Merge branch 'topic/xen' into for-next

Merge Xen para-virtualized frontend driver from Oleksandr Andrushchenko.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

MAINTAINERS

@@ -15494,6 +15494,13 @@ S:	Supported
 F:	arch/x86/xen/*swiotlb*
 F:	drivers/xen/*swiotlb*
 
+XEN SOUND FRONTEND DRIVER
+M:	Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+L:	xen-devel@lists.xenproject.org (moderated for non-subscribers)
+L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
+S:	Supported
+F:	sound/xen/*
+
 XFS FILESYSTEM
 M:	Darrick J. Wong <darrick.wong@oracle.com>
 M:	linux-xfs@vger.kernel.org

sound/Kconfig

@@ -96,6 +96,8 @@ source "sound/x86/Kconfig"
 
 source "sound/synth/Kconfig"
 
+source "sound/xen/Kconfig"
+
 endif # SND
 
 endif # !UML

sound/Makefile

@@ -5,7 +5,7 @@
 obj-$(CONFIG_SOUND) += soundcore.o
 obj-$(CONFIG_DMASOUND) += oss/dmasound/
 obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \
-	firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/
+	firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/
 obj-$(CONFIG_SND_AOA) += aoa/
 
 # This one must be compilable even if sound is configured out

sound/xen/Kconfig

+# ALSA Xen drivers
+
+config SND_XEN_FRONTEND
+	tristate "Xen para-virtualized sound frontend driver"
+	depends on XEN
+	select SND_PCM
+	select XEN_XENBUS_FRONTEND
+	help
+	  Choose this option if you want to enable a para-virtualized
+	  frontend sound driver for Xen guest OSes.

sound/xen/Makefile

+# SPDX-License-Identifier: GPL-2.0 OR MIT
+
+snd_xen_front-objs := xen_snd_front.o \
+		      xen_snd_front_cfg.o \
+		      xen_snd_front_evtchnl.o \
+		      xen_snd_front_shbuf.o \
+		      xen_snd_front_alsa.o
+
+obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o

sound/xen/xen_snd_front.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_SND_FRONT_H
+#define __XEN_SND_FRONT_H
+
+#include "xen_snd_front_cfg.h"
+
+struct xen_snd_front_card_info;
+struct xen_snd_front_evtchnl;
+struct xen_snd_front_evtchnl_pair;
+struct xen_snd_front_shbuf;
+struct xensnd_query_hw_param;
+
+struct xen_snd_front_info {
+	struct xenbus_device *xb_dev;
+
+	struct xen_snd_front_card_info *card_info;
+
+	int num_evt_pairs;
+	struct xen_snd_front_evtchnl_pair *evt_pairs;
+
+	struct xen_front_cfg_card cfg;
+};
+
+int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl,
+					struct xensnd_query_hw_param *hw_param_req,
+					struct xensnd_query_hw_param *hw_param_resp);
+
+int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl,
+				 struct xen_snd_front_shbuf *sh_buf,
+				 u8 format, unsigned int channels,
+				 unsigned int rate, u32 buffer_sz,
+				 u32 period_sz);
+
+int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl);
+
+int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl,
+			       unsigned long pos, unsigned long count);
+
+int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl,
+			      unsigned long pos, unsigned long count);
+
+int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl,
+				 int type);
+
+#endif /* __XEN_SND_FRONT_H */

sound/xen/xen_snd_front_alsa.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_SND_FRONT_ALSA_H
+#define __XEN_SND_FRONT_ALSA_H
+
+struct xen_snd_front_info;
+
+int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
+				       u64 pos_bytes);
+
+#endif /* __XEN_SND_FRONT_ALSA_H */

sound/xen/xen_snd_front_cfg.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_SND_FRONT_CFG_H
+#define __XEN_SND_FRONT_CFG_H
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+struct xen_snd_front_info;
+
+struct xen_front_cfg_stream {
+	int index;
+	char *xenstore_path;
+	struct snd_pcm_hardware pcm_hw;
+};
+
+struct xen_front_cfg_pcm_instance {
+	char name[80];
+	int device_id;
+	struct snd_pcm_hardware pcm_hw;
+	int  num_streams_pb;
+	struct xen_front_cfg_stream *streams_pb;
+	int  num_streams_cap;
+	struct xen_front_cfg_stream *streams_cap;
+};
+
+struct xen_front_cfg_card {
+	char name_short[32];
+	char name_long[80];
+	struct snd_pcm_hardware pcm_hw;
+	int num_pcm_instances;
+	struct xen_front_cfg_pcm_instance *pcm_instances;
+};
+
+int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,
+			   int *stream_cnt);
+
+#endif /* __XEN_SND_FRONT_CFG_H */

