linux/include/xen/arm
Juergen Gross ae0e082687 xen: replace xen_remap() with memremap()
commit 41925b105e upstream.

xen_remap() is used to establish mappings for frames not under direct
control of the kernel: for Xenstore and console ring pages, and for
grant pages of non-PV guests.

Today xen_remap() is defined to use ioremap() on x86 (doing uncached
mappings), and ioremap_cache() on Arm (doing cached mappings).

Uncached mappings for those use cases are bad for performance, so they
should be avoided if possible. As all use cases of xen_remap() don't
require uncached mappings (the mapped area is always physical RAM),
a mapping using the standard WB cache mode is fine.

As sparse is flagging some of the xen_remap() use cases to be not
appropriate for iomem(), as the result is not annotated with the
__iomem modifier, eliminate xen_remap() completely and replace all
use cases with memremap() specifying the MEMREMAP_WB caching mode.

xen_unmap() can be replaced with memunmap().

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220530082634.6339-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Teddy Astie <teddy.astie@vates.tech> [backport to 5.15.y]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-07-17 18:30:48 +02:00
..
hypercall.h xen: fix HYPERVISOR_dm_op() prototype 2017-06-08 19:40:14 +02:00
hypervisor.h xen/arm: remove xen_dma_ops 2019-09-11 12:43:26 +02:00
interface.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page-coherent.h swiotlb-xen: simplify cache maintainance 2019-09-11 12:43:27 +02:00
page.h xen: replace xen_remap() with memremap() 2025-07-17 18:30:48 +02:00
swiotlb-xen.h xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h 2021-05-14 15:52:05 +02:00