From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60152) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBlaR-00087y-4N for qemu-devel@nongnu.org; Wed, 12 Sep 2012 07:58:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TBlaP-0007Lb-PD for qemu-devel@nongnu.org; Wed, 12 Sep 2012 07:58:31 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:56796) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBlaP-0007Kq-4f for qemu-devel@nongnu.org; Wed, 12 Sep 2012 07:58:29 -0400 Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 12 Sep 2012 17:28:21 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8CBwHvc20054032 for ; Wed, 12 Sep 2012 17:28:17 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8CBwGap008180 for ; Wed, 12 Sep 2012 21:58:16 +1000 From: Lei Li Date: Wed, 12 Sep 2012 19:57:22 +0800 Message-Id: <1347451046-5513-2-git-send-email-lilei@linux.vnet.ibm.com> In-Reply-To: <1347451046-5513-1-git-send-email-lilei@linux.vnet.ibm.com> References: <1347451046-5513-1-git-send-email-lilei@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 1/5] qemu-char: Add new char device CirMemCharDriver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aliguori@us.ibm.com, Lei Li , eblake@redhat.com, armbru@redhat.com, lcapitulino@redhat.com Signed-off-by: Lei Li --- qemu-char.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 84 insertions(+), 0 deletions(-) diff --git a/qemu-char.c b/qemu-char.c index 767da93..0470085 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2591,6 +2591,90 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr) return d->outbuf_size; } +/*********************************************************/ +/*CircularMemory chardev*/ + +typedef struct { + size_t cbuf_capacity; + size_t cbuf_in; + size_t cbuf_out; + size_t cbuf_count; + uint8_t *cbuf; +} CircMemCharDriver; + +static int cirmem_chr_is_empty(CharDriverState *chr) +{ + CircMemCharDriver *d = chr->opaque; + + return d->cbuf_count == 0; +} + +static int cirmem_chr_is_full(CharDriverState *chr) +{ + CircMemCharDriver *d = chr->opaque; + + return d->cbuf_count == d->cbuf_capacity; +} + +static int cirmem_chr_write(CharDriverState *chr, const uint8_t *buf, int len) +{ + CircMemCharDriver *d = chr->opaque; + int left; + + if (d->cbuf_capacity < len) { + return -1; + } + + left = d->cbuf_capacity - d->cbuf_count % d->cbuf_capacity; + + /* Some of cbuf need to be overwrited */ + if (left < len) { + memcpy(d->cbuf + d->cbuf_in, buf, left); + memcpy(d->cbuf + d->cbuf_out, buf + left, len - left); + d->cbuf_out = (d->cbuf_out + len - left) % d->cbuf_capacity; + d->cbuf_count = d->cbuf_count + left; + } else { + /* Completely overwrite */ + if (cirmem_chr_is_full(chr)) { + d->cbuf_out = (d->cbuf_out + len) % d->cbuf_capacity; + } else { + /* Enough cbuf to write */ + d->cbuf_count += len; + } + memcpy(d->cbuf + d->cbuf_in, buf, len); + } + + d->cbuf_in = (d->cbuf_in + len) % d->cbuf_capacity; + + return len; +} + +static void cirmem_chr_read(CharDriverState *chr, uint8_t *buf, int len) +{ + CircMemCharDriver *d = chr->opaque; + int left; + + if (cirmem_chr_is_empty(chr)) { + return; + } + + left = d->cbuf_capacity - d->cbuf_count % d->cbuf_capacity; + + if (d->cbuf_capacity < len) { + len = d->cbuf_capacity; + } + + if (left < len) { + memcpy(buf, d->cbuf + d->cbuf_out, left); + memcpy(buf + left, d->cbuf + d->cbuf_out + left, len - left); + } else { + memcpy(buf, d->cbuf + d->cbuf_out, len); + } + + d->cbuf_out = (d->cbuf_out + len) % d->cbuf_capacity; + d->cbuf_count -= len; +} + QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename) { char host[65], port[33], width[8], height[8]; -- 1.7.7.6