Message-Id: <20171213004848.15086-5-david.daney@cavium.com>
Date:   Tue, 12 Dec 2017 16:48:48 -0800
From:   David Daney <david.daney@...ium.com>
To:     linux-mips@...ux-mips.org, ralf@...ux-mips.org,
        James Hogan <james.hogan@...s.com>
Cc:     linux-kernel@...r.kernel.org,
        "Steven J. Hill" <steven.hill@...ium.com>, netdev@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Carlos Munoz <cmunoz@...ium.com>,
        "Steven J . Hill" <Steven.Hill@...ium.com>,
        David Daney <david.daney@...ium.com>
Subject: [PATCH v7 4/4] MIPS: Octeon: Add a global resource manager.

From: Carlos Munoz <cmunoz@...ium.com>

Add a global resource manager to manage tagged pointers within
bootmem allocated memory. This is used by various functional
blocks in the Octeon core like the FPA, Ethernet nexus, etc.

Signed-off-by: Carlos Munoz <cmunoz@...ium.com>
Signed-off-by: Steven J. Hill <Steven.Hill@...ium.com>
Signed-off-by: David Daney <david.daney@...ium.com>
---
 arch/mips/cavium-octeon/Makefile       |   1 +
 arch/mips/cavium-octeon/resource-mgr.c | 351 +++++++++++++++++++++++++++++++++
 arch/mips/include/asm/octeon/octeon.h  |  18 ++
 3 files changed, 370 insertions(+)
 create mode 100644 arch/mips/cavium-octeon/resource-mgr.c

diff --git a/arch/mips/cavium-octeon/Makefile b/arch/mips/cavium-octeon/Makefile
index 7c02e542959a..28c0bb75d1a4 100644
--- a/arch/mips/cavium-octeon/Makefile
+++ b/arch/mips/cavium-octeon/Makefile
@@ -10,6 +10,7 @@
 #
 
