On 11/30/2017 02:53 PM, James Hogan wrote:
On Tue, Nov 28, 2017 at 04:55:35PM -0800, David Daney wrote:
From: Carlos Munoz <cmunoz@cavium.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@cavium.com>
Signed-off-by: Steven J. Hill <Steven.Hill@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
---
arch/mips/cavium-octeon/Makefile | 3 +-
arch/mips/cavium-octeon/resource-mgr.c | 371 +++++++++++++++++++++++++++++++++
arch/mips/include/asm/octeon/octeon.h | 18 ++
3 files changed, 391 insertions(+), 1 deletion(-)
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..0a299ab8719f 100644
--- a/arch/mips/cavium-octeon/Makefile
+++ b/arch/mips/cavium-octeon/Makefile
@@ -9,7 +9,8 @@
# Copyright (C) 2005-2009 Cavium Networks
#
-obj-y := cpu.o setup.o octeon-platform.o octeon-irq.o csrc-octeon.o
+obj-y := cpu.o setup.o octeon-platform.o octeon-irq.o csrc-octeon.o \
+ resource-mgr.o
Maybe put that on a separate line like below.
OK
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..ca25fa953402
--- /dev/null
+++ b/arch/mips/cavium-octeon/resource-mgr.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Resource manager for Octeon.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * 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)
+{
+ unsigned int tmp;
+ u64 lock = (u64)&res_mgr_info->rlock;
presumably this could be a u32 *, avoid the cast to u64, and still work
just fine below.
I will rewrite to just use cmpxchg()
+
+ __asm__ __volatile__(
+ ".set noreorder\n"
+ "1: ll %[tmp], 0(%[addr])\n"
+ " bnez %[tmp], 1b\n"
+ " li %[tmp], 1\n"
I believe the convention for .S files is for instructions in branch
delay slots to be indented an additional space for readability. Maybe
that would be worthwhile here.
+ " sc %[tmp], 0(%[addr])\n"
+ " beqz %[tmp], 1b\n"
+ " nop\n"
and here also.
+ ".set reorder\n" :
nit: strictly speaking there's no need for \n on the last line.
+ [tmp] "=&r"(tmp) :
+ [addr] "r"(lock) :
+ "memory");
minor style thing: its far more common to have : at the beginning of the
line rather than the end.
+}
+
+static void res_mgr_unlock(void)
+{
+ u64 lock = (u64)&res_mgr_info->rlock;
same again
Will rewrite to use WRITE_ONCE().
+
+ /* Wait until all resource operations finish before unlocking. */
+ mb();
+ __asm__ __volatile__(
+ "sw $0, 0(%[addr])\n" : :
+ [addr] "r"(lock) :
+ "memory");
+
+ /* Force a write buffer flush. */
+ mb();
+}
+
+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.
Only -1 seems to be returned. Is it worth returning some standard Linux
error codes instead?
Yep. I fixed this and everything below for the next version of the
patch set.
Thanks,
David Daney
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