add a workaround for fixing the bad performance of the Ubiquiti RouterStation/LS-SR71 boards, until they fix their bootloader.

SVN-Revision: 14556

target/linux/ar71xx/files/arch/mips/include/asm/mach-ar71xx/kernel-entry-init.h

@@ -0,0 +1,32 @@
+/*
+ *  Atheros AR71xx specific kernel entry setup
+ *
+ *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+#ifndef __ASM_MACH_AR71XX_KERNEL_ENTRY_H
+#define __ASM_MACH_AR71XX_KERNEL_ENTRY_H
+
+	/*
+	 * Some bootloaders set the 'Kseg0 coherency algorithm' to
+	 * 'Cacheable, noncoherent, write-through, no write allocate'
+	 * and this cause performance issues. Let's go and change it to
+	 * 'Cacheable, noncoherent, write-back, write allocate'
+	 */
+	.macro	kernel_entry_setup
+	mfc0	t0, CP0_CONFIG
+	li	t1, ~CONF_CM_CMASK
+	and	t0, t1
+	ori	t0, CONF_CM_CACHABLE_NONCOHERENT
+	mtc0	t0, CP0_CONFIG
+	nop
+	.endm
+
+	.macro	smp_slave_setup
+	.endm
+
+#endif /* __ASM_MACH_AR71XX_KERNEL_ENTRY_H */