From: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION provides the mechanism for
invalidate certain memory regions in a cache-incoherent manner.
Currently is used by NVIDMM adn CXL memory. This is mainly done
by the system component and is implementation define per spec.
Provides a method for the platforms register their own invalidate
method and implement ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION.
Architectures can opt in for this support via
CONFIG_GENERIC_CPU_CACHE_INVALIDATE_MEMREGION.
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/base/Kconfig | 3 +++
drivers/base/Makefile | 1 +
drivers/base/cache.c | 46 ++++++++++++++++++++++++++++++++
include/asm-generic/cacheflush.h | 12 +++++++++
4 files changed, 62 insertions(+)
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 064eb52ff7e2..cc6df87a0a96 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -181,6 +181,9 @@ config SYS_HYPERVISOR
bool
default n
+config GENERIC_CPU_CACHE_INVALIDATE_MEMREGION
+ bool
+
config GENERIC_CPU_DEVICES
bool
default n
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 8074a10183dc..0fbfa4300b98 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
obj-$(CONFIG_GENERIC_MSI_IRQ) += platform-msi.o
obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
+obj-$(CONFIG_GENERIC_CPU_CACHE_INVALIDATE_MEMREGION) += cache.o
obj-$(CONFIG_ACPI) += physical_location.o
obj-y += test/
diff --git a/drivers/base/cache.c b/drivers/base/cache.c
new file mode 100644
index 000000000000..8d351657bbef
--- /dev/null
+++ b/drivers/base/cache.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic support for CPU Cache Invalidate Memregion
+ */
+
+#include <linux/spinlock.h>
+#include <linux/export.h>
+#include <asm/cacheflush.h>
+
+
+static const struct system_cache_flush_method *scfm_data;
+DEFINE_SPINLOCK(scfm_lock);
+
+void generic_set_sys_cache_flush_method(const struct system_cache_flush_method *method)
+{
+ guard(spinlock_irqsave)(&scfm_lock);
+ if (scfm_data || !method || !method->invalidate_memregion)
+ return;
+
+ scfm_data = method;
+}
+EXPORT_SYMBOL_GPL(generic_set_sys_cache_flush_method);
+
+void generic_clr_sys_cache_flush_method(const struct system_cache_flush_method *method)
+{
+ guard(spinlock_irqsave)(&scfm_lock);
+ if (scfm_data && scfm_data == method)
+ scfm_data = NULL;
+}
+
+int cpu_cache_invalidate_memregion(int res_desc, phys_addr_t start, size_t len)
+{
+ guard(spinlock_irqsave)(&scfm_lock);
+ if (!scfm_data)
+ return -EOPNOTSUPP;
+
+ return scfm_data->invalidate_memregion(res_desc, start, len);
+}
+EXPORT_SYMBOL_NS_GPL(cpu_cache_invalidate_memregion, "DEVMEM");
+
+bool cpu_cache_has_invalidate_memregion(void)
+{
+ guard(spinlock_irqsave)(&scfm_lock);
+ return !!scfm_data;
+}
+EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, "DEVMEM");
diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h
index 7ee8a179d103..87e64295561e 100644
--- a/include/asm-generic/cacheflush.h
+++ b/include/asm-generic/cacheflush.h
@@ -124,4 +124,16 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
} while (0)
#endif
+#ifdef CONFIG_GENERIC_CPU_CACHE_INVALIDATE_MEMREGION
+
+struct system_cache_flush_method {
+ int (*invalidate_memregion)(int res_desc,
+ phys_addr_t start, size_t len);
+};
+
+void generic_set_sys_cache_flush_method(const struct system_cache_flush_method *method);
+void generic_clr_sys_cache_flush_method(const struct system_cache_flush_method *method);
+
+#endif /* CONFIG_GENERIC_CPU_CACHE_INVALIDATE_MEMREGION */
+
#endif /* _ASM_GENERIC_CACHEFLUSH_H */
--
2.48.1
