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: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Roland Dreier 2009-03-30 08:31:05 -07:00 committed by Roland Dreier
parent 5d80f8e5a9
commit e1d60ec669

View file

@ -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 +