s390x/css: factor out some generic code from virtio_ccw_device_realize() (cf249935) · Commits · SUMMER2020 / students / proj-2021291

hw/s390x/css.c

+143 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

hw/s390x/virtio-ccw.c

+14 −108

Original line number	Diff line number	Diff line
		@@ -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);
		@@ -820,15 +731,10 @@ 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;
		}

		return;

		out_err:
		dev->sch = NULL;
		g_free(sch);
		}
		}

		static int virtio_ccw_exit(VirtioCcwDevice *dev)
		{

hw/s390x/virtio-ccw.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -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

include/hw/s390x/css.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -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