| Message ID | 20220605005049.2155874-10-ira.weiny@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | CXL: Read CDAT and DSMAS data | expand |
On 22-06-04 17:50:49, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > CXL Ports with memory devices attached need the information from the > Device Scoped Memory Affinity Structure (DSMAS). This information is > contained within the CDAT table buffer which is previously read and > cached in the port device. > > If CDAT data is available, parse and cache DSMAS data from the table. > Store this data in unmarshaled struct dsmas data structures for ease of > use later. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes from V8 > Adjust to the cdat data being in cxl_port > > Changes from V7 > Rebased on cxl-pending > > Changes from V6 > Move to port.c > It is not an error if no DSMAS data is found > > 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 > --- > drivers/cxl/cdat.h | 17 +++++++++++ > drivers/cxl/core/pci.c | 65 ++++++++++++++++++++++++++++++++++++++++++ > drivers/cxl/cxl.h | 2 ++ > drivers/cxl/cxlmem.h | 4 +++ > drivers/cxl/cxlpci.h | 1 + > drivers/cxl/mem.c | 1 + > 6 files changed, 90 insertions(+) > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > index 3d8945612511..0a510f73fe6d 100644 > --- a/drivers/cxl/cdat.h > +++ b/drivers/cxl/cdat.h > @@ -85,6 +85,23 @@ > > #define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 > > +/** > + * 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 Device Physical Address associated with this DSMAD > + * @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 length; > + /* Flags */ > + u8 non_volatile:1; > +}; > + > /** > * struct cxl_cdat - CXL CDAT data > * > diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c > index e68f13e66fcf..9666cc4a67aa 100644 > --- a/drivers/cxl/core/pci.c > +++ b/drivers/cxl/core/pci.c > @@ -673,3 +673,68 @@ void read_cdat_data(struct cxl_port *port) > retries); > } > EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL); > + > +void parse_dsmas(struct cxl_memdev *cxlmd, struct cxl_port *port) > +{ > + struct device *dev = &port->dev; > + struct cxl_dsmas *dsmas_ary = NULL; > + u32 *data = port->cdat.table; > + int bytes_left = port->cdat.length; > + int nr_dsmas = 0; > + > + if (!data) { > + dev_info(dev, "No CDAT data available for DSMAS\n"); > + return; > + } > + > + /* 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(dev, dsmas_ary, > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > + GFP_KERNEL); > + if (!new_ary) { > + dev_err(dev, > + "Failed to allocate memory for DSMAS data (nr_dsmas %d)\n", > + nr_dsmas); > + return; > + } > + dsmas_ary = new_ary; I don't love the realloc on every loop (though I've done something similar before). What about allocating enough entries port->cdat.length, and then a single krealloc to shorten the array upon success? I think krealloc pretty much always succeeds when you shrink FWIW. > + > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); Does it make sense to test length/bytes_left before reading cur_rec[1]? > + > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > + dsmas_ary[nr_dsmas].length = CDAT_DSMAS_DPA_LEN(cur_rec); > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > + > + dev_dbg(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].length, > + (dsmas_ary[nr_dsmas].non_volatile ? > + "Persistent" : "Volatile") > + ); > + > + nr_dsmas++; > + } > + > + data += (length / sizeof(u32)); > + bytes_left -= length; > + } > + > + dev_dbg(dev, "Found %d DSMAS entries\n", nr_dsmas); > + cxlmd->dsmas_ary = dsmas_ary; > + cxlmd->nr_dsmas = nr_dsmas; > +} > +EXPORT_SYMBOL_NS_GPL(parse_dsmas, CXL); > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index 531b77d296c7..4d779a8fb807 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -10,6 +10,8 @@ > #include <linux/io.h> > #include "cdat.h" > > +#include "cdat.h" > + > /** > * DOC: cxl objects > * > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 4d2764b865ab..ce5b00f3ebcb 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -36,6 +36,8 @@ > * @cxlds: The device state backing this device > * @detach_work: active memdev lost a port in its ancestry > * @id: id number of this memdev instance. > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > + * @nr_dsmas: Number of entries in dsmas_ary Personally don't think it's necessary to append "_ary". Up to you. > */ > struct cxl_memdev { > struct device dev; > @@ -43,6 +45,8 @@ struct cxl_memdev { > struct cxl_dev_state *cxlds; > struct work_struct detach_work; > int id; > + struct cxl_dsmas *dsmas_ary; > + int nr_dsmas; > }; > > static inline struct cxl_memdev *to_cxl_memdev(struct device *dev) > diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h > index 71009a167a92..44d1c2b83aab 100644 > --- a/drivers/cxl/cxlpci.h > +++ b/drivers/cxl/cxlpci.h > @@ -76,4 +76,5 @@ struct cxl_dev_state; > int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm); > void cxl_cache_cdat_mb(struct cxl_port *port); > void read_cdat_data(struct cxl_port *port); > +void parse_dsmas(struct cxl_memdev *cxlmd, struct cxl_port *port); > #endif /* __CXL_PCI_H__ */ > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c > index c310f1fd3db0..a8768df4ae38 100644 > --- a/drivers/cxl/mem.c > +++ b/drivers/cxl/mem.c > @@ -35,6 +35,7 @@ static int create_endpoint(struct cxl_memdev *cxlmd, > if (IS_ERR(endpoint)) > return PTR_ERR(endpoint); > > + parse_dsmas(cxlmd, endpoint); > dev_dbg(&cxlmd->dev, "add: %s\n", dev_name(&endpoint->dev)); > > if (!endpoint->dev.driver) { > -- > 2.35.1 >
