Messages in this thread | | | Date | Mon, 25 Jul 2011 19:47:14 +0530 | Subject | Re: [RFC] DMAEngine: Define generic transfer request api | From | Jaswinder Singh <> |
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On 25 July 2011 17:00, Vinod Koul <vkoul@infradead.org> wrote: > On Sun, 2011-07-24 at 02:01 +0530, Jassi Brar wrote: >> This is an attempt to define an api that could be used for doing >> fancy data transfers like interleaved to contiguous copy and vice-versa. >> Traditional SG_list based transfers tend to be very inefficient >> in such cases. Such cases call for some very condensed api to convey >> pattern of the transfer. This is an attempt at that condensed api. >> >> The api supports all 4 variants of scatter-gather and contiguous transfer. >> Besides, it could easily represent common operations like >> device_prep_dma_{cyclic, memset, memcpy} > and how do you specify if the transfer is cyclic, memset or mempcy... Sorry I missed this in the dense. Maybe it's a good idea to isolate enough the context and reply in a post ?
Cyclic - I have already explained to Linus. Please ask for clarifications.
Memset (with pattern of source bus-width size) ********* struct xfer_template { bool src_inc = false; bool dst_inc = true; size_t numf = memset_length / pattern_size; size_t frame_size = 1; struct data_chunk sgl[0] represents the pattern to be repeated };
If we need to set memory with a pattern or arbitrary length, we can add read-width and write-width members(actually I just removed before posting). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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