| Message ID | 20220201071952.900068-11-ira.weiny@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | CXL: Read CDAT and DSMAS data from the device | expand |
On 22-01-31 23:19:52, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > CXL memory devices need the information in the Device Scoped Memory > Affinity Structure (DSMAS). This information is contained within the > CDAT table buffer which is already read and cached. > > Parse and cache DSMAS data from the CDAT table. Store this data in > unmarshaled struct dsmas data structures for ease of use. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes from V5 > Fix up sparse warnings > Split out cdat_hdr_valid() > Update cdat_hdr_valid() > Remove revision and cs field parsing > There is no point in these > Add seq check and debug print. > From Jonathan > Add spaces around '+' and '/' > use devm_krealloc() for dmas_ary > > Changes from V4 > New patch > --- > drivers/cxl/cdat.h | 21 ++++++++++++ > drivers/cxl/core/memdev.c | 70 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 91 insertions(+) > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > index a7725d26f2d2..f8c126190d18 100644 > --- a/drivers/cxl/cdat.h > +++ b/drivers/cxl/cdat.h > @@ -83,17 +83,38 @@ > #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) > #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) > > +/** > + * struct cxl_dsmas - host unmarshaled version of DSMAS data > + * > + * As defined in the Coherent Device Attribute Table (CDAT) specification this > + * represents a single DSMAS entry in that table. > + * > + * @dpa_base: The lowest DPA address associated with this DSMAD > + * @dpa_length: Length in bytes of this DSMAD > + * @non_volatile: If set, the memory region represents Non-Volatile memory > + */ > +struct cxl_dsmas { > + u64 dpa_base; > + u64 dpa_length; > + /* Flags */ > + u8 non_volatile:1; > +}; > + > /** > * struct cxl_cdat - CXL CDAT data > * > * @table: cache of CDAT table > * @length: length of cached CDAT table > * @seq: Last read Sequence number of the CDAT table > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > + * @nr_dsmas: Number of entries in dsmas_ary > */ > struct cxl_cdat { > void *table; > size_t length; > u32 seq; > + struct cxl_dsmas *dsmas_ary; > + int nr_dsmas; > }; > > #endif /* !__CXL_CDAT_H__ */ > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 11d721c56f08..32342a15e991 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -6,6 +6,7 @@ > #include <linux/idr.h> > #include <linux/pci.h> > #include <cxlmem.h> > +#include "cdat.h" > #include "core.h" > > static DECLARE_RWSEM(cxl_memdev_rwsem); > @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, > return rc; > } > > +static int parse_dsmas(struct cxl_memdev *cxlmd) > +{ > + struct cxl_dsmas *dsmas_ary = NULL; > + u32 *data = cxlmd->cdat.table; > + int bytes_left = cxlmd->cdat.length; > + int nr_dsmas = 0; > + > + if (!data) > + return -ENXIO; > + > + /* Skip header */ > + data += CDAT_HEADER_LENGTH_DW; > + bytes_left -= CDAT_HEADER_LENGTH_BYTES; > + > + while (bytes_left > 0) { > + u32 *cur_rec = data; > + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); > + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); > + > + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { > + struct cxl_dsmas *new_ary; > + u8 flags; > + > + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > + GFP_KERNEL); > + if (!new_ary) { > + dev_err(&cxlmd->dev, > + "Failed to allocate memory for DSMAS data\n"); > + return -ENOMEM; > + } One thought here - it looks like there are at most 256 DSMAS entries. You could allocate the full 256 up front, and then realloc *down* to the actual number. > + dsmas_ary = new_ary; > + > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); > + > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > + dsmas_ary[nr_dsmas].dpa_length = CDAT_DSMAS_DPA_LEN(cur_rec); > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > + > + dev_dbg(&cxlmd->dev, "DSMAS %d: %llx:%llx %s\n", > + nr_dsmas, > + dsmas_ary[nr_dsmas].dpa_base, > + dsmas_ary[nr_dsmas].dpa_base + > + dsmas_ary[nr_dsmas].dpa_length, > + (dsmas_ary[nr_dsmas].non_volatile ? > + "Persistent" : "Volatile") > + ); > + > + nr_dsmas++; > + } > + > + data += (length / sizeof(u32)); > + bytes_left -= length; > + } > + > + if (nr_dsmas == 0) > + return -ENXIO; Hmm is there documentation that suggests a DSMAS must be implemented? Could this just return 0? I'd put maybe dev_dbg here if it's unexpected but not a failure and return success. > + > + dev_dbg(&cxlmd->dev, "Found %d DSMAS entries\n", nr_dsmas); > + cxlmd->cdat.dsmas_ary = dsmas_ary; > + cxlmd->cdat.nr_dsmas = nr_dsmas; > + > + return 0; > +} > + > struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > { > struct cxl_memdev *cxlmd; > @@ -407,6 +473,10 @@ struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > if (rc) > goto err; > > + rc = parse_dsmas(cxlmd); > + if (rc) > + dev_warn(dev, "No DSMAS data found: %d\n", rc); > + > /* > * Activate ioctl operations, no cxl_memdev_rwsem manipulation > * needed as this is ordered with cdev_add() publishing the device. > -- > 2.31.1 >
On Tue, Feb 01, 2022 at 11:05:32AM -0800, Widawsky, Ben wrote: > On 22-01-31 23:19:52, ira.weiny@intel.com wrote: > > From: Ira Weiny <ira.weiny@intel.com> > > > > CXL memory devices need the information in the Device Scoped Memory > > Affinity Structure (DSMAS). This information is contained within the > > CDAT table buffer which is already read and cached. > > > > Parse and cache DSMAS data from the CDAT table. Store this data in > > unmarshaled struct dsmas data structures for ease of use. > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > --- > > Changes from V5 > > Fix up sparse warnings > > Split out cdat_hdr_valid() > > Update cdat_hdr_valid() > > Remove revision and cs field parsing > > There is no point in these > > Add seq check and debug print. > > From Jonathan > > Add spaces around '+' and '/' > > use devm_krealloc() for dmas_ary > > > > Changes from V4 > > New patch > > --- > > drivers/cxl/cdat.h | 21 ++++++++++++ > > drivers/cxl/core/memdev.c | 70 +++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 91 insertions(+) > > > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > > index a7725d26f2d2..f8c126190d18 100644 > > --- a/drivers/cxl/cdat.h > > +++ b/drivers/cxl/cdat.h > > @@ -83,17 +83,38 @@ > > #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) > > #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) > > > > +/** > > + * struct cxl_dsmas - host unmarshaled version of DSMAS data > > + * > > + * As defined in the Coherent Device Attribute Table (CDAT) specification this > > + * represents a single DSMAS entry in that table. > > + * > > + * @dpa_base: The lowest DPA address associated with this DSMAD > > + * @dpa_length: Length in bytes of this DSMAD > > + * @non_volatile: If set, the memory region represents Non-Volatile memory > > + */ > > +struct cxl_dsmas { > > + u64 dpa_base; > > + u64 dpa_length; > > + /* Flags */ > > + u8 non_volatile:1; > > +}; > > + > > /** > > * struct cxl_cdat - CXL CDAT data > > * > > * @table: cache of CDAT table > > * @length: length of cached CDAT table > > * @seq: Last read Sequence number of the CDAT table > > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > > + * @nr_dsmas: Number of entries in dsmas_ary > > */ > > struct cxl_cdat { > > void *table; > > size_t length; > > u32 seq; > > + struct cxl_dsmas *dsmas_ary; > > + int nr_dsmas; > > }; > > > > #endif /* !