[PATCH v2] cxl: Remove core/acpi.c and cxl core dependency on ACPI

[Dave Jiang <dave.jiang@intel.com>]

It was a mistake to introduce core/acpi.c and putting ACPI dependency on
cxl_core when adding the extended linear cache support. Add a callback
in the cxl_root_decoder to retrieve the extended linear cache size from
ACPI via the cxl_acpi driver.

In order to deal with cxl_test, a device parameter had to be introduced
to the hmat_get_extended_linear_cache_size() call in order to help with
the mock wrapped function from ACPI. Even though the 'struct device' is
not used by the actual hmat_get_extended_linear_cache_size() function.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v2:
- Remove introduction of 'struct device' parameter to
  hmat_get_extended_linear_cache_size().
- Drop comment on flex array (Jonathan)
- Rename cxl_rcd_ops to cxl_rd_ops for 'root decoder ops' (Fabio)
---
 drivers/cxl/acpi.c            | 13 +++++++++++-
 drivers/cxl/core/Makefile     |  1 -
 drivers/cxl/core/acpi.c       | 11 ----------
 drivers/cxl/core/core.h       |  2 --
 drivers/cxl/core/port.c       |  5 ++++-
 drivers/cxl/core/region.c     |  5 ++++-
 drivers/cxl/cxl.h             | 10 ++++++++-
 tools/testing/cxl/Kbuild      |  2 +-
 tools/testing/cxl/test/cxl.c  | 39 +++++++++++++++++++++++++++++++++++
 tools/testing/cxl/test/mock.c | 19 +++++++++++++++++
 tools/testing/cxl/test/mock.h |  3 +++
 11 files changed, 91 insertions(+), 19 deletions(-)
 delete mode 100644 drivers/cxl/core/acpi.c

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index a1a99ec3f12c..48478bc406ee 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -335,6 +335,17 @@ static int add_or_reset_cxl_resource(struct resource *parent, struct resource *r
 	return rc;
 }
 
+static int cxl_acpi_get_extended_linear_cache_size(struct resource *backing_res,
+						   int nid,
+						   resource_size_t *size)
+{
+	return hmat_get_extended_linear_cache_size(backing_res, nid, size);
+}
+
+static const struct cxl_rd_ops acpi_rd_ops = {
+	.get_extended_linear_cache_size = cxl_acpi_get_extended_linear_cache_size,
+};
+
 DEFINE_FREE(put_cxlrd, struct cxl_root_decoder *,
 	    if (!IS_ERR_OR_NULL(_T)) put_device(&_T->cxlsd.cxld.dev))
 DEFINE_FREE(del_cxl_resource, struct resource *, if (_T) del_cxl_resource(_T))
@@ -373,7 +384,7 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
 		return rc;
 
 	struct cxl_root_decoder *cxlrd __free(put_cxlrd) =
-		cxl_root_decoder_alloc(root_port, ways);
+		cxl_root_decoder_alloc(root_port, ways, &acpi_rd_ops);
 
 	if (IS_ERR(cxlrd))
 		return PTR_ERR(cxlrd);
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index 79e2ef81fde8..5ad8fef210b5 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -15,7 +15,6 @@ cxl_core-y += hdm.o
 cxl_core-y += pmu.o
 cxl_core-y += cdat.o
 cxl_core-y += ras.o
-cxl_core-y += acpi.o
 cxl_core-$(CONFIG_TRACING) += trace.o
 cxl_core-$(CONFIG_CXL_REGION) += region.o
 cxl_core-$(CONFIG_CXL_MCE) += mce.o
diff --git a/drivers/cxl/core/acpi.c b/drivers/cxl/core/acpi.c
deleted file mode 100644
index f13b4dae6ac5..000000000000
--- a/drivers/cxl/core/acpi.c
+++ /dev/null
@@ -1,11 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* Copyright(c) 2024 Intel Corporation. All rights reserved. */
-#include <linux/acpi.h>
-#include "cxl.h"
-#include "core.h"
-
-int cxl_acpi_get_extended_linear_cache_size(struct resource *backing_res,
-					    int nid, resource_size_t *size)
-{
-	return hmat_get_extended_linear_cache_size(backing_res, nid, size);
-}
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 29b61828a847..9462aea9ce9d 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -120,8 +120,6 @@ int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
 int cxl_ras_init(void);
 void cxl_ras_exit(void);
 int cxl_gpf_port_setup(struct cxl_dport *dport);
-int cxl_acpi_get_extended_linear_cache_size(struct resource *backing_res,
-					    int nid, resource_size_t *size);
 
