Final MIPS fixes for 4.15

Some final MIPS fixes for 4.15, including important build fixes and a
 MAINTAINERS update:
 
 - Add myself as MIPS co-maintainer.
 - Fix various all*config build failures (particularly as a result of
   switching the default MIPS platform to the "generic" platform).
 - Fix GCC7 build failures (duplicate const and questionable calls to
   missing __multi3 intrinsic on mips64r6).
 - Fix warnings when CPU Idle is enabled (4.14).
 - Fix AR7 serial output (since 3.17).
 - Fix ralink platform_get_irq error checking (since 3.12).
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Merge tag 'mips_fixes_4.15_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips

Pull MIPS fixes from James Hogan:
 "Some final MIPS fixes for 4.15, including important build fixes and a
  MAINTAINERS update:

   - Add myself as MIPS co-maintainer.

   - Fix various all*config build failures (particularly as a result of
     switching the default MIPS platform to the "generic" platform).

   - Fix GCC7 build failures (duplicate const and questionable calls to
     missing __multi3 intrinsic on mips64r6).

   - Fix warnings when CPU Idle is enabled (4.14).

   - Fix AR7 serial output (since 3.17).

   - Fix ralink platform_get_irq error checking (since 3.12)"

* tag 'mips_fixes_4.15_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MAINTAINERS: Add James as MIPS co-maintainer
  MIPS: Fix undefined reference to physical_memsize
  MIPS: Implement __multi3 for GCC7 MIPS64r6 builds
  MIPS: mm: Fix duplicate "const" on insn_table_MM
  MIPS: CM: Drop WARN_ON(vp != 0)
  MIPS: ralink: Fix platform_get_irq's error checking
  MIPS: Fix CPS SMP NS16550 UART defaults
  MIPS: BCM47XX Avoid compile error with MIPS allnoconfig
  MIPS: RB532: Avoid undefined mac_pton without GENERIC_NET_UTILS
  MIPS: RB532: Avoid undefined early_serial_setup() without SERIAL_8250_CONSOLE
  MIPS: ath25: Avoid undefined early_serial_setup() without SERIAL_8250_CONSOLE
  MIPS: AR7: ensure the port type's FCR value is used

MAINTAINERS

@@ -9085,6 +9085,7 @@ F:	drivers/usb/image/microtek.*
 
 MIPS
 M:	Ralf Baechle <ralf@linux-mips.org>
+M:	James Hogan <jhogan@kernel.org>
 L:	linux-mips@linux-mips.org
 W:	http://www.linux-mips.org/
 T:	git git://git.linux-mips.org/pub/scm/ralf/linux.git

arch/mips/Kconfig

@@ -259,6 +259,7 @@ config BCM47XX
 	select LEDS_GPIO_REGISTER
 	select BCM47XX_NVRAM
 	select BCM47XX_SPROM
+	select BCM47XX_SSB if !BCM47XX_BCMA
 	help
 	 Support for BCM47XX based boards
 
@@ -389,6 +390,7 @@ config LANTIQ
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_MIPS16
 	select SYS_SUPPORTS_MULTITHREADING
+	select SYS_SUPPORTS_VPE_LOADER
 	select SYS_HAS_EARLY_PRINTK
 	select GPIOLIB
 	select SWAP_IO_SPACE
@@ -516,6 +518,7 @@ config MIPS_MALTA
 	select SYS_SUPPORTS_MIPS16
 	select SYS_SUPPORTS_MULTITHREADING
 	select SYS_SUPPORTS_SMARTMIPS
+	select SYS_SUPPORTS_VPE_LOADER
 	select SYS_SUPPORTS_ZBOOT
 	select SYS_SUPPORTS_RELOCATABLE
 	select USE_OF
@@ -2281,9 +2284,16 @@ config MIPSR2_TO_R6_EMULATOR
 	  The only reason this is a build-time option is to save ~14K from the
 	  final kernel image.
 
