Re: [PATCH v8 05/27] cxl: move pci generic code

[Dan Williams <dan.j.williams@intel.com>]

alejandro.lucero-palau@ wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> Inside cxl/core/pci.c there are helpers for CXL PCIe initialization
> meanwhile cxl/pci.c implements the functionality for a Type3 device
> initialization.
> 
> Move helper functions from cxl/pci.c to cxl/core/pci.c in order to be
> exported and shared with CXL Type2 device initialization.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
> Reviewed-by: Fan Ni <fan.ni@samsung.com>

This is the patch that causes the cxl-test build error...

> ---
>  drivers/cxl/core/pci.c | 62 ++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlpci.h   |  3 ++
>  drivers/cxl/pci.c      | 71 ------------------------------------------
>  3 files changed, 65 insertions(+), 71 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index bc098b2ce55d..3cca3ae438cd 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -1034,6 +1034,68 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, "CXL");
>  
> +/*
> + * Assume that any RCIEP that emits the CXL memory expander class code
> + * is an RCD
> + */
> +bool is_cxl_restricted(struct pci_dev *pdev)
> +{
> +	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
> +}
> +EXPORT_SYMBOL_NS_GPL(is_cxl_restricted, "CXL");
> +
> +static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
> +				  struct cxl_register_map *map)
> +{
> +	struct cxl_port *port;
> +	struct cxl_dport *dport;
> +	resource_size_t component_reg_phys;
> +
> +	*map = (struct cxl_register_map) {
> +		.host = &pdev->dev,
> +		.resource = CXL_RESOURCE_NONE,
> +	};
> +
> +	port = cxl_pci_find_port(pdev, &dport);
> +	if (!port)
> +		return -EPROBE_DEFER;
> +
> +	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);

...and it is in part due to failing to notice that
cxl_rcd_component_reg_phys() no longer needs to be exported once
cxl_pci_setup_regs() move to the core. Please make sure there are not
other occurrences of EXPORT_SYMBOL() cleanups that can be done in this
series.

Again, as I do not want to inflict cxl-test and --wrap= debugging on
folks, here is an incremental fixup/cleanup below.

Note how I fixed up the is_cxl_restricted() comment to make it relevant
for the accelerator case. Please don't leave stale comments around when
moving code.

Also note renaming the header guard to something more appropriate for
include/cxl/pci.h. That should be folded back to patch1.

-- 8< --
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 800466f96a68..3b33470b8cbc 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -107,6 +107,8 @@ enum cxl_poison_trace_type {
 	CXL_POISON_TRACE_CLEAR,
 };
 
+resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
+					   struct cxl_dport *dport);
 long cxl_pci_get_latency(struct pci_dev *pdev);
 int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c);
 int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr,
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index aaea29bff0f1..afa3bd872dc0 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -1034,16 +1034,6 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, "CXL");
 
-/*
- * Assume that any RCIEP that emits the CXL memory expander class code
- * is an RCD
- */
-bool is_cxl_restricted(struct pci_dev *pdev)
-{
-	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
-}
-EXPORT_SYMBOL_NS_GPL(is_cxl_restricted, "CXL");
-
 static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
 				  struct cxl_register_map *map,
 				  struct cxl_dport *dport)
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index 6432a784f08b..0a218385c480 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -633,4 +633,3 @@ resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
 		return CXL_RESOURCE_NONE;
 	return __rcrb_to_component(dev, &dport->rcrb, CXL_RCRB_UPSTREAM);
 }
-EXPORT_SYMBOL_NS_GPL(cxl_rcd_component_reg_phys, "CXL");
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 22e787748d79..8f241d87127a 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -311,8 +311,6 @@ int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
 		      struct cxl_register_map *map);
 int cxl_setup_regs(struct cxl_register_map *map, unsigned long *caps);
 struct cxl_dport;
-resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
-					   struct cxl_dport *dport);
 int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
 
 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
diff --git a/include/cxl/pci.h b/include/cxl/pci.h
index ad63560caa2c..efed17bc9274 100644
--- a/include/cxl/pci.h
+++ b/include/cxl/pci.h
@@ -1,8 +1,21 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright(c) 2020 Intel Corporation. All rights reserved. */
 
-#ifndef __CXL_ACCEL_PCI_H
-#define __CXL_ACCEL_PCI_H
+#ifndef __LINUX_CXL_PCI_H__
+#define __LINUX_CXL_PCI_H__
+
+#include <linux/pci.h>
+
+/*
+ * Assume that the caller has already validated that @pdev has CXL
+ * capabilities, any RCIEp with CXL capabilities is treated as a
+ * Restricted CXL Device (RCD) and finds upstream port and endpoint
+ * registers in a Root Complex Register Block (RCRB)
+ */
+static inline bool is_cxl_restricted(struct pci_dev *pdev)
+{
+	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
+}
 
 /* CXL 2.0 8.1.3: PCIe DVSEC for CXL Device */
 #define CXL_DVSEC_PCIE_DEVICE					0
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index b1256fee3567..e20d0e767574 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -12,7 +12,6 @@ ldflags-y += --wrap=cxl_await_media_ready
 ldflags-y += --wrap=cxl_hdm_decode_init
 ldflags-y += --wrap=cxl_dvsec_rr_decode
 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
 
diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index 450c7566c33f..af7a5ae09ef8 100644
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -268,23 +268,6 @@ struct cxl_dport *__wrap_devm_cxl_add_rch_dport(struct cxl_port *port,
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_add_rch_dport, "CXL");
 
-resource_size_t __wrap_cxl_rcd_component_reg_phys(struct device *dev,
-						  struct cxl_dport *dport)
-{
-	int index;
-	resource_size_t component_reg_phys;
-	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
-
-	if (ops && ops->is_mock_port(dev))
-		component_reg_phys = CXL_RESOURCE_NONE;
-	else
-		component_reg_phys = cxl_rcd_component_reg_phys(dev, dport);
-	put_cxl_mock_ops(index);
-
-	return component_reg_phys;
-}
-EXPORT_SYMBOL_NS_GPL(__wrap_cxl_rcd_component_reg_phys, "CXL");
-
 void __wrap_cxl_endpoint_parse_cdat(struct cxl_port *port)
 {
 	int index;