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authorNiklas Cassel <cassel@kernel.org>2026-09-18 16:06:42 +0200
committerJens Axboe <axboe@kernel.dk>2026-09-29 12:54:47 -0600
commit684b413b5483f57c890c171b9400076a0143b918 (patch)
treef167daddad3dce9af44773541373eafbccc9ac61 /drivers/clocksource/arc_timer.c
downloadlinux-stable-684b413b5483f57c890c171b9400076a0143b918.tar.gz
linux-stable-684b413b5483f57c890c171b9400076a0143b918.zip
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>
Diffstat (limited to 'drivers/clocksource/arc_timer.c')
-rw-r--r--drivers/clocksource/arc_timer.c373
1 files changed, 373 insertions, 0 deletions
diff --git a/drivers/clocksource/arc_timer.c b/drivers/clocksource/arc_timer.c
new file mode 100644
index 000000000..cb18524cc
--- /dev/null
+++ b/drivers/clocksource/arc_timer.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016-17 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+/* ARC700 has two 32bit independent prog Timers: TIMER0 and TIMER1, Each can be
+ * programmed to go from @count to @limit and optionally interrupt.
+ * We've designated TIMER0 for clockevents and TIMER1 for clocksource
+ *
+ * ARCv2 based HS38 cores have RTC (in-core) and GFRC (inside ARConnect/MCIP)
+ * which are suitable for UP and SMP based clocksources respectively
+ */
+
+#include <linux/interrupt.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <soc/arc/timers.h>
+#include <soc/arc/mcip.h>
+
+
+static unsigned long arc_timer_freq;
+
+static int noinline arc_get_timer_clk(struct device_node *node)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ pr_err("timer missing clk\n");
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Couldn't enable parent clk\n");
+ return ret;
+ }
+
+ arc_timer_freq = clk_get_rate(clk);
+
+ return 0;
+}
+
+/********** Clock Source Device *********/
+
+#ifdef CONFIG_ARC_TIMERS_64BIT
+
+static u64 arc_read_gfrc(struct clocksource *cs)
+{
+ unsigned long flags;
+ u32 l, h;
+
+ /*
+ * From a programming model pov, there seems to be just one instance of
+ * MCIP_CMD/MCIP_READBACK however micro-architecturally there's
+ * an instance PER ARC CORE (not per cluster), and there are dedicated
+ * hardware decode logic (per core) inside ARConnect to handle
+ * simultaneous read/write accesses from cores via those two registers.
+ * So several concurrent commands to ARConnect are OK if they are
+ * trying to access two different sub-components (like GFRC,
+ * inter-core interrupt, etc...). HW also supports simultaneously
+ * accessing GFRC by multiple cores.
+ * That's why it is safe to disable hard interrupts on the local CPU
+ * before access to GFRC instead of taking global MCIP spinlock
+ * defined in arch/arc/kernel/mcip.c
+ */
+ local_irq_save(flags);
+
+ __mcip_cmd(CMD_GFRC_READ_LO, 0);
+ l = read_aux_reg(ARC_REG_MCIP_READBACK);
+
+ __mcip_cmd(CMD_GFRC_READ_HI, 0);
+ h = read_aux_reg(ARC_REG_MCIP_READBACK);
+
+ local_irq_restore(flags);
+
+ return (((u64)h) << 32) | l;
+}
+
+static notrace u64 arc_gfrc_clock_read(void)
+{
+ return arc_read_gfrc(NULL);
+}
+
+static struct clocksource arc_counter_gfrc = {
+ .name = "ARConnect GFRC",
+ .rating = 400,
+ .read = arc_read_gfrc,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init arc_cs_setup_gfrc(struct device_node *node)