+config SYS_SUPPORTS_VPE_LOADER
+	bool
+	depends on SYS_SUPPORTS_MULTITHREADING
+	help
+	  Indicates that the platform supports the VPE loader, and provides
+	  physical_memsize.
+
 config MIPS_VPE_LOADER
 	bool "VPE loader support."
-	depends on SYS_SUPPORTS_MULTITHREADING && MODULES
+	depends on SYS_SUPPORTS_VPE_LOADER && MODULES
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_IRQ_EI
 	select MIPS_MT

arch/mips/Kconfig.debug

@@ -124,30 +124,36 @@ config SCACHE_DEBUGFS
 
 	  If unsure, say N.
 
-menuconfig MIPS_CPS_NS16550
+menuconfig MIPS_CPS_NS16550_BOOL
 	bool "CPS SMP NS16550 UART output"
 	depends on MIPS_CPS
 	help
 	  Output debug information via an ns16550 compatible UART if exceptions
 	  occur early in the boot process of a secondary core.
 
-if MIPS_CPS_NS16550
+if MIPS_CPS_NS16550_BOOL
+
+config MIPS_CPS_NS16550
+	def_bool MIPS_CPS_NS16550_BASE != 0
 
 config MIPS_CPS_NS16550_BASE
 	hex "UART Base Address"
 	default 0x1b0003f8 if MIPS_MALTA
+	default 0
 	help
 	  The base address of the ns16550 compatible UART on which to output
 	  debug information from the early stages of core startup.
 
+	  This is only used if non-zero.
+
 config MIPS_CPS_NS16550_SHIFT
 	int "UART Register Shift"
-	default 0 if MIPS_MALTA
+	default 0
 	help
 	  The number of bits to shift ns16550 register indices by in order to
 	  form their addresses. That is, log base 2 of the span between
 	  adjacent ns16550 registers in the system.
 
-endif # MIPS_CPS_NS16550
+endif # MIPS_CPS_NS16550_BOOL
 
 endmenu

arch/mips/ar7/platform.c

@@ -575,7 +575,7 @@ static int __init ar7_register_uarts(void)
 	uart_port.type		= PORT_AR7;
 	uart_port.uartclk	= clk_get_rate(bus_clk) / 2;
 	uart_port.iotype	= UPIO_MEM32;
-	uart_port.flags		= UPF_FIXED_TYPE;
+	uart_port.flags		= UPF_FIXED_TYPE | UPF_BOOT_AUTOCONF;
 	uart_port.regshift	= 2;
 
 	uart_port.line		= 0;

arch/mips/ath25/devices.c

@@ -73,6 +73,7 @@ const char *get_system_type(void)
 
 void __init ath25_serial_setup(u32 mapbase, int irq, unsigned int uartclk)
 {
+#ifdef CONFIG_SERIAL_8250_CONSOLE
 	struct uart_port s;
 
 	memset(&s, 0, sizeof(s));
@@ -85,6 +86,7 @@ void __init ath25_serial_setup(u32 mapbase, int irq, unsigned int uartclk)
 	s.uartclk = uartclk;
 
 	early_serial_setup(&s);
+#endif /* CONFIG_SERIAL_8250_CONSOLE */
 }
 
 int __init ath25_add_wmac(int nr, u32 base, int irq)

arch/mips/kernel/mips-cm.c

@@ -292,7 +292,6 @@ void mips_cm_lock_other(unsigned int cluster, unsigned int core,
 				  *this_cpu_ptr(&cm_core_lock_flags));
 	} else {
 		WARN_ON(cluster != 0);
-		WARN_ON(vp != 0);
 		WARN_ON(block != CM_GCR_Cx_OTHER_BLOCK_LOCAL);
 
 		/*

arch/mips/lib/Makefile

@@ -16,4 +16,5 @@ obj-$(CONFIG_CPU_R3000)		+= r3k_dump_tlb.o
 obj-$(CONFIG_CPU_TX39XX)	+= r3k_dump_tlb.o
 