sound/xen/xen_snd_front_evtchnl.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_SND_FRONT_EVTCHNL_H
+#define __XEN_SND_FRONT_EVTCHNL_H
+
+#include <xen/interface/io/sndif.h>
+
+struct xen_snd_front_info;
+
+#ifndef GRANT_INVALID_REF
+/*
+ * FIXME: usage of grant reference 0 as invalid grant reference:
+ * grant reference 0 is valid, but never exposed to a PV driver,
+ * because of the fact it is already in use/reserved by the PV console.
+ */
+#define GRANT_INVALID_REF	0
+#endif
+
+/* Timeout in ms to wait for backend to respond. */
+#define VSND_WAIT_BACK_MS	3000
+
+enum xen_snd_front_evtchnl_state {
+	EVTCHNL_STATE_DISCONNECTED,
+	EVTCHNL_STATE_CONNECTED,
+};
+
+enum xen_snd_front_evtchnl_type {
+	EVTCHNL_TYPE_REQ,
+	EVTCHNL_TYPE_EVT,
+};
+
+struct xen_snd_front_evtchnl {
+	struct xen_snd_front_info *front_info;
+	int gref;
+	int port;
+	int irq;
+	int index;
+	/* State of the event channel. */
+	enum xen_snd_front_evtchnl_state state;
+	enum xen_snd_front_evtchnl_type type;
+	/* Either response id or incoming event id. */
+	u16 evt_id;
+	/* Next request id or next expected event id. */
+	u16 evt_next_id;
+	/* Shared ring access lock. */
+	struct mutex ring_io_lock;
+	union {
+		struct {
+			struct xen_sndif_front_ring ring;
+			struct completion completion;
+			/* Serializer for backend IO: request/response. */
+			struct mutex req_io_lock;
+
+			/* Latest response status. */
+			int resp_status;
+			union {
+				struct xensnd_query_hw_param hw_param;
+			} resp;
+		} req;
+		struct {
+			struct xensnd_event_page *page;
+			/* This is needed to handle XENSND_EVT_CUR_POS event. */
+			struct snd_pcm_substream *substream;
+		} evt;
+	} u;
+};
+
+struct xen_snd_front_evtchnl_pair {
+	struct xen_snd_front_evtchnl req;
+	struct xen_snd_front_evtchnl evt;
+};
+
+int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
+				     int num_streams);
+
+void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info);
+
+int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl);
+
+void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
+					      bool is_connected);
+
+void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair);
+
+#endif /* __XEN_SND_FRONT_EVTCHNL_H */

