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-rw-r--r--drivers/Makefile2
-rw-r--r--drivers/cxl/Kconfig4
-rw-r--r--drivers/cxl/Makefile2
-rw-r--r--drivers/cxl/core/Makefile1
-rw-r--r--drivers/cxl/core/suspend.c24
-rw-r--r--drivers/cxl/cxlmem.h11
-rw-r--r--drivers/cxl/mem.c22
-rw-r--r--include/linux/pm.h9
-rw-r--r--kernel/power/hibernate.c2
-rw-r--r--kernel/power/main.c5
-rw-r--r--kernel/power/suspend.c3
11 files changed, 79 insertions, 6 deletions
diff --git a/drivers/Makefile b/drivers/Makefile
index 020780b6b4d2..f735c4955143 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -72,9 +72,9 @@ obj-$(CONFIG_PARPORT) += parport/
obj-y += base/ block/ misc/ mfd/ nfc/
obj-$(CONFIG_LIBNVDIMM) += nvdimm/
obj-$(CONFIG_DAX) += dax/
-obj-$(CONFIG_CXL_BUS) += cxl/
obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
obj-$(CONFIG_NUBUS) += nubus/
+obj-y += cxl/
obj-y += macintosh/
obj-y += scsi/
obj-y += nvme/
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index b88ab956bb7c..f64e3984689f 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -98,4 +98,8 @@ config CXL_PORT
default CXL_BUS
tristate
+config CXL_SUSPEND
+ def_bool y
+ depends on SUSPEND && CXL_MEM
+
endif
diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile
index ce267ef11d93..a78270794150 100644
--- a/drivers/cxl/Makefile
+++ b/drivers/cxl/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_CXL_BUS) += core/
+obj-y += core/
obj-$(CONFIG_CXL_PCI) += cxl_pci.o
obj-$(CONFIG_CXL_MEM) += cxl_mem.o
obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index 6d37cd78b151..9d35085d25af 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CXL_BUS) += cxl_core.o
+obj-$(CONFIG_CXL_SUSPEND) += suspend.o
ccflags-y += -I$(srctree)/drivers/cxl
cxl_core-y := port.o
diff --git a/drivers/cxl/core/suspend.c b/drivers/cxl/core/suspend.c
new file mode 100644
index 000000000000..a5984d96ea1d
--- /dev/null
+++ b/drivers/cxl/core/suspend.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
+#include <linux/atomic.h>
+#include <linux/export.h>
+#include "cxlmem.h"
+
+static atomic_t mem_active;
+
+bool cxl_mem_active(void)
+{
+ return atomic_read(&mem_active) != 0;
+}
+
+void cxl_mem_active_inc(void)
+{
+ atomic_inc(&mem_active);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_active_inc, CXL);
+
+void cxl_mem_active_dec(void)
+{
+ atomic_dec(&mem_active);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_active_dec, CXL);
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 243dd86a8b46..7235d2f976e5 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -353,6 +353,17 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds);
struct cxl_dev_state *cxl_dev_state_create(struct device *dev);
void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
+#ifdef CONFIG_CXL_SUSPEND
+void cxl_mem_active_inc(void);
+void cxl_mem_active_dec(void);
+#else
+static inline void cxl_mem_active_inc(void)
+{
+}
+static inline void cxl_mem_active_dec(void)
+{
+}
+#endif
struct cxl_hdm {
struct cxl_component_regs regs;
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 43e73d259207..1bd2e0b67f59 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -138,6 +138,11 @@ out:
return retval;
}
+static void enable_suspend(void *data)
+{
+ cxl_mem_active_dec();
+}
+
static int cxl_mem_probe(struct device *dev)
{
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
@@ -194,7 +199,22 @@ static int cxl_mem_probe(struct device *dev)
out:
cxl_device_unlock(&parent_port->dev);
put_device(&parent_port->dev);
- return rc;
+
+ /*
+ * The kernel may be operating out of CXL memory on this device,
+ * there is no spec defined way to determine whether this device
+ * preserves contents over suspend, and there is no simple way
+ * to arrange for the suspend image to avoid CXL memory which
+ * would setup a circular dependency between PCI resume and save
+ * state restoration.
+ *
+ * TODO: support suspend when all the regions this device is
+ * hosting are locked and covered by the system address map,
+ * i.e. platform firmware owns restoring the HDM configuration
+ * that it locked.
+ */
+ cxl_mem_active_inc();
+ return devm_add_action_or_reset(dev, enable_suspend, NULL);
}
static struct cxl_driver cxl_mem_driver = {
diff --git a/include/linux/pm.h b/include/linux/pm.h
index e65b3ab28377..7911c4c9a7be 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -36,6 +36,15 @@ static inline void pm_vt_switch_unregister(struct device *dev)
}
#endif /* CONFIG_VT_CONSOLE_SLEEP */
+#ifdef CONFIG_CXL_SUSPEND
+bool cxl_mem_active(void);
+#else
+static inline bool cxl_mem_active(void)
+{
+ return false;
+}
+#endif
+
/*
* Device power management
*/
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 938d5c78b421..20a66bf9f465 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -83,7 +83,7 @@ bool hibernation_available(void)
{
return nohibernate == 0 &&
!security_locked_down(LOCKDOWN_HIBERNATION) &&
- !secretmem_active();
+ !secretmem_active() && !cxl_mem_active();
}
/**
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 7e646079fbeb..3e6be1c33e0b 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -127,7 +127,9 @@ static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
char *s = buf;
suspend_state_t i;
- for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
+ for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
+ if (i >= PM_SUSPEND_MEM && cxl_mem_active())
+ continue;
if (mem_sleep_states[i]) {
const char *label = mem_sleep_states[i];
@@ -136,6 +138,7 @@ static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
else
s += sprintf(s, "%s ", label);
}
+ }
/* Convert the last space to a newline if needed. */
if (s != buf)
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 6fcdee7e87a5..827075944d28 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -236,7 +236,8 @@ EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
static bool sleep_state_supported(suspend_state_t state)
{
- return state == PM_SUSPEND_TO_IDLE || valid_state(state);
+ return state == PM_SUSPEND_TO_IDLE ||
+ (valid_state(state) && !cxl_mem_active());
}
static int platform_suspend_prepare(suspend_state_t state)
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