Re: [PATCH v2 2/8] generic: Support ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: 2025-06-25 16:46:47
Also in:
linux-acpi, linux-arch, linux-cxl, linux-mm
On Tue, 24 Jun 2025 16:47:58 +0100 Jonathan Cameron [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Yicong Yang <yangyicong@hisilicon.com> 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@hisilicon.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>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>
I got carried away dropping some unused headers. This needs linux/memregion.h
+#include <linux/export.h> +#include <asm/cacheflush.h> +
So that the following have 'previous' prototypes.
+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");