Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:
 "Included in these updates are:
   - Performance optimisation to avoid writing the control register at
     every exception.
   - Use static inline instead of extern inline in ftrace code.
   - Crypto ARM assembly updates for big endian
   - Alignment of initrd/.init memory to page sizes when freeing to
     ensure that we fully free the regions
   - Add gcov support
   - A couple of preparatory patches for VDSO support: use
     _install_special_mapping, and randomize the sigpage placement above
     stack.
   - Add L2 ePAPR DT cache properties so that DT can specify the cache
     geometry.
   - Preparatory patch for FIQ (NMI) kernel C code for things like
     spinlock lockup debug.  Following on from this are a couple of my
     patches cleaning up show_regs() and removing an unused (probably
     since 1.x days) do_unexp_fiq() function.
   - Use pr_warn() rather than pr_warning().
   - A number of cleanups (smp, footbridge, return_address)"

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (21 commits)
  ARM: 8167/1: extend the reserved memory for initrd to be page aligned
  ARM: 8168/1: extend __init_end to a page align address
  ARM: 8169/1: l2c: parse cache properties from ePAPR definitions
  ARM: 8160/1: drop warning about return_address not using unwind tables
  ARM: 8161/1: footbridge: select machine dir based on ARCH_FOOTBRIDGE
  ARM: 8158/1: LLVMLinux: use static inline in ARM ftrace.h
  ARM: 8155/1: place sigpage at a random offset above stack
  ARM: 8154/1: use _install_special_mapping for sigpage
  ARM: 8153/1: Enable gcov support on the ARM architecture
  ARM: Avoid writing to control register on every exception
  ARM: 8152/1: Convert pr_warning to pr_warn
  ARM: remove unused do_unexp_fiq() function
  ARM: remove extraneous newline in show_regs()
  ARM: 8150/3: fiq: Replace default FIQ handler
  ARM: 8140/1: ep93xx: Enable DEBUG_LL_UART_PL01X
  ARM: 8139/1: versatile: Enable DEBUG_LL_UART_PL01X
  ARM: 8138/1: drop ISAR0 workaround for B15
  ARM: 8136/1: sa1100: add Micro ASIC platform device
  ARM: 8131/1: arm/smp: Absorb boot_secondary()
  ARM: 8126/1: crypto: enable NEON SHA-384/SHA-512 for big endian
  ...

1 files changed, 23 insertions, 3 deletions

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index a964c9f40f87..0c8b10801d36 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -25,6 +25,7 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/irq.h>
 
 #include <linux/atomic.h>
 #include <asm/cacheflush.h>
@@ -460,10 +461,29 @@ die_sig:
 	arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
 }
 
-asmlinkage void do_unexp_fiq (struct pt_regs *regs)
+/*
+ * Handle FIQ similarly to NMI on x86 systems.
+ *
+ * The runtime environment for NMIs is extremely restrictive
+ * (NMIs can pre-empt critical sections meaning almost all locking is
+ * forbidden) meaning this default FIQ handling must only be used in
+ * circumstances where non-maskability improves robustness, such as
+ * watchdog or debug logic.
+ *
+ * This handler is not appropriate for general purpose use in drivers
+ * platform code and can be overrideen using set_fiq_handler.
+ */
+asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
 {
-	printk("Hmm.  Unexpected FIQ received, but trying to continue\n");
-	printk("You may have a hardware problem...\n");
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	nmi_enter();
+
+	/* nop. FIQ handlers for special arch/arm features can be added here. */
+
+	nmi_exit();
+
+	set_irq_regs(old_regs);
 }
 
 /*