[PATCH 13/28] ARC: make plat_smp_ops weak to allow over-rides
From: Vineet Gupta
Date: Tue Jun 09 2015 - 07:58:13 EST
This allows platforms to provide their own cpu wakeup routines
as well as IPI send / clear backends, while allowing a SMP kernel w/o
any such backend to build/boot
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/Kconfig | 21 +++++---
arch/arc/include/asm/irq.h | 1 +
arch/arc/include/asm/mcip.h | 91 +++++++++++++++++++++++++++++++++
arch/arc/kernel/Makefile | 1 +
arch/arc/kernel/intc-arcv2.c | 2 +-
arch/arc/kernel/mcip.c | 117 +++++++++++++++++++++++++++++++++++++++++++
arch/arc/kernel/smp.c | 2 +-
arch/arc/plat-sim/platform.c | 5 ++
8 files changed, 231 insertions(+), 9 deletions(-)
create mode 100644 arch/arc/include/asm/mcip.h
create mode 100644 arch/arc/kernel/mcip.c
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index f09e03a0d604..301525020af7 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -160,12 +160,12 @@ config CPU_BIG_ENDIAN
Build kernel for Big Endian Mode of ARC CPU
config SMP
- bool "Symmetric Multi-Processing (Incomplete)"
+ bool "Symmetric Multi-Processing"
default n
+ select ARC_HAS_COH_CACHES if ISA_ARCV2
+ select ARC_MCIP if ISA_ARCV2
help
- This enables support for systems with more than one CPU. If you have
- a system with only one CPU, say N. If you have a system with more
- than one CPU, say Y.
+ This enables support for systems with more than one CPU.
if SMP
@@ -175,13 +175,20 @@ config ARC_HAS_COH_CACHES
config ARC_HAS_REENTRANT_IRQ_LV2
def_bool n
-endif #SMP
+config ARC_MCIP
+ bool "ARConnect Multicore IP (MCIP) Support "
+ depends on ISA_ARCV2
+ help
+ This IP block enables SMP in ARC-HS38 cores.
+ It provides for cross-core interrupts, multi-core debug
+ hardware semaphores, shared memory,....
config NR_CPUS
int "Maximum number of CPUs (2-4096)"
range 2 4096
- depends on SMP
- default "2"
+ default "4"
+
+endif #SMP
menuconfig ARC_CACHE
bool "Enable Cache Support"
diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index 49014f0ef36d..bc5103637326 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -19,6 +19,7 @@
#else
#define TIMER0_IRQ 16
#define TIMER1_IRQ 17
+#define IPI_IRQ 19
#endif
#include <linux/interrupt.h>
diff --git a/arch/arc/include/asm/mcip.h b/arch/arc/include/asm/mcip.h
new file mode 100644
index 000000000000..31f9bac77a27
--- /dev/null
+++ b/arch/arc/include/asm/mcip.h
@@ -0,0 +1,91 @@
+/*
+ * ARConnect IP Support (Multi core enabler: Cross core IPI, RTC ...)
+ *
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_MCIP_H
+#define __ASM_MCIP_H
+
+#ifdef CONFIG_ISA_ARCV2
+
+#include <asm/arcregs.h>
+
+#define ARC_REG_MCIP_BCR 0x0d0
+#define ARC_REG_MCIP_CMD 0x600
+#define ARC_REG_MCIP_WDATA 0x601
+#define ARC_REG_MCIP_READBACK 0x602
+
+struct mcip_cmd {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int pad:8, param:16, cmd:8;
+#else
+ unsigned int cmd:8, param:16, pad:8;
+#endif
+
+#define CMD_INTRPT_GENERATE_IRQ 0x01
+#define CMD_INTRPT_GENERATE_ACK 0x02
+#define CMD_INTRPT_READ_STATUS 0x03
+#define CMD_INTRPT_CHECK_SOURCE 0x04
+
+/* Semaphore Commands */
+#define CMD_SEMA_CLAIM_AND_READ 0x11
+#define CMD_SEMA_RELEASE 0x12
+
+#define CMD_DEBUG_SET_MASK 0x34
+#define CMD_DEBUG_SET_SELECT 0x36
+
+#define CMD_IDU_ENABLE 0x71
+#define CMD_IDU_DISABLE 0x72
+#define CMD_IDU_SET_MODE 0x74
+#define CMD_IDU_SET_DEST 0x76
+#define CMD_IDU_SET_MASK 0x7C
+
+#define IDU_M_TRIG_LEVEL 0x0
+#define IDU_M_TRIG_EDGE 0x1
+
+#define IDU_M_DISTRI_RR 0x0
+#define IDU_M_DISTRI_DEST 0x2
+};
+
+/*
+ * MCIP programming model
+ *
+ * - Simple commands write {cmd:8,param:16} to MCIP_CMD aux reg
+ * (param could be irq, common_irq, core_id ...)