sound/xen/xen_snd_front_shbuf.c

+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#include <linux/kernel.h>
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+
+#include "xen_snd_front_shbuf.h"
+
+grant_ref_t xen_snd_front_shbuf_get_dir_start(struct xen_snd_front_shbuf *buf)
+{
+	if (!buf->grefs)
+		return GRANT_INVALID_REF;
+
+	return buf->grefs[0];
+}
+
+void xen_snd_front_shbuf_clear(struct xen_snd_front_shbuf *buf)
+{
+	memset(buf, 0, sizeof(*buf));
+}
+
+void xen_snd_front_shbuf_free(struct xen_snd_front_shbuf *buf)
+{
+	int i;
+
+	if (buf->grefs) {
+		for (i = 0; i < buf->num_grefs; i++)
+			if (buf->grefs[i] != GRANT_INVALID_REF)
+				gnttab_end_foreign_access(buf->grefs[i],
+							  0, 0UL);
+		kfree(buf->grefs);
+	}
+	kfree(buf->directory);
+	free_pages_exact(buf->buffer, buf->buffer_sz);
+	xen_snd_front_shbuf_clear(buf);
+}
+
+/*
+ * number of grant references a page can hold with respect to the
+ * xensnd_page_directory header
+ */
+#define XENSND_NUM_GREFS_PER_PAGE ((XEN_PAGE_SIZE - \
+		offsetof(struct xensnd_page_directory, gref)) / \
+		sizeof(grant_ref_t))
+
+static void fill_page_dir(struct xen_snd_front_shbuf *buf,
+			  int num_pages_dir)
+{
+	struct xensnd_page_directory *page_dir;
+	unsigned char *ptr;
+	int i, cur_gref, grefs_left, to_copy;
+
+	ptr = buf->directory;
+	grefs_left = buf->num_grefs - num_pages_dir;
+	/*
+	 * skip grant references at the beginning, they are for pages granted
+	 * for the page directory itself
+	 */
+	cur_gref = num_pages_dir;
+	for (i = 0; i < num_pages_dir; i++) {
+		page_dir = (struct xensnd_page_directory *)ptr;
+		if (grefs_left <= XENSND_NUM_GREFS_PER_PAGE) {
+			to_copy = grefs_left;
+			page_dir->gref_dir_next_page = GRANT_INVALID_REF;
+		} else {
+			to_copy = XENSND_NUM_GREFS_PER_PAGE;
+			page_dir->gref_dir_next_page = buf->grefs[i + 1];
+		}
+
+		memcpy(&page_dir->gref, &buf->grefs[cur_gref],
+		       to_copy * sizeof(grant_ref_t));
+
+		ptr += XEN_PAGE_SIZE;
+		grefs_left -= to_copy;
+		cur_gref += to_copy;
+	}
+}
+
+static int grant_references(struct xenbus_device *xb_dev,
+			    struct xen_snd_front_shbuf *buf,
+			    int num_pages_dir, int num_pages_buffer,
+			    int num_grefs)
+{
+	grant_ref_t priv_gref_head;
+	unsigned long frame;
+	int ret, i, j, cur_ref;
+	int otherend_id;
+
+	ret = gnttab_alloc_grant_references(num_grefs, &priv_gref_head);
+	if (ret)
+		return ret;
+
+	buf->num_grefs = num_grefs;
+	otherend_id = xb_dev->otherend_id;
+	j = 0;
+
+	for (i = 0; i < num_pages_dir; i++) {
+		cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
+		if (cur_ref < 0) {
+			ret = cur_ref;
+			goto fail;
+		}
+
+		frame = xen_page_to_gfn(virt_to_page(buf->directory +
+						     XEN_PAGE_SIZE * i));
+		gnttab_grant_foreign_access_ref(cur_ref, otherend_id, frame, 0);
+		buf->grefs[j++] = cur_ref;
+	}
+
+	for (i = 0; i < num_pages_buffer; i++) {
+		cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
+		if (cur_ref < 0) {
+			ret = cur_ref;
+			goto fail;
+		}
+
+		frame = xen_page_to_gfn(virt_to_page(buf->buffer +
+						     XEN_PAGE_SIZE * i));
+		gnttab_grant_foreign_access_ref(cur_ref, otherend_id, frame, 0);
+		buf->grefs[j++] = cur_ref;
+	}
+
+	gnttab_free_grant_references(priv_gref_head);
+	fill_page_dir(buf, num_pages_dir);
+	return 0;
+
+fail:
+	gnttab_free_grant_references(priv_gref_head);
+	return ret;
+}
+
+static int alloc_int_buffers(struct xen_snd_front_shbuf *buf,
+			     int num_pages_dir, int num_pages_buffer,
+			     int num_grefs)
+{
+	buf->grefs = kcalloc(num_grefs, sizeof(*buf->grefs), GFP_KERNEL);
+	if (!buf->grefs)
+		return -ENOMEM;
+
+	buf->directory = kcalloc(num_pages_dir, XEN_PAGE_SIZE, GFP_KERNEL);
+	if (!buf->directory)
+		goto fail;
+
+	buf->buffer_sz = num_pages_buffer * XEN_PAGE_SIZE;
+	buf->buffer = alloc_pages_exact(buf->buffer_sz, GFP_KERNEL);
+	if (!buf->buffer)
+		goto fail;
+
+	return 0;
+
+fail:
+	kfree(buf->grefs);
+	buf->grefs = NULL;
+	kfree(buf->directory);
+	buf->directory = NULL;
+	return -ENOMEM;
+}
+
+int xen_snd_front_shbuf_alloc(struct xenbus_device *xb_dev,
+			      struct xen_snd_front_shbuf *buf,
+			      unsigned int buffer_sz)
+{
+	int num_pages_buffer, num_pages_dir, num_grefs;
+	int ret;
+
+	xen_snd_front_shbuf_clear(buf);
+
+	num_pages_buffer = DIV_ROUND_UP(buffer_sz, XEN_PAGE_SIZE);
+	/* number of pages the page directory consumes itself */
+	num_pages_dir = DIV_ROUND_UP(num_pages_buffer,
+				     XENSND_NUM_GREFS_PER_PAGE);
+	num_grefs = num_pages_buffer + num_pages_dir;
+
+	ret = alloc_int_buffers(buf, num_pages_dir,
+				num_pages_buffer, num_grefs);
+	if (ret < 0)
+		return ret;
+
+	ret = grant_references(xb_dev, buf, num_pages_dir, num_pages_buffer,
+			       num_grefs);
+	if (ret < 0)
+		return ret;
+
+	fill_page_dir(buf, num_pages_dir);
+	return 0;
+}

sound/xen/xen_snd_front_shbuf.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ */
+
+#ifndef __XEN_SND_FRONT_SHBUF_H
+#define __XEN_SND_FRONT_SHBUF_H
+
+#include <xen/grant_table.h>
+
+#include "xen_snd_front_evtchnl.h"
+
+struct xen_snd_front_shbuf {
+	int num_grefs;
+	grant_ref_t *grefs;
+	u8 *directory;
+	u8 *buffer;
+	size_t buffer_sz;
+};
+
+grant_ref_t xen_snd_front_shbuf_get_dir_start(struct xen_snd_front_shbuf *buf);
+
+int xen_snd_front_shbuf_alloc(struct xenbus_device *xb_dev,
+			      struct xen_snd_front_shbuf *buf,
+			      unsigned int buffer_sz);
+
+void xen_snd_front_shbuf_clear(struct xen_snd_front_shbuf *buf);
+
+void xen_snd_front_shbuf_free(struct xen_snd_front_shbuf *buf);
+
+#endif /* __XEN_SND_FRONT_SHBUF_H */