[PATCH v7 4/4] MIPS: Octeon: Add a global resource manager.

From: David Daney
Date: Tue Dec 12 2017 - 19:49:51 EST


From: Carlos Munoz <cmunoz@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Steven J. Hill <Steven.Hill@xxxxxxxxxx>
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
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