From: Christoph Hellwig <hch@xxxxxx> Subject: xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv Replacing alloc_vm_area with get_vm_area_caller + apply_page_range allows to fill put the phys_addr values directly instead of doing another loop over all addresses. Link: https://lkml.kernel.org/r/20201002122204.1534411-10-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Nitin Gupta <ngupta@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Cc: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/xen/xenbus/xenbus_client.c | 30 ++++++++++++++------------- 1 file changed, 16 insertions(+), 14 deletions(-) --- a/drivers/xen/xenbus/xenbus_client.c~xen-xenbus-use-apply_to_page_range-directly-in-xenbus_map_ring_pv +++ a/drivers/xen/xenbus/xenbus_client.c @@ -73,16 +73,13 @@ struct map_ring_valloc { struct xenbus_map_node *node; /* Why do we need two arrays? See comment of __xenbus_map_ring */ - union { - unsigned long addrs[XENBUS_MAX_RING_GRANTS]; - pte_t *ptes[XENBUS_MAX_RING_GRANTS]; - }; + unsigned long addrs[XENBUS_MAX_RING_GRANTS]; phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS]; struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS]; struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS]; - unsigned int idx; /* HVM only. */ + unsigned int idx; }; static DEFINE_SPINLOCK(xenbus_valloc_lock); @@ -686,6 +683,14 @@ int xenbus_unmap_ring_vfree(struct xenbu EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree); #ifdef CONFIG_XEN_PV +static int map_ring_apply(pte_t *pte, unsigned long addr, void *data) +{ + struct map_ring_valloc *info = data; + + info->phys_addrs[info->idx++] = arbitrary_virt_to_machine(pte).maddr; + return 0; +} + static int xenbus_map_ring_pv(struct xenbus_device *dev, struct map_ring_valloc *info, grant_ref_t *gnt_refs, @@ -694,18 +699,15 @@ static int xenbus_map_ring_pv(struct xen { struct xenbus_map_node *node = info->node; struct vm_struct *area; - int err = GNTST_okay; - int i; - bool leaked; + bool leaked = false; + int err = -ENOMEM; - area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, info->ptes); + area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP); if (!area) return -ENOMEM; - - for (i = 0; i < nr_grefs; i++) - info->phys_addrs[i] = - arbitrary_virt_to_machine(info->ptes[i]).maddr; - + if (apply_to_page_range(&init_mm, (unsigned long)area->addr, + XEN_PAGE_SIZE * nr_grefs, map_ring_apply, info)) + goto failed; err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles, info, GNTMAP_host_map | GNTMAP_contains_pte, &leaked); _
