bcm53xx: revert patch removing imprecise abort workaround

It seems it still happens on some devices.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 48961

target/linux/bcm53xx/patches-4.4/301-Revert-ARM-BCM5301X-remove-workaround-imprecise-abor.patch

@@ -0,0 +1,66 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
+Date: Tue, 8 Mar 2016 09:03:21 +0100
+Subject: [PATCH] Revert "ARM: BCM5301X: remove workaround imprecise abort
+ fault handler"
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This reverts commit 937b12306ea79044c86f2e69b3061c7279245825.
+
+It seems imprecise external abort (0x1406) can be still happen on
+BCM4709 during PCI initialization.
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+---
+
+--- a/arch/arm/mach-bcm/bcm_5301x.c
++++ b/arch/arm/mach-bcm/bcm_5301x.c
+@@ -9,6 +9,40 @@
+ #include <asm/hardware/cache-l2x0.h>
+ 
+ #include <asm/mach/arch.h>
++#include <asm/siginfo.h>
++#include <asm/signal.h>
++
++
++static bool first_fault = true;
++
++static int bcm5301x_abort_handler(unsigned long addr, unsigned int fsr,
++				 struct pt_regs *regs)
++{
++	if ((fsr == 0x1406 || fsr == 0x1c06) && first_fault) {
++		first_fault = false;
++
++		/*
++		 * These faults with codes 0x1406 (BCM4709) or 0x1c06 happens
++		 * for no good reason, possibly left over from the CFE boot
++		 * loader.
++		 */
++		pr_warn("External imprecise Data abort at addr=%#lx, fsr=%#x ignored.\n",
++			addr, fsr);
++
++		/* Returning non-zero causes fault display and panic */
++		return 0;
++	}
++
++	/* Others should cause a fault */
++	return 1;
++}
++
++static void __init bcm5301x_init_early(void)
++{
++	/* Install our hook */
++	hook_fault_code(16 + 6, bcm5301x_abort_handler, SIGBUS, BUS_OBJERR,
++			"imprecise external abort");
++}
+ 
+ static const char *const bcm5301x_dt_compat[] __initconst = {
+ 	"brcm,bcm4708",
+@@ -18,5 +52,6 @@ static const char *const bcm5301x_dt_com
+ DT_MACHINE_START(BCM5301X, "BCM5301X")
+ 	.l2c_aux_val	= 0,
+ 	.l2c_aux_mask	= ~0,
++	.init_early	= bcm5301x_init_early,
+ 	.dt_compat	= bcm5301x_dt_compat,
+ MACHINE_END