__CXL_CDAT_H__ */ > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > > index 11d721c56f08..32342a15e991 100644 > > --- a/drivers/cxl/core/memdev.c > > +++ b/drivers/cxl/core/memdev.c > > @@ -6,6 +6,7 @@ > > #include <linux/idr.h> > > #include <linux/pci.h> > > #include <cxlmem.h> > > +#include "cdat.h" > > #include "core.h" > > > > static DECLARE_RWSEM(cxl_memdev_rwsem); > > @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, > > return rc; > > } > > > > +static int parse_dsmas(struct cxl_memdev *cxlmd) > > +{ > > + struct cxl_dsmas *dsmas_ary = NULL; > > + u32 *data = cxlmd->cdat.table; > > + int bytes_left = cxlmd->cdat.length; > > + int nr_dsmas = 0; > > + > > + if (!data) > > + return -ENXIO; > > + > > + /* Skip header */ > > + data += CDAT_HEADER_LENGTH_DW; > > + bytes_left -= CDAT_HEADER_LENGTH_BYTES; > > + > > + while (bytes_left > 0) { > > + u32 *cur_rec = data; > > + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); > > + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); > > + > > + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { > > + struct cxl_dsmas *new_ary; > > + u8 flags; > > + > > + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, > > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > > + GFP_KERNEL); > > + if (!new_ary) { > > + dev_err(&cxlmd->dev, > > + "Failed to allocate memory for DSMAS data\n"); > > + return -ENOMEM; > > + } > > One thought here - it looks like there are at most 256 DSMAS entries. You could > allocate the full 256 up front, and then realloc *down* to the actual number. > > > + dsmas_ary = new_ary; > > + > > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); > > + > > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > > + dsmas_ary[nr_dsmas].dpa_length = CDAT_DSMAS_DPA_LEN(cur_rec); > > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > > + > > + dev_dbg(&cxlmd->dev, "DSMAS %d: %llx:%llx %s\n", > > + nr_dsmas, > > + dsmas_ary[nr_dsmas].dpa_base, > > + dsmas_ary[nr_dsmas].dpa_base + > > + dsmas_ary[nr_dsmas].dpa_length, > > + (dsmas_ary[nr_dsmas].non_volatile ? > > + "Persistent" : "Volatile") > > + ); > > + > > + nr_dsmas++; > > + } > > + > > + data += (length / sizeof(u32)); > > + bytes_left -= length; > > + } > > + > > + if (nr_dsmas == 0) > > + return -ENXIO; > > Hmm is there documentation that suggests a DSMAS must be implemented? Could this > just return 0? I'd put maybe dev_dbg here if it's unexpected but not a failure > and return success. For this call I was not envisioning this as an error. I wanted to leave it up to the caller. I think it would make more sense to return the number of DSMAS' found or negative errno on failure... I'll clean it up. Including below... > > > + > > + dev_dbg(&cxlmd->dev, "Found %d DSMAS entries\n", nr_dsmas); > > + cxlmd->cdat.dsmas_ary = dsmas_ary; > > + cxlmd->cdat.nr_dsmas = nr_dsmas; > > + > > + return 0; > > +} > > + > > struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > > { > > struct cxl_memdev *cxlmd; > > @@ -407,6 +473,10 @@ struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > > if (rc) > > goto err; > > > > + rc = parse_dsmas(cxlmd); > > + if (rc) > > + dev_warn(dev, "No DSMAS data found: %d\n", rc); > > + This was changed to dev_warn() because I think here we do expect dsmas data? Don't we? Thanks, Ira > > /* > > * Activate ioctl operations, no cxl_memdev_rwsem manipulation > > * needed as this is ordered with cdev_add() publishing the device. > > -- > > 2.31.1 > >
