[linux-yocto] [PATCH 33/39] arch/arm/mach-axxia: Work-Around for Event Problems in v1.0 Silicon

[Charlie Paul]

From: John Jacques <john.jacques at lsi.com>

SEV/WFE are unusable in v1.0 silicon.  The boot loader now sets bit 7
in the ACLTR register of each core, making wfe a nop.  At present,
bit 7 of the ACTLR does not work in simulation and emulaton.  Until
that is corrected, this work-around is necessary.

Signed-off-by: John Jacques <john.jacques at lsi.com>
---
 arch/arm/include/asm/spinlock.h |    5 ++++
 arch/arm/mach-axxia/Makefile    |    5 ++--
 arch/arm/mach-axxia/ev.c        |   53 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/mach-axxia/ev.c

diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index b07c09e..be4ae62 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -88,7 +88,12 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 	: "cc");
 
 	while (lockval.tickets.next != lockval.tickets.owner) {
+#ifdef CONFIG_ARCH_AXXIA
+		extern void __axxia_arch_wfe(void);
+		__axxia_arch_wfe();
+#else
 		wfe();
+#endif
 		lockval.tickets.owner = ACCESS_ONCE(lock->tickets.owner);
 	}
 
diff --git a/arch/arm/mach-axxia/Makefile b/arch/arm/mach-axxia/Makefile
index 62197f1..8125e97 100644
--- a/arch/arm/mach-axxia/Makefile
+++ b/arch/arm/mach-axxia/Makefile
@@ -3,8 +3,9 @@
 #
 obj-y					+= axxia.o
 obj-y					+= clock.o
-obj-y                                   += io.o
-obj-y                                   += ssp-gpio.o
+obj-y					+= ev.o
+obj-y					+= io.o
+obj-y					+= ssp-gpio.o
 obj-y					+= ncr.o
 obj-y					+= timers.o
 obj-y					+= pci.o
diff --git a/arch/arm/mach-axxia/ev.c b/arch/arm/mach-axxia/ev.c
new file mode 100644
index 0000000..f4630d1
--- /dev/null
+++ b/arch/arm/mach-axxia/ev.c
@@ -0,0 +1,53 @@
+/*
+ * arch/arm/mach-axxia/ev.c
+ *
+ * Support for the LSI Axxia boards based on ARM cores.
+ *
+ * Copyright (C) 2012 LSI
+ *
+ * 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 <linux/module.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <asm/page.h>
+#include <asm/io.h>
+
+static int initialized;
+static int wfe_available;
+
+inline void
+__axxia_arch_wfe(void)
+{
+	if (0 == initialized) {
+		if (of_find_compatible_node(NULL, NULL,
+					    "lsi,axm5516-sim") != NULL ||
+		    of_find_compatible_node(NULL, NULL,
+					    "lsi,axm5516-emu") != NULL)
+			wfe_available = 0;
+		else
+			wfe_available = 1;
+
+		initialized = 1;
+	}
+
+	if (0 != wfe_available)
+		wfe();
+
+	return;
+}
+EXPORT_SYMBOL(__axxia_arch_wfe);
-- 
1.7.9.5