6.6-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams dan.j.williams@intel.com
commit 5c6224bfabbf7f3e491c51ab50fd2c6f92ba1141 upstream.
The expectation is that cxl_parse_cfwms() continues in the face the of failure as evidenced by code like:
cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb); if (IS_ERR(cxlrd)) return 0;
There are other error paths in that function which mistakenly follow idiomatic expectations and return an error when they should not. Most of those mistakes are innocuous checks that hardly ever fail in practice. However, a recent change succeed in making the implementation more fragile by applying an idiomatic, but still wrong "fix" [1]. In this failure case the kernel reports:
cxl root0: Failed to populate active decoder targets cxl_acpi ACPI0017:00: Failed to add decode range: [mem 0x00000000-0x7fffffff flags 0x200]
...which is a real issue with that one window (to be fixed separately), but ends up failing the entirety of cxl_acpi_probe().
Undo that recent breakage while also removing the confusion about ignoring errors. Update all exits paths to return an error per typical expectations and let an outer wrapper function handle dropping the error.
Fixes: 91019b5bc7c2 ("cxl/acpi: Return 'rc' instead of '0' in cxl_parse_cfmws()") [1] Cc: stable@vger.kernel.org Cc: Breno Leitao leitao@debian.org Cc: Alison Schofield alison.schofield@intel.com Cc: Vishal Verma vishal.l.verma@intel.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/cxl/acpi.c | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-)
--- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -194,31 +194,27 @@ struct cxl_cfmws_context { int id; };
-static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, - const unsigned long end) +static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws, + struct cxl_cfmws_context *ctx) { int target_map[CXL_DECODER_MAX_INTERLEAVE]; - struct cxl_cfmws_context *ctx = arg; struct cxl_port *root_port = ctx->root_port; struct resource *cxl_res = ctx->cxl_res; struct cxl_cxims_context cxims_ctx; struct cxl_root_decoder *cxlrd; struct device *dev = ctx->dev; - struct acpi_cedt_cfmws *cfmws; cxl_calc_hb_fn cxl_calc_hb; struct cxl_decoder *cxld; unsigned int ways, i, ig; struct resource *res; int rc;
- cfmws = (struct acpi_cedt_cfmws *) header; - rc = cxl_acpi_cfmws_verify(dev, cfmws); if (rc) { dev_err(dev, "CFMWS range %#llx-%#llx not registered\n", cfmws->base_hpa, cfmws->base_hpa + cfmws->window_size - 1); - return 0; + return rc; }
rc = eiw_to_ways(cfmws->interleave_ways, &ways); @@ -254,7 +250,7 @@ static int cxl_parse_cfmws(union acpi_su
cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb); if (IS_ERR(cxlrd)) - return 0; + return PTR_ERR(cxlrd);
cxld = &cxlrd->cxlsd.cxld; cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions); @@ -295,16 +291,7 @@ err_xormap: put_device(&cxld->dev); else rc = cxl_decoder_autoremove(dev, cxld); - if (rc) { - dev_err(dev, "Failed to add decode range: %pr", res); - return rc; - } - dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n", - dev_name(&cxld->dev), - phys_to_target_node(cxld->hpa_range.start), - cxld->hpa_range.start, cxld->hpa_range.end); - - return 0; + return rc;
err_insert: kfree(res->name); @@ -313,6 +300,29 @@ err_name: return -ENOMEM; }
+static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, + const unsigned long end) +{ + struct acpi_cedt_cfmws *cfmws = (struct acpi_cedt_cfmws *)header; + struct cxl_cfmws_context *ctx = arg; + struct device *dev = ctx->dev; + int rc; + + rc = __cxl_parse_cfmws(cfmws, ctx); + if (rc) + dev_err(dev, + "Failed to add decode range: [%#llx - %#llx] (%d)\n", + cfmws->base_hpa, + cfmws->base_hpa + cfmws->window_size - 1, rc); + else + dev_dbg(dev, "decode range: node: %d range [%#llx - %#llx]\n", + phys_to_target_node(cfmws->base_hpa), cfmws->base_hpa, + cfmws->base_hpa + cfmws->window_size - 1); + + /* never fail cxl_acpi load for a single window failure */ + return 0; +} + __mock struct acpi_device *to_cxl_host_bridge(struct device *host, struct device *dev) {