On Tue, 1 Feb 2022 14:37:17 -0800 Ira Weiny <ira.weiny@intel.com> wrote: > On Tue, Feb 01, 2022 at 11:05:32AM -0800, Widawsky, Ben wrote: > > On 22-01-31 23:19:52, ira.weiny@intel.com wrote: > > > From: Ira Weiny <ira.weiny@intel.com> > > > > > > CXL memory devices need the information in the Device Scoped Memory > > > Affinity Structure (DSMAS). This information is contained within the > > > CDAT table buffer which is already read and cached. > > > > > > Parse and cache DSMAS data from the CDAT table. Store this data in > > > unmarshaled struct dsmas data structures for ease of use. > > > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > > > --- > > > Changes from V5 > > > Fix up sparse warnings > > > Split out cdat_hdr_valid() > > > Update cdat_hdr_valid() > > > Remove revision and cs field parsing > > > There is no point in these > > > Add seq check and debug print. > > > From Jonathan > > > Add spaces around '+' and '/' > > > use devm_krealloc() for dmas_ary > > > > > > Changes from V4 > > > New patch > > > --- > > > drivers/cxl/cdat.h | 21 ++++++++++++ > > > drivers/cxl/core/memdev.c | 70 +++++++++++++++++++++++++++++++++++++++ > > > 2 files changed, 91 insertions(+) > > > > > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > > > index a7725d26f2d2..f8c126190d18 100644 > > > --- a/drivers/cxl/cdat.h > > > +++ b/drivers/cxl/cdat.h > > > @@ -83,17 +83,38 @@ > > > #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) > > > #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) > > > > > > +/** > > > + * struct cxl_dsmas - host unmarshaled version of DSMAS data > > > + * > > > + * As defined in the Coherent Device Attribute Table (CDAT) specification this > > > + * represents a single DSMAS entry in that table. > > > + * > > > + * @dpa_base: The lowest DPA address associated with this DSMAD > > > + * @dpa_length: Length in bytes of this DSMAD > > > + * @non_volatile: If set, the memory region represents Non-Volatile memory > > > + */ > > > +struct cxl_dsmas { > > > + u64 dpa_base; > > > + u64 dpa_length; > > > + /* Flags */ > > > + u8 non_volatile:1; > > > +}; > > > + > > > /** > > > * struct cxl_cdat - CXL CDAT data > > > * > > > * @table: cache of CDAT table > > > * @length: length of cached CDAT table > > > * @seq: Last read Sequence number of the CDAT table > > > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > > > + * @nr_dsmas: Number of entries in dsmas_ary > > > */ > > > struct cxl_cdat { > > > void *table; > > > size_t length; > > > u32 seq; > > > + struct cxl_dsmas *dsmas_ary; > > > + int nr_dsmas; > > > }; > > > > > > #endif /* !__CXL_CDAT_H__ */ > > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > > > index 11d721c56f08..32342a15e991 100644 > > > --- a/drivers/cxl/core/memdev.c > > > +++ b/drivers/cxl/core/memdev.c > > > @@ -6,6 +6,7 @@ > > > #include <linux/idr.h> > > > #include <linux/pci.h> > > > #include <cxlmem.h> > > > +#include "cdat.h" > > > #include "core.h" > > > > > > static DECLARE_RWSEM(cxl_memdev_rwsem); > > > @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, > > > return rc; > > > } > > > > > > +static int parse_dsmas(struct cxl_memdev *cxlmd) > > > +{ > > > + struct cxl_dsmas *dsmas_ary = NULL; > > > + u32 *data = cxlmd->cdat.table; > > > + int bytes_left = cxlmd->cdat.length; > > > + int nr_dsmas = 0; > > > + > > > + if (!data) > > > + return -ENXIO; > > > + > > > + /* Skip header */ > > > + data += CDAT_HEADER_LENGTH_DW; > > > + bytes_left -= CDAT_HEADER_LENGTH_BYTES; > > > + > > > + while (bytes_left > 0) { > > > + u32 *cur_rec = data; > > > + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); > > > + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); > > > + > > > + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { > > > + struct cxl_dsmas *new_ary; > > > + u8 flags; > > > + > > > + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, > > > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > > > + GFP_KERNEL); > > > + if (!new_ary) { > > > + dev_err(&cxlmd->dev, > > > + "Failed to allocate memory for DSMAS data\n"); > > > + return -ENOMEM; > > > + } > > > > One thought here - it looks like there are at most 256 DSMAS entries. You could > > allocate the full 256 up front, and then realloc *down* to the actual number. > > > > > + dsmas_ary = new_ary; > > > + > > > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); > > > + > > > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > > > + dsmas_ary[nr_dsmas].dpa_length = CDAT_DSMAS_DPA_LEN(cur_rec); > > > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > > > + > > > + dev_dbg(&cxlmd->dev, "DSMAS %d: %llx:%llx %s\n", > > > + nr_dsmas, > > > + dsmas_ary[nr_dsmas].dpa_base, > > > + dsmas_ary[nr_dsmas].dpa_base + > > > + dsmas_ary[nr_dsmas].dpa_length, > > > + (dsmas_ary[nr_dsmas].non_volatile ? > > > + "Persistent" : "Volatile") > > > + ); > > > + > > > + nr_dsmas++; > > > + } > > > + > > > + data += (length / sizeof(u32)); > > > + bytes_left -= length; > > > + } > > > + > > > + if (nr_dsmas == 0) > > > + return -ENXIO; > > > > Hmm is there documentation that suggests a DSMAS must be implemented? Could this > > just return 0? I'd put maybe dev_dbg here if it's unexpected but not a failure > > and return success. > > For this call I was not envisioning this as an error. I wanted to leave it up > to the caller. > > I think it would make more sense to return the number of DSMAS' found or > negative errno on failure... > > I'll clean it up. Including below... > > > > > > + > > > + dev_dbg(&cxlmd->dev, "Found %d DSMAS entries\n", nr_dsmas); > > > + cxlmd->cdat.dsmas_ary = dsmas_ary; > > > + cxlmd->cdat.nr_dsmas = nr_dsmas; > > > + > > > + return 0; > > > +} > > > + > > > struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > > > { > > > struct cxl_memdev *cxlmd; > > > @@ -407,6 +473,10 @@ struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) > > > if (rc) > > > goto err; > > > > > > + rc = parse_dsmas(cxlmd); > > > + if (rc) > > > + dev_warn(dev, "No DSMAS data found: %d\n", rc); > > > + > > This was changed to dev_warn() because I think here we do expect dsmas data? > Don't we? There are flags in the CXL Range registers that specify that some stuff is communicated via CDAT. That includes one for whether it is nonvolatile or not which is a DSMAS flag. So if that is set we definitely expect them. We would also expect them if QTG _DSM is in use as that has specific references to DMSAS regions. More generally a switch implementing CDAT wouldn't have DSMAS but we are fairly safe that if a memory device has CDAT at all, DSMAS is expected because most of the other structures reference the DSMAS handle. Message is in general wrong though as it could be a memory failure in parse_dsmas() so you need to check the actual error code. J > > Thanks, > Ira > > > > /* > > > * Activate ioctl operations, no cxl_memdev_rwsem manipulation > > > * needed as this is ordered with cdev_add() publishing the device. > > > -- > > > 2.31.1 > > >
On Mon, 31 Jan 2022 23:19:52 -0800 ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > CXL memory devices need the information in the Device Scoped Memory > Affinity Structure (DSMAS). This information is contained within the > CDAT table buffer which is already read and cached. > > Parse and cache DSMAS data from the CDAT table. Store this data in > unmarshaled struct dsmas data structures for ease of use. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> A few suggests inline but this basically looks good to me. I'll hold off on tags until we resolve the warn or not question Ben raised. > > --- > Changes from V5 > Fix up sparse warnings > Split out cdat_hdr_valid() > Update cdat_hdr_valid() > Remove revision and cs field parsing > There is no point in these > Add seq check and debug print. > From Jonathan > Add spaces around '+' and '/' > use devm_krealloc() for dmas_ary > > Changes from V4 > New patch > --- > drivers/cxl/cdat.h | 21 ++++++++++++ > drivers/cxl/core/memdev.c | 70 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 91 insertions(+) > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > index a7725d26f2d2..f8c126190d18 100644 > --- a/drivers/cxl/cdat.h > +++ b/drivers/cxl/cdat.h > @@ -83,17 +83,38 @@ > #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) > #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) > > +/** > + * struct cxl_dsmas - host unmarshaled version of DSMAS data > + * > + * As defined in the Coherent Device Attribute Table (CDAT) specification this > + * represents a single DSMAS entry in that table. > + * > + * @dpa_base: The lowest DPA address associated with this DSMAD > + * @dpa_length: Length in bytes of this DSMAD > + * @non_volatile: If set, the memory region represents Non-Volatile memory > + */ > +struct cxl_dsmas { > + u64 dpa_base; > + u64 dpa_length; > + /* Flags */ > + u8 non_volatile:1; > +}; > + > /** > * struct cxl_cdat - CXL CDAT data > * > * @table: cache of CDAT table > * @length: length of cached CDAT table > * @seq: Last read Sequence number of the CDAT table > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > + * @nr_dsmas: Number of entries in dsmas_ary > */ > struct cxl_cdat { > void *table; > size_t length; > u32 seq; > + struct cxl_dsmas *dsmas_ary; > + int nr_dsmas; > }; > > #endif /* !__CXL_CDAT_H__ */ > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 11d721c56f08..32342a15e991 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -6,6 +6,7 @@ > #include <linux/idr.h> > #include <linux/pci.h> > #include <cxlmem.h> > +#include "cdat.h" > #include "core.h" > > static DECLARE_RWSEM(cxl_memdev_rwsem); > @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, > return rc; > } > > +static int parse_dsmas(struct cxl_memdev *cxlmd) Looking forwards, it's more than possible this code might be of use for type2 devices. As such, maybe it should avoid taking the cxlmd as a parameter? Really need a dev for the allocations, and the cdat structure. Could fix that up once someone else wants it of course. > +{ > + struct cxl_dsmas *dsmas_ary = NULL; > + u32 *data = cxlmd->cdat.table; > + int bytes_left = cxlmd->cdat.length; > + int nr_dsmas = 0; > + > + if (!data) > + return -ENXIO; > + > + /* Skip header */ > + data += CDAT_HEADER_LENGTH_DW; > + bytes_left -= CDAT_HEADER_LENGTH_BYTES; > + > + while (bytes_left > 0) { > + u32 *cur_rec = data; > + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); > + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); > + > + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { Again, maybe something to do later, but a for_each_cdat_struct() loop (possibly with a type specified) would give us something we are sure to want later when doing switches etc. > + struct cxl_dsmas *new_ary; > + u8 flags; > + > + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > + GFP_KERNEL); > + if (!new_ary) { > + dev_err(&cxlmd->dev, > + "Failed to allocate memory for DSMAS data\n"); > + return -ENOMEM; > + } > + dsmas_ary = new_ary; > + > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); > + > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > + dsmas_ary[nr_dsmas].dpa_length = CDAT_DSMAS_DPA_LEN(cur_rec); > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > + > + dev_dbg(&cxlmd->dev, "DSMAS %d: %llx:%llx %s\n", > + nr_dsmas, > + dsmas_ary[nr_dsmas].dpa_base, > + dsmas_ary[nr_dsmas].dpa_base + > + dsmas_ary[nr_dsmas].dpa_length, > + (dsmas_ary[nr_dsmas].non_volatile ? > + "Persistent" : "Volatile") > + ); > + > + nr_dsmas++; > + } > + > + data += (length / sizeof(u32)); > + bytes_left -= length; > + } > + > + if (nr_dsmas == 0) > + return -ENXIO; > + > + dev_dbg(&cxlmd->dev, "Found %d DSMAS entries\n", nr_dsmas); > + cxlmd->cdat.dsmas_ary = dsmas_ary; > + cxlmd->cdat.nr_dsmas = nr_dsmas; > + > + return 0; > +} > +
