@@ -1340,6 +1340,116 @@ SubchDev *css_find_subch(uint8_t m, uint8_t cssid, uint8_t ssid, uint16_t schid)
return channel_subsys.css[real_cssid]->sch_set[ssid]->sch[schid];
}
+/**
+ * Return free device number in subchannel set.
+ *
+ * Return index of the first free device number in the subchannel set
+ * identified by @p cssid and @p ssid, beginning the search at @p
+ * start and wrapping around at MAX_DEVNO. Return a value exceeding
+ * MAX_SCHID if there are no free device numbers in the subchannel
+ * set.
+ */
+static uint32_t css_find_free_devno(uint8_t cssid, uint8_t ssid,
+ uint16_t start)
+{
+ uint32_t round;
+
+ for (round = 0; round <= MAX_DEVNO; round++) {
+ uint16_t devno = (start + round) % MAX_DEVNO;
+
+ if (!css_devno_used(cssid, ssid, devno)) {
+ return devno;
+ }
+ }
+ return MAX_DEVNO + 1;
+}
+
+/**
+ * Return first free subchannel (id) in subchannel set.
+ *
+ * Return index of the first free subchannel in the subchannel set
+ * identified by @p cssid and @p ssid, if there is any. Return a value
+ * exceeding MAX_SCHID if there are no free subchannels in the
+ * subchannel set.
+ */
+static uint32_t css_find_free_subch(uint8_t cssid, uint8_t ssid)
+{
+ uint32_t schid;
+
+ for (schid = 0; schid <= MAX_SCHID; schid++) {
+ if (!css_find_subch(1, cssid, ssid, schid)) {
+ return schid;
+ }
+ }
+ return MAX_SCHID + 1;
+}
+
+/**
+ * Return first free subchannel (id) in subchannel set for a device number
+ *
+ * Verify the device number @p devno is not used yet in the subchannel
+ * set identified by @p cssid and @p ssid. Set @p schid to the index
+ * of the first free subchannel in the subchannel set, if there is
+ * any. Return true if everything succeeded and false otherwise.
+ */
+static bool css_find_free_subch_for_devno(uint8_t cssid, uint8_t ssid,
+ uint16_t devno, uint16_t *schid,
+ Error **errp)
+{
+ uint32_t free_schid;
+
+ assert(schid);
+ if (css_devno_used(cssid, ssid, devno)) {
+ error_setg(errp, "Device %x.%x.%04x already exists",
+ cssid, ssid, devno);
+ return false;
+ }
+ free_schid = css_find_free_subch(cssid, ssid);
+ if (free_schid > MAX_SCHID) {
+ error_setg(errp, "No free subchannel found for %x.%x.%04x",
+ cssid, ssid, devno);
+ return false;
+ }
+ *schid = free_schid;
+ return true;
+}
+
+/**
+ * Return first free subchannel (id) and device number
+ *
+ * Locate the first free subchannel and first free device number in
+ * any of the subchannel sets of the channel subsystem identified by
+ * @p cssid. Return false if no free subchannel / device number could
+ * be found. Otherwise set @p ssid, @p devno and @p schid to identify
+ * the available subchannel and device number and return true.
+ *
+ * May modify @p ssid, @p devno and / or @p schid even if no free
+ * subchannel / device number could be found.
