Add promotion policy API and use it in I/O path

Promotion policy is supposed to perform ALRU noise filtering by
eliminating one-hit wonders being added to cache and polluting it.

Signed-off-by: Jan Musial <jan.musial@intel.com>

src/promotion/nhit.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#include "../metadata/metadata.h"
+
+#include "nhit.h"
+
+ocf_error_t nhit_init(ocf_cache_t cache, ocf_promotion_policy_t policy)
+{
+	return 0;
+}
+
+void nhit_deinit(ocf_promotion_policy_t policy)
+{
+
+}
+
+ocf_error_t nhit_set_param(ocf_promotion_policy_t policy, uint8_t param_id,
+		uint64_t param_value)
+{
+	return 0;
+}
+
+void nhit_req_purge(ocf_promotion_policy_t policy,
+		struct ocf_request *req)
+{
+
+}
+
+bool nhit_req_should_promote(ocf_promotion_policy_t policy, struct ocf_request *req)
+{
+	return true;
+}
+

src/promotion/nhit.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef NHIT_PROMOTION_POLICY_H_
+#define NHIT_PROMOTION_POLICY_H_
+
+#include "ocf/ocf.h"
+#include "../ocf_request.h"
+#include "promotion.h"
+
+ocf_error_t nhit_init(ocf_cache_t cache, ocf_promotion_policy_t policy);
+
+void nhit_deinit(ocf_promotion_policy_t policy);
+
+ocf_error_t nhit_set_param(ocf_promotion_policy_t policy, uint8_t param_id,
+		uint64_t param_value);
+
+void nhit_req_purge(ocf_promotion_policy_t policy,
+		struct ocf_request *req);
+
+bool nhit_req_should_promote(ocf_promotion_policy_t policy,
+		struct ocf_request *req);
+
+#endif /* NHIT_PROMOTION_POLICY_H_ */

src/promotion/ops.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef PROMOTION_OPS_H_
+#define PROMOTION_OPS_H_
+
+#include "../metadata/metadata.h"
+#include "promotion.h"
+
+struct ocf_promotion_policy {
+	ocf_promotion_t type;
+	void *ctx;
+};
+
+struct promotion_policy_ops {
+	const char *name;
+		/*!< Promotion policy name */
+
+	ocf_error_t (*init)(ocf_cache_t cache, ocf_promotion_policy_t policy);
+		/*!< Allocate and initialize promotion policy */
+
+	void (*deinit)(ocf_promotion_policy_t policy);
+		/*!< Deinit and free promotion policy */
+
+	ocf_error_t (*set_param)(ocf_promotion_policy_t policy, uint8_t param_id,
+			uint64_t param_value);
+		/*!< Set promotion policy parameter */
+
+	void (*req_purge)(ocf_promotion_policy_t policy,
+			struct ocf_request *req);
+		/*!< Call when request core lines have been inserted or it is
+		 * a discard request */
+
+	bool (*req_should_promote)(ocf_promotion_policy_t policy,
+			struct ocf_request *req);
+		/*!< Should request lines be inserted into cache */
+};
+
+#endif /* PROMOTION_OPS_H_ */
+

