Re: [PATCH 01/22] scatterlist: Introduce sg_map helper functions
From: Christoph Hellwig <hidden>
Date: 2017-04-14 08:35:25
Also in:
dri-devel, intel-gfx, linux-crypto, linux-media, linux-mmc, linux-raid, linux-rdma, linux-scsi, lkml, nvdimm
quoted hunk ↗ jump to hunk
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 0007b79..b95934b 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c@@ -37,6 +37,9 @@ #include <uapi/linux/dma-buf.h> +/* Prevent the highmem.h macro from aliasing ops->kunmap_atomic */ +#undef kunmap_atomic + static inline int is_dma_buf_file(struct file *); struct dma_buf_list {
I think the right fix here is to rename the operation to unmap_atomic and send out a little patch for that ASAP.
+ * Flags can be any of: + * * SG_KMAP - Use kmap to create the mapping + * * SG_KMAP_ATOMIC - Use kmap_atomic to map the page atommically. + * Thus, the rules of that function apply: the cpu + * may not sleep until it is unmaped. + * + * Also, consider carefully whether this function is appropriate. It is + * largely not recommended for new code and if the sgl came from another + * subsystem and you don't know what kind of memory might be in the list + * then you definitely should not call it. Non-mappable memory may be in + * the sgl and thus this function may fail unexpectedly. + **/ +static inline void *sg_map_offset(struct scatterlist *sg, size_t offset, + int flags)
I'd rather have separate functions for kmap vs kmap_atomic instead of the flags parameter. And while you're at it just always pass the 0 offset parameter instead of adding a wrapper.. Otherwise this looks good to me. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To post to this group, send email to open-iscsi-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.