| Message ID | 20210506223654.1310516-2-ira.weiny@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Map register blocks individually | expand |
On Thu, May 6, 2021 at 3:37 PM <ira.weiny@intel.com> wrote: > > From: Ira Weiny <ira.weiny@intel.com> > > Previously only the capability ID and offset were decoded. > > Create a version MASK and decode the additional version and length > fields of the header. > I'm not seeing a justification for why Linux would want this patch? > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > --- > drivers/cxl/core.c | 15 ++++++++++++--- > drivers/cxl/cxl.h | 1 + > 2 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c > index b3c3532b53f7..21553386e218 100644 > --- a/drivers/cxl/core.c > +++ b/drivers/cxl/core.c > @@ -501,12 +501,21 @@ void cxl_setup_device_regs(struct device *dev, void __iomem *base, > > for (cap = 1; cap <= cap_count; cap++) { > void __iomem *register_block; > - u32 offset; > + u32 hdr, offset, __maybe_unused length; What's the point of reading the length and not using it? If this is used in a future patch then wait until then to add it. > u16 cap_id; > + u8 version; > + > + hdr = readl(base + cap * 0x10); > + > + cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, hdr); > + version = FIELD_GET(CXLDEV_CAP_HDR_VERSION_MASK, hdr); > + if (version != 1) > + dev_err(dev, "Vendor cap ID: %x incorrect version (0x%x)\n", > + cap_id, version); It's not an error. Any future version needs to be backwards compatible. All this is doing is ensuring that when hardware is updated old kernels will start spamming the log. > > - cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, > - readl(base + cap * 0x10)); > offset = readl(base + cap * 0x10 + 0x4); > + length = readl(base + cap * 0x10 + 0x8); > + > register_block = base + offset; > > switch (cap_id) { > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index 0211f44c95a2..9b315c069557 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -15,6 +15,7 @@ > #define CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32) > /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */ > #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0) > +#define CXLDEV_CAP_HDR_VERSION_MASK GENMASK(23, 16) > /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */ > #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1 > #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2 > -- > 2.28.0.rc0.12.gb6a658bd00c9 >
On Wed, May 19, 2021 at 05:50:44PM -0700, Dan Williams wrote: > On Thu, May 6, 2021 at 3:37 PM <ira.weiny@intel.com> wrote: > > > > From: Ira Weiny <ira.weiny@intel.com> > > > > Previously only the capability ID and offset were decoded. > > > > Create a version MASK and decode the additional version and length > > fields of the header. > > > > I'm not seeing a justification for why Linux would want this patch? > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > > drivers/cxl/core.c | 15 ++++++++++++--- > > drivers/cxl/cxl.h | 1 + > > 2 files changed, 13 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c > > index b3c3532b53f7..21553386e218 100644 > > --- a/drivers/cxl/core.c > > +++ b/drivers/cxl/core.c > > @@ -501,12 +501,21 @@ void cxl_setup_device_regs(struct device *dev, void __iomem *base, > > > > for (cap = 1; cap <= cap_count; cap++) { > > void __iomem *register_block; > > - u32 offset; > > + u32 hdr, offset, __maybe_unused length; > > What's the point of reading the length and not using it? Then length is needed in a future patch and it seemed easier to split by saying we are just going to decode the entire header as a patch. Ben caught this too because sparse found the unused variable... Let me see about squashing this into the future patch. > If this is > used in a future patch then wait until then to add it. ok. > > > u16 cap_id; > > + u8 version; > > + > > + hdr = readl(base + cap * 0x10); > > + > > + cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, hdr); > > + version = FIELD_GET(CXLDEV_CAP_HDR_VERSION_MASK, hdr); > > + if (version != 1) > > + dev_err(dev, "Vendor cap ID: %x incorrect version (0x%x)\n", > > + cap_id, version); > > It's not an error. Any future version needs to be backwards > compatible. All this is doing is ensuring that when hardware is > updated old kernels will start spamming the log. Yep... After deleting this I think I should just 'forward squash' the length into the patch where I need it. Ira > > > > > - cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, > > - readl(base + cap * 0x10)); > > offset = readl(base + cap * 0x10 + 0x4); > > + length = readl(base + cap * 0x10 + 0x8); > > + > > register_block = base + offset; > > > > switch (cap_id) { > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > index 0211f44c95a2..9b315c069557 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -15,6 +15,7 @@ > > #define CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32) > > /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */ > > #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0) > > +#define CXLDEV_CAP_HDR_VERSION_MASK GENMASK(23, 16) > > /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */ > > #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1 > > #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2 > > -- > > 2.28.0.rc0.12.gb6a658bd00c9 > >
diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index b3c3532b53f7..21553386e218 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -501,12 +501,21 @@ void cxl_setup_device_regs(struct device *dev, void __iomem *base, for (cap = 1; cap <= cap_count; cap++) { void __iomem *register_block; - u32 offset; + u32 hdr, offset, __maybe_unused length; u16 cap_id; + u8 version; + + hdr = readl(base + cap * 0x10); + + cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, hdr); + version = FIELD_GET(CXLDEV_CAP_HDR_VERSION_MASK, hdr); + if (version != 1) + dev_err(dev, "Vendor cap ID: %x incorrect version (0x%x)\n", + cap_id, version); - cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, - readl(base + cap * 0x10)); offset = readl(base + cap * 0x10 + 0x4); + length = readl(base + cap * 0x10 + 0x8); + register_block = base + offset; switch (cap_id) { diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 0211f44c95a2..9b315c069557 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -15,6 +15,7 @@ #define CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32) /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */ #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0) +#define CXLDEV_CAP_HDR_VERSION_MASK GENMASK(23, 16) /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */ #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1 #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2