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cxl/acpi: Extract component registers of restricted hosts from RCRB

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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 <terry.bowman@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/Y4dsGZ24aJlxSfI1@rric.localdomain
[djbw: introduce devm_cxl_add_rch_dport()]
Link: https://lore.kernel.org/r/166993044524.1882361.2539922887413208807.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Robert Richter
2022-12-03 00:40:29 -08:00
committed by Dan Williams
parent 1dedb6f3cf
commit d5b1a27143
8 changed files with 207 additions and 11 deletions
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10
tools/testing/cxl/test/cxl.c
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@@ -696,6 +696,15 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
return 0;
}
resource_size_t mock_cxl_rcrb_to_component(struct device *dev,
resource_size_t rcrb,
enum cxl_rcrb which)
{
dev_dbg(dev, "rcrb: %pa which: %d\n", &rcrb, which);
return (resource_size_t) which + 1;
}
static struct cxl_mock_ops cxl_mock_ops = {
.is_mock_adev = is_mock_adev,
.is_mock_bridge = is_mock_bridge,
@@ -704,6 +713,7 @@ static struct cxl_mock_ops cxl_mock_ops = {
.is_mock_dev = is_mock_dev,
.acpi_table_parse_cedt = mock_acpi_table_parse_cedt,
.acpi_evaluate_integer = mock_acpi_evaluate_integer,
.cxl_rcrb_to_component = mock_cxl_rcrb_to_component,
.acpi_pci_find_root = mock_acpi_pci_find_root,
.devm_cxl_port_enumerate_dports = mock_cxl_port_enumerate_dports,
.devm_cxl_setup_hdm = mock_cxl_setup_hdm,