On Mon, Jun 06, 2022 at 12:32:20PM -0700, Ben Widawsky wrote: > On 22-06-04 17:50:49, ira.weiny@intel.com wrote: > > From: Ira Weiny <ira.weiny@intel.com> > > > > CXL Ports with memory devices attached need the information from the > > Device Scoped Memory Affinity Structure (DSMAS). This information is > > contained within the CDAT table buffer which is previously read and > > cached in the port device. > > > > If CDAT data is available, parse and cache DSMAS data from the table. > > Store this data in unmarshaled struct dsmas data structures for ease of > > use later. > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > --- > > Changes from V8 > > Adjust to the cdat data being in cxl_port > > > > Changes from V7 > > Rebased on cxl-pending > > > > Changes from V6 > > Move to port.c > > It is not an error if no DSMAS data is found > > > > 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 > > --- > > drivers/cxl/cdat.h | 17 +++++++++++ > > drivers/cxl/core/pci.c | 65 ++++++++++++++++++++++++++++++++++++++++++ > > drivers/cxl/cxl.h | 2 ++ > > drivers/cxl/cxlmem.h | 4 +++ > > drivers/cxl/cxlpci.h | 1 + > > drivers/cxl/mem.c | 1 + > > 6 files changed, 90 insertions(+) > > > > diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h > > index 3d8945612511..0a510f73fe6d 100644 > > --- a/drivers/cxl/cdat.h > > +++ b/drivers/cxl/cdat.h > > @@ -85,6 +85,23 @@ > > > > #define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 > > > > +/** > > + * 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 Device Physical Address associated with this DSMAD > > + * @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 length; > > + /* Flags */ > > + u8 non_volatile:1; > > +}; > > + > > /** > > * struct cxl_cdat - CXL CDAT data > > * > > diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c > > index e68f13e66fcf..9666cc4a67aa 100644 > > --- a/drivers/cxl/core/pci.c > > +++ b/drivers/cxl/core/pci.c > > @@ -673,3 +673,68 @@ void read_cdat_data(struct cxl_port *port) > > retries); > > } > > EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL); > > + > > +void parse_dsmas(struct cxl_memdev *cxlmd, struct cxl_port *port) > > +{ > > + struct device *dev = &port->dev; > > + struct cxl_dsmas *dsmas_ary = NULL; > > + u32 *data = port->cdat.table; > > + int bytes_left = port->cdat.length; > > + int nr_dsmas = 0; > > + > > + if (!data) { > > + dev_info(dev, "No CDAT data available for DSMAS\n"); > > + return; > > + } > > + > > + /* 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(dev, dsmas_ary, > > + sizeof(*dsmas_ary) * (nr_dsmas + 1), > > + GFP_KERNEL); > > + if (!new_ary) { > > + dev_err(dev, > > + "Failed to allocate memory for DSMAS data (nr_dsmas %d)\n", > > + nr_dsmas); > > + return; > > + } > > + dsmas_ary = new_ary; > > I don't love the realloc on every loop (though I've done something similar > before). What about allocating enough entries port->cdat.length, and then a > single krealloc to shorten the array upon success? I think krealloc pretty much > always succeeds when you shrink FWIW. I'm not sure that it would be better in any significant way honestly. The chances of krealloc failing is small. > > > + > > + flags = FIELD_GET(CDAT_DSMAS_DW1_FLAGS, cur_rec[1]); > > Does it make sense to test length/bytes_left before reading cur_rec[1]? Interesting idea. On the one hand the CDAT was already validated with the checksum. But the checksum could be valid even if the dsmas data was corrupted. Especially by a malicious device. Also, I'm not sure but I think SPDM would protect us from malicious devices once implemented. Overall, it seems like checking bytes_left is a good check to ensure we don't run off the end of our buffer even if it is just some fluke of data reads. As to length I'm not seeing a danger but it might be nice to know that something in the dsmas header was wrong. I'll think on this more. > > > + > > + dsmas_ary[nr_dsmas].dpa_base = CDAT_DSMAS_DPA_OFFSET(cur_rec); > > + dsmas_ary[nr_dsmas].length = CDAT_DSMAS_DPA_LEN(cur_rec); > > + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); > > + > > + dev_dbg(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].length, > > + (dsmas_ary[nr_dsmas].non_volatile ? > > + "Persistent" : "Volatile") > > + ); > > + > > + nr_dsmas++; > > + } > > + > > + data += (length / sizeof(u32)); > > + bytes_left -= length; > > + } > > + > > + dev_dbg(dev, "Found %d DSMAS entries\n", nr_dsmas); > > + cxlmd->dsmas_ary = dsmas_ary; > > + cxlmd->nr_dsmas = nr_dsmas; > > +} > > +EXPORT_SYMBOL_NS_GPL(parse_dsmas, CXL); > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > index 531b77d296c7..4d779a8fb807 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -10,6 +10,8 @@ > > #include <linux/io.h> > > #include "cdat.h" > > > > +#include "cdat.h" > > + > > /** > > * DOC: cxl objects > > * > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > > index 4d2764b865ab..ce5b00f3ebcb 100644 > > --- a/drivers/cxl/cxlmem.h > > +++ b/drivers/cxl/cxlmem.h > > @@ -36,6 +36,8 @@ > > * @cxlds: The device state backing this device > > * @detach_work: active memdev lost a port in its ancestry > > * @id: id number of this memdev instance. > > + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table > > + * @nr_dsmas: Number of entries in dsmas_ary > > Personally don't think it's necessary to append "_ary". Up to you. I think it's fine. Thanks for the review, Ira
diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h index 3d8945612511..0a510f73fe6d 100644 --- a/drivers/cxl/cdat.h +++ b/drivers/cxl/cdat.h @@ -85,6 +85,23 @@ #define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 +/** + * 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 Device Physical Address associated with this DSMAD + * @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 length; + /* Flags */ + u8 non_volatile:1; +}; + /** * struct cxl_cdat - CXL CDAT data * diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index e68f13e66fcf..9666cc4a67aa 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -673,3 +673,68 @@ void read_cdat_data(struct cxl_port *port) retries); } EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL); + +void parse_dsmas(struct cxl_memdev *cxlmd, struct cxl_port *port) +{ + struct device *dev = &port->dev; + struct cxl_dsmas *dsmas_ary = NULL; + u32 *data = port->cdat.table; + int bytes_left = port->cdat.length; + int nr_dsmas = 0; + + if (!data) { + dev_info(dev, "No CDAT data available for DSMAS\n"); + return; + } + + /* 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(dev, dsmas_ary, + sizeof(*dsmas_ary) * (nr_dsmas + 1), + GFP_KERNEL); + if (!new_ary) { + dev_err(dev, + "Failed to allocate memory for DSMAS data (nr_dsmas %d)\n", + nr_dsmas); + return; + } + 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].length = CDAT_DSMAS_DPA_LEN(cur_rec); + dsmas_ary[nr_dsmas].non_volatile = CDAT_DSMAS_NON_VOLATILE(flags); + + dev_dbg(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].length, + (dsmas_ary[nr_dsmas].non_volatile ? + "Persistent" : "Volatile") + ); + + nr_dsmas++; + } + + data += (length / sizeof(u32)); + bytes_left -= length; + } + + dev_dbg(dev, "Found %d DSMAS entries\n", nr_dsmas); + cxlmd->dsmas_ary = dsmas_ary; + cxlmd->nr_dsmas = nr_dsmas; +} +EXPORT_SYMBOL_NS_GPL(parse_dsmas, CXL); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 531b77d296c7..4d779a8fb807 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -10,6 +10,8 @@ #include <linux/io.h> #include "cdat.h" +#include "cdat.h" + /** * DOC: cxl objects * diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 4d2764b865ab..ce5b00f3ebcb 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -36,6 +36,8 @@ * @cxlds: The device state backing this device * @detach_work: active memdev lost a port in its ancestry * @id: id number of this memdev instance. + * @dsmas_ary: Array of DSMAS entries as parsed from the CDAT table + * @nr_dsmas: Number of entries in dsmas_ary */ struct cxl_memdev { struct device dev; @@ -43,6 +45,8 @@ struct cxl_memdev { struct cxl_dev_state *cxlds; struct work_struct detach_work; int id; + struct cxl_dsmas *dsmas_ary; + int nr_dsmas; }; static inline struct cxl_memdev *to_cxl_memdev(struct device *dev) diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h index 71009a167a92..44d1c2b83aab 100644 --- a/drivers/cxl/cxlpci.h +++ b/drivers/cxl/cxlpci.h @@ -76,4 +76,5 @@ struct cxl_dev_state; int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm); void cxl_cache_cdat_mb(struct cxl_port *port); void read_cdat_data(struct cxl_port *port); +void parse_dsmas(struct cxl_memdev *cxlmd, struct cxl_port *port); #endif /* __CXL_PCI_H__ */ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index c310f1fd3db0..a8768df4ae38 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -35,6 +35,7 @@ static int create_endpoint(struct cxl_memdev *cxlmd, if (IS_ERR(endpoint)) return PTR_ERR(endpoint); + parse_dsmas(cxlmd, endpoint); dev_dbg(&cxlmd->dev, "add: %s\n", dev_name(&endpoint->dev)); if (!endpoint->dev.driver) {