Merge tag 'xtensa-20210902' of git://github.com/jcmvbkbc/linux-xtensa

Pull Xtensa updates from Max Filippov:

 - fix kconfig unmet dependency warning for HAVE_FUTEX_CMPXCHG

 - add fairness to handling IRQs of the same priority

 - fix pointer usage before NULL check in ISS console driver

 - build system cleanups

* tag 'xtensa-20210902' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: move core-y in arch/xtensa/Makefile to arch/xtensa/Kbuild
  xtensa: build platform directories unconditionally
  xtensa: do not build variants directory
  xtensa: remove unneeded exports
  xtensa: ISS: don't use string pointer before NULL check
  xtensa: add fairness to IRQ handling
  xtensa: fix kconfig unmet dependency warning for HAVE_FUTEX_CMPXCHG

arch/xtensa/Kbuild

@@ -1 +1,2 @@
 # SPDX-License-Identifier: GPL-2.0-only
+obj-y += kernel/ mm/ platforms/ boot/dts/

arch/xtensa/Kconfig

@@ -31,7 +31,7 @@ config XTENSA
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_EXIT_THREAD
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUTEX_CMPXCHG if !MMU
+	select HAVE_FUTEX_CMPXCHG if !MMU && FUTEX
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_PCI

arch/xtensa/Makefile

@@ -17,7 +17,6 @@
 variant-y := $(patsubst "%",%,$(CONFIG_XTENSA_VARIANT_NAME))
 
 VARIANT = $(variant-y)
-export VARIANT
 
 ifneq ($(VARIANT),)
   ifdef cross_compiling
@@ -33,9 +32,6 @@ platform-$(CONFIG_XTENSA_PLATFORM_XT2000)	:= xt2000
 platform-$(CONFIG_XTENSA_PLATFORM_ISS)		:= iss
 platform-$(CONFIG_XTENSA_PLATFORM_XTFPGA)	:= xtfpga
 
-PLATFORM = $(platform-y)
-export PLATFORM
-
 # temporarily until string.h is fixed
 KBUILD_CFLAGS += -ffreestanding -D__linux__
 KBUILD_CFLAGS += -pipe -mlongcalls -mtext-section-literals
@@ -57,19 +53,11 @@ KBUILD_CPPFLAGS += $(patsubst %,-I$(srctree)/%include,$(vardirs) $(plfdirs))
 
 KBUILD_DEFCONFIG := iss_defconfig
 
-# Only build variant and/or platform if it includes a Makefile
-
-buildvar := $(shell test -e $(srctree)/arch/xtensa/variants/$(VARIANT)/Makefile && echo arch/xtensa/variants/$(VARIANT)/)
-buildplf := $(shell test -e $(srctree)/arch/xtensa/platforms/$(PLATFORM)/Makefile && echo arch/xtensa/platforms/$(PLATFORM)/)
-
 # Find libgcc.a
 
 LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 head-y		:= arch/xtensa/kernel/head.o
-core-y		+= arch/xtensa/kernel/ arch/xtensa/mm/
-core-y		+= $(buildvar) $(buildplf)
-core-y 		+= arch/xtensa/boot/dts/
 
 libs-y		+= arch/xtensa/lib/ $(LIBGCC)
 

arch/xtensa/kernel/traps.c

@@ -268,6 +268,7 @@ void do_interrupt(struct pt_regs *regs)
 		XCHAL_INTLEVEL7_MASK,
 	};
 	struct pt_regs *old_regs;
+	unsigned unhandled = ~0u;
 
 	trace_hardirqs_off();
 
@@ -283,13 +284,19 @@ void do_interrupt(struct pt_regs *regs)
 		for (level = LOCKLEVEL; level > 0; --level) {
 			if (int_at_level & int_level_mask[level]) {
 				int_at_level &= int_level_mask[level];
+				if (int_at_level & unhandled)
+					int_at_level &= unhandled;
+				else
+					unhandled |= int_level_mask[level];
 				break;
 			}
 		}
 
 		if (level == 0)
 			break;
 
+		/* clear lowest pending irq in the unhandled mask */
+		unhandled ^= (int_at_level & -int_at_level);
 		do_IRQ(__ffs(int_at_level), regs);
 	}
 

arch/xtensa/platforms/Makefile

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_XTENSA_PLATFORM_XT2000)	+= xt2000/
+obj-$(CONFIG_XTENSA_PLATFORM_ISS)	+= iss/
+obj-$(CONFIG_XTENSA_PLATFORM_XTFPGA)	+= xtfpga/

arch/xtensa/platforms/iss/console.c

@@ -199,10 +199,10 @@ late_initcall(rs_init);
 
 static void iss_console_write(struct console *co, const char *s, unsigned count)
 {
-	int len = strlen(s);
-
-	if (s != 0 && *s != 0)
+	if (s && *s != 0) {
+		int len = strlen(s);
 		simc_write(1, s, count < len ? count : len);
+	}
 }
 
 static struct tty_driver* iss_console_device(struct console *c, int *index)