ARC fixes for 4.15-rc7

- platform updates for setting up clock correctly
 
  - Fixes to accomodate newer gcc (__builtin_trap, removed inline asm modifier)
 
  - Other fixes
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Merge tag 'arc-4.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:

 - platform updates for setting up clock correctly

 - fixes to accomodate newer gcc (__builtin_trap, removed inline asm
   modifier)

 - other fixes

* tag 'arc-4.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: handle gcc generated __builtin_trap for older compiler
  ARC: handle gcc generated __builtin_trap()
  ARC: uaccess: dont use "l" gcc inline asm constraint modifier
  ARC: [plat-axs103] refactor the quad core DT quirk code
  ARC: [plat-axs103]: Set initial core pll output frequency
  ARC: [plat-hsdk]: Get rid of core pll frequency set in platform code
  ARC: [plat-hsdk]: Set initial core pll output frequency
  ARC: [plat-hsdk] Switch DisplayLink driver from fbdev to DRM
  arc: do not use __print_symbol()
  ARC: Fix detection of dual-issue enabled

arch/arc/boot/dts/axc003.dtsi

@@ -35,6 +35,14 @@
 			reg = <0x80 0x10>, <0x100 0x10>;
 			#clock-cells = <0>;
 			clocks = <&input_clk>;
+
+			/*
+			 * Set initial core pll output frequency to 90MHz.
+			 * It will be applied at the core pll driver probing
+			 * on early boot.
+			 */
+			assigned-clocks = <&core_clk>;
+			assigned-clock-rates = <90000000>;
 		};
 
 		core_intc: archs-intc@cpu {

arch/arc/boot/dts/axc003_idu.dtsi

@@ -35,6 +35,14 @@
 			reg = <0x80 0x10>, <0x100 0x10>;
 			#clock-cells = <0>;
 			clocks = <&input_clk>;
+
+			/*
+			 * Set initial core pll output frequency to 100MHz.
+			 * It will be applied at the core pll driver probing
+			 * on early boot.
+			 */
+			assigned-clocks = <&core_clk>;
+			assigned-clock-rates = <100000000>;
 		};
 
 		core_intc: archs-intc@cpu {

arch/arc/boot/dts/hsdk.dts

@@ -114,6 +114,14 @@
 			reg = <0x00 0x10>, <0x14B8 0x4>;
 			#clock-cells = <0>;
 			clocks = <&input_clk>;
+
+			/*
+			 * Set initial core pll output frequency to 1GHz.
+			 * It will be applied at the core pll driver probing
+			 * on early boot.
+			 */
+			assigned-clocks = <&core_clk>;
+			assigned-clock-rates = <1000000000>;
 		};
 
 		serial: serial@5000 {

arch/arc/configs/hsdk_defconfig

@@ -49,10 +49,11 @@ CONFIG_SERIAL_8250_DW=y
 CONFIG_SERIAL_OF_PLATFORM=y
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
+CONFIG_DRM=y
+# CONFIG_DRM_FBDEV_EMULATION is not set
+CONFIG_DRM_UDL=y
 CONFIG_FB=y
-CONFIG_FB_UDL=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
-CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_HCD_PLATFORM=y
 CONFIG_USB_OHCI_HCD=y

arch/arc/include/asm/uaccess.h

@@ -668,6 +668,7 @@ __arc_strncpy_from_user(char *dst, const char __user *src, long count)
 		return 0;
 
 	__asm__ __volatile__(
+	"	mov	lp_count, %5		\n"
 	"	lp	3f			\n"
 	"1:	ldb.ab  %3, [%2, 1]		\n"
 	"	breq.d	%3, 0, 3f               \n"
@@ -684,8 +685,8 @@ __arc_strncpy_from_user(char *dst, const char __user *src, long count)
 	"	.word   1b, 4b			\n"
 	"	.previous			\n"
 	: "+r"(res), "+r"(dst), "+r"(src), "=r"(val)
-	: "g"(-EFAULT), "l"(count)
+	: "g"(-EFAULT), "r"(count)
-	: "memory");
+	: "lp_count", "lp_start", "lp_end", "memory");
 
 	return res;
 }

arch/arc/kernel/setup.c

@@ -199,7 +199,7 @@ static void read_arc_build_cfg_regs(void)
 			unsigned int exec_ctrl;
 
 			READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
-			cpu->extn.dual_enb = exec_ctrl & 1;
+			cpu->extn.dual_enb = !(exec_ctrl & 1);
 
 			/* dual issue always present for this core */
 			cpu->extn.dual = 1;

arch/arc/kernel/stacktrace.c

@@ -163,7 +163,7 @@ arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs,
  */
 static int __print_sym(unsigned int address, void *unused)
 {
-	__print_symbol("  %s\n", address);
+	printk("  %pS\n", (void *)address);
 	return 0;
 }
 

arch/arc/kernel/traps.c

@@ -83,6 +83,7 @@ DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)
 DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR)
 DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)
 DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN)
+DO_ERROR_INFO(SIGSEGV, "gcc generated __builtin_trap", do_trap5_error, 0)
 
 /*
  * Entry Point for Misaligned Data access Exception, for emulating in software
@@ -115,6 +116,8 @@ void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
  * Thus TRAP_S <n> can be used for specific purpose
  *  -1 used for software breakpointing (gdb)
  *  -2 used by kprobes
+ *  -5 __builtin_trap() generated by gcc (2018.03 onwards) for toggle such as
+ *     -fno-isolate-erroneous-paths-dereference
  */
 void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
 {
@@ -134,6 +137,9 @@ void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
 		kgdb_trap(regs);
 		break;
 
