Merge tag 'arc-v3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc (7ae0e06b) · Commits · 戴 / test

arch/arc/Kconfig

+0 −11

Original line number	Diff line number	Diff line
		@@ -409,17 +409,6 @@ config ARC_DBG_TLB_MISS_COUNT
		Counts number of I and D TLB Misses and exports them via Debugfs
		The counters can be cleared via Debugfs as well

		config CMDLINE_UBOOT
		bool "Support U-boot kernel command line passing"
		default n
		help
		If you are using U-boot (www.denx.de) and wish to pass the kernel
		command line from the U-boot environment to the Linux kernel then
		switch this option on.
		ARC U-boot will setup the cmdline in RAM/flash and set r2 to point
		to it. kernel startup code will append this to DeviceTree
		/bootargs provided cmdline args.

		config ARC_BUILTIN_DTB_NAME
		string "Built in DTB"
		help

arch/arc/include/asm/smp.h

+4 −4

Original line number	Diff line number	Diff line
		@@ -46,14 +46,14 @@ extern int smp_ipi_irq_setup(int cpu, int irq);
		*
		* @info: SoC SMP specific info for /proc/cpuinfo etc
		* @cpu_kick: For Master to kickstart a cpu (optionally at a PC)
		* @ipi_send: To send IPI to a @cpumask
		* @ips_clear: To clear IPI received by @cpu at @irq
		* @ipi_send: To send IPI to a @cpu
		* @ips_clear: To clear IPI received at @irq
		*/
		struct plat_smp_ops {
		const char *info;
		void (*cpu_kick)(int cpu, unsigned long pc);
		void (ipi_send)(void callmap);
		void (*ipi_clear)(int cpu, int irq);
		void (*ipi_send)(int cpu);
		void (*ipi_clear)(int irq);
		};

		/* TBD: stop exporting it for direct population by platform */

arch/arc/kernel/head.S

+7 −19

Original line number	Diff line number	Diff line
		@@ -49,25 +49,13 @@ stext:
		st.ab 0, [r5,4]
		brlt r5, r6, 1b

		#ifdef CONFIG_CMDLINE_UBOOT
		; support for bootloader provided cmdline
		; If cmdline passed by u-boot, then
		; r0 = 1 (because ATAGS parsing, now retired, used to use 0)
		; r1 = magic number (board identity)
		; r2 = addr of cmdline string (somewhere in memory/flash)

		brne r0, 1, .Lother_bootup_chores ; u-boot didn't pass cmdline
		breq r2, 0, .Lother_bootup_chores ; or cmdline is NULL

		mov r5, @command_line
		1:
		ldb.ab r6, [r2, 1]
		breq r6, 0, .Lother_bootup_chores
		b.d 1b
		stb.ab r6, [r5, 1]
		#endif

		.Lother_bootup_chores:
		; Uboot - kernel ABI
		; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
		; r1 = magic number (board identity, unused as of now
		; r2 = pointer to uboot provided cmdline or external DTB in mem
		; These are handled later in setup_arch()
		st r0, [@uboot_tag]
		st r2, [@uboot_arg]

		; Identify if running on ISS vs Silicon
		; IDENTITY Reg [ 3 2 1 0 ]

arch/arc/kernel/setup.c

+36 −12

Original line number	Diff line number	Diff line
		@@ -29,7 +29,10 @@

		int running_on_hw = 1; /* vs. on ISS */

		char __initdata command_line[COMMAND_LINE_SIZE];
		/* Part of U-boot ABI: see head.S */
		int __initdata uboot_tag;
		char __initdata *uboot_arg;

		const struct machine_desc *machine_desc;

		struct task_struct _current_task[NR_CPUS]; / For stack switching */
		@@ -311,19 +314,40 @@ void setup_processor(void)
		arc_chk_fpu();
		}

		static inline int is_kernel(unsigned long addr)
		{
		if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
		return 1;
		return 0;
		}

		void __init setup_arch(char **cmdline_p)
		{
		/* This also populates @boot_command_line from /bootargs */
		/* make sure that uboot passed pointer to cmdline/dtb is valid */
		if (uboot_tag && is_kernel((unsigned long)uboot_arg))
		panic("Invalid uboot arg\n");

		/* See if u-boot passed an external Device Tree blob */
		machine_desc = setup_machine_fdt(uboot_arg); /* uboot_tag == 2 */
		if (!machine_desc) {
		/* No, so try the embedded one */
		machine_desc = setup_machine_fdt(__dtb_start);
		if (!machine_desc)
		panic("Embedded DT invalid\n");

		/* Append any u-boot provided cmdline */
		#ifdef CONFIG_CMDLINE_UBOOT
		/* Add a whitespace seperator between the 2 cmdlines */
		/*
		* If we are here, it is established that @uboot_arg didn't
		* point to DT blob. Instead if u-boot says it is cmdline,
		* Appent to embedded DT cmdline.
		* setup_machine_fdt() would have populated @boot_command_line
		*/
		if (uboot_tag == 1) {
		/* Ensure a whitespace between the 2 cmdlines */
		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
		strlcat(boot_command_line, command_line, COMMAND_LINE_SIZE);
		#endif
		strlcat(boot_command_line, uboot_arg,
		COMMAND_LINE_SIZE);
		}
		}

		/* Save unparsed command line copy for /proc/cmdline */
		*cmdline_p = boot_command_line;

arch/arc/kernel/smp.c

+70 −54

Original line number	Diff line number	Diff line
		@@ -197,51 +197,65 @@ int __init setup_profiling_timer(unsigned int multiplier)
		/* Inter Processor Interrupt Handling */
		/*****************************************************************************/