 #ifdef CONFIG_CXL_FEATURES
 struct cxl_feat_entry *
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index eb46c6764d20..cbb9c5a3c309 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1793,6 +1793,7 @@ static int cxl_switch_decoder_init(struct cxl_port *port,
  * cxl_root_decoder_alloc - Allocate a root level decoder
  * @port: owning CXL root of this decoder
  * @nr_targets: static number of downstream targets
+ * @ops: root decoder callback operations
  *
  * Return: A new cxl decoder to be registered by cxl_decoder_add(). A
  * 'CXL root' decoder is one that decodes from a top-level / static platform
@@ -1800,7 +1801,8 @@ static int cxl_switch_decoder_init(struct cxl_port *port,
  * topology.
  */
 struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
-						unsigned int nr_targets)
+						unsigned int nr_targets,
+						const struct cxl_rd_ops *ops)
 {
 	struct cxl_root_decoder *cxlrd;
 	struct cxl_switch_decoder *cxlsd;
@@ -1839,6 +1841,7 @@ struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
 
 	atomic_set(&cxlrd->region_id, rc);
 	cxlrd->qos_class = CXL_QOS_CLASS_INVALID;
+	cxlrd->ops = ops;
 	return cxlrd;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, "CXL");
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 6e5e1460068d..0a5effbc0529 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3287,7 +3287,10 @@ static int cxl_extended_linear_cache_resize(struct cxl_region *cxlr,
 	resource_size_t cache_size, start;
 	int rc;
 
-	rc = cxl_acpi_get_extended_linear_cache_size(res, nid, &cache_size);
+	if (!cxlrd->ops || !cxlrd->ops->get_extended_linear_cache_size)
+		return -EOPNOTSUPP;
+
+	rc = cxlrd->ops->get_extended_linear_cache_size(res, nid, &cache_size);
 	if (rc)
 		return rc;
 
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 3f1695c96abc..9a17e8beca7a 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -420,6 +420,11 @@ struct cxl_switch_decoder {
 struct cxl_root_decoder;
 typedef u64 (*cxl_hpa_to_spa_fn)(struct cxl_root_decoder *cxlrd, u64 hpa);
 
+struct cxl_rd_ops {
+	int (*get_extended_linear_cache_size)(struct resource *backing_res,
+					      int nid, resource_size_t *size);
+};
+
 /**
  * struct cxl_root_decoder - Static platform CXL address decoder
  * @res: host / parent resource for region allocations
@@ -428,6 +433,7 @@ typedef u64 (*cxl_hpa_to_spa_fn)(struct cxl_root_decoder *cxlrd, u64 hpa);
  * @platform_data: platform specific configuration data
  * @range_lock: sync region autodiscovery by address range
  * @qos_class: QoS performance class cookie
+ * @ops: root decoder specific operations
  * @cxlsd: base cxl switch decoder
  */
 struct cxl_root_decoder {
@@ -437,6 +443,7 @@ struct cxl_root_decoder {
 	void *platform_data;
 	struct mutex range_lock;
 	int qos_class;
+	const struct cxl_rd_ops *ops;
 	struct cxl_switch_decoder cxlsd;
 };
 
@@ -775,7 +782,8 @@ bool is_root_decoder(struct device *dev);
 bool is_switch_decoder(struct device *dev);
 bool is_endpoint_decoder(struct device *dev);
 struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
-						unsigned int nr_targets);
+						unsigned int nr_targets,
+						const struct cxl_rd_ops *ops);
 struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
 						    unsigned int nr_targets);
 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 31a2d73c963f..c4fd68db41ba 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -15,6 +15,7 @@ ldflags-y += --wrap=devm_cxl_add_rch_dport
 ldflags-y += --wrap=cxl_rcd_component_reg_phys
 ldflags-y += --wrap=cxl_endpoint_parse_cdat
 ldflags-y += --wrap=cxl_dport_init_ras_reporting
+ldflags-y += --wrap=hmat_get_extended_linear_cache_size
 