+{
+ struct mcip_bcr mp;
+ int ret;
+
+ READ_BCR(ARC_REG_MCIP_BCR, mp);
+ if (!mp.gfrc) {
+ pr_warn("Global-64-bit-Ctr clocksource not detected\n");
+ return -ENXIO;
+ }
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return ret;
+
+ sched_clock_register(arc_gfrc_clock_read, 64, arc_timer_freq);
+
+ return clocksource_register_hz(&arc_counter_gfrc, arc_timer_freq);
+}
+TIMER_OF_DECLARE(arc_gfrc, "snps,archs-timer-gfrc", arc_cs_setup_gfrc);
+
+#define AUX_RTC_CTRL 0x103
+#define AUX_RTC_LOW 0x104
+#define AUX_RTC_HIGH 0x105
+
+static u64 arc_read_rtc(struct clocksource *cs)
+{
+ unsigned long status;
+ u32 l, h;
+
+ /*
+ * hardware has an internal state machine which tracks readout of
+ * low/high and updates the CTRL.status if
+ * - interrupt/exception taken between the two reads
+ * - high increments after low has been read
+ */
+ do {
+ l = read_aux_reg(AUX_RTC_LOW);
+ h = read_aux_reg(AUX_RTC_HIGH);
+ status = read_aux_reg(AUX_RTC_CTRL);
+ } while (!(status & BIT(31)));
+
+ return (((u64)h) << 32) | l;
+}
+
+static notrace u64 arc_rtc_clock_read(void)
+{
+ return arc_read_rtc(NULL);
+}
+
+static struct clocksource arc_counter_rtc = {
+ .name = "ARCv2 RTC",
+ .rating = 350,
+ .read = arc_read_rtc,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init arc_cs_setup_rtc(struct device_node *node)
+{
+ struct bcr_timer timer;
+ int ret;
+
+ READ_BCR(ARC_REG_TIMERS_BCR, timer);
+ if (!timer.rtc) {
+ pr_warn("Local-64-bit-Ctr clocksource not detected\n");
+ return -ENXIO;
+ }
+
+ /* Local to CPU hence not usable in SMP */
+ if (IS_ENABLED(CONFIG_SMP)) {
+ pr_warn("Local-64-bit-Ctr not usable in SMP\n");
+ return -EINVAL;
+ }
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return ret;
+
+ write_aux_reg(AUX_RTC_CTRL, 1);
+
+ sched_clock_register(arc_rtc_clock_read, 64, arc_timer_freq);
+
+ return clocksource_register_hz(&arc_counter_rtc, arc_timer_freq);
+}
+TIMER_OF_DECLARE(arc_rtc, "snps,archs-timer-rtc", arc_cs_setup_rtc);
+
+#endif
+
+/*
+ * 32bit TIMER1 to keep counting monotonically and wraparound
+ */
+
+static u64 arc_read_timer1(struct clocksource *cs)
+{
+ return (u64) read_aux_reg(ARC_REG_TIMER1_CNT);
+}
+
+static notrace u64 arc_timer1_clock_read(void)
+{
+ return arc_read_timer1(NULL);
+}
+
+static struct clocksource arc_counter_timer1 = {
+ .name = "ARC Timer1",
+ .rating = 300,
+ .read = arc_read_timer1,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init arc_cs_setup_timer1(struct device_node *node)
+{
+ int ret;
+
+ /* Local to CPU hence not usable in SMP */
+ if (IS_ENABLED(CONFIG_SMP))
+ return -EINVAL;
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return ret;
+
+ write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMERN_MAX);
+ write_aux_reg(ARC_REG_TIMER1_CNT, 0);
+ write_aux_reg(ARC_REG_TIMER1_CTRL, ARC_TIMER_CTRL_NH);
+
+ sched_clock_register(arc_timer1_clock_read, 32, arc_timer_freq);
+
+ return clocksource_register_hz(&arc_counter_timer1, arc_timer_freq);
+}
+
+/********** Clock Event Device *********/
+
+static int arc_timer_irq;
+
+/*
+ * Arm the timer to interrupt after @cycles
+ * The distinction for oneshot/periodic is done in arc_event_timer_ack() below
+ */
+static void arc_timer_event_setup(unsigned int cycles)
+{
