[U-Boot] [PATCH 1/3] Add support to disable cpu's in multicore processors

Kumar Gala galak at kernel.crashing.org
Tue Jan 12 20:03:28 CET 2010


Add a disable sub-command to the cpu command that allows for disabling
cores in multicore processors.  This can be useful for systems that are
using multicore chips but aren't utilizing all the cores as a way to
reduce power and possibly improve performance.

Also updated an added missing copyright.

Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
---
 common/cmd_mp.c  |    3 +++
 cpu/mpc85xx/mp.c |    8 +++++++-
 cpu/mpc86xx/mp.c |   28 ++++++++++++++++++++++++++++
 include/common.h |    1 +
 4 files changed, 39 insertions(+), 1 deletions(-)

diff --git a/common/cmd_mp.c b/common/cmd_mp.c
index 71e4303..d78c209 100644
--- a/common/cmd_mp.c
+++ b/common/cmd_mp.c
@@ -46,6 +46,8 @@ cpu_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 			cpu_reset(cpuid);
 		} else if (strncmp(argv[2], "status", 6) == 0) {
 			cpu_status(cpuid);
+		} else if (strncmp(argv[2], "disable", 7) == 0) {
+			return cpu_disable(cpuid);
 		} else {
 			cmd_usage(cmdtp);
 			return 1;
@@ -86,6 +88,7 @@ U_BOOT_CMD(
 	"Multiprocessor CPU boot manipulation and release",
 	    "<num> reset                 - Reset cpu <num>\n"
 	"cpu <num> status                - Status of cpu <num>\n"
+	"cpu <num> disable               - Disable cpu <num>\n"
 	"cpu <num> release <addr> [args] - Release cpu <num> at <addr> with [args]"
 #ifdef CPU_ARCH_HELP
 	"\n"
diff --git a/cpu/mpc85xx/mp.c b/cpu/mpc85xx/mp.c
index 6530cb1..6ae7f0a 100644
--- a/cpu/mpc85xx/mp.c
+++ b/cpu/mpc85xx/mp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2009 Freescale Semiconductor, Inc.
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -68,6 +68,12 @@ int cpu_status(int nr)
 	return 0;
 }
 
+int cpu_disable(int nr)
+{
+	/* dummy function so common/cmd_mp.c will build */
+	return 1;
+}
+
 static u8 boot_entry_map[4] = {
 	0,
 	BOOT_ENTRY_PIR,
diff --git a/cpu/mpc86xx/mp.c b/cpu/mpc86xx/mp.c
index 2940673..ecdf2fb 100644
--- a/cpu/mpc86xx/mp.c
+++ b/cpu/mpc86xx/mp.c
@@ -1,3 +1,25 @@
+/*
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
 #include <common.h>
 #include <asm/processor.h>
 #include <asm/mmu.h>
@@ -24,6 +46,12 @@ int cpu_status(int nr)
 	return 0;
 }
 
+int cpu_disable(int nr)
+{
+	/* dummy function so common/cmd_mp.c will build */
+	return 1;
+}
+
 int cpu_release(int nr, int argc, char *argv[])
 {
 	/* dummy function so common/cmd_mp.c will build
diff --git a/include/common.h b/include/common.h
index 07897f6..f90da23 100644
--- a/include/common.h
+++ b/include/common.h
@@ -703,6 +703,7 @@ void show_boot_progress(int val);
 #ifdef CONFIG_MP
 int cpu_status(int nr);
 int cpu_reset(int nr);
+int cpu_disable(int nr);
 int cpu_release(int nr, int argc, char *argv[]);
 #endif
 
-- 
1.6.0.6



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