On Tue, Jun 15, 2021 at 03:01:06PM -0700, Dan Williams wrote: > On Tue, Jun 15, 2021 at 2:09 PM Alison Schofield > <alison.schofield@xxxxxxxxx> wrote: > > > > Thanks for the review Dan... > > > > On Tue, Jun 15, 2021 at 11:48:43AM -0700, Dan Williams wrote: > > > [ add linu-acpi for variable length array question below ] > > > > > > > > > On Mon, Jun 14, 2021 at 3:57 PM Alison Schofield > > > <alison.schofield@xxxxxxxxx> wrote: > > > > > > > > The ACPI CXL Early Discovery Table (CEDT) includes a list of CXL memory > > > > resources in CXL Fixed Memory Window Structures (CFMWS). Retrieve each > > > > CFMWS in the CEDT and add a cxl_decoder object to the root port (root0) > > > > for each memory resource. > > > > > > > > Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx> > > > > --- > > > > drivers/cxl/acpi.c | 106 +++++++++++++++++++++++++++++++++++++++++++++ > > > > 1 file changed, 106 insertions(+) > > > > > > > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > > > > index 16f60bc6801f..ac4b3e37e294 100644 > > > > --- a/drivers/cxl/acpi.c > > > > +++ b/drivers/cxl/acpi.c > > > > @@ -8,8 +8,112 @@ > > > > #include <linux/pci.h> > > > > #include "cxl.h" > > > > > > > > +/* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */ > > > > +#define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways) > > > > +#define CFMWS_INTERLEAVE_GRANULARITY(x) ((x)->granularity + 8) > > > > + > > > > +/* > > > > + * CFMWS Restrictions mapped to CXL Decoder Flags > > > > + * Restrictions defined in CXL 2.0 ECN CEDT CFMWS > > > > + * Decoder Flags defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register > > > > + */ > > > > +#define CFMWS_TO_DECODE_TYPE2(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) << 2) > > > > +#define CFMWS_TO_DECODE_TYPE3(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) << 2) > > > > +#define CFMWS_TO_DECODE_RAM(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) >> 2) > > > > +#define CFMWS_TO_DECODE_PMEM(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_PMEM) >> 2) > > > > +#define CFMWS_TO_DECODE_FIXED(x) (x & ACPI_CEDT_CFMWS_RESTRICT_FIXED) > > > > + > > > > +#define CFMWS_TO_DECODER_FLAGS(x) (CFMWS_TO_DECODE_TYPE2(x) | \ > > > > + CFMWS_TO_DECODE_TYPE3(x) | \ > > > > + CFMWS_TO_DECODE_RAM(x) | \ > > > > + CFMWS_TO_DECODE_PMEM(x) | \ > > > > + CFMWS_TO_DECODE_FIXED(x)) > > > > > > I don't understand the approach taken above. It seems to assume that > > > the CXL_DECODER_F_* values are fixed. Those flag values are arbitrary > > > and mutable. There is no guarantee that today's CXL_DECODER_F_* values > > > match tomorrow's so I'd rather not have 2 places to check when / if > > > that happens. > > > > > > > Here's my next take - making the handling resilient. > > Not so sure on gracefulness. Open for suggestions. > > > > -#define CFMWS_TO_DECODE_TYPE2(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) << 2) > > -#define CFMWS_TO_DECODE_TYPE3(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) << 2) > > -#define CFMWS_TO_DECODE_RAM(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) >> 2) > > -#define CFMWS_TO_DECODE_PMEM(x) ((x & ACPI_CEDT_CFMWS_RESTRICT_PMEM) >> 2) > > -#define CFMWS_TO_DECODE_FIXED(x) (x & ACPI_CEDT_CFMWS_RESTRICT_FIXED) > > - > > -#define CFMWS_TO_DECODER_FLAGS(x) (CFMWS_TO_DECODE_TYPE2(x) | \ > > - CFMWS_TO_DECODE_TYPE3(x) | \ > > - CFMWS_TO_DECODE_RAM(x) | \ > > - CFMWS_TO_DECODE_PMEM(x) | \ > > - CFMWS_TO_DECODE_FIXED(x)) > > +#define FLAG_TYPE2(x) \ > > + ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) ? CXL_DECODER_F_TYPE2 : 0) > > +#define FLAG_TYPE3(x) \ > > + ((x & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) ? CXL_DECODER_F_TYPE3 : 0) > > +#define FLAG_RAM(x) \ > > + ((x & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) ? CXL_DECODER_F_RAM : 0) > > +#define FLAG_PMEM(x) \ > > + ((x & ACPI_CEDT_CFMWS_RESTRICT_PMEM) ? CXL_DECODER_F_PMEM : 0) > > +#define FLAG_FIXED(x) \ > > + ((x & ACPI_CEDT_CFMWS_RESTRICT_FIXED) ? CXL_DECODER_F_LOCK : 0) > > + > > +#define CFMWS_TO_DECODER_FLAGS(x) (FLAG_TYPE2(x) | FLAG_TYPE3(x) | \ > > + FLAG_RAM(x) | FLAG_PMEM(x)| FLAG_FIXED(x)) > > Hmm, why the macros? Just make CFMWS_TO_DECODER_FLAGS a proper function. > > if (cfmws->restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) > flags |= CXL_DECODER_F_TYPE2; > > ...etc > > Unless you foresee where macros were going to be reused somewhere else > I would just as soon open code them like above. Open code it is! Thanks
