates that it may return arch-specific errors (for example, tce_buildmulti_pSeriesLP()). Hence, coalesce all of those errors into -EIO, per the documentation on dma_map_sgtable(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geoff Levand <geoff@infradead.org> --- arch/powerpc/kernel/iommu.c | 4 ++-- arch/powerpc/platforms/ps3/system-bus.c | 2 +- arch/powerpc/platforms/pseries/vio.c | 5 +++-- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 2af89a5e379f..a8ec4fe42817 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -473,7 +473,7 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, BUG_ON(direction == DMA_NONE); if ((nelems == 0) || !tbl) - return 0; + return -EINVAL; outs = s = segstart = &sglist[0]; outcount = 1; @@ -599,7 +599,7 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, if (s == outs) break; } - return 0; + return -EIO; } diff --git a/arch/powerpc/platforms/ps3/system-bus.c b/arch/powerpc/platforms/ps3/system-bus.c index 1a5665875165..c54eb46f0cfb 100644 --- a/arch/powerpc/platforms/ps3/system-bus.c +++ b/arch/powerpc/platforms/ps3/system-bus.c @@ -663,7 +663,7 @@ static int ps3_ioc0_map_sg(struct device *_dev, struct scatterlist *sg, unsigned long attrs) { BUG(); - return 0; + return -EINVAL; } static void ps3_sb_unmap_sg(struct device *_dev, struct scatterlist *sg, diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c index e00f3725ec96..e31e59c54f30 100644 --- a/arch/powerpc/platforms/pseries/vio.c +++ b/arch/powerpc/platforms/pseries/vio.c @@ -560,7 +560,8 @@ static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sgl, nelems, count) alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl)); - if (vio_cmo_alloc(viodev, alloc_size)) + ret = vio_cmo_alloc(viodev, alloc_size); + if (ret) goto out_fail; ret = ppc_iommu_map_sg(dev, tbl, sglist, nelems, dma_get_mask(dev), direction, attrs); @@ -577,7 +578,7 @@ static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist, vio_cmo_dealloc(viodev, alloc_size); out_fail: atomic_inc(&viodev->cmo.allocs_failed); - return 0; + return ret; } static void vio_dma_iommu_unmap_sg(struct device *dev, -- 2.20.1
Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geoff Levand <geoff@infradead.org> --- arch/powerpc/kernel/iommu.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index a8ec4fe42817..30b7736f0896 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -575,7 +575,6 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, */ if (outcount < incount) { outs = sg_next(outs); - outs->dma_address = DMA_MAPPING_ERROR; outs->dma_length = 0; } @@ -593,7 +592,6 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, npages = iommu_num_pages(s->dma_address, s->dma_length, IOMMU_PAGE_SIZE(tbl)); __iommu_free(tbl, vaddr, npages); - s->dma_address = DMA_MAPPING_ERROR; s->dma_length = 0; } if (s == outs) -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. So propagate the error from __s390_dma_map_sg() up. __s390_dma_map_sg() returns either -ENOMEM on allocation failure or -EINVAL which is the same as what's expected by dma_map_sgtable(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> --- arch/s390/pci/pci_dma.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index ebc9a49523aa..c78b02012764 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -487,7 +487,7 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, unsigned int max = dma_get_max_seg_size(dev); unsigned int size = s->offset + s->length; unsigned int offset = s->offset; - int count = 0, i; + int count = 0, i, ret; for (i = 1; i < nr_elements; i++) { s = sg_next(s); @@ -497,8 +497,9 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) { - if (__s390_dma_map_sg(dev, start, size, - &dma->dma_address, dir)) + ret = __s390_dma_map_sg(dev, start, size, + &dma->dma_address, dir); + if (ret) goto unmap; dma->dma_address += offset; @@ -511,7 +512,8 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, } size += s->length; } - if (__s390_dma_map_sg(dev, start, size, &dma->dma_address, dir)) + ret = __s390_dma_map_sg(dev, start, size, &dma->dma_address, dir); + if (ret) goto unmap; dma->dma_address += offset; @@ -523,7 +525,7 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs); - return 0; + return ret; } static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg, -- 2.20.1
Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> --- arch/s390/pci/pci_dma.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index c78b02012764..be48e5b5bfcf 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -492,7 +492,6 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, for (i = 1; i < nr_elements; i++) { s = sg_next(s); - s->dma_address = DMA_MAPPING_ERROR; s->dma_length = 0; if (s->offset || (size & ~PAGE_MASK) || -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. Returning an errno from __sbus_iommu_map_sg() results in sbus_iommu_map_sg_gflush() and sbus_iommu_map_sg_pflush() returning an errno, as those functions are wrappers around __sbus_iommu_map_sg(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> --- arch/sparc/kernel/iommu.c | 4 ++-- arch/sparc/kernel/pci_sun4v.c | 4 ++-- arch/sparc/mm/iommu.