From patchwork Tue Feb 19 17:29:11 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Campbell X-Patchwork-Id: 2163791 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id BF507DF24C for ; Tue, 19 Feb 2013 17:31:56 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U7r0G-00015S-GO; Tue, 19 Feb 2013 17:29:16 +0000 Received: from smtp02.citrix.com ([66.165.176.63]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U7r0C-00013b-SH for linux-arm-kernel@lists.infradead.org; Tue, 19 Feb 2013 17:29:14 +0000 X-IronPort-AV: E=Sophos;i="4.84,696,1355097600"; d="scan'208";a="7818939" Received: from accessns.citrite.net (HELO FTLPEX01CL01.citrite.net) ([10.9.154.239]) by FTLPIPO02.CITRIX.COM with ESMTP/TLS/AES128-SHA; 19 Feb 2013 17:29:12 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.78) with Microsoft SMTP Server id 14.2.318.1; Tue, 19 Feb 2013 12:29:11 -0500 Received: from drall.uk.xensource.com ([10.80.16.71]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1U7r0B-0003DI-88; Tue, 19 Feb 2013 17:29:11 +0000 From: Ian Campbell To: Subject: [PATCH LINUX v4] xen: event channel arrays are xen_ulong_t and not unsigned long Date: Tue, 19 Feb 2013 17:29:11 +0000 Message-ID: <1361294951-28633-1-git-send-email-ian.campbell@citrix.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1361285327.1051.115.camel@zakaz.uk.xensource.com> References: <1361285327.1051.115.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130219_122913_225695_54DF2669 X-CRM114-Status: GOOD ( 20.68 ) X-Spam-Score: -3.3 (---) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-3.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [66.165.176.63 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: "Keir \(Xen.org\)" , Ian Campbell , Stefano Stabellini , Konrad Rzeszutek Wilk , Tim Deegan , linux-kernel@vger.kernel.org, Jan Beulich , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On ARM we want these to be the same size on 32- and 64-bit. This is an ABI change on ARM. X86 does not change. Signed-off-by: Ian Campbell Cc: Jan Beulich Cc: Keir (Xen.org) Cc: Tim Deegan Cc: Stefano Stabellini Cc: linux-arm-kernel@lists.infradead.org Cc: xen-devel@lists.xen.org Cc: Konrad Rzeszutek Wilk --- Changes since V3 s/read_evtchn_pending_sel/xchg_xen_ulong/ in a comment. Changes since V2 Add comments about the correct bitops to use, and on the ordering/barrier requirements on xchg_xen_ulong. Changes since V1 use find_first_set not __ffs fix some more unsigned long -> xen_ulong_t use more generic xchg_xen_ulong instead of ...read_evtchn... --- arch/arm/include/asm/xen/events.h | 22 +++++++ arch/x86/include/asm/xen/events.h | 3 + drivers/xen/events.c | 113 +++++++++++++++++++++---------------- include/xen/interface/xen.h | 8 +- 4 files changed, 94 insertions(+), 52 deletions(-) diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 94b4e90..5c27696 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -15,4 +15,26 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) return raw_irqs_disabled_flags(regs->ARM_cpsr); } +/* + * We cannot use xchg because it does not support 8-byte + * values. However it is safe to use {ldr,dtd}exd directly because all + * platforms which Xen can run on support those instructions. + */ +static inline xen_ulong_t xchg_xen_ulong(xen_ulong_t *ptr, xen_ulong_t val) +{ + xen_ulong_t oldval; + unsigned int tmp; + + wmb(); + asm volatile("@ xchg_xen_ulong\n" + "1: ldrexd %0, %H0, [%3]\n" + " strexd %1, %2, %H2, [%3]\n" + " teq %1, #0\n" + " bne 1b" + : "=&r" (oldval), "=&r" (tmp) + : "r" (val), "r" (ptr) + : "memory", "cc"); + return oldval; +} + #endif /* _ASM_ARM_XEN_EVENTS_H */ diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h index cc146d5..ca842f2 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -16,4 +16,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) return