+ */
+static bool css_find_free_subch_and_devno(uint8_t cssid, uint8_t *ssid,
+ uint16_t *devno, uint16_t *schid,
+ Error **errp)
+{
+ uint32_t free_schid, free_devno;
+
+ assert(ssid && devno && schid);
+ for (*ssid = 0; *ssid <= MAX_SSID; (*ssid)++) {
+ free_schid = css_find_free_subch(cssid, *ssid);
+ if (free_schid > MAX_SCHID) {
+ continue;
+ }
+ free_devno = css_find_free_devno(cssid, *ssid, free_schid);
+ if (free_devno > MAX_DEVNO) {
+ continue;
+ }
+ *schid = free_schid;
+ *devno = free_devno;
+ return true;
+ }
+ error_setg(errp, "Virtual channel subsystem is full!");
+ return false;
+}
+
bool css_subch_visible(SubchDev *sch)
{
if (sch->ssid > channel_subsys.max_ssid) {
@@ -1762,3 +1872,36 @@ PropertyInfo css_devid_propinfo = {
.get = get_css_devid,
.set = set_css_devid,
};
+
+SubchDev *css_create_virtual_sch(CssDevId bus_id, Error **errp)
+{
+ uint16_t schid = 0;
+ SubchDev *sch;
+
+ if (bus_id.valid) {
+ /* Enforce use of virtual cssid. */
+ if (bus_id.cssid != VIRTUAL_CSSID) {
+ error_setg(errp, "cssid %hhx not valid for virtual devices",
+ bus_id.cssid);
+ return NULL;
+ }
+ if (!css_find_free_subch_for_devno(bus_id.cssid, bus_id.ssid,
+ bus_id.devid, &schid, errp)) {
+ return NULL;
+ }
+ } else {
+ bus_id.cssid = VIRTUAL_CSSID;
+ if (!css_find_free_subch_and_devno(bus_id.cssid, &bus_id.ssid,
+ &bus_id.devid, &schid, errp)) {
+ return NULL;
+ }
+ }
+
+ sch = g_malloc0(sizeof(*sch));
+ sch->cssid = bus_id.cssid;
+ sch->ssid = bus_id.ssid;
+ sch->devno = bus_id.devid;
+ sch->schid = schid;
+ css_subch_assign(sch->cssid, sch->ssid, schid, sch->devno, sch);
+ return sch;
+}
@@ -703,116 +703,27 @@ static void virtio_sch_disable_cb(SubchDev *sch)
static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
{
- unsigned int schid;
- bool found = false;
- SubchDev *sch;
- Error *err = NULL;
VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
+ SubchDev *sch = css_create_virtual_sch(dev->bus_id, errp);
+ Error *err = NULL;
- sch = g_malloc0(sizeof(SubchDev));
-
- sch->driver_data = dev;
- dev->sch = sch;
-
- dev->indicators = NULL;
-
- /* Initialize subchannel structure. */
- sch->channel_prog = 0x0;
- sch->last_cmd_valid = false;
- sch->thinint_active = false;
- /*
- * Use a device number if provided. Otherwise, fall back to subchannel
- * number.
- */
- if (dev->bus_id.valid) {
- /* Enforce use of virtual cssid. */
- if (dev->bus_id.cssid != VIRTUAL_CSSID) {
- error_setg(errp, "cssid %x not valid for virtio devices",
- dev->bus_id.cssid);
- goto out_err;
- }
- if (css_devno_used(dev->bus_id.cssid, dev->bus_id.ssid,
- dev->bus_id.devid)) {
- error_setg(errp, "Device %x.%x.%04x already exists",
- dev->bus_id.cssid, dev->bus_id.ssid,
- dev->bus_id.devid);
- goto out_err;
- }
- sch->cssid = dev->bus_id.cssid;
- sch->ssid = dev->bus_id.ssid;
- sch->devno = dev->bus_id.devid;
-
- /* Find the next free id. */
- for (schid = 0; schid <= MAX_SCHID; schid++) {
- if (!css_find_subch(1, sch->cssid, sch->ssid, schid)) {
- sch->schid = schid;
- css_subch_assign(sch->cssid, sch->ssid, sch->schid,
- sch->devno, sch);
- found = true;
- break;
- }
- }
- if (!found) {
- error_setg(errp, "No free subchannel found for %x.%x.%04x",
- sch->cssid, sch->ssid, sch->devno);
- goto out_err;
- }
- trace_virtio_ccw_new_device(sch->cssid, sch->ssid, sch->schid,
- sch->devno, "user-configured");
- } else {
- unsigned int cssid = VIRTUAL_CSSID, ssid, devno;
-
- for (ssid = 0; ssid <= MAX_SSID; ssid++) {
- for (schid = 0; schid <= MAX_SCHID; schid++) {
- if (!css_find_subch(1, cssid, ssid, schid)) {
- sch->cssid = cssid;
- sch->ssid = ssid;
- sch->schid = schid;
- devno = schid;
- /*
- * If the devno is already taken, look further in this
- * subchannel set.
