[PATCH v11 05/20] cxl/port: Pre-initialize component register mappings

Robert Richter
2023-09-27T15:47:09Z

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.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
drivers/cxl/core/port.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index b993dea61436..28ba8922d0a4 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -694,16 +694,18 @@ static struct cxl_port *cxl_port_alloc(struct device *uport_dev,
static int cxl_setup_comp_regs(struct device *host, 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) {
.host = host,
- .reg_type = CXL_REGLOC_RBI_COMPONENT,
+ .reg_type = CXL_REGLOC_RBI_EMPTY,
.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);
}

--
2.30.2