 DRIVERS := ../../../drivers
 CXL_SRC := $(DRIVERS)/cxl
@@ -62,7 +63,6 @@ cxl_core-y += $(CXL_CORE_SRC)/hdm.o
 cxl_core-y += $(CXL_CORE_SRC)/pmu.o
 cxl_core-y += $(CXL_CORE_SRC)/cdat.o
 cxl_core-y += $(CXL_CORE_SRC)/ras.o
-cxl_core-y += $(CXL_CORE_SRC)/acpi.o
 cxl_core-$(CONFIG_TRACING) += $(CXL_CORE_SRC)/trace.o
 cxl_core-$(CONFIG_CXL_REGION) += $(CXL_CORE_SRC)/region.o
 cxl_core-$(CONFIG_CXL_MCE) += $(CXL_CORE_SRC)/mce.o
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 8a5815ca870d..3f6780179752 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -470,6 +470,43 @@ struct cxl_cedt_context {
 	struct device *dev;
 };
 
+static int match_root_decoder_by_range(struct device *dev, const void *data)
+{
+	const struct range *r1, *r2 = data;
+	struct cxl_root_decoder *cxlrd;
+
+	if (!is_root_decoder(dev))
+		return 0;
+
+	cxlrd = to_cxl_root_decoder(dev);
+	r1 = &cxlrd->cxlsd.cxld.hpa_range;
+	return range_contains(r1, r2);
+}
+
+static int mock_hmat_get_extended_linear_cache_size(struct resource *backing_res,
+						    int nid, resource_size_t *size)
+{
+	struct range backing_range = {
+		.start = backing_res->start,
+		.end = backing_res->end,
+	};
+	struct cxl_decoder *cxld;
+	struct cxl_port *port;
+	struct device *dev;
+
+	dev = bus_find_device(&cxl_bus_type, NULL, &backing_range,
+			      match_root_decoder_by_range);
+	if (!dev)
+		return -ENODEV;
+
+	cxld = to_cxl_decoder(dev);
+	port = to_cxl_port(cxld->dev.parent);
+	if (is_mock_dev(port->uport_dev))
+		return -EOPNOTSUPP;
+
+	return hmat_get_extended_linear_cache_size(backing_res, nid, size);
+}
+
 static int mock_acpi_table_parse_cedt(enum acpi_cedt_type id,
 				      acpi_tbl_entry_handler_arg handler_arg,
 				      void *arg)
@@ -1040,6 +1077,8 @@ static struct cxl_mock_ops cxl_mock_ops = {
 	.devm_cxl_enumerate_decoders = mock_cxl_enumerate_decoders,
 	.cxl_endpoint_parse_cdat = mock_cxl_endpoint_parse_cdat,
 	.list = LIST_HEAD_INIT(cxl_mock_ops.list),
+	.hmat_get_extended_linear_cache_size =
+		mock_hmat_get_extended_linear_cache_size,
 };
 
 static void mock_companion(struct acpi_device *adev, struct device *dev)
diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index 1989ae020df3..ec8fc4a44073 100644
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -78,6 +78,25 @@ int __wrap_acpi_table_parse_cedt(enum acpi_cedt_type id,
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_acpi_table_parse_cedt, "ACPI");
 
+int __wrap_hmat_get_extended_linear_cache_size(struct resource *res,
+					       int nid,
+					       resource_size_t *size)
+{
+	int index;
+	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+	int rc;
+
+	if (ops)
+		rc = ops->hmat_get_extended_linear_cache_size(res, nid, size);
+	else
+		rc = hmat_get_extended_linear_cache_size(res, nid, size);
+
+	put_cxl_mock_ops(index);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(__wrap_hmat_get_extended_linear_cache_size, "CXL");
+
 acpi_status __wrap_acpi_evaluate_integer(acpi_handle handle,
 					 acpi_string pathname,
 					 struct acpi_object_list *arguments,
diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index d1b0271d2822..469a270ee245 100644
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -26,6 +26,9 @@ struct cxl_mock_ops {
 	int (*devm_cxl_enumerate_decoders)(
 		struct cxl_hdm *hdm, struct cxl_endpoint_dvsec_info *info);
 	void (*cxl_endpoint_parse_cdat)(struct cxl_port *port);
+	int (*hmat_get_extended_linear_cache_size)(struct resource *backing_res,
+						   int nid,
+						   resource_size_t *size);
 };
 
 void register_cxl_mock_ops(struct cxl_mock_ops *ops);

base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
-- 
2.49.0