+ write_aux_reg(ARC_REG_TIMER0_LIMIT, cycles);
+ write_aux_reg(ARC_REG_TIMER0_CNT, 0); /* start from 0 */
+
+ write_aux_reg(ARC_REG_TIMER0_CTRL, ARC_TIMER_CTRL_IE | ARC_TIMER_CTRL_NH);
+}
+
+
+static int arc_clkevent_set_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ arc_timer_event_setup(delta);
+ return 0;
+}
+
+static int arc_clkevent_set_periodic(struct clock_event_device *dev)
+{
+ /*
+ * At X Hz, 1 sec = 1000ms -> X cycles;
+ * 10ms -> X / 100 cycles
+ */
+ arc_timer_event_setup(arc_timer_freq / HZ);
+ return 0;
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, arc_clockevent_device) = {
+ .name = "ARC Timer0",
+ .features = CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_PERIODIC,
+ .rating = 300,
+ .set_next_event = arc_clkevent_set_next_event,
+ .set_state_periodic = arc_clkevent_set_periodic,
+};
+
+static irqreturn_t timer_irq_handler(int irq, void *dev_id)
+{
+ /*
+ * Note that generic IRQ core could have passed @evt for @dev_id if
+ * irq_set_chip_and_handler() asked for handle_percpu_devid_irq()
+ */
+ struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+ int irq_reenable = clockevent_state_periodic(evt);
+
+ /*
+ * 1. ACK the interrupt
+ * - For ARC700, any write to CTRL reg ACKs it, so just rewrite
+ * Count when [N]ot [H]alted bit.
+ * - For HS3x, it is a bit subtle. On taken count-down interrupt,
+ * IP bit [3] is set, which needs to be cleared for ACK'ing.
+ * The write below can only update the other two bits, hence
+ * explicitly clears IP bit
+ * 2. Re-arm interrupt if periodic by writing to IE bit [0]
+ */
+ write_aux_reg(ARC_REG_TIMER0_CTRL, irq_reenable | ARC_TIMER_CTRL_NH);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+
+static int arc_timer_starting_cpu(unsigned int cpu)
+{
+ struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+
+ evt->cpumask = cpumask_of(smp_processor_id());
+
+ clockevents_config_and_register(evt, arc_timer_freq, 0, ARC_TIMERN_MAX);
+ enable_percpu_irq(arc_timer_irq, 0);
+ return 0;
+}
+
+static int arc_timer_dying_cpu(unsigned int cpu)
+{
+ disable_percpu_irq(arc_timer_irq);
+ return 0;
+}
+
+/*
+ * clockevent setup for boot CPU
+ */
+static int __init arc_clockevent_setup(struct device_node *node)
+{
+ struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+ int ret;
+
+ arc_timer_irq = irq_of_parse_and_map(node, 0);
+ if (arc_timer_irq <= 0) {
+ pr_err("clockevent: missing irq\n");
+ return -EINVAL;
+ }
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return ret;
+
+ /* Needs apriori irq_set_percpu_devid() done in intc map function */
+ ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
+ "Timer0 (per-cpu-tick)", evt);
+ if (ret) {
+ pr_err("clockevent: unable to request irq\n");
+ return ret;
+ }
+
+ ret = cpuhp_setup_state(CPUHP_AP_ARC_TIMER_STARTING,
+ "clockevents/arc/timer:starting",
+ arc_timer_starting_cpu,
+ arc_timer_dying_cpu);
+ if (ret) {
+ pr_err("Failed to setup hotplug state\n");
+ return ret;
+ }
+ return 0;
+}
+
+static int __init arc_of_timer_init(struct device_node *np)
+{
+ static int init_count = 0;
+ int ret;
+
+ if (!init_count) {
+ init_count = 1;
+ ret = arc_clockevent_setup(np);
+ } else {
+ ret = arc_cs_setup_timer1(np);
+ }
+
+ return ret;
+}
+TIMER_OF_DECLARE(arc_clkevt, "snps,arc-timer", arc_of_timer_init);