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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/clocksource/arm_global_timer.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/clocksource/arm_global_timer.c')
-rw-r--r--drivers/clocksource/arm_global_timer.c442
1 files changed, 442 insertions, 0 deletions
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
new file mode 100644
index 000000000..44a61dc6f
--- /dev/null
+++ b/drivers/clocksource/arm_global_timer.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/clocksource/arm_global_timer.c
+ *
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited.
+ * Author: Stuart Menefy <stuart.menefy@st.com>
+ * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+
+#include <asm/cputype.h>
+
+#define GT_COUNTER0 0x00
+#define GT_COUNTER1 0x04
+
+#define GT_CONTROL 0x08
+#define GT_CONTROL_TIMER_ENABLE BIT(0) /* this bit is NOT banked */
+#define GT_CONTROL_COMP_ENABLE BIT(1) /* banked */
+#define GT_CONTROL_IRQ_ENABLE BIT(2) /* banked */
+#define GT_CONTROL_AUTO_INC BIT(3) /* banked */
+#define GT_CONTROL_PRESCALER_SHIFT 8
+#define GT_CONTROL_PRESCALER_MAX 0xF
+#define GT_CONTROL_PRESCALER_MASK (GT_CONTROL_PRESCALER_MAX << \
+ GT_CONTROL_PRESCALER_SHIFT)
+
+#define GT_INT_STATUS 0x0c
+#define GT_INT_STATUS_EVENT_FLAG BIT(0)
+
+#define GT_COMP0 0x10
+#define GT_COMP1 0x14
+#define GT_AUTO_INC 0x18
+
+#define MAX_F_ERR 50
+/*
+ * We are expecting to be clocked by the ARM peripheral clock.
+ *
+ * Note: it is assumed we are using a prescaler value of zero, so this is
+ * the units for all operations.
+ */
+static void __iomem *gt_base;
+static struct notifier_block gt_clk_rate_change_nb;
+static u32 gt_psv_new, gt_psv_bck, gt_target_rate;
+static int gt_ppi;
+static struct clock_event_device __percpu *gt_evt;
+
+/*
+ * To get the value from the Global Timer Counter register proceed as follows:
+ * 1. Read the upper 32-bit timer counter register
+ * 2. Read the lower 32-bit timer counter register
+ * 3. Read the upper 32-bit timer counter register again. If the value is
+ * different to the 32-bit upper value read previously, go back to step 2.
+ * Otherwise the 64-bit timer counter value is correct.
+ */
+static u64 notrace _gt_counter_read(void)
+{
+ u64 counter;
+ u32 lower;
+ u32 upper, old_upper;
+
+ upper = readl_relaxed(gt_base + GT_COUNTER1);
+ do {
+ old_upper = upper;
+ lower = readl_relaxed(gt_base + GT_COUNTER0);
+ upper = readl_relaxed(gt_base + GT_COUNTER1);
+ } while (upper != old_upper);
+
+ counter = upper;
+ counter <<= 32;
+ counter |= lower;
+ return counter;
+}
+
+static u64 gt_counter_read(void)
+{
+ return _gt_counter_read();
+}
+
+/**
+ * To ensure that updates to comparator value register do not set the
+ * Interrupt Status Register proceed as follows:
+ * 1. Clear the Comp Enable bit in the Timer Control Register.
+ * 2. Write the lower 32-bit Comparator Value Register.
+ * 3. Write the upper 32-bit Comparator Value Register.
+ * 4. Set the Comp Enable bit and, if necessary, the IRQ enable bit.
+ */
+static void gt_compare_set(unsigned long delta, int periodic)
+{
+ u64 counter = gt_counter_read();
+ unsigned long ctrl;
+
+ counter += delta;
+ ctrl = readl(gt_base + GT_CONTROL);
+ ctrl &= ~(GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE |
+ GT_CONTROL_AUTO_INC);
+ ctrl |= GT_CONTROL_TIMER_ENABLE;
+ writel_relaxed(ctrl, gt_base + GT_CONTROL);
+ writel_relaxed(lower_32_bits(counter), gt_base + GT_COMP0);
+ writel_relaxed(upper_32_bits(counter), gt_base + GT_COMP1);
+
+ if (periodic) {
+ writel_relaxed(delta, gt_base + GT_AUTO_INC);
+ ctrl |= GT_CONTROL_AUTO_INC;
+ }
+
+ ctrl |= GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE;
+ writel_relaxed(ctrl, gt_base + GT_CONTROL);
+}
+
+static int gt_clockevent_shutdown(struct clock_event_device *evt)
+{
+ unsigned long ctrl;
+
+ ctrl = readl(gt_base + GT_CONTROL);
+ ctrl &= ~(GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE |
+ GT_CONTROL_AUTO_INC);
+ writel(ctrl, gt_base + GT_CONTROL);
+ return 0;
+}
+
+static int gt_clockevent_set_periodic(struct clock_event_device *evt)
+{
+ gt_compare_set(DIV_ROUND_CLOSEST(gt_target_rate, HZ), 1);
+ return 0;
+}
+
+static int gt_clockevent_set_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ gt_compare_set(evt, 0);
+ return 0;
+}
+
+static irqreturn_t gt_clockevent_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+
+ if (!(readl_relaxed(gt_base + GT_INT_STATUS) &
+ GT_INT_STATUS_EVENT_FLAG))
+ return IRQ_NONE;
+
+ /**
+ * ERRATA 740657( Global Timer can send 2 interrupts for
+ * the same event in single-shot mode)
+ * Workaround:
+ * Either disable single-shot mode.