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index a034f571d869..0589acd34201 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -448,7 +448,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, iommu = dev->archdata.iommu; strbuf = dev->archdata.stc; if (nelems == 0 || !iommu) - return 0; + return -EINVAL; spin_lock_irqsave(&iommu->lock, flags); @@ -580,7 +580,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, } spin_unlock_irqrestore(&iommu->lock, flags); - return 0; + return -EINVAL; } /* If contexts are being used, they are the same in all of the mappings diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 9de57e88f7a1..d90e80fa5705 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -486,7 +486,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, iommu = dev->archdata.iommu; if (nelems == 0 || !iommu) - return 0; + return -EINVAL; atu = iommu->atu; prot = HV_PCI_MAP_ATTR_READ; @@ -619,7 +619,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, } local_irq_restore(flags); - return 0; + return -EINVAL; } static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist, diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c index 0c0342e5b10d..9e3f6933ca13 100644 --- a/arch/sparc/mm/iommu.c +++ b/arch/sparc/mm/iommu.c @@ -256,7 +256,7 @@ static int __sbus_iommu_map_sg(struct device *dev, struct scatterlist *sgl, sg->dma_address =__sbus_iommu_map_page(dev, sg_page(sg), sg->offset, sg->length, per_page_flush); if (sg->dma_address == DMA_MAPPING_ERROR) - return 0; + return -EIO; sg->dma_length = sg->length; } -- 2.20.1
Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> --- arch/sparc/kernel/iommu.c | 2 -- arch/sparc/kernel/pci_sun4v.c | 2 -- 2 files changed, 4 deletions(-) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 0589acd34201..da0363692528 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -546,7 +546,6 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, if (outcount < incount) { outs = sg_next(outs); - outs->dma_address = DMA_MAPPING_ERROR; outs->dma_length = 0; } @@ -572,7 +571,6 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, iommu_tbl_range_free(&iommu->tbl, vaddr, npages, IOMMU_ERROR_CODE); - s->dma_address = DMA_MAPPING_ERROR; s->dma_length = 0; } if (s == outs) diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index d90e80fa5705..384480971805 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -594,7 +594,6 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, if (outcount < incount) { outs = sg_next(outs); - outs->dma_address = DMA_MAPPING_ERROR; outs->dma_length = 0; } @@ -611,7 +610,6 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, iommu_tbl_range_free(tbl, vaddr, npages, IOMMU_ERROR_CODE); /* XXX demap? XXX */ - s->dma_address = DMA_MAPPING_ERROR; s->dma_length = 0; } if (s == outs) -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. Return -EINVAL if the ioc cannot be obtained. Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> --- drivers/parisc/ccio-dma.c | 2 +- drivers/parisc/sba_iommu.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c index b5f9ee81a46c..452e72b7bd01 100644 --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -918,7 +918,7 @@ ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents, BUG_ON(!dev); ioc = GET_IOC(dev); if (!ioc) - return 0; + return -EINVAL; DBG_RUN_SG("%s() START %d entries\n", __func__, nents); diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c index dce4cdf786cd..e60690d38d67 100644 --- a/drivers/parisc/sba_iommu.c +++ b/drivers/parisc/sba_iommu.c @@ -947,7 +947,7 @@ sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents, ioc = GET_IOC(dev); if (!ioc) - return 0; + return -EINVAL; /* Fast path single entry scatterlists. */ if (nents == 1) { -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. xen_swiotlb_map_sg() may only fail if xen_swiotlb_map_page() fails, but xen_swiotlb_map_page() only supports returning errors as DMA_MAPPING_ERROR. So coalesce all errors into EIO per the documentation for dma_map_sgtable(). Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> --- drivers/xen/swiotlb-xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 24d11861ac7d..85d58b720a24 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -509,7 +509,7 @@ xen_swiotlb_map_sg(struct device *dev, struct scatterlist *sgl, int nelems, out_unmap: xen_swiotlb_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); sg_dma_len(sgl) = 0; - return 0; + return -EIO; } static void -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. So make __dma_map_cont() return a valid errno (which is then propagated to gart_map_sg() via dma_map_cont()) and return it in case of failure. Also, return -EINVAL in case of invalid nents. Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Michael Ellerman <mpe@ellerman.id.au> --- arch/x86/kernel/amd_gart_64.