| Message ID | 20210923172647.72738-2-ben.widawsky@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v2,1/9] cxl: Convert "RBI" to enum | expand |
Please spell out "register block indicator" in the subject so that the shortlog remains somewhat readable. On Thu, Sep 23, 2021 at 10:27 AM Ben Widawsky <ben.widawsky@intel.com> wrote: > > In preparation for passing around the Register Block Indicator (RBI) as > a parameter, it is desirable to convert the type to an enum so that the > interface can use a well defined type checked parameter. C wouldn't type check this unless it failed an integer conversion, right? It would need to be a struct to get useful type checking. I don't mind this for the self documenting properties it has for the functions that will take this as a parameter, but maybe clarify what you mean by type checked parameter? > > As a result of this change, should future versions of the spec add > sparsely defined identifiers, it could become a problem if checking for > invalid identifiers since the code currently checks for the max > identifier. This is not an issue with current spec, and the algorithm to > obtain the register blocks will change before those possible additions > are made. In general let's not spend changelog space trying to guess what future specs may or may not do. I.e. I think this text can be dropped, especially because enums can support sparse number spaces.
diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h index 8c1a58813816..7d3e4bf06b45 100644 --- a/drivers/cxl/pci.h +++ b/drivers/cxl/pci.h @@ -20,13 +20,15 @@ #define CXL_REGLOC_BIR_MASK GENMASK(2, 0) /* Register Block Identifier (RBI) */ -#define CXL_REGLOC_RBI_MASK GENMASK(15, 8) -#define CXL_REGLOC_RBI_EMPTY 0 -#define CXL_REGLOC_RBI_COMPONENT 1 -#define CXL_REGLOC_RBI_VIRT 2 -#define CXL_REGLOC_RBI_MEMDEV 3 -#define CXL_REGLOC_RBI_TYPES CXL_REGLOC_RBI_MEMDEV + 1 +enum cxl_regloc_type { + CXL_REGLOC_RBI_EMPTY = 0, + CXL_REGLOC_RBI_COMPONENT, + CXL_REGLOC_RBI_VIRT, + CXL_REGLOC_RBI_MEMDEV, + CXL_REGLOC_RBI_TYPES +}; +#define CXL_REGLOC_RBI_MASK GENMASK(15, 8) #define CXL_REGLOC_ADDR_MASK GENMASK(31, 16) #endif /* __CXL_PCI_H__ */
In preparation for passing around the Register Block Indicator (RBI) as a parameter, it is desirable to convert the type to an enum so that the interface can use a well defined type checked parameter. As a result of this change, should future versions of the spec add sparsely defined identifiers, it could become a problem if checking for invalid identifiers since the code currently checks for the max identifier. This is not an issue with current spec, and the algorithm to obtain the register blocks will change before those possible additions are made. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> --- drivers/cxl/pci.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)