src/promotion/promotion.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#include "../metadata/metadata.h"
+
+#include "promotion.h"
+#include "ops.h"
+#include "nhit.h"
+
+struct promotion_policy_ops ocf_promotion_policies[ocf_promotion_max] = {
+	[ocf_promotion_nop] = {
+		.name = "nop",
+	},
+	[ocf_promotion_nhit] = {
+		.name = "nhit",
+		.init = nhit_init,
+		.deinit = nhit_deinit,
+		.set_param = nhit_set_param,
+		.req_purge = nhit_req_purge,
+		.req_should_promote = nhit_req_should_promote,
+	},
+};
+
+ocf_error_t ocf_promotion_init(ocf_cache_t cache, ocf_promotion_policy_t *policy)
+{
+	ocf_promotion_t type = cache->conf_meta->promotion_policy_type;
+	ocf_error_t result = 0;
+
+	ENV_BUG_ON(type >= ocf_promotion_max);
+
+	*policy = env_vmalloc(sizeof(**policy));
+	if (!*policy)
+		return -OCF_ERR_NO_MEM;
+
+	(*policy)->type = type;
+
+	if (ocf_promotion_policies[type].init)
+		result = ocf_promotion_policies[type].init(cache, *policy);
+
+	return result;
+}
+
+void ocf_promotion_deinit(ocf_promotion_policy_t policy)
+{
+	ocf_promotion_t type = policy->type;
+
+	ENV_BUG_ON(type >= ocf_promotion_max);
+
+	if (ocf_promotion_policies[type].deinit)
+		ocf_promotion_policies[type].deinit(policy);
+
+	env_vfree(policy);
+}
+
+ocf_error_t ocf_promotion_set_param(ocf_promotion_policy_t policy,
+		uint8_t param_id, uint64_t param_value)
+{
+	ocf_promotion_t type = policy->type;
+	ocf_error_t result = 0;
+
+	ENV_BUG_ON(type >= ocf_promotion_max);
+
+	if (ocf_promotion_policies[type].set_param) {
+		result = ocf_promotion_policies[type].set_param(policy, param_id,
+				param_value);
+	}
+
+	return result;
+}
+
+void ocf_promotion_req_purge(ocf_promotion_policy_t policy,
+		struct ocf_request *req)
+{
+	ocf_promotion_t type = policy->type;
+
+	ENV_BUG_ON(type >= ocf_promotion_max);
+
+	if (ocf_promotion_policies[type].req_purge)
+		ocf_promotion_policies[type].req_purge(policy, req);
+}
+
+bool ocf_promotion_req_should_promote(ocf_promotion_policy_t policy,
+		struct ocf_request *req)
+{
+	ocf_promotion_t type = policy->type;
+	bool result = true;
+
+	ENV_BUG_ON(type >= ocf_promotion_max);
+
+	if (ocf_promotion_policies[type].req_should_promote) {
+		result = ocf_promotion_policies[type].req_should_promote(policy,
+				req);
+	}
+
+	return result;
+}
+

src/promotion/promotion.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef PROMOTION_H_
+#define PROMOTION_H_
+
+#include "ocf/ocf.h"
+#include "../ocf_request.h"
+
+typedef struct ocf_promotion_policy *ocf_promotion_policy_t;
+/**
+ * @brief Allocate and initialize promotion policy. Should be called after cache
+ * metadata has been allocated and cache->conf_meta->promotion_policy_type has
+ * been set.
+ *
+ * @param[in] cache OCF cache instance
+ * @param[out] param initialized policy handle
+ *
+ * @retval ocf_error_t
+ */
+ocf_error_t ocf_promotion_init(ocf_cache_t cache, ocf_promotion_policy_t *policy);
+
+/**
+ * @brief Stop, deinitialize and free promotion policy structures.
+ *
+ * @param[in] policy promotion policy handle
+ *
+ * @retval none
+ */
+void ocf_promotion_deinit(ocf_promotion_policy_t policy);
+
+/**
+ * @brief Set promotion policy parameter
+ *
+ * @param[in] policy promotion policy handle
+ * @param[in] param_id id of parameter to be set
+ * @param[in] param_value value of parameter to be set
+ *
+ * @retval ocf_error_t
+ */
+ocf_error_t ocf_promotion_set_param(ocf_promotion_policy_t policy,
+		uint8_t param_id, uint64_t param_value);
+
+/**
+ * @brief Update promotion policy after cache lines have been promoted to cache
+ * or discarded from core device
+ *
+ * @param[in] policy promotion policy handle
+ * @param[in] req OCF request to be purged
+ *
+ * @retval none
+ */
+void ocf_promotion_req_purge(ocf_promotion_policy_t policy,
+		struct ocf_request *req);
+
+/**
+ * @brief Check in promotion policy whether core lines in request can be promoted
+ *
+ * @param[in] policy promotion policy handle
+ * @param[in] req OCF request which is to be promoted
+ *
+ * @retval should core lines belonging to this request be promoted
+ */
+bool ocf_promotion_req_should_promote(ocf_promotion_policy_t policy,
+		struct ocf_request *req);
+
+#endif /* PROMOTION_H_ */