5.15-stable review patch. If anyone has any objections, please let me know.
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From: Juergen Gross jgross@suse.com
commit 41925b105e345ebc84cedb64f59d20cb14a62613 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 --- arch/x86/include/asm/xen/page.h | 3 --- drivers/tty/hvc/hvc_xen.c | 2 +- drivers/xen/grant-table.c | 6 +++--- drivers/xen/xenbus/xenbus_probe.c | 3 +-- include/xen/arm/page.h | 3 --- 5 files changed, 5 insertions(+), 12 deletions(-)
--- 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 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) --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -270,7 +270,7 @@ static int xen_hvm_console_init(void) if (r < 0 || v == 0) goto err; gfn = v; - info->intf = xen_remap(gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE); + info->intf = memremap(gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB); if (info->intf == NULL) goto err; info->vtermno = HVC_COOKIE; --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -743,7 +743,7 @@ int gnttab_setup_auto_xlat_frames(phys_a 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_a } 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; --- 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"); --- a/include/xen/arm/page.h +++ b/include/xen/arm/page.h @@ -109,9 +109,6 @@ static inline bool set_phys_to_machine(u return __set_phys_to_machine(pfn, mfn); }
-#define xen_remap(cookie, size) ioremap_cache((cookie), (size)) -#define xen_unmap(cookie) iounmap((cookie)) - bool xen_arch_need_swiotlb(struct device *dev, phys_addr_t phys, dma_addr_t dev_addr);