From 24b18197184ac39bb8566fb82c0bf788bcd0d45b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 3 Apr 2023 16:01:32 -0700 Subject: [PATCH] cxl/hdm: Extend DVSEC range register emulation for region enumeration One motivation for mapping range registers to decoder objects is to use those settings for region autodiscovery. The need to map a region for devices programmed to use range registers is especially urgent now that the kernel no longer routes "Soft Reserved" ranges in the memory map to device-dax by default. The CXL memory range loses all access mechanisms. Complete the implementation by marking the DPA reservation and setting the endpoint-decoder state to signal autodiscovery. Note that the default settings of ways=1 and granularity=4096 set in cxl_decode_init() do not need to be updated. Fixes: 09d09e04d2fc ("cxl/dax: Create dax devices for CXL RAM regions") Tested-by: Dave Jiang Tested-by: Gregory Price Link: https://lore.kernel.org/r/168012575521.221280.14177293493678527326.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Dave Jiang Signed-off-by: Dan Williams --- drivers/cxl/core/hdm.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 9884b6d..02cc2c3 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -738,14 +738,20 @@ static int cxl_decoder_reset(struct cxl_decoder *cxld) return 0; } -static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port, - struct cxl_decoder *cxld, int which, - struct cxl_endpoint_dvsec_info *info) +static int cxl_setup_hdm_decoder_from_dvsec( + struct cxl_port *port, struct cxl_decoder *cxld, u64 *dpa_base, + int which, struct cxl_endpoint_dvsec_info *info) { + struct cxl_endpoint_decoder *cxled; + u64 len; + int rc; + if (!is_cxl_endpoint(port)) return -EOPNOTSUPP; - if (!range_len(&info->dvsec_range[which])) + cxled = to_cxl_endpoint_decoder(&cxld->dev); + len = range_len(&info->dvsec_range[which]); + if (!len) return -ENOENT; cxld->target_type = CXL_DECODER_EXPANDER; @@ -760,6 +766,16 @@ static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port, cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK; port->commit_end = cxld->id; + rc = devm_cxl_dpa_reserve(cxled, *dpa_base, len, 0); + if (rc) { + dev_err(&port->dev, + "decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)", + port->id, cxld->id, *dpa_base, *dpa_base + len - 1, rc); + return rc; + } + *dpa_base += len; + cxled->state = CXL_DECODER_STATE_AUTO; + return 0; } @@ -779,7 +795,8 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, } target_list; if (should_emulate_decoders(info)) - return cxl_setup_hdm_decoder_from_dvsec(port, cxld, which, info); + return cxl_setup_hdm_decoder_from_dvsec(port, cxld, dpa_base, + which, info); ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which)); base = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which)); -- 2.7.4