On Tue, 1 Feb 2022 14:37:17 -0800 Ira Weiny <ira.weiny@intel.com> wrote: > On Tue, Feb 01, 2022 at 11:05:32AM -0800, Widawsky, Ben wrote: > > On 22-01-31 23:19:52, ira.weiny@intel.com wrote: > > > From: Ira Weiny <ira.weiny@intel.com> > > > > > > CXL memory devices need the information in the Device Scoped Memory > > > Affinity Structure (DSMAS). This information is contained within the > > > CDAT table buffer which is already read and cached. > > > > > > Parse and cache DSMAS data from the CDAT table. Store this data in > > > unmarshaled struct dsmas data structures for ease of use. > > > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > > > --- > > > Changes from V5 > > > Fix up sparse warnings > > > Split out cdat_hdr_valid() > > > Update cdat_hdr_valid() > > > Remove revision and cs field parsing > > > There is no point in these > > > Add seq check and debug print. > > > From Jonathan > > > Add spaces around '+' and '/' > > > use devm_krealloc() for dmas_ary > > > > > > Changes from V4 > > > New patch > > > --- > > > drivers/cxl/cdat.h | 21 ++++++++++++ > > > drivers/cxl/core/memdev.c | 70 +++++++++++++++++++++++++++++++++++++++ > > > 2 files changed, 91 insertions(+) > > > > > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > > > index a7725d26f2d2..f8c126190d18 100644 > > > --- a/drivers/cxl/cdat.h > > > +++ b/drivers/cxl/cdat.h > > > @@ -83,17 +83,38 @@ > > > #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) > > > #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) > > > > > > +/** > > > + * struct cxl_dsmas - host unmarshaled version of DSMAS data > > > + * > > > + * As defined in the Coherent Device Attribute Table (CDAT) specification this > > > + * represents a single DSMAS entry in that table. > > > + * > > > + * @dpa_base: The lowest DPA address associated with this DSMAD > > > + * @dpa_length: Length in bytes of this DSMAD > > > + * @non_volatile: If set, the memory region represents Non-Volatile memory > > > + */ > > > +struct cxl_dsmas { > > > + u64 dpa_base; > > > + u64 dpa_length; > > > + /* Flags */ > > > + u8 non_volatile:1; > > > +}; > > > + > > > /** > > > * struct cxl_cdat - CXL CDAT data > > > * > > > * @table: cache of CDAT table > > > * @length: length of cached CDAT table > > > * @seq: Last read Sequence number of the CDAT table > > > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > > > + * @nr_dsmas: Number of entries in dsmas_ary > > > */ > > > struct cxl_cdat { > > > void *table; > > > size_t length; > > > u32 seq; > > > + struct cxl_dsmas *dsmas_ary; > > > + int nr_dsmas; > > > }; > > > > > > #endif /* !__CXL_CDAT_H__ */ > > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > > > index 11d721c56f08..32342a15e991 100644 > > > --- a/drivers/cxl/core/memdev.c > > > +++ b/drivers/cxl/core/memdev.c > > > @@ -6,6 +6,7 @@ > > > #include <linux/idr.h> > > > #include <linux/pci.h> > > > #include <cxlmem.h> > > > +#include "cdat.h" > > > #include "core.h" > > > > > > static DECLARE_RWSEM(cxl_memdev_rwsem); > > > @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, > > > return rc; > > > } > > > > > > +static int parse_dsmas(struct cxl_memdev *cxlmd) > > > +{ > > > + struct cxl_dsmas *dsmas_ary = NULL; > > > + u32 *data = cxlmd->cdat.table; > > > + int bytes_left = cxlmd->cdat.length; > > > + int nr_dsmas = 0; > > > + > > > + if (!data) > > > + return -ENXIO; > > > + > > > + /* Skip header */ > > > + data += CDAT_HEADER_LENGTH_DW; > > > + bytes_left -= CDAT_HEADER_LENGTH_BYTES; > > > + > > > + while (bytes_left > 0) { > > > + u32 *cur_rec = data; > > > + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); > > > + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); > > > + > > > + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { > > > + struct cxl_dsmas *new_ary; > > > + u8 flags; > > > + > > > + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, > > > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > > > + GFP_KERNEL); > > > + if (!new_ary) { > > > + dev_err(&cxlmd->dev, > > > + "Failed to allocate memory for DSMAS data\n"); > > > + return -ENOMEM; > > > + } > > > > One thought here - it looks like there are at most 256 DSMAS entries. You could > > allocate the full 256 up front, and then realloc *down* to the actual number. Gut feeling is there will be 1 or 2 on at typical device, so not sure it is worth a large allocation and shrink. Plus not a hot path and this is easy to follow.
diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h index a7725d26f2d2..f8c126190d18 100644 --- a/drivers/cxl/cdat.h +++ b/drivers/cxl/cdat.h @@ -83,17 +83,38 @@ #define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) #define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) +/** + * struct cxl_dsmas - host unmarshaled version of DSMAS data + * + * As defined in the Coherent Device Attribute Table (CDAT) specification this + * represents a single DSMAS entry in that table. + * + * @dpa_base: The lowest DPA address associated with this DSMAD + * @dpa_length: Length in bytes of this DSMAD + * @non_volatile: If set, the memory region represents Non-Volatile memory + */ +struct cxl_dsmas { + u64 dpa_base; + u64 dpa_length; + /* Flags */ + u8 non_volatile:1; +}; + /** * struct cxl_cdat - CXL CDAT data * * @table: cache of CDAT table * @length: length of cached CDAT table * @seq: Last read Sequence number of the CDAT table + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table + * @nr_dsmas: Number of entries in dsmas_ary */ struct cxl_cdat { void *table; size_t length; u32 seq; + struct cxl_dsmas *dsmas_ary; + int nr_dsmas; }; #endif /* !__CXL_CDAT_H__ */ diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index 11d721c56f08..32342a15e991 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -6,6 +6,7 @@ #include <linux/idr.h> #include <linux/pci.h> #include <cxlmem.h> +#include "cdat.h" #include "core.h" static DECLARE_RWSEM(cxl_memdev_rwsem); @@ -386,6 +387,71 @@ static int read_cdat_data(struct cxl_memdev *cxlmd, return rc; } +static int parse_dsmas(struct cxl_memdev *cxlmd) +{ + struct cxl_dsmas *dsmas_ary = NULL; + u32 *data = cxlmd->cdat.table; + int bytes_left = cxlmd->cdat.length; + int nr_dsmas = 0; + + if (!data) + return -ENXIO; + + /* Skip header */ + data += CDAT_HEADER_LENGTH_DW; + bytes_left -= CDAT_HEADER_LENGTH_BYTES; + + while (bytes_left > 0) { + u32 *cur_rec = data; + u8 type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, cur_rec[0]); + u16 length = FIELD_GET(CDAT_STRUCTURE_DW0_LENGTH, cur_rec[0]); + + if (type == CDAT_STRUCTURE_DW0_TYPE_DSMAS) { + struct cxl_dsmas *new_ary; + u8 flags; + + new_ary = devm_krealloc(&cxlmd->dev, dsmas_ary, + sizeof(*dsmas_ary) * (nr_dsmas + 1), + GFP_KERNEL); + if (!new_ary) { + dev_err(&cxlmd->dev, + "Failed to allocate memory for DSMAS data\n"); + return -ENOMEM; + } + dsmas_ary = new_ary; + + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); + + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); + dsmas_ary[nr_dsmas].dpa_length = CDAT_DSMAS_DPA_LEN(cur_rec); + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); + + dev_dbg(&cxlmd->dev, "DSMAS %d: %llx:%llx %s\n", + nr_dsmas, + dsmas_ary[nr_dsmas].dpa_base, + dsmas_ary[nr_dsmas].dpa_base + + dsmas_ary[nr_dsmas].dpa_length, + (dsmas_ary[nr_dsmas].non_volatile ? + "Persistent" : "Volatile") + ); + + nr_dsmas++; + } + + data += (length / sizeof(u32)); + bytes_left -= length; + } + + if (nr_dsmas == 0) + return -ENXIO; + + dev_dbg(&cxlmd->dev, "Found %d DSMAS entries\n", nr_dsmas); + cxlmd->cdat.dsmas_ary = dsmas_ary; + cxlmd->cdat.nr_dsmas = nr_dsmas; + + return 0; +} + struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) { struct cxl_memdev *cxlmd; @@ -407,6 +473,10 @@ struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds) if (rc) goto err; + rc = parse_dsmas(cxlmd); + if (rc) + dev_warn(dev, "No DSMAS data found: %d\n", rc); + /* * Activate ioctl operations, no cxl_memdev_rwsem manipulation * needed as this is ordered with cdev_add() publishing the device.