Robert Richter wrote: > On 02.12.22 23:04:49, Dan Williams wrote: > > Robert Richter wrote: > > > On 01.12.22 13:34:05, Dan Williams wrote: > > > > From: Robert Richter <[email protected]> > > > > > > > > A downstream port must be connected to a component register block. > > > > For restricted hosts the base address is determined from the RCRB. The > > > > RCRB is provided by the host's CEDT CHBS entry. Rework CEDT parser to > > > > get the RCRB and add code to extract the component register block from > > > > it. > > > > > > > > RCRB's BAR[0..1] point to the component block containing CXL subsystem > > > > component registers. MEMBAR extraction follows the PCI base spec here, > > > > esp. 64 bit extraction and memory range alignment (6.0, 7.5.1.2.1). The > > > > RCRB base address is cached in the cxl_dport per-host bridge so that the > > > > upstream port component registers can be retrieved later by an RCD > > > > (RCIEP) associated with the host bridge. > > > > > > > > Note: Right now the component register block is used for HDM decoder > > > > capability only which is optional for RCDs. If unsupported by the RCD, > > > > the HDM init will fail. It is future work to bypass it in this case. > > > > > > > > Co-developed-by: Terry Bowman <[email protected]> > > > > Signed-off-by: Terry Bowman <[email protected]> > > > > Signed-off-by: Robert Richter <[email protected]> > > > > Link: https://lore.kernel.org/r/[email protected] > > > > [djbw: introduce devm_cxl_add_rch_dport()] > > > > Signed-off-by: Dan Williams <[email protected]> > > > > > > Found an issue below. Patch looks good to me otherwise. > > > > > > > --- > > > > drivers/cxl/acpi.c | 51 ++++++++++++++++++++++++++++----- > > > > drivers/cxl/core/port.c | 53 ++++++++++++++++++++++++++++++---- > > > > drivers/cxl/core/regs.c | 64 > > > > +++++++++++++++++++++++++++++++++++++++++ > > > > drivers/cxl/cxl.h | 16 ++++++++++ > > > > tools/testing/cxl/Kbuild | 1 + > > > > tools/testing/cxl/test/cxl.c | 10 ++++++ > > > > tools/testing/cxl/test/mock.c | 19 ++++++++++++ > > > > tools/testing/cxl/test/mock.h | 3 ++ > > > > 8 files changed, 203 insertions(+), 14 deletions(-) > > > > > > > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > > > > > > > @@ -274,21 +301,29 @@ static int add_host_bridge_dport(struct device > > > > *match, void *arg) > > > > dev_dbg(match, "UID found: %lld\n", uid); > > > > > > > > ctx = (struct cxl_chbs_context) { > > > > - .dev = host, > > > > + .dev = match, > > > > .uid = uid, > > > > }; > > > > acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx); > > > > > > > > - if (ctx.chbcr == 0) { > > > > + if (ctx.rcrb != CXL_RESOURCE_NONE) > > > > + dev_dbg(match, "RCRB found for UID %lld: %pa\n", uid, > > > > &ctx.rcrb); > > > > + > > > > + if (ctx.chbcr == CXL_RESOURCE_NONE) { > > > > dev_warn(match, "No CHBS found for Host Bridge (UID > > > > %lld)\n", uid); > > > > return 0; > > > > } > > > > > > The logic must be changed to handle the case where the chbs entry is > > > missing: > > > > > > if (!ctx.chbcr) { > > > dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n", > > > uid); > > > return 0; > > > } > > > > Noted, and folded into the patch. > > In the (ctx.chbcr == CXL_RESOURCE_NONE) case there is a slighly > different error reason. The CHBS was found but the CHBCR was invalid > or something else failed to determine it. That's why a different > message should be reported, e.g.: > > dev_warn(match, "CHBCR invalid for Host Bridge (UID %lld)\n", uid); > > (Note I originally used "missing", but "invalid" is more reasonable > as there is something but it's not correct.) >
Care to send a patch on top of cxl/next to fix this up?