 obj-y := cpu.o setup.o octeon-platform.o octeon-irq.o csrc-octeon.o
+obj-y += resource-mgr.o
 obj-y += dma-octeon.o
 obj-y += octeon-memcpy.o
 obj-y += executive/
diff --git a/arch/mips/cavium-octeon/resource-mgr.c b/arch/mips/cavium-octeon/resource-mgr.c
new file mode 100644
index 000000000000..74efda5420ff
--- /dev/null
+++ b/arch/mips/cavium-octeon/resource-mgr.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Resource manager for Octeon.
+ *
+ * Copyright (C) 2017 Cavium, Inc.
+ */
+#include <linux/module.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-bootmem.h>
+
+#define RESOURCE_MGR_BLOCK_NAME		"cvmx-global-resources"
+#define MAX_RESOURCES			128
+#define INST_AVAILABLE			-88
+#define OWNER				0xbadc0de
+
+struct global_resource_entry {
+	struct global_resource_tag tag;
+	u64 phys_addr;
+	u64 size;
+};
+
+struct global_resources {
+#ifdef __LITTLE_ENDIAN_BITFIELD
+	u32 rlock;
+	u32 pad;
+#else
+	u32 pad;
+	u32 rlock;
+#endif
+	u64 entry_cnt;
+	struct global_resource_entry resource_entry[];
+};
+
+static struct global_resources *res_mgr_info;
+
+
+/*
+ * The resource manager interacts with software running outside of the
+ * Linux kernel, which necessitates locking to maintain data structure
+ * consistency.  These custom locking functions implement the locking
+ * protocol, and cannot be replaced by kernel locking functions that
+ * may use different in-memory structures.
+ */
+
+static void res_mgr_lock(void)
+{
+	while (cmpxchg(&res_mgr_info->rlock, 0, 1))
+		; /* Loop while not zero */
+	rmb();
+}
+
+static void res_mgr_unlock(void)
+{
+	/* Wait until all resource operations finish before unlocking. */
+	wmb();
+	WRITE_ONCE(res_mgr_info->rlock, 0);
+	/* Force a write buffer flush. */
+	wmb();
+}
+
+static int res_mgr_find_resource(struct global_resource_tag tag)
+{
+	struct global_resource_entry *res_entry;
+	int i;
+
+	for (i = 0; i < res_mgr_info->entry_cnt; i++) {
+		res_entry = &res_mgr_info->resource_entry[i];
+		if (res_entry->tag.lo == tag.lo && res_entry->tag.hi == tag.hi)
+			return i;
+	}
+	return -1;
+}
+
+/**
+ * res_mgr_create_resource() - Create a resource.
+ * @tag: Identifies the resource.
+ * @inst_cnt: Number of resource instances to create.
+ *
+ * Returns 0 if the source was created successfully.
+ * Returns < 0 for error codes.
+ */
+int res_mgr_create_resource(struct global_resource_tag tag, int inst_cnt)
+{
+	struct global_resource_entry *res_entry;
+	u64 size;
+	u64 *res_addr;
+	int res_index, i, rc = 0;
+
+	res_mgr_lock();
+
+	/* Make sure resource doesn't already exist. */
+	res_index = res_mgr_find_resource(tag);
+	if (res_index >= 0) {
+		rc = -EEXIST;
+		goto err;
+	}
+
+	if (res_mgr_info->entry_cnt >= MAX_RESOURCES) {
+		pr_err("Resource max limit reached, not created\n");
+		rc = -ENOSPC;
+		goto err;
+	}
+
+	/*
+	 * Each instance is kept in an array of u64s. The first array element
+	 * holds the number of allocated instances.
+	 */
+	size = sizeof(u64) * (inst_cnt + 1);
+	res_addr = cvmx_bootmem_alloc_range(size, CVMX_CACHE_LINE_SIZE, 0, 0);
+	if (!res_addr) {
+		pr_err("Failed to allocate resource. not created\n");
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	/* Initialize the newly created resource. */
+	*res_addr = inst_cnt;
+	for (i = 1; i <= inst_cnt; i++)
+		res_addr[i] = INST_AVAILABLE;
+
+	res_index = res_mgr_info->entry_cnt;
+	res_entry = &res_mgr_info->resource_entry[res_index];
+	res_entry->tag = tag;
+	res_entry->phys_addr = virt_to_phys(res_addr);
+	res_entry->size = size;
+	res_mgr_info->entry_cnt++;
+
+err:
+	res_mgr_unlock();
+
+	return rc;
+}
+EXPORT_SYMBOL(res_mgr_create_resource);
+
+/**
+ * res_mgr_alloc_range() - Allocate a range of resource instances.
+ * @tag: Identifies the resource.
+ * @req_inst: Requested start of instance range to allocate.
+ *	      Range instances are guaranteed to be sequential
+ *	      (-1 for don't care).
+ * @req_cnt: Number of instances to allocate.
+ * @use_last_avail: Set to request the last available instance.
+ * @inst: Updated with the allocated instances.
+ *
+ * Returns 0 if the source was created successfully.
+ * Returns < 0 for error codes.
+ */
+int res_mgr_alloc_range(struct global_resource_tag tag, int req_inst,
+			int req_cnt, bool use_last_avail, int *inst)
+{
+	struct global_resource_entry *res_entry;
+	int res_index;
+	u64 *res_addr;
+	u64 inst_cnt;
+	int alloc_cnt, i, rc = -ENOENT;
+
+	/* Start with no instances allocated. */
+	for (i = 0; i < req_cnt; i++)
+		inst[i] = INST_AVAILABLE;
+
+	res_mgr_lock();
+
+	/* Find the resource. */
+	res_index = res_mgr_find_resource(tag);
+	if (res_index < 0) {
+		pr_err("Resource not found, can't allocate instance\n");
+		goto err;
+	}
+
+	/* Get resource data. */
+	res_entry = &res_mgr_info->resource_entry[res_index];
+	res_addr = phys_to_virt(res_entry->phys_addr);
+	inst_cnt = *res_addr;
+
+	/* Allocate the requested instances. */
+	if (req_inst >= 0) {
+		/* Specific instance range requested. */
+		if (req_inst + req_cnt >= inst_cnt) {
+			pr_err("Requested instance out of range\n");
+			goto err;
+		}
+
+		for (i = 0; i < req_cnt; i++) {