raw_irqs_disabled_flags(regs->flags); } +/* No need for a barrier -- XCHG is a barrier on x86. */ +#define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) + #endif /* _ASM_X86_XEN_EVENTS_H */ diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 0be4df3..b8d84f5 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -80,6 +80,12 @@ enum xen_irq_type { }; /* + * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t + * array. Primarily to avoid long lines (hence the terse name). + */ +#define BM(x) (unsigned long *)(x) + +/* * Packed IRQ information: * type - enum xen_irq_type * event channel - irq->event channel mapping @@ -120,7 +126,14 @@ static unsigned long *pirq_eoi_map; #endif static bool (*pirq_needs_eoi)(unsigned irq); -static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG], +/* + * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be + * careful to only use bitops which allow for this (e.g test_bit and + * friends but not __ffs). + */ +#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8) + +static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD], cpu_evtchn_mask); /* Xen will never allocate port zero for any purpose. */ @@ -294,9 +307,9 @@ static bool pirq_needs_eoi_flag(unsigned irq) return info->u.pirq.flags & PIRQ_NEEDS_EOI; } -static inline unsigned long active_evtchns(unsigned int cpu, - struct shared_info *sh, - unsigned int idx) +static inline xen_ulong_t active_evtchns(unsigned int cpu, + struct shared_info *sh, + unsigned int idx) { return sh->evtchn_pending[idx] & per_cpu(cpu_evtchn_mask, cpu)[idx] & @@ -312,8 +325,8 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu) cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu)); #endif - clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq))); - set_bit(chn, per_cpu(cpu_evtchn_mask, cpu)); + clear_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)))); + set_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu))); info_for_irq(irq)->cpu = cpu; } @@ -339,19 +352,19 @@ static void init_evtchn_cpu_bindings(void) static inline void clear_evtchn(int port) { struct shared_info *s = HYPERVISOR_shared_info; - sync_clear_bit(port, &s->evtchn_pending[0]); + sync_clear_bit(port, BM(&s->evtchn_pending[0])); } static inline void set_evtchn(int port) { struct shared_info *s = HYPERVISOR_shared_info; - sync_set_bit(port, &s->evtchn_pending[0]); + sync_set_bit(port, BM(&s->evtchn_pending[0])); } static inline int test_evtchn(int port) { struct shared_info *s = HYPERVISOR_shared_info; - return sync_test_bit(port, &s->evtchn_pending[0]); + return sync_test_bit(port, BM(&s->evtchn_pending[0])); } @@ -375,7 +388,7 @@ EXPORT_SYMBOL_GPL(notify_remote_via_irq); static void mask_evtchn(int port) { struct shared_info *s = HYPERVISOR_shared_info; - sync_set_bit(port, &s->evtchn_mask[0]); + sync_set_bit(port, BM(&s->evtchn_mask[0])); } static void unmask_evtchn(int port) @@ -389,7 +402,7 @@ static void unmask_evtchn(int port) if (unlikely((cpu != cpu_from_evtchn(port)))) do_hypercall = 1; else - evtchn_pending = sync_test_bit(port, &s->evtchn_pending[0]); + evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0])); if (unlikely(evtchn_pending && xen_hvm_domain())) do_hypercall = 1; @@ -403,7 +416,7 @@ static void unmask_evtchn(int port) } else { struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); - sync_clear_bit(port, &s->evtchn_mask[0]); + sync_clear_bit(port, BM(&s->evtchn_mask[0])); /* * The following is basically the equivalent of @@ -411,8 +424,8 @@ static void unmask_evtchn(int port) * the interrupt edge' if the channel is masked. */ if (evtchn_pending && - !sync_test_and_set_bit(port / BITS_PER_LONG, - &vcpu_info->evtchn_pending_sel)) + !