+	case 5:
+		do_trap5_error(address, regs);
+		break;
 	default:
 		break;
 	}
@@ -155,3 +161,11 @@ void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
 
 	insterror_is_error(address, regs);
 }
+
+/*
+ * abort() call generated by older gcc for __builtin_trap()
+ */
+void abort(void)
+{
+	__asm__ __volatile__("trap_s  5\n");
+}

arch/arc/kernel/troubleshoot.c

@@ -163,6 +163,9 @@ static void show_ecr_verbose(struct pt_regs *regs)
 		else
 			pr_cont("Bus Error, check PRM\n");
 #endif
+	} else if (vec == ECR_V_TRAP) {
+		if (regs->ecr_param == 5)
+			pr_cont("gcc generated __builtin_trap\n");
 	} else {
 		pr_cont("Check Programmer's Manual\n");
 	}

arch/arc/plat-axs10x/axs10x.c

@@ -317,25 +317,23 @@ static void __init axs103_early_init(void)
 	 * Instead of duplicating defconfig/DT for SMP/QUAD, add a small hack
 	 * of fudging the freq in DT
 	 */
+#define AXS103_QUAD_CORE_CPU_FREQ_HZ	50000000
+
 	unsigned int num_cores = (read_aux_reg(ARC_REG_MCIP_BCR) >> 16) & 0x3F;
 	if (num_cores > 2) {
-		u32 freq = 50, orig;
+		u32 freq;
-		/*
-		 * TODO: use cpu node "cpu-freq" param instead of platform-specific
-		 * "/cpu_card/core_clk" as it works only if we use fixed-clock for cpu.
-		 */
 		int off = fdt_path_offset(initial_boot_params, "/cpu_card/core_clk");
 		const struct fdt_property *prop;
 
 		prop = fdt_get_property(initial_boot_params, off,
-					"clock-frequency", NULL);
+					"assigned-clock-rates", NULL);
-		orig = be32_to_cpu(*(u32*)(prop->data)) / 1000000;
+		freq = be32_to_cpu(*(u32 *)(prop->data));
 
 		/* Patching .dtb in-place with new core clock value */
-		if (freq != orig ) {
+		if (freq != AXS103_QUAD_CORE_CPU_FREQ_HZ) {
-			freq = cpu_to_be32(freq * 1000000);
+			freq = cpu_to_be32(AXS103_QUAD_CORE_CPU_FREQ_HZ);
 			fdt_setprop_inplace(initial_boot_params, off,
-					    "clock-frequency", &freq, sizeof(freq));
+					    "assigned-clock-rates", &freq, sizeof(freq));
 		}
 	}
 #endif

arch/arc/plat-hsdk/platform.c

@@ -38,42 +38,6 @@ static void __init hsdk_init_per_cpu(unsigned int cpu)
 #define CREG_PAE		(CREG_BASE + 0x180)
 #define CREG_PAE_UPDATE		(CREG_BASE + 0x194)
 
-#define CREG_CORE_IF_CLK_DIV	(CREG_BASE + 0x4B8)
-#define CREG_CORE_IF_CLK_DIV_2	0x1
-#define CGU_BASE		ARC_PERIPHERAL_BASE
-#define CGU_PLL_STATUS		(ARC_PERIPHERAL_BASE + 0x4)
-#define CGU_PLL_CTRL		(ARC_PERIPHERAL_BASE + 0x0)
-#define CGU_PLL_STATUS_LOCK	BIT(0)
-#define CGU_PLL_STATUS_ERR	BIT(1)
-#define CGU_PLL_CTRL_1GHZ	0x3A10
-#define HSDK_PLL_LOCK_TIMEOUT	500
-
-#define HSDK_PLL_LOCKED() \
-	!!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK)
-
-#define HSDK_PLL_ERR() \
-	!!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR)
-
-static void __init hsdk_set_cpu_freq_1ghz(void)
-{
-	u32 timeout = HSDK_PLL_LOCK_TIMEOUT;
-
-	/*
-	 * As we set cpu clock which exceeds 500MHz, the divider for the interface
-	 * clock must be programmed to div-by-2.
-	 */
-	iowrite32(CREG_CORE_IF_CLK_DIV_2, (void __iomem *) CREG_CORE_IF_CLK_DIV);
-
-	/* Set cpu clock to 1GHz */
-	iowrite32(CGU_PLL_CTRL_1GHZ, (void __iomem *) CGU_PLL_CTRL);
-
-	while (!HSDK_PLL_LOCKED() && timeout--)
-		cpu_relax();
-
-	if (!HSDK_PLL_LOCKED() || HSDK_PLL_ERR())
-		pr_err("Failed to setup CPU frequency to 1GHz!");
-}
-
 #define SDIO_BASE		(ARC_PERIPHERAL_BASE + 0xA000)
 #define SDIO_UHS_REG_EXT	(SDIO_BASE + 0x108)
 #define SDIO_UHS_REG_EXT_DIV_2	(2 << 30)
@@ -98,12 +62,6 @@ static void __init hsdk_init_early(void)
 	 * minimum possible div-by-2.
 	 */
 	iowrite32(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT);
-
-	/*
-	 * Setup CPU frequency to 1GHz.
-	 * TODO: remove it after smart hsdk pll driver will be introduced.
-	 */
-	hsdk_set_cpu_freq_1ghz();
 }
 
 static const char *hsdk_compat[] __initconst = {