+ * Or
+ * Modify the Interrupt Handler to avoid the
+ * offending sequence. This is achieved by clearing
+ * the Global Timer flag _after_ having incremented
+ * the Comparator register value to a higher value.
+ */
+ if (clockevent_state_oneshot(evt))
+ gt_compare_set(ULONG_MAX, 0);
+
+ writel_relaxed(GT_INT_STATUS_EVENT_FLAG, gt_base + GT_INT_STATUS);
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static int gt_starting_cpu(unsigned int cpu)
+{
+ struct clock_event_device *clk = this_cpu_ptr(gt_evt);
+
+ clk->name = "arm_global_timer";
+ clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_PERCPU;
+ clk->set_state_shutdown = gt_clockevent_shutdown;
+ clk->set_state_periodic = gt_clockevent_set_periodic;
+ clk->set_state_oneshot = gt_clockevent_shutdown;
+ clk->set_state_oneshot_stopped = gt_clockevent_shutdown;
+ clk->set_next_event = gt_clockevent_set_next_event;
+ clk->cpumask = cpumask_of(cpu);
+ clk->rating = 300;
+ clk->irq = gt_ppi;
+ clockevents_config_and_register(clk, gt_target_rate,
+ 1, 0xffffffff);
+ enable_percpu_irq(clk->irq, IRQ_TYPE_NONE);
+ return 0;
+}
+
+static int gt_dying_cpu(unsigned int cpu)
+{
+ struct clock_event_device *clk = this_cpu_ptr(gt_evt);
+
+ gt_clockevent_shutdown(clk);
+ disable_percpu_irq(clk->irq);
+ return 0;
+}
+
+static u64 gt_clocksource_read(struct clocksource *cs)
+{
+ return gt_counter_read();
+}
+
+static void gt_resume(struct clocksource *cs)
+{
+ unsigned long ctrl;
+
+ ctrl = readl(gt_base + GT_CONTROL);
+ if (!(ctrl & GT_CONTROL_TIMER_ENABLE))
+ /* re-enable timer on resume */
+ writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
+}
+
+static struct clocksource gt_clocksource = {
+ .name = "arm_global_timer",
+ .rating = 300,
+ .read = gt_clocksource_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .resume = gt_resume,
+};
+
+#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
+static u64 notrace gt_sched_clock_read(void)
+{
+ return _gt_counter_read();
+}
+#endif
+
+static unsigned long gt_read_long(void)
+{
+ return readl_relaxed(gt_base + GT_COUNTER0);
+}
+
+static struct delay_timer gt_delay_timer = {
+ .read_current_timer = gt_read_long,
+};
+
+static void gt_write_presc(u32 psv)
+{
+ u32 reg;
+
+ reg = readl(gt_base + GT_CONTROL);
+ reg &= ~GT_CONTROL_PRESCALER_MASK;
+ reg |= psv << GT_CONTROL_PRESCALER_SHIFT;
+ writel(reg, gt_base + GT_CONTROL);
+}
+
+static u32 gt_read_presc(void)
+{
+ u32 reg;
+
+ reg = readl(gt_base + GT_CONTROL);
+ reg &= GT_CONTROL_PRESCALER_MASK;
+ return reg >> GT_CONTROL_PRESCALER_SHIFT;
+}
+
+static void __init gt_delay_timer_init(void)
+{
+ gt_delay_timer.freq = gt_target_rate;
+ register_current_timer_delay(&gt_delay_timer);
+}
+
+static int __init gt_clocksource_init(void)
+{
+ writel(0, gt_base + GT_CONTROL);
+ writel(0, gt_base + GT_COUNTER0);
+ writel(0, gt_base + GT_COUNTER1);
+ /* set prescaler and enable timer on all the cores */
+ writel(((CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) <<
+ GT_CONTROL_PRESCALER_SHIFT)
+ | GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
+
+#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
+ sched_clock_register(gt_sched_clock_read, 64, gt_target_rate);
+#endif
+ return clocksource_register_hz(&gt_clocksource, gt_target_rate);
+}
+
+static int gt_clk_rate_change_cb(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ {
+ int psv;
+
+ psv = DIV_ROUND_CLOSEST(ndata->new_rate,
+ gt_target_rate);
+
+ if (abs(gt_target_rate - (ndata->new_rate / psv)) > MAX_F_ERR)
+ return NOTIFY_BAD;
+
+ psv--;
+
+ /* prescaler within legal range? */
+ if (psv < 0 || psv > GT_CONTROL_PRESCALER_MAX)
+ return NOTIFY_BAD;
+
+ /*
+ * store timer clock ctrl register so we can restore it in case
+ * of an abort.
