From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [Patch v4 3/5] x86/hpet: Post cleanup Date: Wed, 13 Nov 2013 17:59:12 +0000 Message-ID: <1384365554-11017-4-git-send-email-andrew.cooper3@citrix.com> References: <1384365554-11017-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1384365554-11017-1-git-send-email-andrew.cooper3@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Andrew Cooper , Keir Fraser , Jan Beulich , Tim Deegan List-Id: xen-devel@lists.xenproject.org These changes are ones which were able to be pulled out of the previous patch. They are all misc cleanup without functional implications * Shift HPET_EVT_* definitions up now that USED has moved out * Shuffle struct hpet_event_channel ** Reflow horizontally and comment current use ** Promote 'shift' to unsigned. It is the constant 32 but can be more easily optimised. ** Move 'flags' up to fill 4 byte hole ** Move 'cpumask' and 'lock' into second cache line as they are diried from other cpus * The new locking requirements guarentee that interrupts are disabled in hpet_set_counter. Leave an ASSERT() just in case. Signed-off-by: Andrew Cooper CC: Keir Fraser CC: Jan Beulich CC: Tim Deegan --- xen/arch/x86/hpet.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c index 20339b4..0bb3c31 100644 --- a/xen/arch/x86/hpet.c +++ b/xen/arch/x86/hpet.c @@ -19,22 +19,22 @@ #define MAX_DELTA_NS MILLISECS(10*1000) #define MIN_DELTA_NS MICROSECS(20) -#define HPET_EVT_DISABLE_BIT 1 +#define HPET_EVT_DISABLE_BIT 0 #define HPET_EVT_DISABLE (1 << HPET_EVT_DISABLE_BIT) -#define HPET_EVT_LEGACY_BIT 2 +#define HPET_EVT_LEGACY_BIT 1 #define HPET_EVT_LEGACY (1 << HPET_EVT_LEGACY_BIT) struct hpet_event_channel { - unsigned long mult; - int shift; - s_time_t next_event; - cpumask_var_t cpumask; - spinlock_t lock; - unsigned int idx; /* physical channel idx */ - unsigned int cpu; /* msi target */ - struct msi_desc msi;/* msi state */ - unsigned int flags; /* HPET_EVT_x */ + unsigned long mult; /* tick <-> time conversion */ + unsigned int shift; /* tick <-> time conversion */ + unsigned int flags; /* HPET_EVT_x */ + s_time_t next_event; /* expected time of next interrupt */ + unsigned int idx; /* HPET counter index */ + unsigned int cpu; /* owner of channel (or -1) */ + struct msi_desc msi; /* msi state */ + cpumask_var_t cpumask; /* cpus wishing to be woken */ + spinlock_t lock; } __cacheline_aligned; static struct hpet_event_channel *__read_mostly hpet_events; @@ -107,14 +107,13 @@ static inline unsigned long ns2ticks(unsigned long nsec, int shift, static int hpet_set_counter(struct hpet_event_channel *ch, unsigned long delta) { uint32_t cnt, cmp; - unsigned long flags; - local_irq_save(flags); + ASSERT(!local_irq_is_enabled()); + cnt = hpet_read32(HPET_COUNTER); cmp = cnt + delta; hpet_write32(cmp, HPET_Tn_CMP(ch->idx)); cmp = hpet_read32(HPET_COUNTER); - local_irq_restore(flags); /* Are we within two ticks of the deadline passing? Then we may miss. */ return ((cmp + 2 - cnt) > delta) ? -ETIME : 0; -- 1.7.10.4