From 6c15e9bfb687f40cc92759536ef2a918fb04349b Mon Sep 17 00:00:00 2001 From: Jing Liu Date: Mon, 19 Sep 2016 09:10:43 +0200 Subject: s390x/css: Add an algorithm to find a free chpid This introduces a function named css_find_free_chpid() to find a free channel path. Because virtio-ccw device used zero as its channel path number, it would be sensible to skip the reserved one and search upwards. Signed-off-by: Jing Liu Reviewed-by: QingFeng Hao Reviewed-by: Dong Jia Shi Signed-off-by: Cornelia Huck --- hw/s390x/css.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'hw/s390x') diff --git a/hw/s390x/css.c b/hw/s390x/css.c index c03bb20bc9..d94498a97b 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -1302,6 +1302,27 @@ bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid) (MAX_SCHID + 1) / sizeof(unsigned long)); } +unsigned int css_find_free_chpid(uint8_t cssid) +{ + CssImage *css = channel_subsys.css[cssid]; + unsigned int chpid; + + if (!css) { + return MAX_CHPID + 1; + } + + for (chpid = 0; chpid <= MAX_CHPID; chpid++) { + /* skip reserved chpid */ + if (chpid == VIRTIO_CCW_CHPID) { + continue; + } + if (!css->chpids[chpid].in_use) { + return chpid; + } + } + return MAX_CHPID + 1; +} + static int css_add_virtual_chpid(uint8_t cssid, uint8_t chpid, uint8_t type) { CssImage *css; -- cgit v1.2.1