From 3ce0fefc51bd56381b1b9a92835cf8f9db3f2ef8 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Thu, 29 Sep 2016 10:00:14 -0700 Subject: [PATCH] ARCv2: intc: untangle SMP, MCIP and IDU The IDU intc is technically part of MCIP (Multi-core IP) hence historically was only available in a SMP hardware build (and thus only in a SMP kernel build). Now that hardware restriction has been lifted, so a UP kernel needs to support it. This requires breaking mcip.c into parts which are strictly SMP (inter-core interrupts) and IDU which in reality is just another intc and thus has no bearing on SMP. This change allows IDU in UP builds and with a suitable device tree, we can have the cascaded intc system ARCv2 core intc <---> ARCv2 IDU intc <---> periperals Signed-off-by: Vineet Gupta --- arch/arc/Kconfig | 17 +++++++++-------- arch/arc/include/asm/mcip.h | 16 ++++++++++++++++ arch/arc/kernel/mcip.c | 31 +++++++++++-------------------- 3 files changed, 36 insertions(+), 28 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index ecd12379e2cd..6f67895cd9c4 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -186,14 +186,6 @@ if SMP config ARC_HAS_COH_CACHES def_bool n -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 @@ -211,6 +203,15 @@ config ARC_SMP_HALT_ON_RESET endif #SMP +config ARC_MCIP + bool "ARConnect Multicore IP (MCIP) Support " + depends on ISA_ARCV2 + default y if SMP + help + This IP block enables SMP in ARC-HS38 cores. + It provides for cross-core interrupts, multi-core debug + hardware semaphores, shared memory,.... + menuconfig ARC_CACHE bool "Enable Cache Support" default y diff --git a/arch/arc/include/asm/mcip.h b/arch/arc/include/asm/mcip.h index 847e3bbe387f..c8fbe4114bad 100644 --- a/arch/arc/include/asm/mcip.h +++ b/arch/arc/include/asm/mcip.h @@ -55,6 +55,22 @@ struct mcip_cmd { #define IDU_M_DISTRI_DEST 0x2 }; +struct mcip_bcr { +#ifdef CONFIG_CPU_BIG_ENDIAN + unsigned int pad3:8, + idu:1, llm:1, num_cores:6, + iocoh:1, gfrc: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, gfrc:1, iocoh:1, + num_cores:6, llm:1, idu:1, + pad3:8; +#endif +}; + /* * MCIP programming model * diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c index 72f9179b1a24..c424d5abc318 100644 --- a/arch/arc/kernel/mcip.c +++ b/arch/arc/kernel/mcip.c @@ -15,11 +15,12 @@ #include #include -static char smp_cpuinfo_buf[128]; -static int idu_detected; - static DEFINE_RAW_SPINLOCK(mcip_lock); +#ifdef CONFIG_SMP + +static char smp_cpuinfo_buf[128]; + static void mcip_setup_per_cpu(int cpu) { smp_ipi_irq_setup(cpu, IPI_IRQ); @@ -86,21 +87,7 @@ static void mcip_ipi_clear(int irq) static void mcip_probe_n_setup(void) { - struct mcip_bcr { -#ifdef CONFIG_CPU_BIG_ENDIAN - unsigned int pad3:8, - idu:1, llm:1, num_cores:6, - iocoh:1, gfrc: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, gfrc:1, iocoh:1, - num_cores:6, llm:1, idu:1, - pad3:8; -#endif - } mp; + struct mcip_bcr mp; READ_BCR(ARC_REG_MCIP_BCR, mp); @@ -114,7 +101,6 @@ static void mcip_probe_n_setup(void) IS_AVAIL1(mp.gfrc, "GFRC")); cpuinfo_arc700[0].extn.gfrc = mp.gfrc; - idu_detected = mp.idu; if (mp.dbg) { __mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, 0xf); @@ -130,6 +116,8 @@ struct plat_smp_ops plat_smp_ops = { .ipi_clear = mcip_ipi_clear, }; +#endif + /*************************************************************************** * ARCv2 Interrupt Distribution Unit (IDU) * @@ -295,8 +283,11 @@ idu_of_init(struct device_node *intc, struct device_node *parent) /* Read IDU BCR to confirm nr_irqs */ int nr_irqs = of_irq_count(intc); int i, irq; + struct mcip_bcr mp; + + READ_BCR(ARC_REG_MCIP_BCR, mp); - if (!idu_detected) + if (!mp.idu) panic("IDU not detected, but DeviceTree using it"); pr_info("MCIP: IDU referenced from Devicetree %d irqs\n", nr_irqs); -- 2.20.1