diff options
Diffstat (limited to 'drivers/xen/xen-front-pgdir-shbuf.c')
| -rw-r--r-- | drivers/xen/xen-front-pgdir-shbuf.c | 70 |
1 files changed, 34 insertions, 36 deletions
diff --git a/drivers/xen/xen-front-pgdir-shbuf.c b/drivers/xen/xen-front-pgdir-shbuf.c index 48a658dc7ccf..223870a0111b 100644 --- a/drivers/xen/xen-front-pgdir-shbuf.c +++ b/drivers/xen/xen-front-pgdir-shbuf.c @@ -21,16 +21,7 @@ #include <xen/xen-front-pgdir-shbuf.h> -#ifndef GRANT_INVALID_REF /* - * FIXME: usage of grant reference 0 as invalid grant reference: - * grant reference 0 is valid, but never exposed to a PV driver, - * because of the fact it is already in use/reserved by the PV console. - */ -#define GRANT_INVALID_REF 0 -#endif - -/** * This structure represents the structure of a shared page * that contains grant references to the pages of the shared * buffer. This structure is common to many Xen para-virtualized @@ -38,10 +29,11 @@ */ struct xen_page_directory { grant_ref_t gref_dir_next_page; - grant_ref_t gref[1]; /* Variable length */ +#define XEN_GREF_LIST_END 0 + grant_ref_t gref[]; /* Variable length */ }; -/** +/* * Shared buffer ops which are differently implemented * depending on the allocation mode, e.g. if the buffer * is allocated by the corresponding backend or frontend. @@ -69,7 +61,7 @@ struct xen_front_pgdir_shbuf_ops { int (*unmap)(struct xen_front_pgdir_shbuf *buf); }; -/** +/* * Get granted reference to the very first page of the * page directory. Usually this is passed to the backend, * so it can find/fill the grant references to the buffer's @@ -83,13 +75,13 @@ grant_ref_t xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf *buf) { if (!buf->grefs) - return GRANT_INVALID_REF; + return INVALID_GRANT_REF; return buf->grefs[0]; } EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_get_dir_start); -/** +/* * Map granted references of the shared buffer. * * Depending on the shared buffer mode of allocation @@ -97,7 +89,7 @@ EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_get_dir_start); * shared by the frontend itself) or map the provided granted * references onto the backing storage (buf->pages). * - * \param buf shared buffer which grants to be maped. + * \param buf shared buffer which grants to be mapped. * \return zero on success or a negative number on failure. */ int xen_front_pgdir_shbuf_map(struct xen_front_pgdir_shbuf *buf) @@ -110,7 +102,7 @@ int xen_front_pgdir_shbuf_map(struct xen_front_pgdir_shbuf *buf) } EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_map); -/** +/* * Unmap granted references of the shared buffer. * * Depending on the shared buffer mode of allocation @@ -118,7 +110,7 @@ EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_map); * shared by the frontend itself) or unmap the provided granted * references. * - * \param buf shared buffer which grants to be unmaped. + * \param buf shared buffer which grants to be unmapped. * \return zero on success or a negative number on failure. */ int xen_front_pgdir_shbuf_unmap(struct xen_front_pgdir_shbuf *buf) @@ -131,7 +123,7 @@ int xen_front_pgdir_shbuf_unmap(struct xen_front_pgdir_shbuf *buf) } EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_unmap); -/** +/* * Free all the resources of the shared buffer. * * \param buf shared buffer which resources to be freed. @@ -142,9 +134,8 @@ void xen_front_pgdir_shbuf_free(struct xen_front_pgdir_shbuf *buf) int i; for (i = 0; i < buf->num_grefs; i++) - if (buf->grefs[i] != GRANT_INVALID_REF) - gnttab_end_foreign_access(buf->grefs[i], - 0, 0UL); + if (buf->grefs[i] != INVALID_GRANT_REF) + gnttab_end_foreign_access(buf->grefs[i], NULL); } kfree(buf->grefs); kfree(buf->directory); @@ -159,7 +150,7 @@ EXPORT_SYMBOL_GPL(xen_front_pgdir_shbuf_free); offsetof(struct xen_page_directory, \ gref)) / sizeof(grant_ref_t)) -/** +/* * Get the number of pages the page directory consumes itself. * * \param buf shared buffer. @@ -169,7 +160,7 @@ static int get_num_pages_dir(struct xen_front_pgdir_shbuf *buf) return DIV_ROUND_UP(buf->num_pages, XEN_NUM_GREFS_PER_PAGE); } -/** +/* * Calculate the number of grant references needed to share the buffer * and its pages when backend allocates the buffer. * @@ -181,7 +172,7 @@ static void backend_calc_num_grefs(struct xen_front_pgdir_shbuf *buf) buf->num_grefs = get_num_pages_dir(buf); } -/** +/* * Calculate the number of grant references needed to share the buffer * and its pages when frontend allocates the buffer. * @@ -199,7 +190,7 @@ static void guest_calc_num_grefs(struct xen_front_pgdir_shbuf *buf) #define xen_page_to_vaddr(page) \ ((uintptr_t)pfn_to_kaddr(page_to_xen_pfn(page))) -/** +/* * Unmap the buffer previously mapped with grant references * provided by the backend. * @@ -247,7 +238,7 @@ static int backend_unmap(struct xen_front_pgdir_shbuf *buf) return ret; } -/** +/* * Map the buffer with grant references provided by the backend. * * \param buf shared buffer. @@ -305,11 +296,18 @@ static int backend_map(struct xen_front_pgdir_shbuf *buf) /* Save handles even if error, so we can unmap. */ for (cur_page = 0; cur_page < buf->num_pages; cur_page++) { - buf->backend_map_handles[cur_page] = map_ops[cur_page].handle; - if (unlikely(map_ops[cur_page].status != GNTST_okay)) + if (likely(map_ops[cur_page].status == GNTST_okay)) { + buf->backend_map_handles[cur_page] = + map_ops[cur_page].handle; + } else { + buf->backend_map_handles[cur_page] = + INVALID_GRANT_HANDLE; + if (!ret) + ret = -ENXIO; dev_err(&buf->xb_dev->dev, "Failed to map page %d: %d\n", cur_page, map_ops[cur_page].status); + } } if (ret) { @@ -322,7 +320,7 @@ static int backend_map(struct xen_front_pgdir_shbuf *buf) return ret; } -/** +/* * Fill page directory with grant references to the pages of the * page directory itself. * @@ -349,10 +347,10 @@ static void backend_fill_page_dir(struct xen_front_pgdir_shbuf *buf) } /* Last page must say there is no more pages. */ page_dir = (struct xen_page_directory *)ptr; - page_dir->gref_dir_next_page = GRANT_INVALID_REF; + page_dir->gref_dir_next_page = XEN_GREF_LIST_END; } -/** +/* * Fill page directory with grant references to the pages of the * page directory and the buffer we share with the backend. * @@ -378,7 +376,7 @@ static void guest_fill_page_dir(struct xen_front_pgdir_shbuf *buf) if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) { to_copy = grefs_left; - page_dir->gref_dir_next_page = GRANT_INVALID_REF; + page_dir->gref_dir_next_page = XEN_GREF_LIST_END; } else { to_copy = XEN_NUM_GREFS_PER_PAGE; page_dir->gref_dir_next_page = buf->grefs[i + 1]; @@ -391,7 +389,7 @@ static void guest_fill_page_dir(struct xen_front_pgdir_shbuf *buf) } } -/** +/* * Grant references to the frontend's buffer pages. * * These will be shared with the backend, so it can @@ -420,7 +418,7 @@ static int guest_grant_refs_for_buffer(struct xen_front_pgdir_shbuf *buf, return 0; } -/** +/* * Grant all the references needed to share the buffer. * * Grant references to the page directory pages and, if @@ -468,7 +466,7 @@ static int grant_references(struct xen_front_pgdir_shbuf *buf) return 0; } -/** +/* * Allocate all required structures to mange shared buffer. * * \param buf shared buffer. @@ -508,7 +506,7 @@ static const struct xen_front_pgdir_shbuf_ops local_ops = { .grant_refs_for_buffer = guest_grant_refs_for_buffer, }; -/** +/* * Allocate a new instance of a shared buffer. * * \param cfg configuration to be used while allocating a new shared buffer. |