From fb702b942bf638baa6cbbbda9f76794db62921ef Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Fri, 25 Jun 2010 16:41:11 -0400 Subject: arch/tile: Enable more sophisticated IRQ model for 32-bit chips. This model is based on the on-chip interrupt model used by the TILE-Gx next-generation hardware, and interacts much more cleanly with the Linux generic IRQ layer. The change includes modifications to the Tilera hypervisor, which are reflected in the hypervisor headers in arch/tile/include/arch/. Signed-off-by: Chris Metcalf Acked-by: Thomas Gleixner --- arch/tile/include/arch/chip_tile64.h | 3 + arch/tile/include/arch/chip_tilepro.h | 3 + arch/tile/include/asm/irq.h | 62 +++++++- arch/tile/include/asm/smp.h | 27 +++- arch/tile/include/hv/hypervisor.h | 117 ++++++++------- arch/tile/include/hv/pagesize.h | 32 +++++ arch/tile/kernel/hvglue.lds | 14 +- arch/tile/kernel/irq.c | 259 ++++++++++++++++++++++++---------- arch/tile/kernel/smp.c | 72 ++++++++-- 9 files changed, 435 insertions(+), 154 deletions(-) create mode 100644 arch/tile/include/hv/pagesize.h (limited to 'arch/tile') diff --git a/arch/tile/include/arch/chip_tile64.h b/arch/tile/include/arch/chip_tile64.h index 18b5bc8e563f..1246573be59e 100644 --- a/arch/tile/include/arch/chip_tile64.h +++ b/arch/tile/include/arch/chip_tile64.h @@ -248,5 +248,8 @@ /** Does the chip support rev1 DMA packets? */ #define CHIP_HAS_REV1_DMA_PACKETS() 0 +/** Does the chip have an IPI shim? */ +#define CHIP_HAS_IPI() 0 + #endif /* !__OPEN_SOURCE__ */ #endif /* __ARCH_CHIP_H__ */ diff --git a/arch/tile/include/arch/chip_tilepro.h b/arch/tile/include/arch/chip_tilepro.h index 9852af163862..e864c47fc89c 100644 --- a/arch/tile/include/arch/chip_tilepro.h +++ b/arch/tile/include/arch/chip_tilepro.h @@ -248,5 +248,8 @@ /** Does the chip support rev1 DMA packets? */ #define CHIP_HAS_REV1_DMA_PACKETS() 1 +/** Does the chip have an IPI shim? */ +#define CHIP_HAS_IPI() 0 + #endif /* !__OPEN_SOURCE__ */ #endif /* __ARCH_CHIP_H__ */ diff --git a/arch/tile/include/asm/irq.h b/arch/tile/include/asm/irq.h index 9be1f849fac9..572fd3ef1d73 100644 --- a/arch/tile/include/asm/irq.h +++ b/arch/tile/include/asm/irq.h @@ -23,15 +23,65 @@ /* IRQ numbers used for linux IPIs. */ #define IRQ_RESCHEDULE 1 -/* The HV interrupt state object. */ -DECLARE_PER_CPU(HV_IntrState, dev_intr_state); - void ack_bad_irq(unsigned int irq); /* - * Paravirtualized drivers should call this when their init calls - * discover a valid HV IRQ. + * Different ways of handling interrupts. Tile interrupts are always + * per-cpu; there is no global interrupt controller to implement + * enable/disable. Most onboard devices can send their interrupts to + * many tiles at the same time, and Tile-specific drivers know how to + * deal with this. + * + * However, generic devices (usually PCIE based, sometimes GPIO) + * expect that interrupts will fire on a single core at a time and + * that the irq can be enabled or disabled from any core at any time. + * We implement this by directing such interrupts to a single core. + * + * One added wrinkle is that PCI interrupts can be either + * hardware-cleared (legacy interrupts) or software cleared (MSI). + * Other generic device systems (GPIO) are always software-cleared. + * + * The enums below are used by drivers for onboard devices, including + * the internals of PCI root complex and GPIO. They allow the driver + * to tell the generic irq code what kind of interrupt is mapped to a + * particular IRQ number. + */ +enum { + /* per-cpu interrupt; use