x86/apb_timer: Remove driver for deprecated platform

Intel Moorestown and Medfield are quite old Intel Atom based
32-bit platforms, which were in limited use in some Android phones,
tablets and consumer electronics more than eight years ago.

There are no bugs or problems ever reported outside from Intel
for breaking any of that platforms for years. It seems no real
users exists who run more or less fresh kernel on it. Commit
05f4434bc130 ("ASoC: Intel: remove mfld_machine") is also in align
with this theory.

Due to above and to reduce a burden of supporting outdated drivers,
remove the support for outdated platforms completely.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 0 insertions, 347 deletions

diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
deleted file mode 100644
index 263eeaddb0aa..000000000000
--- a/arch/x86/kernel/apb_timer.c
+++ /dev/null
@@ -1,347 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * apb_timer.c: Driver for Langwell APB timers
- *
- * (C) Copyright 2009 Intel Corporation
- * Author: Jacob Pan (jacob.jun.pan@intel.com)
- *
- * Note:
- * Langwell is the south complex of Intel Moorestown MID platform. There are
- * eight external timers in total that can be used by the operating system.
- * The timer information, such as frequency and addresses, is provided to the
- * OS via SFI tables.
- * Timer interrupts are routed via FW/HW emulated IOAPIC independently via
- * individual redirection table entries (RTE).
- * Unlike HPET, there is no master counter, therefore one of the timers are
- * used as clocksource. The overall allocation looks like:
- *  - timer 0 - NR_CPUs for per cpu timer
- *  - one timer for clocksource
- *  - one timer for watchdog driver.
- * It is also worth notice that APB timer does not support true one-shot mode,
- * free-running mode will be used here to emulate one-shot mode.
- * APB timer can also be used as broadcast timer along with per cpu local APIC
- * timer, but by default APB timer has higher rating than local APIC timers.
- */
-
-#include <linux/delay.h>
-#include <linux/dw_apb_timer.h>
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/pm.h>
-#include <linux/sfi.h>
-#include <linux/interrupt.h>
-#include <linux/cpu.h>
-#include <linux/irq.h>
-
-#include <asm/fixmap.h>
-#include <asm/apb_timer.h>
-#include <asm/intel-mid.h>
-#include <asm/time.h>
-
-#define APBT_CLOCKEVENT_RATING		110
-#define APBT_CLOCKSOURCE_RATING		250
-
-#define APBT_CLOCKEVENT0_NUM   (0)
-#define APBT_CLOCKSOURCE_NUM   (2)
-
-static phys_addr_t apbt_address;
-static int apb_timer_block_enabled;
-static void __iomem *apbt_virt_address;
-
-/*
- * Common DW APB timer info
- */
-static unsigned long apbt_freq;
-
-struct apbt_dev {
-	struct dw_apb_clock_event_device	*timer;
-	unsigned int				num;
-	int					cpu;
-	unsigned int				irq;
-	char					name[10];
-};
-
-static struct dw_apb_clocksource *clocksource_apbt;
-
-static inline void __iomem *adev_virt_addr(struct apbt_dev *adev)
-{
-	return apbt_virt_address + adev->num * APBTMRS_REG_SIZE;
-}
-
-static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev);
-
-#ifdef CONFIG_SMP
-static unsigned int apbt_num_timers_used;
-#endif
-
-static inline void apbt_set_mapping(void)
-{
-	struct sfi_timer_table_entry *mtmr;
-	int phy_cs_timer_id = 0;
-
-	if (apbt_virt_address) {
-		pr_debug("APBT base already mapped\n");
-		return;
-	}
-	mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM);
-	if (mtmr == NULL) {
-		printk(KERN_ERR "Failed to get MTMR %d from SFI\n",
-		       APBT_CLOCKEVENT0_NUM);
-		return;
-	}
-	apbt_address = (phys_addr_t)mtmr->phys_addr;
-	if (!apbt_address) {
-		printk(KERN_WARNING "No timer base from SFI, use default\n");
-		apbt_address = APBT_DEFAULT_BASE;
-	}
-	apbt_virt_address = ioremap(apbt_address, APBT_MMAP_SIZE);
-	if (!apbt_virt_address) {
-		pr_debug("Failed mapping APBT phy address at %lu\n",\
