In case init_hdm_decoder() finds invalid settings, skip to the next valid decoder. Only fail port enumeration if zero valid decoders are found. This protects the driver init against broken hardware and / or future interleave capabilities.
Signed-off-by: Dan Williams <[email protected]> --- drivers/cxl/core/hdm.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index c966ab0d51fe..4955ba16c9c8 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -150,8 +150,8 @@ static int to_interleave_ways(u32 ctrl) } } -static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, - void __iomem *hdm, int which) +static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, + int *target_map, void __iomem *hdm, int which) { u64 size, base; u32 ctrl; @@ -167,6 +167,11 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, if (!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED)) size = 0; + if (base == U64_MAX || size == U64_MAX) { + dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n", + port->id, cxld->id); + return -ENXIO; + } cxld->decoder_range = (struct range) { .start = base, @@ -180,6 +185,12 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, cxld->flags |= CXL_DECODER_F_LOCK; } cxld->interleave_ways = to_interleave_ways(ctrl); + if (!cxld->interleave_ways) { + dev_warn(&port->dev, + "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n", + port->id, cxld->id, ctrl); + return -ENXIO; + } cxld->interleave_granularity = to_interleave_granularity(ctrl); if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl)) @@ -188,12 +199,14 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, cxld->target_type = CXL_DECODER_ACCELERATOR; if (is_cxl_endpoint(to_cxl_port(cxld->dev.parent))) - return; + return 0; target_list.value = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which)); for (i = 0; i < cxld->interleave_ways; i++) target_map[i] = target_list.target_id[i]; + + return 0; } /** @@ -204,7 +217,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) { void __iomem *hdm = cxlhdm->regs.hdm_decoder; struct cxl_port *port = cxlhdm->port; - int i, committed; + int i, committed, failed; u32 ctrl; /* @@ -224,7 +237,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) if (committed != cxlhdm->decoder_count) msleep(20); - for (i = 0; i < cxlhdm->decoder_count; i++) { + for (i = 0, failed = 0; i < cxlhdm->decoder_count; i++) { int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 }; int rc, target_count = cxlhdm->target_count; struct cxl_decoder *cxld; @@ -239,7 +252,13 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) return PTR_ERR(cxld); } - init_hdm_decoder(cxld, target_map, cxlhdm->regs.hdm_decoder, i); + rc = init_hdm_decoder(port, cxld, target_map, + cxlhdm->regs.hdm_decoder, i); + if (rc) { + put_device(&cxld->dev); + failed++; + continue; + } rc = add_hdm_decoder(port, cxld, target_map); if (rc) { dev_warn(&port->dev, @@ -248,6 +267,11 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) } } + if (failed == cxlhdm->decoder_count) { + dev_err(&port->dev, "No valid decoders found\n"); + return -ENXIO; + } + return 0; } EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);
