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Commit e1d60ec6 authored by Roland Dreier's avatar Roland Dreier Committed by Roland Dreier
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IB/mlx4: Use pgprot_writecombine() for BlueFlame pages 



The PAT work on x86 has finally made pgprot_writecombine() a usable API
for modular drivers.  As the comment indicates, this is exactly what we
want to use in mlx4_ib to map BlueFlame pages up to userspace, since
using WC for these pages improves small message latency significantly.

Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 5d80f8e5

drivers/infiniband/hw/mlx4/main.c

+1 −2
Original line number Diff line number Diff line
@@ -394,8 +394,7 @@ static int mlx4_ib_mmap(struct ib_ucontext *context, struct vm_area_struct *vma) 
				       PAGE_SIZE, vma->vm_page_prot))

			return -EAGAIN;

	} else if (vma->vm_pgoff == 1 && dev->dev->caps.bf_reg_size != 0) {

		/* FIXME want pgprot_writecombine() for BlueFlame pages */

		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);



		if (io_remap_pfn_range(vma, vma->vm_start,

				       to_mucontext(context)->uar.pfn +