cxl/pci: Move cxl_await_media_ready() to the core

Allow cxl_await_media_ready() to be mocked for testing purposes rather
than carrying the maintenance burden of an indirect function call in the
mainline driver.

With the move cxl_await_media_ready() can no longer reuse the mailbox
timeout override, so add a media_ready_timeout module parameter to the
core to backfill.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165291688340.1426646.4755627801983775011.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/pci.c

@@ -1,8 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright(c) 2021 Intel Corporation. All rights reserved. */
+#include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/device.h>
+#include <linux/delay.h>
 #include <linux/pci.h>
 #include <cxlpci.h>
+#include <cxlmem.h>
 #include <cxl.h>
 #include "core.h"
 
@@ -13,6 +16,10 @@
  * a set of helpers for CXL interactions which occur via PCIe.
  */
 
+static unsigned short media_ready_timeout = 60;
+module_param(media_ready_timeout, ushort, 0644);
+MODULE_PARM_DESC(media_ready_timeout, "seconds to wait for media ready");
+
 struct cxl_walk_context {
 	struct pci_bus *bus;
 	struct cxl_port *port;
@@ -94,3 +101,44 @@ int devm_cxl_port_enumerate_dports(struct cxl_port *port)
 	return ctx.count;
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL);
+
+/*
+ * Wait up to @media_ready_timeout for the device to report memory
+ * active.
+ */
+int cxl_await_media_ready(struct cxl_dev_state *cxlds)
+{
+	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	int d = cxlds->cxl_dvsec;
+	bool active = false;
+	u64 md_status;
+	int rc, i;
+
+	for (i = media_ready_timeout; i; i--) {
+		u32 temp;
+
+		rc = pci_read_config_dword(
+			pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp);
+		if (rc)
+			return rc;
+
+		active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp);
+		if (active)
+			break;
+		msleep(1000);
+	}
+
+	if (!active) {
+		dev_err(&pdev->dev,
+			"timeout awaiting memory active after %d seconds\n",
+			media_ready_timeout);
+		return -ETIMEDOUT;
+	}
+
+	md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
+	if (!CXLMDEV_READY(md_status))
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_await_media_ready, CXL);

drivers/cxl/cxlmem.h

@@ -192,7 +192,6 @@ struct cxl_endpoint_dvsec_info {
  * @info: Cached DVSEC information about the device.
  * @serial: PCIe Device Serial Number
  * @mbox_send: @dev specific transport for transmitting mailbox commands
- * @wait_media_ready: @dev specific method to await media ready
  *
  * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
  * details on capacity parameters.
@@ -227,7 +226,6 @@ struct cxl_dev_state {
 	u64 serial;
 
 	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
-	int (*wait_media_ready)(struct cxl_dev_state *cxlds);
 };
 
 enum cxl_opcode {
@@ -348,6 +346,7 @@ struct cxl_mem_command {
 int cxl_mbox_send_cmd(struct cxl_dev_state *cxlds, u16 opcode, void *in,
 		      size_t in_size, void *out, size_t out_size);
 int cxl_dev_state_identify(struct cxl_dev_state *cxlds);
+int cxl_await_media_ready(struct cxl_dev_state *cxlds);
 int cxl_enumerate_cmds(struct cxl_dev_state *cxlds);
 int cxl_mem_create_range_info(struct cxl_dev_state *cxlds);
 struct cxl_dev_state *cxl_dev_state_create(struct device *dev);

drivers/cxl/mem.c

@@ -165,7 +165,7 @@ unlock:
 	if (rc)
 		return rc;
 
-	rc = cxlds->wait_media_ready(cxlds);
+	rc = cxl_await_media_ready(cxlds);
 	if (rc) {
 		dev_err(dev, "Media not active (%d)\n", rc);
 		return rc;

drivers/cxl/pci.c

@@ -48,8 +48,7 @@
  */
 static unsigned short mbox_ready_timeout = 60;
 module_param(mbox_ready_timeout, ushort, 0644);
-MODULE_PARM_DESC(mbox_ready_timeout,
+MODULE_PARM_DESC(mbox_ready_timeout, "seconds to wait for mailbox ready");
-		 "seconds to wait for mailbox ready / memory active status");
 
 static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
 {
@@ -419,46 +418,6 @@ static int wait_for_valid(struct cxl_dev_state *cxlds)
 	return -ETIMEDOUT;
 }
 
-/*
- * Wait up to @mbox_ready_timeout for the device to report memory
- * active.
- */
-static int cxl_await_media_ready(struct cxl_dev_state *cxlds)
-{
-	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
-	int d = cxlds->cxl_dvsec;
-	bool active = false;
-	u64 md_status;
-	int rc, i;
-
-	for (i = mbox_ready_timeout; i; i--) {
-		u32 temp;
-
-		rc = pci_read_config_dword(
-			pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp);
-		if (rc)
-			return rc;
-
-		active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp);
-		if (active)
-			break;
-		msleep(1000);
-	}
-
-	if (!active) {
-		dev_err(&pdev->dev,
-			"timeout awaiting memory active after %d seconds\n",
-			mbox_ready_timeout);
-		return -ETIMEDOUT;
-	}
-
-	md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
-	if (!CXLMDEV_READY(md_status))
-		return -EIO;
-
-	return 0;
-}
-
 /*
  * Return positive number of non-zero ranges on success and a negative
  * error code on failure. The cxl_mem driver depends on ranges == 0 to
@@ -589,8 +548,6 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		dev_warn(&pdev->dev,
 			 "Device DVSEC not present, skip CXL.mem init\n");
 
-	cxlds->wait_media_ready = cxl_await_media_ready;
-
 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
 	if (rc)
 		return rc;

tools/testing/cxl/Kbuild

@@ -8,6 +8,7 @@ ldflags-y += --wrap=devm_cxl_port_enumerate_dports
 ldflags-y += --wrap=devm_cxl_setup_hdm
 ldflags-y += --wrap=devm_cxl_add_passthrough_decoder
 ldflags-y += --wrap=devm_cxl_enumerate_decoders
+ldflags-y += --wrap=cxl_await_media_ready
 
 DRIVERS := ../../../drivers
 CXL_SRC := $(DRIVERS)/cxl

tools/testing/cxl/test/mem.c

@@ -237,12 +237,6 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
 	return rc;
 }
 
-static int cxl_mock_wait_media_ready(struct cxl_dev_state *cxlds)
-{
-	msleep(100);
-	return 0;
-}
-
 static void label_area_release(void *lsa)
 {
 	vfree(lsa);
@@ -278,7 +272,6 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 
 	cxlds->serial = pdev->id;
 	cxlds->mbox_send = cxl_mock_mbox_send;
-	cxlds->wait_media_ready = cxl_mock_wait_media_ready;
 	cxlds->payload_size = SZ_4K;
 
 	rc = cxl_enumerate_cmds(cxlds);

tools/testing/cxl/test/mock.c

@@ -193,6 +193,21 @@ int __wrap_devm_cxl_port_enumerate_dports(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_port_enumerate_dports, CXL);
 
+int __wrap_cxl_await_media_ready(struct cxl_dev_state *cxlds)
+{
+	int rc, index;
+	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+
+	if (ops && ops->is_mock_dev(cxlds->dev))
+		rc = 0;
+	else
+		rc = cxl_await_media_ready(cxlds);
+	put_cxl_mock_ops(index);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(__wrap_cxl_await_media_ready, CXL);
+
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(ACPI);
 MODULE_IMPORT_NS(CXL);