Introduce a waitqueue mechanism to coordinate initialization between the
cxl_pci and cxl_mem drivers.
Launch a background worker from cxl_acpi_probe() that waits for both
drivers to complete initialization before invoking wait_for_device_probe().
Without this, the probe completion wait could begin prematurely, before
the drivers are present, leading to missed updates.
Co-developed-by: Nathan Fontenot <Nathan.Fontenot@xxxxxxx>
Signed-off-by: Nathan Fontenot <Nathan.Fontenot@xxxxxxx>
Co-developed-by: Terry Bowman <terry.bowman@xxxxxxx>
Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@xxxxxxx>
---
drivers/cxl/acpi.c | 23 +++++++++++++++++++++++
drivers/cxl/core/suspend.c | 21 +++++++++++++++++++++
drivers/cxl/cxl.h | 2 ++
3 files changed, 46 insertions(+)
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index cb14829bb9be..978f63b32b41 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -813,6 +813,24 @@ static int pair_cxl_resource(struct device *dev, void *data)
return 0;
}
+static void cxl_softreserv_mem_work_fn(struct work_struct *work)
+{
+ /* Wait for cxl_pci and cxl_mem drivers to load */
+ cxl_wait_for_pci_mem();
+
+ /*
+ * Wait for the driver probe routines to complete after cxl_pci
+ * and cxl_mem drivers are loaded.
+ */
+ wait_for_device_probe();
+}
+static DECLARE_WORK(cxl_sr_work, cxl_softreserv_mem_work_fn);
+
+static void cxl_softreserv_mem_update(void)
+{
+ schedule_work(&cxl_sr_work);
+}
+
static int cxl_acpi_probe(struct platform_device *pdev)
{
int rc;
@@ -887,6 +905,10 @@ static int cxl_acpi_probe(struct platform_device *pdev)
/* In case PCI is scanned before ACPI re-trigger memdev attach */
cxl_bus_rescan();
+
+ /* Update SOFT RESERVE resources that intersect with CXL regions */
+ cxl_softreserv_mem_update();
+
return 0;
}
@@ -918,6 +940,7 @@ static int __init cxl_acpi_init(void)
static void __exit cxl_acpi_exit(void)
{
+ cancel_work_sync(&cxl_sr_work);
platform_driver_unregister(&cxl_acpi_driver);
cxl_bus_drain();
}
diff --git a/drivers/cxl/core/suspend.c b/drivers/cxl/core/suspend.c
index 72818a2c8ec8..c0d8f70aed56 100644
--- a/drivers/cxl/core/suspend.c
+++ b/drivers/cxl/core/suspend.c
@@ -2,12 +2,15 @@
/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
#include <linux/atomic.h>
#include <linux/export.h>
+#include <linux/wait.h>
#include "cxlmem.h"
#include "cxlpci.h"
static atomic_t mem_active;
static atomic_t pci_loaded;
+static DECLARE_WAIT_QUEUE_HEAD(cxl_wait_queue);
+
bool cxl_mem_active(void)
{
if (IS_ENABLED(CONFIG_CXL_MEM))
@@ -19,6 +22,7 @@ bool cxl_mem_active(void)
void cxl_mem_active_inc(void)
{
atomic_inc(&mem_active);
+ wake_up(&cxl_wait_queue);
}
EXPORT_SYMBOL_NS_GPL(cxl_mem_active_inc, "CXL");
@@ -28,8 +32,25 @@ void cxl_mem_active_dec(void)
}
EXPORT_SYMBOL_NS_GPL(cxl_mem_active_dec, "CXL");
+static bool cxl_pci_loaded(void)
+{
+ if (IS_ENABLED(CONFIG_CXL_PCI))
+ return atomic_read(&pci_loaded) != 0;
+
+ return false;
+}
+
void mark_cxl_pci_loaded(void)
{
atomic_inc(&pci_loaded);
+ wake_up(&cxl_wait_queue);
}
EXPORT_SYMBOL_NS_GPL(mark_cxl_pci_loaded, "CXL");
+
+void cxl_wait_for_pci_mem(void)
+{
+ if (!wait_event_timeout(cxl_wait_queue, cxl_pci_loaded() &&
+ cxl_mem_active(), 30 * HZ))
+ pr_debug("Timeout waiting for cxl_pci or cxl_mem probing\n");
+}
+EXPORT_SYMBOL_NS_GPL(cxl_wait_for_pci_mem, "CXL");
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index a9ab46eb0610..1ba7d39c2991 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -902,6 +902,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
+void cxl_wait_for_pci_mem(void);
+
/*
* Unit test builds overrides this to __weak, find the 'strong' version
* of these symbols in tools/testing/cxl/.
--
2.17.1