enable/disable_percpu_irq() to mask */ + TILE_IRQ_PERCPU, + /* global interrupt, hardware responsible for clearing. */ + TILE_IRQ_HW_CLEAR, + /* global interrupt, software responsible for clearing. */ + TILE_IRQ_SW_CLEAR, +}; + + +/* + * Paravirtualized drivers should call this when they dynamically + * allocate a new IRQ or discover an IRQ that was pre-allocated by the + * hypervisor for use with their particular device. This gives the + * IRQ subsystem an opportunity to do interrupt-type-specific + * initialization. + * + * ISSUE: We should modify this API so that registering anything + * except percpu interrupts also requires providing callback methods + * for enabling and disabling the interrupt. This would allow the + * generic IRQ code to proxy enable/disable_irq() calls back into the + * PCI subsystem, which in turn could enable or disable the interrupt + * at the PCI shim. */ -void tile_irq_activate(unsigned int irq); +void tile_irq_activate(unsigned int irq, int tile_irq_type); + +/* + * For onboard, non-PCI (e.g. TILE_IRQ_PERCPU) devices, drivers know + * how to use enable/disable_percpu_irq() to manage interrupts on each + * core. We can't use the generic enable/disable_irq() because they + * use a single reference count per irq, rather than per cpu per irq. + */ +void enable_percpu_irq(unsigned int irq); +void disable_percpu_irq(unsigned int irq); + + +void setup_irq_regs(void); #endif /* _ASM_TILE_IRQ_H */ diff --git a/arch/tile/include/asm/smp.h b/arch/tile/include/asm/smp.h index da24858a7392..532124ae4b12 100644 --- a/arch/tile/include/asm/smp.h +++ b/arch/tile/include/asm/smp.h @@ -20,6 +20,7 @@ #include #include #include +#include /* Set up this tile to support receiving hypervisor messages */ void init_messaging(void); @@ -39,9 +40,6 @@ void send_IPI_single(int dest, int tag); /* Process an IPI message */ void evaluate_message(int tag); -/* Process an IRQ_RESCHEDULE IPI. */ -irqreturn_t handle_reschedule_ipi(int irq, void *token); - /* Boot a secondary cpu */ void online_secondary(void); @@ -56,6 +54,20 @@ extern HV_Topology smp_topology; #define smp_height (smp_topology.height) #define smp_width (smp_topology.width) +/* Convenience functions for converting cpu <-> coords. */ +static inline int cpu_x(int cpu) +{ + return cpu % smp_width; +} +static inline int cpu_y(int cpu) +{ + return cpu / smp_width; +} +static inline int xy_to_cpu(int x, int y) +{ + return y * smp_width + x; +} + /* Hypervisor message tags sent via the tile send_IPI*() routines. */ #define MSG_TAG_START_CPU 1 #define MSG_TAG_STOP_CPU 2 @@ -85,6 +97,9 @@ void print_disabled_cpus(void); #define smp_master_cpu 0 #define smp_height 1 #define smp_width 1 +#define cpu_x(cpu) 0 +#define cpu_y(cpu) 0 +#define xy_to_cpu(x, y) 0 #endif /* !CONFIG_SMP */ @@ -123,4 +138,10 @@ static inline int __cpulist_parse_crop(const char *buf, struct cpumask *dstp, return bitmap_parselist_crop(buf, cpumask_bits(dstp), nbits); } +/* Initialize the IPI subsystem. */ +void ipi_init(void); + +/* Function for start-cpu message to cause us to jump to. */ +extern unsigned long start_cpu_function_addr; + #endif /* _ASM_TILE_SMP_H */ diff --git a/arch/tile/include/hv/hypervisor.h b/arch/tile/include/hv/hypervisor.h index 84b31551080a..a90d2989587a 100644 --- a/arch/tile/include/hv/hypervisor.h +++ b/arch/tile/include/hv/hypervisor.h @@ -20,12 +20,9 @@ #ifndef _TILE_HV_H #define _TILE_HV_H -#ifdef __tile__ #include -#else -/* HACK: Allow use by "tools/cpack/". */ -#include "install/include/arch/chip.h" -#endif + +#include /* Linux builds want