+ Ohad On 07/22/2013 03:47 AM, Rusty Russell wrote: > Michal Simek <mon...@monstr.eu> writes: >> Hi Rusty and Jens, >> >> I am getting problem with your patch which you have added to the kernel. >> The problem is with my arm zynq remoteproc driver where >> I use dma_declare_coherent_memory() to specify memory for remoteproc >> which is ioremap to the vmalloc area. >> >> Based on that buf addr is not inside ram even this coherent memory is in ram. >> That's why virt_addr_valid(buf) is failing. > > But sg_set_buf() calls virt_to_page(buf). So does that work? > > I would think calling sg_set_page() directly would be what you want > here...
Let me take some code from virtio_rpmsg_bus.c to show that problematic part.
bufs_va = dma_alloc_coherent(vdev->dev.parent->parent,
RPMSG_TOTAL_BUF_SPACE,
&vrp->bufs_dma, GFP_KERNEL);
vrp->rbufs = bufs_va;
for (i = 0; i < RPMSG_NUM_BUFS / 2; i++) {
struct scatterlist sg;
void *cpu_addr = vrp->rbufs + i * RPMSG_BUF_SIZE;
sg_init_one(&sg, cpu_addr, RPMSG_BUF_SIZE);
}
dma_alloc_coherent returns ioremaped ram address and sg_init_one()
is checking if addr is valid.
It is no problem to call instead of sg_init_one()
sg_init_table(sg, 1);
sg_set_page(sg, virt_to_page(cpu_addr), RPMSG_BUF_SIZE,
offset_in_page(cpu_addr));
But my question is if SG lists have to be used just for memory which is not
remapped.
Ohad: Can you see similar problem with your remoteproc drivers when DEBUG_SG is
enabled?
Thanks,
Michal
--
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform
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