diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2023-06-17 04:24:34 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-06-25 23:45:40 +0300 |
| commit | 2ab47045ac96a605e3037d479a7d5854570ee5bf (patch) | |
| tree | 4930bd13b8c12be472fc8b2f7f0f6c3c32550753 | |
| parent | d1257d098a5a38753a0736a50db0a26a62377ad7 (diff) | |
| download | linux-2ab47045ac96a605e3037d479a7d5854570ee5bf.tar.xz | |
cxl/region: Flag partially torn down regions as unusable
cxl_region_decode_reset() walks all the decoders associated with a given
region and disables them. Due to decoder ordering rules it is possible
that a switch in the topology notices that a given decoder can not be
shutdown before another region with a higher HPA is shutdown first. That
can leave the region in a partially committed state.
Capture that state in a new CXL_REGION_F_NEEDS_RESET flag and require
that a successful cxl_region_decode_reset() attempt must be completed
before cxl_region_probe() accepts the region.
This is a corollary for the bug that Jonathan identified in "CXL/region
: commit reset of out of order region appears to succeed." [1].
Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Link: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com [1]
Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168696507423.3590522.16254212607926684429.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | drivers/cxl/core/region.c | 12 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 8 |
2 files changed, 20 insertions, 0 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 594ce3c2565d..fa29bd2ec322 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -182,14 +182,19 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) rc = cxld->reset(cxld); if (rc) return rc; + set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); } endpoint_reset: rc = cxled->cxld.reset(&cxled->cxld); if (rc) return rc; + set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); } + /* all decoders associated with this region have been torn down */ + clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); + return 0; } @@ -2864,6 +2869,13 @@ static int cxl_region_probe(struct device *dev) goto out; } + if (test_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags)) { + dev_err(&cxlr->dev, + "failed to activate, re-commit region and retry\n"); + rc = -ENXIO; + goto out; + } + /* * From this point on any path that changes the region's state away from * CXL_CONFIG_COMMIT is also responsible for releasing the driver. diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 21ee135d91b6..492673d04da2 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -469,6 +469,14 @@ struct cxl_region_params { */ #define CXL_REGION_F_AUTO 0 +/* + * Require that a committed region successfully complete a teardown once + * any of its associated decoders have been torn down. This maintains + * the commit state for the region since there are committed decoders, + * but blocks cxl_region_probe(). + */ +#define CXL_REGION_F_NEEDS_RESET 1 + /** * struct cxl_region - CXL region * @dev: This region's device |