unsigned long constants, but assembler wants numbers */ #ifdef __ASSEMBLER__ @@ -39,7 +36,6 @@ #define __HV_SIZE_ONE 1UL #endif - /** The log2 of the span of a level-1 page table, in bytes. */ #define HV_LOG2_L1_SPAN 32 @@ -48,21 +44,11 @@ */ #define HV_L1_SPAN (__HV_SIZE_ONE << HV_LOG2_L1_SPAN) -/** The log2 of the size of small pages, in bytes. This value should - * be verified at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_SMALL). - */ -#define HV_LOG2_PAGE_SIZE_SMALL 16 - /** The size of small pages, in bytes. This value should be verified * at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_SMALL). */ #define HV_PAGE_SIZE_SMALL (__HV_SIZE_ONE << HV_LOG2_PAGE_SIZE_SMALL) -/** The log2 of the size of large pages, in bytes. This value should be - * verified at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_LARGE). - */ -#define HV_LOG2_PAGE_SIZE_LARGE 24 - /** The size of large pages, in bytes. This value should be verified * at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_LARGE). */ @@ -93,7 +79,7 @@ #define HV_DISPATCH_ENTRY_SIZE 32 /** Version of the hypervisor interface defined by this file */ -#define _HV_VERSION 10 +#define _HV_VERSION 11 /* Index into hypervisor interface dispatch code blocks. * @@ -253,8 +239,10 @@ /** hv_set_command_line */ #define HV_DISPATCH_SET_COMMAND_LINE 47 -/** hv_dev_register_intr_state */ -#define HV_DISPATCH_DEV_REGISTER_INTR_STATE 48 +#if !CHIP_HAS_IPI() + +/** hv_clear_intr */ +#define HV_DISPATCH_CLEAR_INTR 48 /** hv_enable_intr */ #define HV_DISPATCH_ENABLE_INTR 49 @@ -262,20 +250,30 @@ /** hv_disable_intr */ #define HV_DISPATCH_DISABLE_INTR 50 +/** hv_raise_intr */ +#define HV_DISPATCH_RAISE_INTR 51 + /** hv_trigger_ipi */ -#define HV_DISPATCH_TRIGGER_IPI 51 +#define HV_DISPATCH_TRIGGER_IPI 52 + +#endif /* !CHIP_HAS_IPI() */ /** hv_store_mapping */ -#define HV_DISPATCH_STORE_MAPPING 52 +#define HV_DISPATCH_STORE_MAPPING 53 /** hv_inquire_realpa */ -#define HV_DISPATCH_INQUIRE_REALPA 53 +#define HV_DISPATCH_INQUIRE_REALPA 54 /** hv_flush_all */ -#define HV_DISPATCH_FLUSH_ALL 54 +#define HV_DISPATCH_FLUSH_ALL 55 + +#if CHIP_HAS_IPI() +/** hv_get_ipi_pte */ +#define HV_DISPATCH_GET_IPI_PTE 56 +#endif /** One more than the largest dispatch value */ -#define _HV_DISPATCH_END 55 +#define _HV_DISPATCH_END 57 #ifndef __ASSEMBLER__ @@ -484,21 +482,6 @@ typedef enum { */ int hv_confstr(HV_ConfstrQuery query, HV_VirtAddr buf, int len); -/** State object used to enable and disable one-shot and level-sensitive - * interrupts. */ -typedef struct -{ -#if CHIP_VA_WIDTH() > 32 - __hv64 opaque[2]; /**< No user-serviceable parts inside */ -#else - __hv32 opaque[2]; /**< No user-serviceable parts inside */ -#endif -} -HV_IntrState; - -/** A set of interrupts. */ -typedef __hv32 HV_IntrMask; - /** Tile coordinate */ typedef struct { @@ -509,34 +492,51 @@ typedef struct int y; } HV_Coord; + +#if CHIP_HAS_IPI() + +/** Get the PTE for sending an IPI to a particular tile. + * + * @param tile Tile which will receive the IPI. + * @param pl Indicates which IPI registers: 0 = IPI_0, 1 = IPI_1. + * @param pte Filled with resulting PTE. + * @result Zero if no error, non-zero for invalid parameters. + */ +int hv_get_ipi_pte(HV_Coord tile, int pl, HV_PTE* pte); + +#else /* !CHIP_HAS_IPI() */ + +/** A set of interrupts. */ +typedef __hv32 HV_IntrMask; + /** The low interrupt numbers are reserved for use by the client in * delivering IPIs. Any interrupt numbers higher than this value are * reserved for use by HV device drivers. */ #define