From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751361AbbLHRIv (ORCPT ); Tue, 8 Dec 2015 12:08:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42911 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbbLHRHt (ORCPT ); Tue, 8 Dec 2015 12:07:49 -0500 From: Vitaly Kuznetsov To: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" , Haiyang Zhang , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/5] Drivers: hv: ring_buffer: remove code duplication from hv_ringbuffer_peek/read() Date: Tue, 8 Dec 2015 18:07:38 +0100 Message-Id: <1449594460-22588-4-git-send-email-vkuznets@redhat.com> In-Reply-To: <1449594460-22588-1-git-send-email-vkuznets@redhat.com> References: <1449594460-22588-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hv_ringbuffer_peek() does the same as hv_ringbuffer_read() without advancing the read index. The only functional change this patch brings is moving hv_need_to_signal_on_read() call under the ring_lock but this function is just a couple of comparisons. Signed-off-by: Vitaly Kuznetsov --- drivers/hv/ring_buffer.c | 68 ++++++++++++++++++------------------------------ 1 file changed, 25 insertions(+), 43 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 7bca513..07f9408 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -380,47 +380,9 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, return 0; } - -/* Read without advancing the read index. */ -int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, - void *Buffer, u32 buflen) -{ - u32 bytes_avail_towrite; - u32 bytes_avail_toread; - u32 next_read_location = 0; - unsigned long flags; - - spin_lock_irqsave(&Inring_info->ring_lock, flags); - - hv_get_ringbuffer_availbytes(Inring_info, - &bytes_avail_toread, - &bytes_avail_towrite); - - /* Make sure there is something to read */ - if (bytes_avail_toread < buflen) { - - spin_unlock_irqrestore(&Inring_info->ring_lock, flags); - - return -EAGAIN; - } - - /* Convert to byte offset */ - next_read_location = hv_get_next_read_location(Inring_info); - - next_read_location = hv_copyfrom_ringbuffer(Inring_info, - Buffer, - buflen, - next_read_location); - - spin_unlock_irqrestore(&Inring_info->ring_lock, flags); - - return 0; -} - - -/* Read and advance the read index. */ -int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, - u32 buflen, u32 offset, bool *signal) +static inline int __hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen, u32 offset, + bool *signal, bool advance) { u32 bytes_avail_towrite; u32 bytes_avail_toread; @@ -452,6 +414,9 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, buflen, next_read_location); + if (!advance) + goto out_unlock; + next_read_location = hv_copyfrom_ringbuffer(inring_info, &prev_indices, sizeof(u64), @@ -467,9 +432,26 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, /* Update the read index */ hv_set_next_read_location(inring_info, next_read_location); - spin_unlock_irqrestore(&inring_info->ring_lock, flags); - *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info); +out_unlock: + spin_unlock_irqrestore(&inring_info->ring_lock, flags); return 0; } + +/* Read from ring buffer without advancing the read index. */ +int hv_ringbuffer_peek(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen) +{ + return __hv_ringbuffer_read(inring_info, buffer, buflen, + 0, NULL, false); +} + +/* Read from ring buffer and advance the read index. */ +int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen, u32 offset, + bool *signal) +{ + return __hv_ringbuffer_read(inring_info, buffer, buflen, + offset, signal, true); +} -- 2.4.3