+ */
+ gt_psv_bck = gt_read_presc();
+ gt_psv_new = psv;
+ /* scale down: adjust divider in post-change notification */
+ if (ndata->new_rate < ndata->old_rate)
+ return NOTIFY_DONE;
+
+ /* scale up: adjust divider now - before frequency change */
+ gt_write_presc(psv);
+ break;
+ }
+ case POST_RATE_CHANGE:
+ /* scale up: pre-change notification did the adjustment */
+ if (ndata->new_rate > ndata->old_rate)
+ return NOTIFY_OK;
+
+ /* scale down: adjust divider now - after frequency change */
+ gt_write_presc(gt_psv_new);
+ break;
+
+ case ABORT_RATE_CHANGE:
+ /* we have to undo the adjustment in case we scale up */
+ if (ndata->new_rate < ndata->old_rate)
+ return NOTIFY_OK;
+
+ /* restore original register value */
+ gt_write_presc(gt_psv_bck);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int __init global_timer_of_register(struct device_node *np)
+{
+ struct clk *gt_clk;
+ static unsigned long gt_clk_rate;
+ int err = 0;
+
+ /*
+ * In A9 r2p0 the comparators for each processor with the global timer
+ * fire when the timer value is greater than or equal to. In previous
+ * revisions the comparators fired when the timer value was equal to.
+ */
+ if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9
+ && (read_cpuid_id() & 0xf0000f) < 0x200000) {
+ pr_warn("global-timer: non support for this cpu version.\n");
+ return -ENOSYS;
+ }
+
+ gt_ppi = irq_of_parse_and_map(np, 0);
+ if (!gt_ppi) {
+ pr_warn("global-timer: unable to parse irq\n");
+ return -EINVAL;
+ }
+
+ gt_base = of_iomap(np, 0);
+ if (!gt_base) {
+ pr_warn("global-timer: invalid base address\n");
+ return -ENXIO;
+ }
+
+ gt_clk = of_clk_get(np, 0);
+ if (!IS_ERR(gt_clk)) {
+ err = clk_prepare_enable(gt_clk);
+ if (err)
+ goto out_unmap;
+ } else {
+ pr_warn("global-timer: clk not found\n");
+ err = -EINVAL;
+ goto out_unmap;
+ }
+
+ gt_clk_rate = clk_get_rate(gt_clk);
+ gt_target_rate = gt_clk_rate / CONFIG_ARM_GT_INITIAL_PRESCALER_VAL;
+ gt_clk_rate_change_nb.notifier_call =
+ gt_clk_rate_change_cb;
+ err = clk_notifier_register(gt_clk, &gt_clk_rate_change_nb);
+ if (err) {
+ pr_warn("Unable to register clock notifier\n");
+ goto out_clk;
+ }
+
+ gt_evt = alloc_percpu(struct clock_event_device);
+ if (!gt_evt) {
+ pr_warn("global-timer: can't allocate memory\n");
+ err = -ENOMEM;
+ goto out_clk_nb;
+ }
+
+ err = request_percpu_irq(gt_ppi, gt_clockevent_interrupt,
+ "gt", gt_evt);
+ if (err) {
+ pr_warn("global-timer: can't register interrupt %d (%d)\n",
+ gt_ppi, err);
+ goto out_free;
+ }
+
+ /* Register and immediately configure the timer on the boot CPU */
+ err = gt_clocksource_init();
+ if (err)
+ goto out_irq;
+
+ err = cpuhp_setup_state(CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
+ "clockevents/arm/global_timer:starting",
+ gt_starting_cpu, gt_dying_cpu);
+ if (err)
+ goto out_irq;
+
+ gt_delay_timer_init();
+
+ return 0;
+
+out_irq:
+ free_percpu_irq(gt_ppi, gt_evt);
+out_free:
+ free_percpu(gt_evt);
+out_clk_nb:
+ clk_notifier_unregister(gt_clk, &gt_clk_rate_change_nb);
+out_clk:
+ clk_disable_unprepare(gt_clk);
+out_unmap:
+ iounmap(gt_base);
+ WARN(err, "ARM Global timer register failed (%d)\n", err);
+
+ return err;
+}
+
+/* Only tested on r2p2 and r3p0 */
+TIMER_OF_DECLARE(arm_gt, "arm,cortex-a9-global-timer",
+ global_timer_of_register);