HV_MAX_IPI_INTERRUPT 7 -/** Register an interrupt state object. This object is used to enable and - * disable one-shot and level-sensitive interrupts. Once the state is - * registered, the client must not read or write the state object; doing - * so will cause undefined results. +/** Enable a set of device interrupts. * - * @param intr_state Pointer to interrupt state object. - * @return HV_OK on success, or a hypervisor error code. + * @param enab_mask Bitmap of interrupts to enable. */ -HV_Errno hv_dev_register_intr_state(HV_IntrState* intr_state); +void hv_enable_intr(HV_IntrMask enab_mask); -/** Enable a set of one-shot and level-sensitive interrupts. +/** Disable a set of device interrupts. * - * @param intr_state Pointer to interrupt state object. - * @param enab_mask Bitmap of interrupts to enable. + * @param disab_mask Bitmap of interrupts to disable. */ -void hv_enable_intr(HV_IntrState* intr_state, HV_IntrMask enab_mask); +void hv_disable_intr(HV_IntrMask disab_mask); -/** Disable a set of one-shot and level-sensitive interrupts. +/** Clear a set of device interrupts. * - * @param intr_state Pointer to interrupt state object. - * @param disab_mask Bitmap of interrupts to disable. + * @param clear_mask Bitmap of interrupts to clear. */ -void hv_disable_intr(HV_IntrState* intr_state, HV_IntrMask disab_mask); +void hv_clear_intr(HV_IntrMask clear_mask); + +/** Assert a set of device interrupts. + * + * @param assert_mask Bitmap of interrupts to clear. + */ +void hv_assert_intr(HV_IntrMask assert_mask); /** Trigger a one-shot interrupt on some tile * @@ -547,6 +547,8 @@ void hv_disable_intr(HV_IntrState* intr_state, HV_IntrMask disab_mask); */ HV_Errno hv_trigger_ipi(HV_Coord tile, int interrupt); +#endif // !CHIP_HAS_IPI() + /** Store memory mapping in debug memory so that external debugger can read it. * A maximum of 16 entries can be stored. * @@ -1010,6 +1012,13 @@ int hv_console_write(HV_VirtAddr bytes, int len); * it will return to the code which was interrupted by the INTCTRL_1 * interrupt. * + * Under some circumstances, the firing of INTCTRL_1 can race with + * the lowering of a device interrupt. In such a case, the + * hv_downcall_dispatch service may issue an iret instruction instead + * of entering one of the client's actual downcall-handling interrupt + * vectors. This will return execution to the location that was + * interrupted by INTCTRL_1. + * * Any saving of registers should be done by the actual handling * vectors; no registers should be changed by the INTCTRL_1 handler. * In particular, the client should not use a jal instruction to invoke diff --git a/arch/tile/include/hv/pagesize.h b/arch/tile/include/hv/pagesize.h new file mode 100644 index 000000000000..58bed114fedd --- /dev/null +++ b/arch/tile/include/hv/pagesize.h @@ -0,0 +1,32 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +/** + * @file pagesize.h + */ + +#ifndef _HV_PAGESIZE_H +#define _HV_PAGESIZE_H + +/** The log2 of the size of small pages, in bytes. This value should + * be verified at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_SMALL). + */ +#define HV_LOG2_PAGE_SIZE_SMALL 16 + +/** The log2 of the size of large pages, in bytes. This value should be + * verified at runtime by calling hv_sysconf(HV_SYSCONF_PAGE_SIZE_LARGE). + */ +#define HV_LOG2_PAGE_SIZE_LARGE 24 + +#endif /* _HV_PAGESIZE_H */ diff --git a/arch/tile/kernel/hvglue.lds b/arch/tile/kernel/hvglue.lds index 698489b4c7ab..2b7cd0a659a9 100644 --- a/arch/tile/kernel/hvglue.lds +++ b/arch/tile/kernel/hvglue.lds @@ -46,11 +46,13 @@ hv_inquire_tiles = TEXT_OFFSET + 0x10580; hv_confstr = TEXT_OFFSET + 0x105a0; hv_reexec = TEXT_OFFSET + 0x105c0; hv_set_command_line = TEXT_OFFSET + 0x105e0; -hv_dev_register_intr_state = TEXT_OFFSET + 0x10600; +hv_clear_intr = TEXT_OFFSET + 0x10600; hv_enable_intr = TEXT_OFFSET + 0x10620; hv_disable_intr = TEXT_OFFSET + 0x10640; -hv_trigger_ipi = TEXT_OFFSET + 0x10660; -hv_store_mapping = TEXT_OFFSET + 0x10680; -hv_inquire_realpa = TEXT_OFFSET + 0x106a0; -hv_flush_all = TEXT_OFFSET + 0x106c0; -hv_glue_internals = TEXT_OFFSET + 0x106e0; +hv_raise_intr = TEXT_OFFSET + 0x10660; +hv_trigger_ipi = TEXT_OFFSET + 0x10680; +hv_store_mapping = TEXT_OFFSET + 0x106a0; +hv_inquire_realpa = TEXT_OFFSET + 0x106c0; +hv_flush_all = TEXT_OFFSET + 0x106e0; +hv_get_ipi_pte = TEXT_OFFSET + 0x10700; +hv_glue_internals = TEXT_OFFSET + 0x10720; diff --git a/arch/tile/kernel/irq.c b/arch/tile/kernel/irq.c index 24cc6b2abc2c..596c60086930 100644 --- a/arch/tile/kernel/irq.c +++ b/arch/tile/kernel/irq.c @@ -19,6 +19,11 @@ #include #include #include +#include +#include + +/* Bit-flag stored in irq_desc->chip_data to indicate HW-cleared irqs. */ +#define IS_HW_CLEARED 1 /* * The set of interrupts we enable for raw_local_irq_enable(). @@ -31,30 +36,74 @@ DEFINE_PER_CPU(unsigned long long, interrupts_enabled_mask) = INITIAL_INTERRUPTS_ENABLED; EXPORT_PER_CPU_SYMBOL(interrupts_enabled_mask); -/* Define per-tile device interrupt state */ -DEFINE_PER_CPU(HV_IntrState, dev_intr_state); - +/* Define per-tile device interrupt statistics state. */ DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp; EXPORT_PER_CPU_SYMBOL(irq_stat); +/* + * Define per-tile irq disable mask; the hardware/HV only has a single + * mask that we use to implement both masking and disabling. + */ +static DEFINE_PER_CPU(unsigned long, irq_disable_mask) + ____cacheline_internodealigned_in_smp; + +/* + * Per-tile IRQ nesting depth. Used to make sure we enable newly + * enabled IRQs before exiting the outermost interrupt. + */ +static DEFINE_PER_CPU(int, irq_depth); + +/* State for allocating IRQs on Gx. */ +#if CHIP_HAS_IPI() +static unsigned long available_irqs = ~(1UL << IRQ_RESCHEDULE); +static DEFINE_SPINLOCK(available_irqs_lock); +#endif +#if CHIP_HAS_IPI() +/* Use SPRs to manipulate device interrupts. */ +#define mask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_SET_1, irq_mask) +#define unmask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_RESET_1, irq_mask) +#define clear_irqs(irq_mask) __insn_mtspr(SPR_IPI_EVENT_RESET_1, irq_mask) +#else +/* Use HV to manipulate device interrupts. */ +#define mask_irqs(irq_mask) hv_disable_intr(irq_mask) +#define unmask_irqs(irq_mask) hv_enable_intr(irq_mask) +#define clear_irqs(irq_mask) hv_clear_intr(irq_mask) +#endif /* - * Interrupt dispatcher, invoked upon a hypervisor device interrupt downcall + * The interrupt handling path, implemented in terms of HV interrupt + * emulation on TILE64 and TILEPro, and IPI hardware on TILE-Gx. */ void tile_dev_intr(struct pt_regs *regs, int intnum) { - int irq; + int depth = __get_cpu_var(irq_depth)++; + unsigned long original_irqs; + unsigned long remaining_irqs; + struct pt_regs *old_regs; +#if CHIP_HAS_IPI() /* - * Get the device interrupt pending mask from where the hypervisor - * has tucked it away for us. + * Pending interrupts are listed in an SPR. We might be + * nested, so be sure to only handle irqs that weren't already + * masked by a previous interrupt. Then, mask out the ones + * we're going to handle. */ - unsigned long pending_dev_intr_mask = __insn_mfspr(SPR_SYSTEM_SAVE_1_3); - + unsigned long masked = __insn_mfspr(SPR_IPI_MASK_1); + original_irqs = __insn_mfspr(SPR_IPI_EVENT_1) & ~masked; + __insn_mtspr(SPR_IPI_MASK_SET_1, original_irqs); +#else + /* + * Hypervisor performs the equivalent of the Gx code above and + * then puts the pending interrupt mask into a system save reg + * for us to find. + */ + original_irqs = __insn_mfspr(SPR_SYSTEM_SAVE_1_3); +#endif + remaining_irqs = original_irqs; /* Track time spent here in an interrupt context. */ - struct pt_regs *old_regs = set_irq_regs(regs); + old_regs = set_irq_regs(regs); irq_enter(); #ifdef CONFIG_DEBUG_STACKOVERFLOW @@ -62,25 +111,34 @@ void tile_dev_intr(struct pt_regs *regs, int intnum) { long sp = stack_pointer - (long) current_thread_info(); if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { - printk(KERN_EMERG "tile_dev_intr: " + pr_emerg("tile_dev_intr: " "stack overflow: %ld\n", sp - sizeof(struct thread_info)); dump_stack(); } } #endif + while (remaining_irqs) { + unsigned long irq = __ffs(remaining_irqs); + remaining_irqs &= ~(1UL << irq); - for (irq = 0; pending_dev_intr_mask; ++irq) { - if (pending_dev_intr_mask & 0x1) { - generic_handle_irq(irq); + /* Count device irqs; Linux IPIs are counted elsewhere. */ + if (irq != IRQ_RESCHEDULE) + __get_cpu_var(irq_stat).irq_dev_intr_count++; - /* Count device irqs; IPIs are counted elsewhere. */ - if (irq > HV_MAX_IPI_INTERRUPT) - __get_cpu_var(irq_stat).irq_dev_intr_count++; - } - pending_dev_intr_mask >>= 1; + generic_handle_irq(irq); } + /* + * If we weren't nested, turn on all enabled interrupts, + * including any that were reenabled during interrupt + * handling. + */ + if (depth == 0) + unmask_irqs(~__get_cpu_var(irq_disable_mask)); + + __get_cpu_var(irq_depth)--; + /* * Track time spent against the current process again and * process any softirqs if they are waiting. @@ -90,97 +148,114 @@ void tile_dev_intr(struct pt_regs *regs, int intnum) } +/* + * Remove an irq from the disabled mask. If we're in an interrupt + * context, defer enabling the HW interrupt until we leave. + */ +void enable_percpu_irq(unsigned int irq) +{ + get_cpu_var(irq_disable_mask) &= ~(1UL << irq); + if (__get_cpu_var(irq_depth) == 0) + unmask_irqs(1UL << irq); + put_cpu_var(irq_disable_mask); +} +EXPORT_SYMBOL(enable_percpu_irq); + +/* + * Add an irq to the disabled mask. We disable the HW interrupt + * immediately so that there's no possibility of it firing. If we're + * in an interrupt context, the return path is careful to avoid + * unmasking a newly disabled interrupt. + */ +void disable_percpu_irq(unsigned int irq) +{ + get_cpu_var(irq_disable_mask) |= (1UL << irq); + mask_irqs(1UL << irq); + put_cpu_var(irq_disable_mask); +} +EXPORT_SYMBOL(disable_percpu_irq); + /* Mask an interrupt. */ -static void hv_dev_irq_mask(unsigned int irq) +static void tile_irq_chip_mask(unsigned int irq) { - HV_IntrState *p_intr_state = &__get_cpu_var(dev_intr_state); - hv_disable_intr(p_intr_state, 1 << irq); + mask_irqs(1UL << irq); } /* Unmask an interrupt. */ -static void hv_dev_irq_unmask(unsigned int irq) +static void tile_irq_chip_unmask(unsigned int irq) { - /* Re-enable the hypervisor to generate interrupts. */ - HV_IntrState *p_intr_state = &__get_cpu_var(dev_intr_state); - hv_enable_intr(p_intr_state, 1 << irq); + unmask_irqs(1UL << irq); } /* - * The HV doesn't latch incoming interrupts while an interrupt is - * disabled, so we need to reenable interrupts before running the - * handler. - * - * ISSUE: Enabling the interrupt