Messages in this thread | | | Date | Thu, 31 Aug 2023 14:22:35 +0200 | From | Robert Richter <> | Subject | Re: [PATCH v9 01/15] cxl/port: Pre-initialize component register mappings |
| |
On 29.08.23 14:38:51, Jonathan Cameron wrote: > On Fri, 25 Aug 2023 18:31:57 -0500 > Terry Bowman <terry.bowman@amd.com> wrote: > > > From: Robert Richter <rrichter@amd.com> > > Hi Robert, Terry, > > > > > The component registers of a component may not exist or are not > > needed. > > How do we now it's not needed in this function? > Perhaps "may not exist." is the bit that matters in this sentence. > > > The setup may fail for that reason. In some cases the > > initialization should continue anyway. Thus, always initialize struct > > cxl_register_map with valid values. In case of errors, zero it, set a > > value for @dev and make @resource a the valid value using > > make @resource CXL_RESOURCE_NONE. > > (not "a the") > > > CXL_RESOURCE_NONE. > > It might be worth making it clear that this will (I think) only matter > for future usecases and isn't a fix for how this function is used today.
I reworded the whole text:
""" The component registers of a component may not exist and cxl_setup_comp_regs() will fail for that reason. In another case, Software may not use and set those registers up. cxl_setup_comp_regs() is then called with a base address of CXL_RESOURCE_NONE. Both are valid cases, but the function returns without initializing the register map.
Now, a missing component register block is not necessarily a reason to fail (feature is optional or its existence checked later). Change cxl_setup_comp_regs() to also use components with the component register block missing. Thus, always initialize struct cxl_register_map with valid values, set @dev and make @resource CXL_RESOURCE_NONE.
The change is in preparation of follow-on patches. """
I hope that is better now.
> > > > > Signed-off-by: Robert Richter <rrichter@amd.com> > > Signed-off-by: Terry Bowman <terry.bowman@amd.com> > Otherwise seems sensible to me with one comment below. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > > --- > > drivers/cxl/core/port.c | 11 ++++++----- > > 1 file changed, 6 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > > index 724be8448eb4..2d22e7a5629b 100644 > > --- a/drivers/cxl/core/port.c > > +++ b/drivers/cxl/core/port.c > > @@ -693,16 +693,17 @@ static struct cxl_port *cxl_port_alloc(struct device *uport_dev, > > static int cxl_setup_comp_regs(struct device *dev, struct cxl_register_map *map, > > resource_size_t component_reg_phys) > > { > > - if (component_reg_phys == CXL_RESOURCE_NONE) > > - return 0; > > - > > *map = (struct cxl_register_map) { > > .dev = dev, > > - .reg_type = CXL_REGLOC_RBI_COMPONENT, > > Could set this explicitly to CXL_REGLOC_RBI_EMPTY > which is what happens anyway, but it isn't obvious that > 0 maps to something that indicates this doesn't exist.
Will change that.
Thanks,
-Robert
> > > .resource = component_reg_phys, > > - .max_size = CXL_COMPONENT_REG_BLOCK_SIZE, > > }; > > > > + if (component_reg_phys == CXL_RESOURCE_NONE) > > + return 0; > > + > > + map->reg_type = CXL_REGLOC_RBI_COMPONENT; > > + map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE; > > + > > return cxl_setup_regs(map); > > } > > >
| |