+			if (*(res_addr + req_inst + 1 + i) == INST_AVAILABLE) {
+				inst[i] = req_inst + i;
+			} else {
+				inst[0] = INST_AVAILABLE;
+				break;
+			}
+		}
+	} else if (use_last_avail) {
+		/* Last available instance requested. */
+		alloc_cnt = 0;
+		for (i = inst_cnt; i > 0; i--) {
+			if (*(res_addr + i) == INST_AVAILABLE) {
+				/*
+				 * Instance off by 1 (first element holds the
+				 * count).
+				 */
+				inst[alloc_cnt] = i - 1;
+
+				alloc_cnt++;
+				if (alloc_cnt == req_cnt)
+					break;
+			}
+		}
+
+		if (i == 0)
+			inst[0] = INST_AVAILABLE;
+	} else {
+		/* Next available instance requested. */
+		alloc_cnt = 0;
+		for (i = 1; i <= inst_cnt; i++) {
+			if (*(res_addr + i) == INST_AVAILABLE) {
+				/*
+				 * Instance off by 1 (first element holds the
+				 * count).
+				 */
+				inst[alloc_cnt] = i - 1;
+
+				alloc_cnt++;
+				if (alloc_cnt == req_cnt)
+					break;
+			}
+		}
+
+		if (i > inst_cnt)
+			inst[0] = INST_AVAILABLE;
+	}
+
+	if (inst[0] != INST_AVAILABLE) {
+		for (i = 0; i < req_cnt; i++)
+			*(res_addr + inst[i] + 1) = OWNER;
+		rc = 0;
+	}
+
+err:
+	res_mgr_unlock();
+
+	return rc;
+}
+EXPORT_SYMBOL(res_mgr_alloc_range);
+
+/**
+ * res_mgr_alloc() - Allocate a resource instance.
+ * @tag: Identifies the resource.
+ * @req_inst: Requested instance to allocate (-1 for don't care).
+ * @use_last_avail: Set to request the last available instance.
+ *
+ * Returns: Allocated resource instance if successful.
+ * Returns <0 for error codes.
+ */
+int res_mgr_alloc(struct global_resource_tag tag, int req_inst,
+		  bool use_last_avail)
+{
+	int inst, rc;
+
+	rc = res_mgr_alloc_range(tag, req_inst, 1, use_last_avail, &inst);
+	if (!rc)
+		return inst;
+	return rc;
+}
+EXPORT_SYMBOL(res_mgr_alloc);
+
+/**
+ * res_mgr_free_range() - Free a resource instance range.
+ * @tag: Identifies the resource.
+ * @inst: Requested instance to free.
+ * @req_cnt: Number of instances to free.
+ */
+void res_mgr_free_range(struct global_resource_tag tag, const int *inst,
+			int req_cnt)
+{
+	struct global_resource_entry *res_entry;
+	int res_index, i;
+	u64 *res_addr;
+
+	res_mgr_lock();
+
+	/* Find the resource. */
+	res_index = res_mgr_find_resource(tag);
+	if (res_index < 0) {
+		pr_err("Resource not found, can't free instance\n");
+		goto err;
+	}
+
+	/* Get the resource data. */
+	res_entry = &res_mgr_info->resource_entry[res_index];
+	res_addr = phys_to_virt(res_entry->phys_addr);
+
+	/* Free the resource instances. */
+	for (i = 0; i < req_cnt; i++) {
+		/* Instance off by 1 (first element holds the count). */
+		*(res_addr + inst[i] + 1) = INST_AVAILABLE;
+	}
+
+err:
+	res_mgr_unlock();
+}
+EXPORT_SYMBOL(res_mgr_free_range);
+
+/**
+ * res_mgr_free() - Free a resource instance.
+ * @tag: Identifies the resource.
+ * @req_inst: Requested instance to free.
+ */
+void res_mgr_free(struct global_resource_tag tag, int inst)
+{
+	res_mgr_free_range(tag, &inst, 1);
+}
+EXPORT_SYMBOL(res_mgr_free);
+
+static int __init res_mgr_init(void)
+{
+	struct cvmx_bootmem_named_block_desc *block;
+	int block_size;
+	u64 addr;
+
+	cvmx_bootmem_lock();
+
+	/* Search for the resource manager data in boot memory. */
+	block = cvmx_bootmem_phy_named_block_find(RESOURCE_MGR_BLOCK_NAME,
+						  CVMX_BOOTMEM_FLAG_NO_LOCKING);
+	if (block) {
+		/* Found. */
+		res_mgr_info = phys_to_virt(block->base_addr);
+	} else {
+		/* Create it. */
+		block_size = sizeof(struct global_resources) +
+			sizeof(struct global_resource_entry) * MAX_RESOURCES;
+		addr = cvmx_bootmem_phy_named_block_alloc(block_size, 0, 0,
+				CVMX_CACHE_LINE_SIZE, RESOURCE_MGR_BLOCK_NAME,
+				CVMX_BOOTMEM_FLAG_NO_LOCKING);
+		if (!addr) {
+			pr_err("Failed to allocate name block %s\n",
+			       RESOURCE_MGR_BLOCK_NAME);
+		} else {
+			res_mgr_info = phys_to_virt(addr);
+			memset(res_mgr_info, 0, block_size);
+		}
+	}
+
+	cvmx_bootmem_unlock();
+
+	return 0;
+}
+device_initcall(res_mgr_init);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cavium, Inc. Octeon resource manager");
diff --git a/arch/mips/include/asm/octeon/octeon.h b/arch/mips/include/asm/octeon/octeon.h
index f01af2469874..4dafeaf262b5 100644
--- a/arch/mips/include/asm/octeon/octeon.h
+++ b/arch/mips/include/asm/octeon/octeon.h
@@ -346,6 +346,24 @@ void octeon_mult_restore3_end(void);
 void octeon_mult_restore2(void);
 void octeon_mult_restore2_end(void);
 
+/*
+ * This definition must be kept in sync with the one in
+ * cvmx-global-resources.c
+ */
+struct global_resource_tag {
+	uint64_t lo;
+	uint64_t hi;
+};
+
+void res_mgr_free(struct global_resource_tag tag, int inst);
+void res_mgr_free_range(struct global_resource_tag tag, const int *inst,
+			int req_cnt);
+int res_mgr_alloc(struct global_resource_tag tag, int req_inst,
+		  bool use_last_avail);
+int res_mgr_alloc_range(struct global_resource_tag tag, int req_inst,
+			int req_cnt, bool use_last_avail, int *inst);
+int res_mgr_create_resource(struct global_resource_tag tag, int inst_cnt);
+
 /**
  * Read a 32bit value from the Octeon NPI register space
  *
-- 
2.14.3

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