Merge tag 'cache-for-v6.19' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into soc/drivers-late

standalone cache drivers for v6.19

ccache:
Add a compatible for the pic64gx SoC. No driver change needed, as it
falls back to the PolarFire SoC.

hisi hha/generic cpu cache maintenance:
Add support for a non-architectural mechanism for invalidating memory
regions, needed for some cxl implementations on arm64 (and probably
elsewhere in the future). The HiSilicon Hydra Home Agent is the first
driver to provide this support.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

* tag 'cache-for-v6.19' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
  MAINTAINERS: refer to intended file in STANDALONE CACHE CONTROLLER DRIVERS
  cache: Support cache maintenance for HiSilicon SoC Hydra Home Agent
  cache: Make top level Kconfig menu a boolean dependent on RISCV
  MAINTAINERS: Add Jonathan Cameron to drivers/cache and add lib/cache_maint.c + header
  arm64: Select GENERIC_CPU_CACHE_MAINTENANCE
  lib: Support ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
  memregion: Support fine grained invalidate by cpu_cache_invalidate_memregion()
  memregion: Drop unused IORES_DESC_* parameter from cpu_cache_invalidate_memregion()
  dt-bindings: cache: sifive,ccache0: add a pic64gx compatible

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 143 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index e629449dd2a3..2923924bea78 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -542,6 +542,9 @@ config MEMREGION
 config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
 	bool
 
+config GENERIC_CPU_CACHE_MAINTENANCE
+	bool
+
 config ARCH_HAS_MEMREMAP_COMPAT_ALIGN
 	bool
 
diff --git a/lib/Makefile b/lib/Makefile
index 1ab2c4be3b66..aaf677cf4527 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -127,6 +127,8 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
 obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
 obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
 
+obj-$(CONFIG_GENERIC_CPU_CACHE_MAINTENANCE) += cache_maint.o
+
 lib-y += logic_pio.o
 
 lib-$(CONFIG_INDIRECT_IOMEM) += logic_iomem.o
diff --git a/lib/cache_maint.c b/lib/cache_maint.c
new file mode 100644
index 000000000000..9256a9ffc34c
--- /dev/null
+++ b/lib/cache_maint.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic support for Memory System Cache Maintenance operations.
+ *
+ * Coherency maintenance drivers register with this simple framework that will
+ * iterate over each registered instance to first kick off invalidation and
+ * then to wait until it is complete.
+ *
+ * If no implementations are registered yet cpu_cache_has_invalidate_memregion()
+ * will return false. If this runs concurrently with unregistration then a
+ * race exists but this is no worse than the case where the operations instance
+ * responsible for a given memory region has not yet registered.
+ */
+#include <linux/cache_coherency.h>
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/export.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/memregion.h>
+#include <linux/module.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+
+static LIST_HEAD(cache_ops_instance_list);
+static DECLARE_RWSEM(cache_ops_instance_list_lock);
+
+static void __cache_coherency_ops_instance_free(struct kref *kref)
+{
+	struct cache_coherency_ops_inst *cci =
+		container_of(kref, struct cache_coherency_ops_inst, kref);
+	kfree(cci);
+}
+
+void cache_coherency_ops_instance_put(struct cache_coherency_ops_inst *cci)
+{
+	kref_put(&cci->kref, __cache_coherency_ops_instance_free);
+}
+EXPORT_SYMBOL_GPL(cache_coherency_ops_instance_put);
+
+static int cache_inval_one(struct cache_coherency_ops_inst *cci, void *data)
+{
+	if (!cci->ops)
+		return -EINVAL;
+
+	return cci->ops->wbinv(cci, data);
+}
+
+static int cache_inval_done_one(struct cache_coherency_ops_inst *cci)
+{
+	if (!cci->ops)
+		return -EINVAL;
+
+	if (!cci->ops->done)
+		return 0;
+
+	return cci->ops->done(cci);
+}
+
+static int cache_invalidate_memregion(phys_addr_t addr, size_t size)
+{
+	int ret;
+	struct cache_coherency_ops_inst *cci;
+	struct cc_inval_params params = {
+		.addr = addr,
+		.size = size,
+	};
+
+	guard(rwsem_read)(&cache_ops_instance_list_lock);
+	list_for_each_entry(cci, &cache_ops_instance_list, node) {
+		ret = cache_inval_one(cci, &params);
+		if (ret)
+			return ret;
+	}
+	list_for_each_entry(cci, &cache_ops_instance_list, node) {
+		ret = cache_inval_done_one(cci);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+struct cache_coherency_ops_inst *
+_cache_coherency_ops_instance_alloc(const struct cache_coherency_ops *ops,
+				    size_t size)
+{
+	struct cache_coherency_ops_inst *cci;
+
+	if (!ops || !ops->wbinv)
+		return NULL;
+
+	cci = kzalloc(size, GFP_KERNEL);
+	if (!cci)
+		return NULL;
+
+	cci->ops = ops;
+	INIT_LIST_HEAD(&cci->node);
+	kref_init(&cci->kref);
+
+	return cci;
+}
+EXPORT_SYMBOL_NS_GPL(_cache_coherency_ops_instance_alloc, "CACHE_COHERENCY");
+
+int cache_coherency_ops_instance_register(struct cache_coherency_ops_inst *cci)
+{
+	guard(rwsem_write)(&cache_ops_instance_list_lock);
+	list_add(&cci->node, &cache_ops_instance_list);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cache_coherency_ops_instance_register, "CACHE_COHERENCY");
+
+void cache_coherency_ops_instance_unregister(struct cache_coherency_ops_inst *cci)
+{
+	guard(rwsem_write)(&cache_ops_instance_list_lock);
+	list_del(&cci->node);
+}
+EXPORT_SYMBOL_NS_GPL(cache_coherency_ops_instance_unregister, "CACHE_COHERENCY");
+
+int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len)
+{
+	return cache_invalidate_memregion(start, len);
+}
+EXPORT_SYMBOL_NS_GPL(cpu_cache_invalidate_memregion, "DEVMEM");
+
+/*
+ * Used for optimization / debug purposes only as removal can race
+ *
+ * Machines that do not support invalidation, e.g. VMs, will not have any
+ * operations instance to register and so this will always return false.
+ */
+bool cpu_cache_has_invalidate_memregion(void)
+{
+	guard(rwsem_read)(&cache_ops_instance_list_lock);
+	return !list_empty(&cache_ops_instance_list);
+}
+EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, "DEVMEM");