- */
- while (css_devno_used(cssid, ssid, devno)) {
- if (devno == MAX_SCHID) {
- devno = 0;
- } else if (devno == schid - 1) {
- error_setg(errp, "No free devno found");
- goto out_err;
- } else {
- devno++;
- }
- }
- sch->devno = devno;
- css_subch_assign(cssid, ssid, schid, devno, sch);
- found = true;
- break;
- }
- }
- if (found) {
- break;
- }
- }
- if (!found) {
- error_setg(errp, "Virtual channel subsystem is full!");
- goto out_err;
- }
- trace_virtio_ccw_new_device(cssid, ssid, schid, devno,
- "auto-configured");
+ if (!sch) {
+ return;
}
- /* Build initial schib. */
- css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
-
+ sch->driver_data = dev;
sch->ccw_cb = virtio_ccw_cb;
sch->disable_cb = virtio_sch_disable_cb;
-
- /* Build senseid data. */
- memset(&sch->id, 0, sizeof(SenseId));
sch->id.reserved = 0xff;
sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
-
+ dev->sch = sch;
+ dev->indicators = NULL;
dev->revision = -1;
+ css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
+
+ trace_virtio_ccw_new_device(
+ sch->cssid, sch->ssid, sch->schid, sch->devno,
+ dev->bus_id.valid ? "user-configured" : "auto-configured");
if (k->realize) {
k->realize(dev, &err);
@@ -820,14 +731,9 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
if (err) {
error_propagate(errp, err);
css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
- goto out_err;
+ dev->sch = NULL;
+ g_free(sch);
}
-
- return;
-
-out_err:
- dev->sch = NULL;
- g_free(sch);
}
static int virtio_ccw_exit(VirtioCcwDevice *dev)
@@ -27,8 +27,6 @@
#include <hw/s390x/s390_flic.h>
#include <hw/s390x/css.h>
-#define VIRTUAL_CSSID 0xfe
-
#define VIRTIO_CCW_CU_TYPE 0x3832
#define VIRTIO_CCW_CHPID_TYPE 0x32
@@ -17,6 +17,7 @@
#include "hw/s390x/ioinst.h"
/* Channel subsystem constants. */
+#define MAX_DEVNO 65535
#define MAX_SCHID 65535
#define MAX_SSID 3
#define MAX_CSSID 254 /* 255 is reserved */
@@ -24,6 +25,8 @@
#define MAX_CIWS 62
+#define VIRTUAL_CSSID 0xfe
+
typedef struct CIW {
uint8_t type;
uint8_t command;
@@ -169,4 +172,19 @@ extern PropertyInfo css_devid_propinfo;
#define DEFINE_PROP_CSS_DEV_ID(_n, _s, _f) \
DEFINE_PROP(_n, _s, _f, css_devid_propinfo, CssDevId)
+/**
+ * Create a subchannel for the given bus id.
+ *
+ * If @p bus_id is valid, verify that it uses the virtual channel
+ * subsystem id and is not already in use, and find a free subchannel
+ * id for it. If @p bus_id is not valid, find a free subchannel id and
+ * device number across all subchannel sets. If either of the former
+ * actions succeed, allocate a subchannel structure, initialise it
+ * with the bus id, subchannel id and device number, register it with
+ * the CSS and return it. Otherwise return NULL.
+ *
+ * The caller becomes owner of the returned subchannel structure and
+ * is responsible for unregistering and freeing it.
+ */
+SubchDev *css_create_virtual_sch(CssDevId bus_id, Error **errp);
#endif