From b0f212633b31ddca99c76aa38f812fe492e8410a Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 11 Mar 2022 11:34:28 +0100 Subject: [PATCH] xen/grant-table: remove gnttab_*transfer*() functions All grant table operations related to the "transfer" functionality are unused currently. There have been users in the old days of the "Xen-o-Linux" kernel, but those didn't make it upstream. So remove the "transfer" related functions. Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20220311103429.12845-2-jgross@suse.com Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/grant-table.c | 113 +------------------------------------- include/xen/grant_table.h | 8 --- 2 files changed, 2 insertions(+), 119 deletions(-) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 5c83d41766c8..8963af8ec764 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -109,7 +109,7 @@ struct gnttab_ops { void (*unmap_frames)(void); /* * Introducing a valid entry into the grant table, granting the frame of - * this grant entry to domain for accessing or transfering. Ref + * this grant entry to domain for accessing. Ref * parameter is reference of this introduced grant entry, domid is id of * granted domain, frame is the page frame to be granted, and flags is * status of the grant entry to be updated. @@ -125,14 +125,6 @@ struct gnttab_ops { * access for this entry and return success(==1). */ int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); - /* - * Stop granting a grant entry to domain for transfer. Ref parameter is - * reference of a grant entry whose grant transfer will be stopped. If - * tranfer has not started, just reclaim the grant entry and return - * failure(==0). Otherwise, wait for the transfer to complete and then - * return the frame. - */ - unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); /* * Read the frame number related to a given grant reference. */ @@ -230,10 +222,7 @@ static void put_free_entry(grant_ref_t ref) * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. * Introducing a valid entry into the grant table: * 1. Write ent->domid. - * 2. Write ent->frame: - * GTF_permit_access: Frame to which access is permitted. - * GTF_accept_transfer: Pseudo-phys frame slot being filled by new - * frame, or zero if none. + * 2. Write ent->frame: Frame to which access is permitted. * 3. Write memory barrier (WMB). * 4. Write ent->flags, inc. valid type. */ @@ -455,102 +444,6 @@ void gnttab_end_foreign_access(grant_ref_t ref, int readonly, } EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); -int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) -{ - int ref; - - ref = get_free_entries(1); - if (unlikely(ref < 0)) - return -ENOSPC; - gnttab_grant_foreign_transfer_ref(ref, domid, pfn); - - return ref; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); - -void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, - unsigned long pfn) -{ - gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); - -static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) -{ - unsigned long frame; - u16 flags; - u16 *pflags; - - pflags = &gnttab_shared.v1[ref].flags; - - /* - * If a transfer is not even yet started, try to reclaim the grant - * reference and return failure (== 0). - */ - while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) - return 0; - cpu_relax(); - } - - /* If a transfer is in progress then wait until it is completed. */ - while (!(flags & GTF_transfer_completed)) { - flags = *pflags; - cpu_relax(); - } - - rmb(); /* Read the frame number /after/ reading completion status. */ - frame = gnttab_shared.v1[ref].frame; - BUG_ON(frame == 0); - - return frame; -} - -static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) -{ - unsigned long frame; - u16 flags; - u16 *pflags; - - pflags = &gnttab_shared.v2[ref].hdr.flags; - - /* - * If a transfer is not even yet started, try to reclaim the grant - * reference and return failure (== 0). - */ - while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) - return 0; - cpu_relax(); - } - - /* If a transfer is in progress then wait until it is completed. */ - while (!(flags & GTF_transfer_completed)) { - flags = *pflags; - cpu_relax(); - } - - rmb(); /* Read the frame number /after/ reading completion status. */ - frame = gnttab_shared.v2[ref].full_page.frame; - BUG_ON(frame == 0); - - return frame; -} - -unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) -{ - return gnttab_interface->end_foreign_transfer_ref(ref); -} -EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); - -unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) -{ - unsigned long frame = gnttab_end_foreign_transfer_ref(ref); - put_free_entry(ref); - return frame; -} -EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); - void gnttab_free_grant_reference(grant_ref_t ref) { put_free_entry(ref); @@ -1423,7 +1316,6 @@ static const struct gnttab_ops gnttab_v1_ops = { .unmap_frames = gnttab_unmap_frames_v1, .update_entry = gnttab_update_entry_v1, .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, - .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, .read_frame = gnttab_read_frame_v1, }; @@ -1435,7 +1327,6 @@ static const struct gnttab_ops gnttab_v2_ops = { .unmap_frames = gnttab_unmap_frames_v2, .update_entry = gnttab_update_entry_v2, .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, - .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, .read_frame = gnttab_read_frame_v2, }; diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index c9fea9389ebe..9f9b1a297f0d 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -125,11 +125,6 @@ void gnttab_end_foreign_access(grant_ref_t ref, int readonly, */ int gnttab_try_end_foreign_access(grant_ref_t ref); -int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); - -unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); -unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); - /* * operations on reserved batches of grant references */ @@ -162,9 +157,6 @@ static inline void gnttab_page_grant_foreign_access_ref_one( readonly); } -void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, - unsigned long pfn); - static inline void gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, uint32_t flags, grant_ref_t ref, domid_t domid)