From 0c33b3935265cd5aafa18904363bab0c545adeee Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 24 May 2022 12:04:58 -0700 Subject: cxl/hdm: Track next decoder to allocate The CXL specification enforces that endpoint decoders are committed in hw instance id order. In preparation for adding dynamic DPA allocation, record the hw instance id in endpoint decoders, and enforce allocations to occur in hw instance id order. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165784328827.1758207.9627538529944559954.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- drivers/cxl/core/hdm.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/cxl/core/hdm.c') diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index c2cff5783fda..14354f4cd92e 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -160,6 +160,7 @@ EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) { struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); struct cxl_dev_state *cxlds = cxlmd->cxlds; struct resource *res = cxled->dpa_res; resource_size_t skip_start; @@ -173,6 +174,7 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) __release_region(&cxlds->dpa_res, skip_start, cxled->skip); cxled->skip = 0; cxled->dpa_res = NULL; + port->hdm_end--; } static void cxl_dpa_release(void *cxled) @@ -203,6 +205,18 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, return -EBUSY; } + if (port->hdm_end + 1 != cxled->cxld.id) { + /* + * Assumes alloc and commit order is always in hardware instance + * order per expectations from 8.2.5.12.20 Committing Decoder + * Programming that enforce decoder[m] committed before + * decoder[m+1] commit start. + */ + dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id, + cxled->cxld.id, port->id, port->hdm_end + 1); + return -EBUSY; + } + if (skipped) { res = __request_region(&cxlds->dpa_res, base - skipped, skipped, dev_name(&cxled->cxld.dev), 0); @@ -235,6 +249,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, cxled->cxld.id, cxled->dpa_res); cxled->mode = CXL_DECODER_MIXED; } + port->hdm_end++; return 0; } -- cgit v1.2.3