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD, + BM(&vcpu_info->evtchn_pending_sel))) vcpu_info->evtchn_upcall_pending = 1; } @@ -1189,7 +1202,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id) { struct shared_info *sh = HYPERVISOR_shared_info; int cpu = smp_processor_id(); - unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu); + xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu); int i; unsigned long flags; static DEFINE_SPINLOCK(debug_lock); @@ -1205,7 +1218,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id) pending = (get_irq_regs() && i == cpu) ? xen_irqs_disabled(get_irq_regs()) : v->evtchn_upcall_mask; - printk("%d: masked=%d pending=%d event_sel %0*lx\n ", i, + printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n ", i, pending, v->evtchn_upcall_pending, (int)(sizeof(v->evtchn_pending_sel)*2), v->evtchn_pending_sel); @@ -1214,49 +1227,52 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id) printk("\npending:\n "); for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--) - printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2, + printk("%0*"PRI_xen_ulong"%s", + (int)sizeof(sh->evtchn_pending[0])*2, sh->evtchn_pending[i], i % 8 == 0 ? "\n " : " "); printk("\nglobal mask:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) - printk("%0*lx%s", + printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(sh->evtchn_mask[0])*2), sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\nglobally unmasked:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) - printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2), + printk("%0*"PRI_xen_ulong"%s", + (int)(sizeof(sh->evtchn_mask[0])*2), sh->evtchn_pending[i] & ~sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\nlocal cpu%d mask:\n ", cpu); - for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--) - printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2), + for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--) + printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2), cpu_evtchn[i], i % 8 == 0 ? "\n " : " "); printk("\nlocally unmasked:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) { - unsigned long pending = sh->evtchn_pending[i] + xen_ulong_t pending = sh->evtchn_pending[i] & ~sh->evtchn_mask[i] & cpu_evtchn[i]; - printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2), + printk("%0*"PRI_xen_ulong"%s", + (int)(sizeof(sh->evtchn_mask[0])*2), pending, i % 8 == 0 ? "\n " : " "); } printk("\npending list:\n"); for (i = 0; i < NR_EVENT_CHANNELS; i++) { - if (sync_test_bit(i, sh->evtchn_pending)) { - int word_idx = i / BITS_PER_LONG; + if (sync_test_bit(i, BM(sh->evtchn_pending))) { + int word_idx = i / BITS_PER_EVTCHN_WORD; printk(" %d: event %d -> irq %d%s%s%s\n", cpu_from_evtchn(i), i, evtchn_to_irq[i], - sync_test_bit(word_idx, &v->evtchn_pending_sel) + sync_test_bit(word_idx, BM(&v->evtchn_pending_sel)) ? "" : " l2-clear", - !sync_test_bit(i, sh->evtchn_mask) + !sync_test_bit(i, BM(sh->evtchn_mask)) ? "" : " globally-masked", - sync_test_bit(i, cpu_evtchn) + sync_test_bit(i, BM(cpu_evtchn)) ? "" : " locally-masked"); } } @@ -1273,7 +1289,7 @@ static DEFINE_PER_CPU(unsigned int, current_bit_idx); /* * Mask out the i least significant bits of w */ -#define MASK_LSBS(w, i) (w & ((~0UL) << i)) +#define MASK_LSBS(w, i) (w & ((~((xen_ulong_t)0UL)) << i)) /* * Search the CPUs pending events bitmasks. For each one found, map @@ -1295,18 +1311,19 @@ static void __xen_evtchn_do_upcall(void) unsigned count; do { - unsigned long pending_words; + xen_ulong_t pending_words; vcpu_info->evtchn_upcall_pending = 0; if (__this_cpu_inc_return(xed_nesting_count) - 1) goto out; -#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */ - /* Clear master flag /before/ clearing selector flag. */ - wmb(); -#endif - pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0); + /* + * Master flag must be /before/ clearing selector + * flag. xchg_xen_ulong must contain an appropriate + * barrier. + */ + pending_words = xchg_xen_ulong(&vcpu_info->evtchn_pending_sel, 0); start_word_idx = __this_cpu_read(current_word_idx); start_bit_idx = __this_cpu_read(current_bit_idx); @@ -1314,8 +1331,8 @@ static void __xen_evtchn_do_upcall(void) word_idx = start_word_idx; for (i = 0; pending_words != 0; i++) { - unsigned long pending_bits; - unsigned long words; + xen_ulong_t pending_bits; + xen_ulong_t words; words = MASK_LSBS(pending_words, word_idx); @@ -1327,7 +1344,7 @@ static void __xen_evtchn_do_upcall(void) bit_idx = 0; continue; } - word_idx = __ffs(words); + word_idx = find_first_bit(BM(&words), sizeof(words)); pending_bits = active_evtchns(cpu, s, word_idx); bit_idx = 0; /* usually scan entire word from start */ @@ -1342,7 +1359,7 @@ static void __xen_evtchn_do_upcall(void) } do { - unsigned long bits; + xen_ulong_t bits; int port, irq; struct irq_desc *desc; @@ -1352,10 +1369,10 @@ static void __xen_evtchn_do_upcall(void) if (bits == 0) break; - bit_idx = __ffs(bits); + bit_idx = find_first_bit(BM(&bits), sizeof(bits)); /* Process port. */ - port = (word_idx * BITS_PER_LONG) + bit_idx; + port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx; irq = evtchn_to_irq[port]; if (irq != -1) { @@ -1364,12 +1381,12 @@ static void __xen_evtchn_do_upcall(void) generic_handle_irq_desc(irq, desc); } - bit_idx = (bit_idx + 1) % BITS_PER_LONG; + bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD; /* Next caller starts at last processed + 1 */ __this_cpu_write(current_word_idx, bit_idx ? word_idx : - (word_idx+1) % BITS_PER_LONG); + (word_idx+1) % BITS_PER_EVTCHN_WORD); __this_cpu_write(current_bit_idx, bit_idx); } while (bit_idx != 0); @@ -1377,7 +1394,7 @@ static void __xen_evtchn_do_upcall(void) if ((word_idx != start_word_idx) || (i != 0)) pending_words &= ~(1UL << word_idx); - word_idx = (word_idx + 1) % BITS_PER_LONG; + word_idx = (word_idx + 1) % BITS_PER_EVTCHN_WORD; } BUG_ON(!irqs_disabled()); @@ -1487,8 +1504,8 @@ int resend_irq_on_evtchn(unsigned int irq) if (!VALID_EVTCHN(evtchn)) return 1; - masked = sync_test_and_set_bit(evtchn, s->evtchn_mask); - sync_set_bit(evtchn, s->evtchn_pending); + masked = sync_test_and_set_bit(evtchn, BM(s->evtchn_mask)); + sync_set_bit(evtchn, BM(s->evtchn_pending)); if (!masked) unmask_evtchn(evtchn); @@ -1536,8 +1553,8 @@ static int retrigger_dynirq(struct irq_data *data) if (VALID_EVTCHN(evtchn)) { int masked; - masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask); - sync_set_bit(evtchn, sh->evtchn_pending); + masked = sync_test_and_set_bit(evtchn, BM(sh->evtchn_mask)); + sync_set_bit(evtchn, BM(sh->evtchn_pending)); if (!masked) unmask_evtchn(evtchn); ret = 1; diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 5d6c272..a9075df 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -285,7 +285,7 @@ DEFINE_GUEST_HANDLE_STRUCT(multicall_entry); * Event channel endpoints per domain: * 1024 if a long is 32 bits; 4096 if a long is 64 bits. */ -#define NR_EVENT_CHANNELS (sizeof(unsigned long) * sizeof(unsigned long) * 64) +#define NR_EVENT_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64) struct vcpu_time_info { /* @@ -341,7 +341,7 @@ struct vcpu_info { */ uint8_t evtchn_upcall_pending; uint8_t evtchn_upcall_mask; - unsigned long evtchn_pending_sel; + xen_ulong_t evtchn_pending_sel; struct arch_vcpu_info arch; struct pvclock_vcpu_time_info time; }; /* 64 bytes (x86) */ @@ -384,8 +384,8 @@ struct shared_info { * per-vcpu selector word to be set. Each bit in the selector covers a * 'C long' in the PENDING bitfield array. */ - unsigned long evtchn_pending[sizeof(unsigned long) * 8]; - unsigned long evtchn_mask[sizeof(unsigned long) * 8]; + xen_ulong_t evtchn_pending[sizeof(xen_ulong_t) * 8]; + xen_ulong_t evtchn_mask[sizeof(xen_ulong_t) * 8]; /* * Wallclock time: updated only by control software. Guests should base