Messages in this thread | | | From | Olga Kitaina <> | Subject | using ioremap() memory in dma_map_sg() | Date | Mon, 19 Nov 2018 19:02:22 +0300 |
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Hi. As part of our driver, we want to have some device memory to be available to other devices via the DMA-BUF subsystem. The device memory is managed by genpool, and mapped from the sram driver via ioremap_wc(). We initially used sg_set_buf() with the virtual address returned from gen_pool_dma_alloc(), but it seems like the wrong thing to do, since the virt_addr_valid() check fails. Attempting to use vmalloc_to_page() results in a failure down the line, such as:
Unable to handle kernel paging request at virtual address ba405000 Backtrace: (dma_cache_maint_page) from (__dma_page_dev_to_cpu+0x88/0x108) (__dma_page_dev_to_cpu) from (arm_dma_map_page+0x5c/0x60) (arm_dma_unmap_page) from (arm_dma_map_sg+0x64/0x8c) (arm_dma_unmap_sg) from(foo_dmabuf_map+0x60/0x8c [foo])
Is there an appropriate way to put an ioremapped buffer into an SG table?
Thanks, Olga.
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