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, 215 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-gxp.c b/drivers/clocksource/timer-gxp.c
new file mode 100644
index 000000000..1becc9433
--- /dev/null
+++ b/drivers/clocksource/timer-gxp.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sched_clock.h>
+
+#define TIMER0_FREQ	1000000
+#define GXP_TIMER_CNT_OFS 0x00
+#define GXP_TIMESTAMP_OFS 0x08
+#define GXP_TIMER_CTRL_OFS 0x14
+
+/* TCS Stands for Timer Control/Status: these are masks to be used in */
+/* the Timer Count Registers */
+#define MASK_TCS_ENABLE	0x01
+#define MASK_TCS_PERIOD	0x02
+#define MASK_TCS_RELOAD	0x04
+#define MASK_TCS_TC	0x80
+
+struct gxp_timer {
+	void __iomem *counter;
+	void __iomem *control;
+	struct clock_event_device evt;
+};
+
+static struct gxp_timer *gxp_timer;
+
+static void __iomem *system_clock __ro_after_init;
+
+static inline struct gxp_timer *to_gxp_timer(struct clock_event_device *evt_dev)
+{
+	return container_of(evt_dev, struct gxp_timer, evt);
+}
+
+static u64 notrace gxp_sched_read(void)
+{
+	return readl_relaxed(system_clock);
+}
+
+static int gxp_time_set_next_event(unsigned long event, struct clock_event_device *evt_dev)
+{
+	struct gxp_timer *timer = to_gxp_timer(evt_dev);
+
+	/* Stop counting and disable interrupt before updating */
+	writeb_relaxed(MASK_TCS_TC, timer->control);
+	writel_relaxed(event, timer->counter);
+	writeb_relaxed(MASK_TCS_TC | MASK_TCS_ENABLE, timer->control);
+
+	return 0;
+}
+
+static irqreturn_t gxp_timer_interrupt(int irq, void *dev_id)
+{
+	struct gxp_timer *timer = (struct gxp_timer *)dev_id;
+
+	if (!(readb_relaxed(timer->control) & MASK_TCS_TC))
+		return IRQ_NONE;
+
+	writeb_relaxed(MASK_TCS_TC, timer->control);
+
+	timer->evt.event_handler(&timer->evt);
+
+	return IRQ_HANDLED;
+}
+
+static int __init gxp_timer_init(struct device_node *node)
+{
+	void __iomem *base;
+	struct clk *clk;
+	u32 freq;
+	int ret, irq;
+
+	gxp_timer = kzalloc_obj(*gxp_timer);
+	if (!gxp_timer) {
+		ret = -ENOMEM;
+		pr_err("Can't allocate gxp_timer");
+		return ret;
+	}
+
+	clk = of_clk_get(node, 0);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		pr_err("%pOFn clock not found: %d\n", node, ret);
+		goto err_free;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("%pOFn clock enable failed: %d\n", node, ret);
+		goto err_clk_enable;
+	}
+
+	base = of_iomap(node, 0);
+	if (!base) {
+		ret = -ENXIO;
+		pr_err("Can't map timer base registers");
+		goto err_iomap;
+	}
+
+	/* Set the offsets to the clock register and timer registers */
+	gxp_timer->counter = base + GXP_TIMER_CNT_OFS;
+	gxp_timer->control = base + GXP_TIMER_CTRL_OFS;
+	system_clock = base + GXP_TIMESTAMP_OFS;
+
+	gxp_timer->evt.name = node->name;
+	gxp_timer->evt.rating = 300;
+	gxp_timer->evt.features = CLOCK_EVT_FEAT_ONESHOT;
+	gxp_timer->evt.set_next_event = gxp_time_set_next_event;
+	gxp_timer->evt.cpumask = cpumask_of(0);
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (irq <= 0) {
+		ret = -EINVAL;
+		pr_err("GXP Timer Can't parse IRQ %d", irq);
+		goto err_exit;
+	}
+
+	freq = clk_get_rate(clk);
+
+	ret = clocksource_mmio_init(system_clock, node->name, freq,
+				    300, 32, clocksource_mmio_readl_up);
+	if (ret) {
+		pr_err("%pOFn init clocksource failed: %d", node, ret);
+		goto err_exit;
+	}
+
+	sched_clock_register(gxp_sched_read, 32, freq);
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (irq <= 0) {
+		ret = -EINVAL;
+		pr_err("%pOFn Can't parse IRQ %d", node, irq);
+		goto err_exit;
+	}
+
+	clockevents_config_and_register(&gxp_timer->evt, TIMER0_FREQ,
+					0xf, 0xffffffff);
+
+	ret = request_irq(irq, gxp_timer_interrupt, IRQF_TIMER | IRQF_SHARED,
+			  node->name, gxp_timer);
+	if (ret) {
+		pr_err("%pOFn request_irq() failed: %d", node, ret);
+		goto err_exit;
+	}
+
+	pr_debug("gxp: system timer (irq = %d)\n", irq);
+	return 0;
+
+err_exit:
+	iounmap(base);
+err_iomap:
+	clk_disable_unprepare(clk);
+err_clk_enable:
+	clk_put(clk);
+err_free:
+	kfree(gxp_timer);
+	return ret;
+}
+
+/*
+ * This probe gets called after the timer is already up and running. This will create
+ * the watchdog device as a child since the registers are shared.
+ */
+
+static int gxp_timer_probe(struct platform_device *pdev)
+{
+	struct platform_device *gxp_watchdog_device;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (!gxp_timer) {
+		pr_err("Gxp Timer not initialized, cannot create watchdog");
+		return -ENOMEM;
+	}
+
+	gxp_watchdog_device = platform_device_alloc("gxp-wdt", -1);
+	if (!gxp_watchdog_device) {
+		pr_err("Timer failed to allocate gxp-wdt");
+		return -ENOMEM;
+	}
+
+	/* Pass the base address (counter) as platform data and nothing else */
+	gxp_watchdog_device->dev.platform_data = gxp_timer->counter;
+	gxp_watchdog_device->dev.parent = dev;
+
+	ret = platform_device_add(gxp_watchdog_device);
+	if (ret)
+		platform_device_put(gxp_watchdog_device);
+
+	return ret;
+}
+
+static const struct of_device_id gxp_timer_of_match[] = {
+	{ .compatible = "hpe,gxp-timer", },
+	{},
+};
+
+static struct platform_driver gxp_timer_driver = {
+	.probe  = gxp_timer_probe,
+	.driver = {
+		.name = "gxp-timer",
+		.of_match_table = gxp_timer_of_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+builtin_platform_driver(gxp_timer_driver);
+
+TIMER_OF_DECLARE(gxp, "hpe,gxp-timer", gxp_timer_init);