 # libgcc-style stuff needed in the kernel
-obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o ucmpdi2.o
+obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o multi3.o \
+	 ucmpdi2.o

arch/mips/lib/libgcc.h

@@ -10,10 +10,18 @@ typedef int word_type __attribute__ ((mode (__word__)));
 struct DWstruct {
 	int high, low;
 };
+
+struct TWstruct {
+	long long high, low;
+};
 #elif defined(__LITTLE_ENDIAN)
 struct DWstruct {
 	int low, high;
 };
+
+struct TWstruct {
+	long long low, high;
+};
 #else
 #error I feel sick.
 #endif
@@ -23,4 +31,13 @@ typedef union {
 	long long ll;
 } DWunion;
 
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6)
+typedef int ti_type __attribute__((mode(TI)));
+
+typedef union {
+	struct TWstruct s;
+	ti_type ti;
+} TWunion;
+#endif
+
 #endif /* __ASM_LIBGCC_H */

arch/mips/lib/multi3.c

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+
+#include "libgcc.h"
+
+/*
+ * GCC 7 suboptimally generates __multi3 calls for mips64r6, so for that
+ * specific case only we'll implement it here.
+ *
+ * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82981
+ */
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6) && (__GNUC__ == 7)
+
+/* multiply 64-bit values, low 64-bits returned */
+static inline long long notrace dmulu(long long a, long long b)
+{
+	long long res;
+
+	asm ("dmulu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+	return res;
+}
+
+/* multiply 64-bit unsigned values, high 64-bits of 128-bit result returned */
+static inline long long notrace dmuhu(long long a, long long b)
+{
+	long long res;
+
+	asm ("dmuhu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+	return res;
+}
+
+/* multiply 128-bit values, low 128-bits returned */
+ti_type notrace __multi3(ti_type a, ti_type b)
+{
+	TWunion res, aa, bb;
+
+	aa.ti = a;
+	bb.ti = b;
+
+	/*
+	 * a * b =           (a.lo * b.lo)
+	 *         + 2^64  * (a.hi * b.lo + a.lo * b.hi)
+	 *        [+ 2^128 * (a.hi * b.hi)]
+	 */
+	res.s.low = dmulu(aa.s.low, bb.s.low);
+	res.s.high = dmuhu(aa.s.low, bb.s.low);
+	res.s.high += dmulu(aa.s.high, bb.s.low);
+	res.s.high += dmulu(aa.s.low, bb.s.high);
+
+	return res.ti;
+}
+EXPORT_SYMBOL(__multi3);
+
+#endif /* 64BIT && CPU_MIPSR6 && GCC7 */

arch/mips/mm/uasm-micromips.c

@@ -40,7 +40,7 @@
 
 #include "uasm.c"
 
-static const struct insn const insn_table_MM[insn_invalid] = {
+static const struct insn insn_table_MM[insn_invalid] = {
 	[insn_addu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD},
 	[insn_addiu]	= {M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
 	[insn_and]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD},

arch/mips/ralink/timer.c

@@ -109,9 +109,9 @@ static int rt_timer_probe(struct platform_device *pdev)
 	}
 
 	rt->irq = platform_get_irq(pdev, 0);
-	if (!rt->irq) {
+	if (rt->irq < 0) {
 		dev_err(&pdev->dev, "failed to load irq\n");
-		return -ENOENT;
+		return rt->irq;
 	}
 
 	rt->membase = devm_ioremap_resource(&pdev->dev, res);

arch/mips/rb532/Makefile

@@ -2,4 +2,6 @@
 # Makefile for the RB532 board specific parts of the kernel
 #
 
-obj-y	 += irq.o time.o setup.o serial.o prom.o gpio.o devices.o
+obj-$(CONFIG_SERIAL_8250_CONSOLE) += serial.o
+
+obj-y	 += irq.o time.o setup.o prom.o gpio.o devices.o

arch/mips/rb532/devices.c

@@ -310,6 +310,8 @@ static int __init plat_setup_devices(void)
 	return platform_add_devices(rb532_devs, ARRAY_SIZE(rb532_devs));
 }
 
+#ifdef CONFIG_NET
+
 static int __init setup_kmac(char *s)
 {
 	printk(KERN_INFO "korina mac = %s\n", s);
@@ -322,4 +324,6 @@ static int __init setup_kmac(char *s)
 
 __setup("kmac=", setup_kmac);
 
+#endif /* CONFIG_NET */
+
 arch_initcall(plat_setup_devices);