virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 188 insertions, 0 deletions

diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c
new file mode 100644
index 000000000..440bfc52c
--- /dev/null
+++ b/drivers/soundwire/master.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright(c) 2019-2020 Intel Corporation.
+
+#include <linux/device.h>
+#include <linux/acpi.h>
+#include <linux/pm_runtime.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include "bus.h"
+
+/*
+ * The 3s value for autosuspend will only be used if there are no
+ * devices physically attached on a bus segment. In practice enabling
+ * the bus operation will result in children devices become active and
+ * the master device will only suspend when all its children are no
+ * longer active.
+ */
+#define SDW_MASTER_SUSPEND_DELAY_MS 3000
+
+/*
+ * The sysfs for properties reflects the MIPI description as given
+ * in the MIPI DisCo spec
+ *
+ * Base file is:
+ *	sdw-master-N
+ *      |---- revision
+ *      |---- clk_stop_modes
+ *      |---- max_clk_freq
+ *      |---- clk_freq
+ *      |---- clk_gears
+ *      |---- default_row
+ *      |---- default_col
+ *      |---- dynamic_shape
+ *      |---- err_threshold
+ */
+
+#define sdw_master_attr(field, format_string)				\
+static ssize_t field##_show(struct device *dev,				\
+			    struct device_attribute *attr,		\
+			    char *buf)					\
+{									\
+	struct sdw_master_device *md = dev_to_sdw_master_device(dev);	\
+	return sprintf(buf, format_string, md->bus->prop.field);	\
+}									\
+static DEVICE_ATTR_RO(field)
+
+sdw_master_attr(revision, "0x%x\n");
+sdw_master_attr(clk_stop_modes, "0x%x\n");
+sdw_master_attr(max_clk_freq, "%d\n");
+sdw_master_attr(default_row, "%d\n");
+sdw_master_attr(default_col, "%d\n");
+sdw_master_attr(default_frame_rate, "%d\n");
+sdw_master_attr(dynamic_frame, "%d\n");
+sdw_master_attr(err_threshold, "%d\n");
+
+static ssize_t clock_frequencies_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct sdw_master_device *md = dev_to_sdw_master_device(dev);
+	ssize_t size = 0;
+	int i;
+
+	for (i = 0; i < md->bus->prop.num_clk_freq; i++)
+		size += sprintf(buf + size, "%8d ",
+				md->bus->prop.clk_freq[i]);
+	size += sprintf(buf + size, "\n");
+
+	return size;
+}
+static DEVICE_ATTR_RO(clock_frequencies);
+
+static ssize_t clock_gears_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct sdw_master_device *md = dev_to_sdw_master_device(dev);
+	ssize_t size = 0;
+	int i;
+
+	for (i = 0; i < md->bus->prop.num_clk_gears; i++)
+		size += sprintf(buf + size, "%8d ",
+				md->bus->prop.clk_gears[i]);
+	size += sprintf(buf + size, "\n");
+
+	return size;
+}
+static DEVICE_ATTR_RO(clock_gears);
+
+static struct attribute *master_node_attrs[] = {
+	&dev_attr_revision.attr,
+	&dev_attr_clk_stop_modes.attr,
+	&dev_attr_max_clk_freq.attr,
+	&dev_attr_default_row.attr,
+	&dev_attr_default_col.attr,
+	&dev_attr_default_frame_rate.attr,
+	&dev_attr_dynamic_frame.attr,
+	&dev_attr_err_threshold.attr,
+	&dev_attr_clock_frequencies.attr,
+	&dev_attr_clock_gears.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(master_node);
+
+static void sdw_master_device_release(struct device *dev)
+{
+	struct sdw_master_device *md = dev_to_sdw_master_device(dev);
+
+	kfree(md);
+}
+
+static const struct dev_pm_ops master_dev_pm = {
+	SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend,
+			   pm_generic_runtime_resume, NULL)
+};
+
+const struct device_type sdw_master_type = {
+	.name =		"soundwire_master",
+	.release =	sdw_master_device_release,
+	.pm = &master_dev_pm,
+};
+
+/**
+ * sdw_master_device_add() - create a Linux Master Device representation.
+ * @bus: SDW bus instance
+ * @parent: parent device
+ * @fwnode: firmware node handle
+ */
+int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
+			  struct fwnode_handle *fwnode)
+{
+	struct sdw_master_device *md;
+	int ret;
+
+	if (!parent)
+		return -EINVAL;
+
+	md = kzalloc_obj(*md);
+	if (!md)
+		return -ENOMEM;
+
+	md->dev.bus = &sdw_bus_type;
+	md->dev.type = &sdw_master_type;
+	md->dev.parent = parent;
+	md->dev.groups = master_node_groups;
+	md->dev.of_node = parent->of_node;
+	md->dev.fwnode = fwnode;
+	md->dev.dma_mask = parent->dma_mask;
+
+	dev_set_name(&md->dev, "sdw-master-%d-%d", bus->controller_id, bus->link_id);
+
+	ret = device_register(&md->dev);
+	if (ret) {
+		dev_err(parent, "Failed to add master: ret %d\n", ret);
+		/*
+		 * On err, don't free but drop ref as this will be freed
+		 * when release method is invoked.
+		 */
+		put_device(&md->dev);
+		goto device_register_err;
+	}
+
+	/* add shortcuts to improve code readability/compactness */
+	md->bus = bus;
+	bus->dev = &md->dev;
+	bus->md = md;
+
+	pm_runtime_set_autosuspend_delay(&bus->md->dev, SDW_MASTER_SUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(&bus->md->dev);
+	pm_runtime_mark_last_busy(&bus->md->dev);
+	pm_runtime_set_active(&bus->md->dev);
+	pm_runtime_enable(&bus->md->dev);
+	pm_runtime_idle(&bus->md->dev);
+device_register_err:
+	return ret;
+}
+
+/**
+ * sdw_master_device_del() - delete a Linux Master Device representation.
+ * @bus: bus handle
+ *
+ * This function is the dual of sdw_master_device_add()
+ */
+int sdw_master_device_del(struct sdw_bus *bus)
+{
+	pm_runtime_disable(&bus->md->dev);
+	device_unregister(bus->dev);
+
+	return 0;
+}