this early avoids any race conditions - * but introduces the possibility of nested interrupt stack overflow. - * An imminent change to the HV IRQ model will fix this. + * Clear an interrupt before processing it so that any new assertions + * will trigger another irq. */ -static void hv_dev_irq_ack(unsigned int irq) +static void tile_irq_chip_ack(unsigned int irq) { - hv_dev_irq_unmask(irq); + if ((unsigned long)get_irq_chip_data(irq) != IS_HW_CLEARED) + clear_irqs(1UL << irq); } /* - * Since ack() reenables interrupts, there's nothing to do at eoi(). + * For per-cpu interrupts, we need to avoid unmasking any interrupts + * that we disabled via disable_percpu_irq(). */ -static void hv_dev_irq_eoi(unsigned int irq) +static void tile_irq_chip_eoi(unsigned int irq) { + if (!(__get_cpu_var(irq_disable_mask) & (1UL << irq))) + unmask_irqs(1UL << irq); } -static struct irq_chip hv_dev_irq_chip = { - .typename = "hv_dev_irq_chip", - .ack = hv_dev_irq_ack, - .mask = hv_dev_irq_mask, - .unmask = hv_dev_irq_unmask, - .eoi = hv_dev_irq_eoi, -}; - -static struct irqaction resched_action = { - .handler = handle_reschedule_ipi, - .name = "resched", - .dev_id = handle_reschedule_ipi /* unique token */, +static struct irq_chip tile_irq_chip = { + .typename = "tile_irq_chip", + .ack = tile_irq_chip_ack, + .eoi = tile_irq_chip_eoi, + .mask = tile_irq_chip_mask, + .unmask = tile_irq_chip_unmask, }; void __init init_IRQ(void) { - /* Bind IPI irqs. Does this belong somewhere else in init? */ - tile_irq_activate(IRQ_RESCHEDULE); - BUG_ON(setup_irq(IRQ_RESCHEDULE, &resched_action)); + ipi_init(); } -void __cpuinit init_per_tile_IRQs(void) +void __cpuinit setup_irq_regs(void) { - int rc; - - /* Set the pointer to the per-tile device interrupt state. */ - HV_IntrState *sv_ptr = &__get_cpu_var(dev_intr_state); - rc = hv_dev_register_intr_state(sv_ptr); - if (rc != HV_OK) - panic("hv_dev_register_intr_state: error %d", rc); - + /* Enable interrupt delivery. */ + unmask_irqs(~0UL); +#if CHIP_HAS_IPI() + raw_local_irq_unmask(INT_IPI_1); +#endif } -void tile_irq_activate(unsigned int irq) +void tile_irq_activate(unsigned int irq, int tile_irq_type) { /* - * Paravirtualized drivers can call up to the HV to find out - * which irq they're associated with. The HV interface - * doesn't provide a generic call for discovering all valid - * IRQs, so drivers must call this method to initialize newly - * discovered IRQs. - * - * We could also just initialize all 32 IRQs at startup, but - * doing so would lead to a kernel fault if an unexpected - * interrupt fires and jumps to a NULL action. By defering - * the set_irq_chip_and_handler() call, unexpected IRQs are - * handled properly by handle_bad_irq(). + * We use handle_level_irq() by default because the pending + * interrupt vector (whether modeled by the HV on TILE64 and + * TILEPro or implemented in hardware on TILE-Gx) has + * level-style semantics for each bit. An interrupt fires + * whenever a bit is high, not just at edges. + */ + irq_flow_handler_t handle = handle_level_irq; + if (tile_irq_type == TILE_IRQ_PERCPU) + handle = handle_percpu_irq; + set_irq_chip_and_handler(irq, &tile_irq_chip, handle); + + /* + * Flag interrupts that are hardware-cleared so that ack() + * won't clear them. */ - hv_dev_irq_mask(irq); - set_irq_chip_and_handler(irq, &hv_dev_irq_chip, handle_percpu_irq); + if (tile_irq_type == TILE_IRQ_HW_CLEAR) + set_irq_chip_data(irq, (void *)IS_HW_CLEARED); } +EXPORT_SYMBOL(tile_irq_activate); + void ack_bad_irq(unsigned int