diff options
Diffstat (limited to 'drivers/s390/cio/itcw.c')
| -rw-r--r-- | drivers/s390/cio/itcw.c | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/drivers/s390/cio/itcw.c b/drivers/s390/cio/itcw.c index a0ae29564774..358ee16d10a2 100644 --- a/drivers/s390/cio/itcw.c +++ b/drivers/s390/cio/itcw.c @@ -93,6 +93,7 @@ EXPORT_SYMBOL(itcw_get_tcw); size_t itcw_calc_size(int intrg, int max_tidaws, int intrg_max_tidaws) { size_t len; + int cross_count; /* Main data. */ len = sizeof(struct itcw); @@ -105,12 +106,27 @@ size_t itcw_calc_size(int intrg, int max_tidaws, int intrg_max_tidaws) /* TSB */ sizeof(struct tsb) + /* TIDAL */ intrg_max_tidaws * sizeof(struct tidaw); } + /* Maximum required alignment padding. */ len += /* Initial TCW */ 63 + /* Interrogate TCCB */ 7; - /* Maximum padding for structures that may not cross 4k boundary. */ - if ((max_tidaws > 0) || (intrg_max_tidaws > 0)) - len += max(max_tidaws, intrg_max_tidaws) * - sizeof(struct tidaw) - 1; + + /* TIDAW lists may not cross a 4k boundary. To cross a + * boundary we need to add a TTIC TIDAW. We need to reserve + * one additional TIDAW for a TTIC that we may need to add due + * to the placement of the data chunk in memory, and a further + * TIDAW for each page boundary that the TIDAW list may cross + * due to it's own size. + */ + if (max_tidaws) { + cross_count = 1 + ((max_tidaws * sizeof(struct tidaw) - 1) + >> PAGE_SHIFT); + len += cross_count * sizeof(struct tidaw); + } + if (intrg_max_tidaws) { + cross_count = 1 + ((intrg_max_tidaws * sizeof(struct tidaw) - 1) + >> PAGE_SHIFT); + len += cross_count * sizeof(struct tidaw); + } return len; } EXPORT_SYMBOL(itcw_calc_size); @@ -165,6 +181,7 @@ struct itcw *itcw_init(void *buffer, size_t size, int op, int intrg, void *chunk; addr_t start; addr_t end; + int cross_count; /* Check for 2G limit. */ start = (addr_t) buffer; @@ -177,8 +194,17 @@ struct itcw *itcw_init(void *buffer, size_t size, int op, int intrg, if (IS_ERR(chunk)) return chunk; itcw = chunk; - itcw->max_tidaws = max_tidaws; - itcw->intrg_max_tidaws = intrg_max_tidaws; + /* allow for TTIC tidaws that may be needed to cross a page boundary */ + cross_count = 0; + if (max_tidaws) + cross_count = 1 + ((max_tidaws * sizeof(struct tidaw) - 1) + >> PAGE_SHIFT); + itcw->max_tidaws = max_tidaws + cross_count; + cross_count = 0; + if (intrg_max_tidaws) + cross_count = 1 + ((intrg_max_tidaws * sizeof(struct tidaw) - 1) + >> PAGE_SHIFT); + itcw->intrg_max_tidaws = intrg_max_tidaws + cross_count; /* Main TCW. */ chunk = fit_chunk(&start, end, sizeof(struct tcw), 64, 0); if (IS_ERR(chunk)) @@ -198,7 +224,7 @@ struct itcw *itcw_init(void *buffer, size_t size, int op, int intrg, /* Data TIDAL. */ if (max_tidaws > 0) { chunk = fit_chunk(&start, end, sizeof(struct tidaw) * - max_tidaws, 16, 1); + itcw->max_tidaws, 16, 0); if (IS_ERR(chunk)) return chunk; tcw_set_data(itcw->tcw, chunk, 1); @@ -206,7 +232,7 @@ struct itcw *itcw_init(void *buffer, size_t size, int op, int intrg, /* Interrogate data TIDAL. */ if (intrg && (intrg_max_tidaws > 0)) { chunk = fit_chunk(&start, end, sizeof(struct tidaw) * - intrg_max_tidaws, 16, 1); + itcw->intrg_max_tidaws, 16, 0); if (IS_ERR(chunk)) return chunk; tcw_set_data(itcw->intrg_tcw, chunk, 1); @@ -283,13 +309,29 @@ EXPORT_SYMBOL(itcw_add_dcw); * the new tidaw on success or -%ENOSPC if the new tidaw would exceed the * available space. * - * Note: the tidaw-list is assumed to be contiguous with no ttics. The - * last-tidaw flag for the last tidaw in the list will be set by itcw_finalize. + * Note: TTIC tidaws are automatically added when needed, so explicitly calling + * this interface with the TTIC flag is not supported. The last-tidaw flag + * for the last tidaw in the list will be set by itcw_finalize. */ struct tidaw *itcw_add_tidaw(struct itcw *itcw, u8 flags, void *addr, u32 count) { + struct tidaw *following; + if (itcw->num_tidaws >= itcw->max_tidaws) return ERR_PTR(-ENOSPC); + /* + * Is the tidaw, which follows the one we are about to fill, on the next + * page? Then we have to insert a TTIC tidaw first, that points to the + * tidaw on the new page. + */ + following = ((struct tidaw *) tcw_get_data(itcw->tcw)) + + itcw->num_tidaws + 1; + if (itcw->num_tidaws && !((unsigned long) following & ~PAGE_MASK)) { + tcw_add_tidaw(itcw->tcw, itcw->num_tidaws++, + TIDAW_FLAGS_TTIC, following, 0); + if (itcw->num_tidaws >= itcw->max_tidaws) + return ERR_PTR(-ENOSPC); + } return tcw_add_tidaw(itcw->tcw, itcw->num_tidaws++, flags, addr, count); } EXPORT_SYMBOL(itcw_add_tidaw); |