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| author | Dan Williams <dan.j.williams@intel.com> | 2023-06-17 04:24:28 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-06-25 23:45:40 +0300 |
| commit | d1257d098a5a38753a0736a50db0a26a62377ad7 (patch) | |
| tree | 06246d4de796183e8c45f0c60ec8ac970a3d4c35 /drivers/cxl/cxl.h | |
| parent | 858fd168a95c5b9669aac8db6c14a9aeab446375 (diff) | |
| download | linux-d1257d098a5a38753a0736a50db0a26a62377ad7.tar.xz | |
cxl/region: Move cache invalidation before region teardown, and before setup
Vikram raised a concern with the theoretical case of a CPU sending
MemClnEvict to a device that is not prepared to receive. MemClnEvict is
a message that is sent after a CPU has taken ownership of a cacheline
from accelerator memory (HDM-DB). In the case of hotplug or HDM decoder
reconfiguration it is possible that the CPU is holding old contents for
a new device that has taken over the physical address range being cached
by the CPU.
To avoid this scenario, invalidate caches prior to tearing down an HDM
decoder configuration.
Now, this poses another problem that it is possible for something to
speculate into that space while the decode configuration is still up, so
to close that gap also invalidate prior to establish new contents behind
a given physical address range.
With this change the cache invalidation is now explicit and need not be
checked in cxl_region_probe(), and that obviates the need for
CXL_REGION_F_INCOHERENT.
Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Fixes: d18bc74aced6 ("cxl/region: Manage CPU caches relative to DPA invalidation events")
Reported-by: Vikram Sethi <vsethi@nvidia.com>
Closes: http://lore.kernel.org/r/BYAPR12MB33364B5EB908BF7239BB996BBD53A@BYAPR12MB3336.namprd12.prod.outlook.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168696506886.3590522.4597053660991916591.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/cxl.h')
| -rw-r--r-- | drivers/cxl/cxl.h | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index f93a28538962..21ee135d91b6 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -463,17 +463,11 @@ struct cxl_region_params { }; /* - * Flag whether this region needs to have its HPA span synchronized with - * CPU cache state at region activation time. - */ -#define CXL_REGION_F_INCOHERENT 0 - -/* * Indicate whether this region has been assembled by autodetection or * userspace assembly. Prevent endpoint decoders outside of automatic * detection from being added to the region. */ -#define CXL_REGION_F_AUTO 1 +#define CXL_REGION_F_AUTO 0 /** * struct cxl_region - CXL region |