Date: Mon, 17 Oct 2016 08:29:16 +0000 (UTC) From: Sepherosa Ziehau <sephe@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r307506 - stable/11/sys/x86/x86 Message-ID: <201610170829.u9H8TGJw033533@repo.freebsd.org>
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Author: sephe Date: Mon Oct 17 08:29:16 2016 New Revision: 307506 URL: https://svnweb.freebsd.org/changeset/base/307506 Log: MFC 305722 x86: Use sx lock for interrupt sources. - Certain pic_assign_cpu, e.g. msi_assign_cpu can have quite a long call chain. For msi_assign_cpu, mutex makes complex PCI bridge drivers more tricky, e.g. sleep can note be called, etc, it will be pretty tricky for upcoming Hyper-V PCI bridge driver for PCI pass-through. - It is not used on any hot code path nor non-sleepable context, so sx should have the same effect as mutex. PIC list is still protected by mutex to keep suspend/resume work. Discussed with: jhb Reviewed by: jhb Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D7784 Modified: stable/11/sys/x86/x86/intr_machdep.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/x86/x86/intr_machdep.c ============================================================================== --- stable/11/sys/x86/x86/intr_machdep.c Mon Oct 17 08:27:18 2016 (r307505) +++ stable/11/sys/x86/x86/intr_machdep.c Mon Oct 17 08:29:16 2016 (r307506) @@ -46,6 +46,7 @@ #include <sys/mutex.h> #include <sys/proc.h> #include <sys/smp.h> +#include <sys/sx.h> #include <sys/syslog.h> #include <sys/systm.h> #include <machine/clock.h> @@ -73,7 +74,8 @@ typedef void (*mask_fn)(void *); static int intrcnt_index; static struct intsrc *interrupt_sources[NUM_IO_INTS]; -static struct mtx intr_table_lock; +static struct sx intrsrc_lock; +static struct mtx intrpic_lock; static struct mtx intrcnt_lock; static TAILQ_HEAD(pics_head, pic) pics; @@ -117,14 +119,14 @@ intr_register_pic(struct pic *pic) { int error; - mtx_lock(&intr_table_lock); + mtx_lock(&intrpic_lock); if (intr_pic_registered(pic)) error = EBUSY; else { TAILQ_INSERT_TAIL(&pics, pic, pics); error = 0; } - mtx_unlock(&intr_table_lock); + mtx_unlock(&intrpic_lock); return (error); } @@ -148,16 +150,16 @@ intr_register_source(struct intsrc *isrc vector); if (error) return (error); - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); if (interrupt_sources[vector] != NULL) { - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); intr_event_destroy(isrc->is_event); return (EEXIST); } intrcnt_register(isrc); interrupt_sources[vector] = isrc; isrc->is_handlers = 0; - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); return (0); } @@ -181,14 +183,14 @@ intr_add_handler(const char *name, int v error = intr_event_add_handler(isrc->is_event, name, filter, handler, arg, intr_priority(flags), flags, cookiep); if (error == 0) { - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); intrcnt_updatename(isrc); isrc->is_handlers++; if (isrc->is_handlers == 1) { isrc->is_pic->pic_enable_intr(isrc); isrc->is_pic->pic_enable_source(isrc); } - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); } return (error); } @@ -202,14 +204,14 @@ intr_remove_handler(void *cookie) isrc = intr_handler_source(cookie); error = intr_event_remove_handler(cookie); if (error == 0) { - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); isrc->is_handlers--; if (isrc->is_handlers == 0) { isrc->is_pic->pic_disable_source(isrc, PIC_NO_EOI); isrc->is_pic->pic_disable_intr(isrc); } intrcnt_updatename(isrc); - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); } return (error); } @@ -283,12 +285,12 @@ intr_resume(bool suspend_cancelled) #ifndef DEV_ATPIC atpic_reset(); #endif - mtx_lock(&intr_table_lock); + mtx_lock(&intrpic_lock); TAILQ_FOREACH(pic, &pics, pics) { if (pic->pic_resume != NULL) pic->pic_resume(pic, suspend_cancelled); } - mtx_unlock(&intr_table_lock); + mtx_unlock(&intrpic_lock); } void @@ -296,12 +298,12 @@ intr_suspend(void) { struct pic *pic; - mtx_lock(&intr_table_lock); + mtx_lock(&intrpic_lock); TAILQ_FOREACH_REVERSE(pic, &pics, pics_head, pics) { if (pic->pic_suspend != NULL) pic->pic_suspend(pic); } - mtx_unlock(&intr_table_lock); + mtx_unlock(&intrpic_lock); } static int @@ -322,9 +324,9 @@ intr_assign_cpu(void *arg, int cpu) if (assign_cpu && cpu != NOCPU) { #endif isrc = arg; - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); error = isrc->is_pic->pic_assign_cpu(isrc, cpu_apic_ids[cpu]); - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); } else error = 0; return (error); @@ -384,7 +386,8 @@ intr_init(void *dummy __unused) intrcnt_setname("???", 0); intrcnt_index = 1; TAILQ_INIT(&pics); - mtx_init(&intr_table_lock, "intr sources", NULL, MTX_DEF); + mtx_init(&intrpic_lock, "intrpic", NULL, MTX_DEF); + sx_init(&intrsrc_lock, "intrsrc"); mtx_init(&intrcnt_lock, "intrcnt", NULL, MTX_SPIN); } SYSINIT(intr_init, SI_SUB_INTR, SI_ORDER_FIRST, intr_init, NULL); @@ -449,7 +452,7 @@ intr_reprogram(void) struct intsrc *is; int v; - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); for (v = 0; v < NUM_IO_INTS; v++) { is = interrupt_sources[v]; if (is == NULL) @@ -457,7 +460,7 @@ intr_reprogram(void) if (is->is_pic->pic_reprogram_pin != NULL) is->is_pic->pic_reprogram_pin(is); } - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); } #ifdef DDB @@ -562,7 +565,7 @@ intr_shuffle_irqs(void *arg __unused) return; /* Round-robin assign a CPU to each enabled source. */ - mtx_lock(&intr_table_lock); + sx_xlock(&intrsrc_lock); assign_cpu = 1; for (i = 0; i < NUM_IO_INTS; i++) { isrc = interrupt_sources[i]; @@ -583,7 +586,7 @@ intr_shuffle_irqs(void *arg __unused) } } - mtx_unlock(&intr_table_lock); + sx_xunlock(&intrsrc_lock); } SYSINIT(intr_shuffle_irqs, SI_SUB_SMP, SI_ORDER_SECOND, intr_shuffle_irqs, NULL);
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