From: Dan Williams Date: Sat, 17 Dec 2022 01:33:38 +0000 (-0800) Subject: cxl/region: Clarify when a cxld->commit() callback is mandatory X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=af3ea9ab61d728d5a8be01bbec6d5cf7551b9600;p=linux.git cxl/region: Clarify when a cxld->commit() callback is mandatory Both cxl_switch_decoders() and cxl_endpoint_decoders() are considered by cxl_region_decode_commit(). Flag cases where cxl_switch_decoders with multiple targets, or cxl_endpoint_decoders do not have a commit callback set. The switch case is unlikely to happen since switches are only enumerated by the CXL core, but the endpoint case may support decoders defined by drivers outside of drivers/cxl, like accerator drivers. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/167124081824.1626103.1555704405392757219.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index c11a6ab5e48d5..60828d01972ac 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -156,6 +156,22 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) return 0; } +static int commit_decoder(struct cxl_decoder *cxld) +{ + struct cxl_switch_decoder *cxlsd = NULL; + + if (cxld->commit) + return cxld->commit(cxld); + + if (is_switch_decoder(&cxld->dev)) + cxlsd = to_cxl_switch_decoder(&cxld->dev); + + if (dev_WARN_ONCE(&cxld->dev, !cxlsd || cxlsd->nr_targets > 1, + "->commit() is required\n")) + return -ENXIO; + return 0; +} + static int cxl_region_decode_commit(struct cxl_region *cxlr) { struct cxl_region_params *p = &cxlr->params; @@ -174,8 +190,7 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr) iter = to_cxl_port(iter->dev.parent)) { cxl_rr = cxl_rr_load(iter, cxlr); cxld = cxl_rr->decoder; - if (cxld->commit) - rc = cxld->commit(cxld); + rc = commit_decoder(cxld); if (rc) break; }