irq) { - printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq); + pr_err("unexpected IRQ trap at vector %02x\n", irq); } /* @@ -225,3 +300,35 @@ skip: } return 0; } + +#if CHIP_HAS_IPI() +int create_irq(void) +{ + unsigned long flags; + int result; + + spin_lock_irqsave(&available_irqs_lock, flags); + if (available_irqs == 0) + result = -ENOMEM; + else { + result = __ffs(available_irqs); + available_irqs &= ~(1UL << result); + dynamic_irq_init(result); + } + spin_unlock_irqrestore(&available_irqs_lock, flags); + + return result; +} +EXPORT_SYMBOL(create_irq); + +void destroy_irq(unsigned int irq) +{ + unsigned long flags; + + spin_lock_irqsave(&available_irqs_lock, flags); + available_irqs |= (1UL << irq); + dynamic_irq_cleanup(irq); + spin_unlock_irqrestore(&available_irqs_lock, flags); +} +EXPORT_SYMBOL(destroy_irq); +#endif diff --git a/arch/tile/kernel/smp.c b/arch/tile/kernel/smp.c index 782c1bfa6dfe..1cb5ec79de04 100644 --- a/arch/tile/kernel/smp.c +++ b/arch/tile/kernel/smp.c @@ -15,10 +15,18 @@ */ #include +#include +#include #include +#include #include HV_Topology smp_topology __write_once; +EXPORT_SYMBOL(smp_topology); + +#if CHIP_HAS_IPI() +static unsigned long __iomem *ipi_mappings[NR_CPUS]; +#endif /* @@ -100,7 +108,6 @@ void on_each_cpu_mask(const struct cpumask *mask, void (*func)(void *), /* Handler to start the current cpu. */ static void smp_start_cpu_interrupt(void) { - extern unsigned long start_cpu_function_addr; get_irq_regs()->pc = start_cpu_function_addr; } @@ -174,12 +181,8 @@ void flush_icache_range(unsigned long start, unsigned long end) } -/* - * The smp_send_reschedule() path does not use the hv_message_intr() - * path but instead the faster tile_dev_intr() path for interrupts. - */ - -irqreturn_t handle_reschedule_ipi(int irq, void *token) +/* Called when smp_send_reschedule() triggers IRQ_RESCHEDULE. */ +static irqreturn_t handle_reschedule_ipi(int irq, void *token) { /* * Nothing to do here; when we return from interrupt, the @@ -191,12 +194,63 @@ irqreturn_t handle_reschedule_ipi(int irq, void *token) return IRQ_HANDLED; } +static struct irqaction resched_action = { + .handler = handle_reschedule_ipi, + .name = "resched", + .dev_id = handle_reschedule_ipi /* unique token */, +}; + +void __init ipi_init(void) +{ +#if CHIP_HAS_IPI() + int cpu; + /* Map IPI trigger MMIO addresses. */ + for_each_possible_cpu(cpu) { + HV_Coord tile; + HV_PTE pte; + unsigned long offset; + + tile.x = cpu_x(cpu); + tile.y = cpu_y(cpu); + if (hv_get_ipi_pte(tile, 1, &pte) != 0) + panic("Failed to initialize IPI for cpu %d\n", cpu); + + offset = hv_pte_get_pfn(pte) << PAGE_SHIFT; + ipi_mappings[cpu] = ioremap_prot(offset, PAGE_SIZE, pte); + } +#endif + + /* Bind handle_reschedule_ipi() to IRQ_RESCHEDULE. */ + tile_irq_activate(IRQ_RESCHEDULE, TILE_IRQ_PERCPU); + BUG_ON(setup_irq(IRQ_RESCHEDULE, &resched_action)); +} + +#if CHIP_HAS_IPI() + +void smp_send_reschedule(int cpu) +{ + WARN_ON(cpu_is_offline(cpu)); + + /* + * We just want to do an MMIO store. The traditional writeq() + * functions aren't really correct here, since they're always + * directed at the PCI shim. For now, just do a raw store, + * casting away the __iomem attribute. + */ + ((unsigned long __force *)ipi_mappings[cpu])[IRQ_RESCHEDULE] = 0; +} + +#else + void smp_send_reschedule(int cpu) { HV_Coord coord; WARN_ON(cpu_is_offline(cpu)); - coord.y = cpu / smp_width; - coord.x = cpu % smp_width; + + coord.y = cpu_y(cpu); + coord.x = cpu_x(cpu); hv_trigger_ipi(coord, IRQ_RESCHEDULE); } + +#endif /* CHIP_HAS_IPI() */ -- cgit v1.2.2