From: Juergen Gross jgross@suse.com

[ upstream commit 41925b105e345ebc84cedb64f59d20cb14a62613 ]

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] --- arch/x86/include/asm/xen/page.h | 3 --- drivers/xen/grant-table.c | 6 +++--- drivers/xen/xenbus/xenbus_probe.c | 3 +-- 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 1a162e559753..c183b7f9efef 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -355,9 +355,6 @@ unsigned long arbitrary_virt_to_mfn(void *vaddr); void make_lowmem_page_readonly(void *vaddr); void make_lowmem_page_readwrite(void *vaddr);

-#define xen_remap(cookie, size) ioremap((cookie), (size)) -#define xen_unmap(cookie) iounmap((cookie)) - static inline bool xen_arch_need_swiotlb(struct device *dev, phys_addr_t phys, dma_addr_t dev_addr) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 0a2d24d6ac6f..a10e0741bec5 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -743,7 +743,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) if (xen_auto_xlat_grant_frames.count) return -EINVAL;

- vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes); + vaddr = memremap(addr, XEN_PAGE_SIZE * max_nr_gframes, MEMREMAP_WB); if (vaddr == NULL) { pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", &addr); @@ -751,7 +751,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) } pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); if (!pfn) { - xen_unmap(vaddr); + memunmap(vaddr); return -ENOMEM; } for (i = 0; i < max_nr_gframes; i++) @@ -770,7 +770,7 @@ void gnttab_free_auto_xlat_frames(void) if (!xen_auto_xlat_grant_frames.count) return; kfree(xen_auto_xlat_grant_frames.pfn); - xen_unmap(xen_auto_xlat_grant_frames.vaddr); + memunmap(xen_auto_xlat_grant_frames.vaddr);

xen_auto_xlat_grant_frames.pfn = NULL; xen_auto_xlat_grant_frames.count = 0; diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 2068f83556b7..77ca24611293 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -982,8 +982,7 @@ static int __init xenbus_init(void) #endif xen_store_gfn = (unsigned long)v; xen_store_interface = - xen_remap(xen_store_gfn << XEN_PAGE_SHIFT, - XEN_PAGE_SIZE); + memremap(xen_store_gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB); break; default: pr_warn("Xenstore state unknown\n");