+ * - More involved commands setup MCIP_WDATA with cmd specific data
+ * before invoking the simple command
+ */
+static inline void __mcip_cmd(unsigned int cmd, unsigned int param)
+{
+ struct mcip_cmd buf;
+
+ buf.pad = 0;
+ buf.cmd = cmd;
+ buf.param = param;
+
+ WRITE_AUX(ARC_REG_MCIP_CMD, buf);
+}
+
+/*
+ * Setup additional data for a cmd
+ * Callers need to lock to ensure atomicity
+ */
+static inline void __mcip_cmd_data(unsigned int cmd, unsigned int param,
+ unsigned int data)
+{
+ write_aux_reg(ARC_REG_MCIP_WDATA, data);
+
+ __mcip_cmd(cmd, param);
+}
+
+extern void mcip_init_early_smp(void);
+extern void mcip_init_smp(unsigned int cpu);
+
+#endif
+
+#endif
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index 0be7ba087260..e7f3625a19b5 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_ISA_ARCV2) += entry-arcv2.o intc-arcv2.o
obj-$(CONFIG_MODULES) += arcksyms.o module.o
obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_ARC_MCIP) += mcip.o
obj-$(CONFIG_ARC_DW2_UNWIND) += unwind.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_ARC_EMUL_UNALIGNED) += unaligned.o
diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
index 3876e11d4553..945162c1242d 100644
--- a/arch/arc/kernel/intc-arcv2.c
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -90,7 +90,7 @@ static struct irq_chip arcv2_irq_chip = {
static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
- if (irq == TIMER0_IRQ)
+ if (irq == TIMER0_IRQ || irq == IPI_IRQ)
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_percpu_irq);
else
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_level_irq);
diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
new file mode 100644
index 000000000000..e6ad6e64440a
--- /dev/null
+++ b/arch/arc/kernel/mcip.c
@@ -0,0 +1,117 @@
+/*
+ * ARC ARConnect (MultiCore IP) support (formerly known as MCIP)
+ *
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/smp.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <asm/mcip.h>
+
+static char smp_cpuinfo_buf[128];
+
+static DEFINE_RAW_SPINLOCK(mcip_lock);
+
+
+/*
+ * Any SMP specific init any CPU does when it comes up.
+ * Here we setup the CPU to enable Inter-Processor-Interrupts
+ * Called for each CPU
+ * -Master : init_IRQ()
+ * -Other(s) : start_kernel_secondary()
+ */
+void mcip_init_smp(unsigned int cpu)
+{
+ smp_ipi_irq_setup(cpu, IPI_IRQ);
+}
+
+static void mcip_ipi_send(int cpu)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&mcip_lock, flags);
+ __mcip_cmd(CMD_INTRPT_GENERATE_IRQ, cpu);
+ raw_spin_unlock_irqrestore(&mcip_lock, flags);
+}
+
+static void mcip_ipi_clear(int irq)
+{
+ unsigned int cpu;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&mcip_lock, flags);
+
+ /* Who sent the IPI */
+ __mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0);
+
+ cpu = read_aux_reg(ARC_REG_MCIP_READBACK); /* 1,2,4,8... */
+
+ __mcip_cmd(CMD_INTRPT_GENERATE_ACK, __ffs(cpu)); /* 0,1,2,3... */
+
+ raw_spin_unlock_irqrestore(&mcip_lock, flags);
+}
+
+volatile int wake_flag;
+
+static void mcip_wakeup_cpu(int cpu, unsigned long pc)
+{
+ BUG_ON(cpu == 0);
+ wake_flag = cpu;
+}
+
+void arc_platform_smp_wait_to_boot(int cpu)
+{
+ while (wake_flag != cpu)
+ ;
+
+ wake_flag = 0;
+ __asm__ __volatile__("j @first_lines_of_secondary \n");
+}
+
+struct plat_smp_ops plat_smp_ops = {
+ .info = smp_cpuinfo_buf,
+ .cpu_kick = mcip_wakeup_cpu,
+ .ipi_send = mcip_ipi_send,
+ .ipi_clear = mcip_ipi_clear,
+};
+
+void mcip_init_early_smp(void)
+{
+#define IS_AVAIL1(var, str) ((var) ? str : "")
+
+ struct mcip_bcr {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int pad3:8,
+ idu:1, llm:1, num_cores:6,
+ iocoh:1, grtc:1, dbg:1, pad2:1,
+ msg:1, sem:1, ipi:1, pad:1,
+ ver:8;
+#else
+ unsigned int ver:8,
+ pad:1, ipi:1, sem:1, msg:1,
+ pad2:1, dbg:1, grtc:1, iocoh:1,
+ num_cores:6, llm:1, idu:1,
+ pad3:8;
+#endif
+ } mp;
+
+ READ_BCR(ARC_REG_MCIP_BCR, mp);
+
+ sprintf(smp_cpuinfo_buf,
+ "Extn [SMP]\t: ARConnect (v%d): %d cores with %s%s%s%s\n",
+ mp.ver, mp.num_cores,
+ IS_AVAIL1(mp.ipi, "IPI "),
+ IS_AVAIL1(mp.idu, "IDU "),
+ IS_AVAIL1(mp.dbg, "DEBUG "),
+ IS_AVAIL1(mp.grtc, "GRTC"));
+
+ if (mp.dbg) {
+ __mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, 0xf);
+ __mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xf, 0xf);
+ }
+}
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index ee2982dda5a6..d07cb53d7641 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -31,7 +31,7 @@ arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
#endif
-struct plat_smp_ops plat_smp_ops;
+struct plat_smp_ops __weak plat_smp_ops;
/* XXX: per cpu ? Only needed once in early seconday boot */
struct task_struct *secondary_idle_tsk;
diff --git a/arch/arc/plat-sim/platform.c b/arch/arc/plat-sim/platform.c
index 114fdc30941c..8795ae2ef48a 100644
--- a/arch/arc/plat-sim/platform.c
+++ b/arch/arc/plat-sim/platform.c
@@ -10,6 +10,7 @@
#include <linux/init.h>
#include <asm/mach_desc.h>
+#include <asm/mcip.h>
/*----------------------- Machine Descriptions ------------------------------
*
@@ -27,4 +28,8 @@ static const char *simulation_compat[] __initconst = {
MACHINE_START(SIMULATION, "simulation")
.dt_compat = simulation_compat,
+#ifdef CONFIG_ARC_MCIP
+ .init_early = mcip_init_early_smp,
+ .init_smp = mcip_init_smp,
+#endif
MACHINE_END
--
1.9.1
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