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index 9ac696487b13..46aea9a4f26b 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -331,7 +331,7 @@ static int __dma_map_cont(struct device *dev, struct scatterlist *start, int i; if (iommu_start == -1) - return -1; + return -ENOMEM; for_each_sg(start, s, nelems, i) { unsigned long pages, addr; @@ -380,13 +380,13 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) { struct scatterlist *s, *ps, *start_sg, *sgmap; - int need = 0, nextneed, i, out, start; + int need = 0, nextneed, i, out, start, ret; unsigned long pages = 0; unsigned int seg_size; unsigned int max_seg_size; if (nents == 0) - return 0; + return -EINVAL; out = 0; start = 0; @@ -414,8 +414,9 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, if (!iommu_merge || !nextneed || !need || s->offset || (s->length + seg_size > max_seg_size) || (ps->offset + ps->length) % PAGE_SIZE) { - if (dma_map_cont(dev, start_sg, i - start, - sgmap, pages, need) < 0) + ret = dma_map_cont(dev, start_sg, i - start, + sgmap, pages, need); + if (ret < 0) goto error; out++; @@ -432,7 +433,8 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, pages += iommu_num_pages(s->offset, s->length, PAGE_SIZE); ps = s; } - if (dma_map_cont(dev, start_sg, i - start, sgmap, pages, need) < 0) + ret = dma_map_cont(dev, start_sg, i - start, sgmap, pages, need); + if (ret < 0) goto error; out++; flush_gart(); @@ -458,7 +460,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, iommu_full(dev, pages << PAGE_SHIFT, dir); for_each_sg(sg, s, nents, i) s->dma_address = DMA_MAPPING_ERROR; - return 0; + return ret; } /* allocate and map a coherent mapping */ -- 2.20.1
Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Michael Ellerman <mpe@ellerman.id.au> --- arch/x86/kernel/amd_gart_64.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index 46aea9a4f26b..ed837383de5c 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -458,8 +458,6 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, panic("dma_map_sg: overflow on %lu pages\n", pages); iommu_full(dev, pages << PAGE_SHIFT, dir); - for_each_sg(sg, s, nents, i) - s->dma_address = DMA_MAPPING_ERROR; return ret; } -- 2.20.1
From: Martin Oliveira <martin.oliveira@eideticom.com> The .map_sg() op now expects an error code instead of zero on failure. The only errno to return is -EINVAL in the case when DMA is not supported. Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/dummy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/dma/dummy.c b/kernel/dma/dummy.c index eacd4c5b10bf..b492d59ac77e 100644 --- a/kernel/dma/dummy.c +++ b/kernel/dma/dummy.c @@ -22,7 +22,7 @@ static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl, int nelems, enum dma_data_direction dir, unsigned long attrs) { - return 0; + return -EINVAL; } static int dma_dummy_supported(struct device *hwdev, u64 mask) -- 2.20.1
Now that all the .map_sg operations have been converted to returning proper error codes, drop the code to handle a zero return value, add a warning if a zero is returned and update the comment for the map_sg operation. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/mapping.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b8dc8b1cb402..86a8a421344a 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -194,6 +194,9 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, else ents = ops->map_sg(dev, sg, nents, dir, attrs); + if (WARN_ON_ONCE(ents == 0)) + return -EIO; + if (ents > 0) debug_dma_map_sg(dev, sg, nents, ents, dir); @@ -259,9 +262,7 @@ int dma_map_sgtable(struct device *dev, struct sg_table *sgt, int nents; nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents == 0) - return -EIO; - else if (nents < 0) { + if (nents < 0) { if (WARN_ON_ONCE(nents != -EINVAL && nents != -ENOMEM && nents != -EIO)) return -EIO; -- 2.20.1
[-- Attachment #1: Type: text/plain, Size: 336 bytes --] Am Freitag, 23. Juli 2021, 19:50:08 CEST schrieb Logan Gunthorpe: > Now that all the .map_sg operations have been converted to returning > proper error codes, drop the code to handle a zero return value, > add a warning if a zero is returned and update the comment for the > map_sg operation. I see no comment being touched here. Eike [-- Attachment #2: This is a digitally signed message part. --] [-- Type: application/pgp-signature, Size: 195 bytes --]
> +int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
> + enum dma_data_direction dir, unsigned long attrs)
> +{
> + int nents;
> +
> + nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
> + if (nents == 0)
> + return -EIO;
> + else if (nents < 0) {
> + if (WARN_ON_ONCE(nents != -EINVAL && nents != -ENOMEM &&
> + nents != -EIO))
> + return -EIO;
I think this validation of the errnos needs to go into __dma_map_sg_attrs,
so that we catch it for the classic dma_map_sg callers as well.
On Fri, 2021-07-23 at 11:50 -0600, Logan Gunthorpe wrote:
> Setting the ->dma_address to DMA_MAPPING_ERROR is not part of
> the ->map_sg calling convention, so remove it.
>
> Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> arch/s390/pci/pci_dma.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
> index c78b02012764..be48e5b5bfcf 100644
> --- a/arch/s390/pci/pci_dma.c
> +++ b/arch/s390/pci/pci_dma.c
> @@ -492,7 +492,6 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
> for (i = 1; i < nr_elements; i++) {
> s = sg_next(s);
>
> - s->dma_address = DMA_MAPPING_ERROR;
> s->dma_length = 0;
>
> if (s->offset || (size & ~PAGE_MASK) ||
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Thanks!