		/*
		* structures for inter-processor calls
		* A Collection of single bit ipi messages
		*
		*/

		/*
		* TODO_rajesh investigate tlb message types.
		* IPI Timer not needed because each ARC has an individual Interrupting Timer
		*/
		enum ipi_msg_type {
		IPI_NOP = 0,
		IPI_EMPTY = 0,
		IPI_RESCHEDULE = 1,
		IPI_CALL_FUNC,
		IPI_CPU_STOP
		IPI_CPU_STOP,
		};

		struct ipi_data {
		unsigned long bits;
		};
		/*
		* In arches with IRQ for each msg type (above), receiver can use IRQ-id to
		* figure out what msg was sent. For those which don't (ARC has dedicated IPI
		* IRQ), the msg-type needs to be conveyed via per-cpu data
		*/

		static DEFINE_PER_CPU(struct ipi_data, ipi_data);
		static DEFINE_PER_CPU(unsigned long, ipi_data);

		static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
		static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg)
		{
		unsigned long __percpu *ipi_data_ptr = per_cpu_ptr(&ipi_data, cpu);
		unsigned long old, new;
		unsigned long flags;
		unsigned int cpu;

		pr_debug("%d Sending msg [%d] to %d\n", smp_processor_id(), msg, cpu);

		local_irq_save(flags);

		for_each_cpu(cpu, callmap) {
		struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
		set_bit(msg, &ipi->bits);
		}
		/*
		* Atomically write new msg bit (in case others are writing too),
		* and read back old value
		*/
		do {
		new = old = *ipi_data_ptr;
		new \|= 1U << msg;
		} while (cmpxchg(ipi_data_ptr, old, new) != old);

		/* Call the platform specific cross-CPU call function */
		if (plat_smp_ops.ipi_send)
		plat_smp_ops.ipi_send((void *)callmap);
		/*
		* Call the platform specific IPI kick function, but avoid if possible:
		* Only do so if there's no pending msg from other concurrent sender(s).
		* Otherwise, recevier will see this msg as well when it takes the
		* IPI corresponding to that msg. This is true, even if it is already in
		* IPI handler, because !@old means it has not yet dequeued the msg(s)
		* so @new msg can be a free-loader
		*/
		if (plat_smp_ops.ipi_send && !old)
		plat_smp_ops.ipi_send(cpu);

		local_irq_restore(flags);
		}

		static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
		{
		unsigned int cpu;

		for_each_cpu(cpu, callmap)
		ipi_send_msg_one(cpu, msg);
		}

		void smp_send_reschedule(int cpu)
		{
		ipi_send_msg(cpumask_of(cpu), IPI_RESCHEDULE);
		ipi_send_msg_one(cpu, IPI_RESCHEDULE);
		}

		void smp_send_stop(void)
		@@ -254,7 +268,7 @@ void smp_send_stop(void)

		void arch_send_call_function_single_ipi(int cpu)
		{
		ipi_send_msg(cpumask_of(cpu), IPI_CALL_FUNC);
		ipi_send_msg_one(cpu, IPI_CALL_FUNC);
		}

		void arch_send_call_function_ipi_mask(const struct cpumask *mask)
		@@ -265,18 +279,13 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask)
		/*
		* ipi_cpu_stop - handle IPI from smp_send_stop()
		*/
		static void ipi_cpu_stop(unsigned int cpu)
		static void ipi_cpu_stop(void)
		{
		machine_halt();
		}

		static inline void __do_IPI(unsigned long ops, struct ipi_data ipi, int cpu)
		static inline void __do_IPI(unsigned long msg)
		{
		unsigned long msg = 0;

		do {
		msg = find_next_bit(ops, BITS_PER_LONG, msg+1);

		switch (msg) {
		case IPI_RESCHEDULE:
		scheduler_ipi();
		@@ -287,11 +296,12 @@ static inline void __do_IPI(unsigned long ops, struct ipi_data ipi, int cpu)
		break;

		case IPI_CPU_STOP:
		ipi_cpu_stop(cpu);
		ipi_cpu_stop();
		break;
		}
		} while (msg < BITS_PER_LONG);

		default:
		pr_warn("IPI with unexpected msg %ld\n", msg);
		}
		}

		/*
		@@ -300,19 +310,25 @@ static inline void __do_IPI(unsigned long ops, struct ipi_data ipi, int cpu)
		*/
		irqreturn_t do_IPI(int irq, void *dev_id)
		{
		int cpu = smp_processor_id();
		struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
		unsigned long ops;
		unsigned long pending;

		pr_debug("IPI [%ld] received on cpu %d\n",
		*this_cpu_ptr(&ipi_data), smp_processor_id());

		if (plat_smp_ops.ipi_clear)
		plat_smp_ops.ipi_clear(cpu, irq);
		plat_smp_ops.ipi_clear(irq);

		/*
		* XXX: is this loop really needed
		* And do we need to move ipi_clean inside
		* "dequeue" the msg corresponding to this IPI (and possibly other
		* piggybacked msg from elided IPIs: see ipi_send_msg_one() above)
		*/
		while ((ops = xchg(&ipi->bits, 0)) != 0)
		__do_IPI(&ops, ipi, cpu);
		pending = xchg(this_cpu_ptr(&ipi_data), 0);

		do {
		unsigned long msg = __ffs(pending);
		__do_IPI(msg);
		pending &= ~(1U << msg);
		} while (pending);

		return IRQ_HANDLED;
		}

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