-			 (unsigned long)apbt_address);
-		goto panic_noapbt;
-	}
-	apbt_freq = mtmr->freq_hz;
-	sfi_free_mtmr(mtmr);
-
-	/* Now figure out the physical timer id for clocksource device */
-	mtmr = sfi_get_mtmr(APBT_CLOCKSOURCE_NUM);
-	if (mtmr == NULL)
-		goto panic_noapbt;
-
-	/* Now figure out the physical timer id */
-	pr_debug("Use timer %d for clocksource\n",
-		 (int)(mtmr->phys_addr & 0xff) / APBTMRS_REG_SIZE);
-	phy_cs_timer_id = (unsigned int)(mtmr->phys_addr & 0xff) /
-		APBTMRS_REG_SIZE;
-
-	clocksource_apbt = dw_apb_clocksource_init(APBT_CLOCKSOURCE_RATING,
-		"apbt0", apbt_virt_address + phy_cs_timer_id *
-		APBTMRS_REG_SIZE, apbt_freq);
-	return;
-
-panic_noapbt:
-	panic("Failed to setup APB system timer\n");
-
-}
-
-static inline void apbt_clear_mapping(void)
-{
-	iounmap(apbt_virt_address);
-	apbt_virt_address = NULL;
-}
-
-static int __init apbt_clockevent_register(void)
-{
-	struct sfi_timer_table_entry *mtmr;
-	struct apbt_dev *adev = this_cpu_ptr(&cpu_apbt_dev);
-
-	mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM);
-	if (mtmr == NULL) {
-		printk(KERN_ERR "Failed to get MTMR %d from SFI\n",
-		       APBT_CLOCKEVENT0_NUM);
-		return -ENODEV;
-	}
-
-	adev->num = smp_processor_id();
-	adev->timer = dw_apb_clockevent_init(smp_processor_id(), "apbt0",
-		intel_mid_timer_options == INTEL_MID_TIMER_LAPIC_APBT ?
-		APBT_CLOCKEVENT_RATING - 100 : APBT_CLOCKEVENT_RATING,
-		adev_virt_addr(adev), 0, apbt_freq);
-	/* Firmware does EOI handling for us. */
-	adev->timer->eoi = NULL;
-
-	if (intel_mid_timer_options == INTEL_MID_TIMER_LAPIC_APBT) {
-		global_clock_event = &adev->timer->ced;
-		printk(KERN_DEBUG "%s clockevent registered as global\n",
-		       global_clock_event->name);
-	}
-
-	dw_apb_clockevent_register(adev->timer);
-
-	sfi_free_mtmr(mtmr);
-	return 0;
-}
-
-#ifdef CONFIG_SMP
-
-static void apbt_setup_irq(struct apbt_dev *adev)
-{
-	irq_modify_status(adev->irq, 0, IRQ_MOVE_PCNTXT);
-	irq_set_affinity(adev->irq, cpumask_of(adev->cpu));
-}
-
-/* Should be called with per cpu */
-void apbt_setup_secondary_clock(void)
-{
-	struct apbt_dev *adev;
-	int cpu;
-
-	/* Don't register boot CPU clockevent */
-	cpu = smp_processor_id();
-	if (!cpu)
-		return;
-
-	adev = this_cpu_ptr(&cpu_apbt_dev);
-	if (!adev->timer) {
-		adev->timer = dw_apb_clockevent_init(cpu, adev->name,
-			APBT_CLOCKEVENT_RATING, adev_virt_addr(adev),
-			adev->irq, apbt_freq);
-		adev->timer->eoi = NULL;
-	} else {
-		dw_apb_clockevent_resume(adev->timer);
-	}
-
-	printk(KERN_INFO "Registering CPU %d clockevent device %s, cpu %08x\n",
-	       cpu, adev->name, adev->cpu);
-
-	apbt_setup_irq(adev);
-	dw_apb_clockevent_register(adev->timer);
-
-	return;
-}
-
-/*
- * this notify handler process CPU hotplug events. in case of S0i3, nonboot
- * cpus are disabled/enabled frequently, for performance reasons, we keep the
- * per cpu timer irq registered so that we do need to do free_irq/request_irq.
- *
- * TODO: it might be more reliable to directly disable percpu clockevent device
- * without the notifier chain. currently, cpu 0 may get interrupts from other
- * cpu timers during the offline process due to the ordering of notification.
- * the extra interrupt is harmless.
- */
-static int apbt_cpu_dead(unsigned int cpu)
-{
-	struct apbt_dev *adev = &per_cpu(cpu_apbt_dev, cpu);
-
-	dw_apb_clockevent_pause(adev->timer);
-	if (system_state == SYSTEM_RUNNING) {
-		pr_debug("skipping APBT CPU %u offline\n", cpu);
-	} else {
-		pr_debug("APBT clockevent for cpu %u offline\n", cpu);
-		dw_apb_clockevent_stop(adev->timer);
-	}
-	return 0;
-}
-
-static __init int apbt_late_init(void)
-{
-	if (intel_mid_timer_options == INTEL_MID_TIMER_LAPIC_APBT ||
-		!apb_timer_block_enabled)
-		return 0;
-	return cpuhp_setup_state(CPUHP_X86_APB_DEAD, "x86/apb:dead", NULL,
-				 apbt_cpu_dead);
-}
-fs_initcall(apbt_late_init);
-#else
-
-void apbt_setup_secondary_clock(void) {}
-
-#endif /* CONFIG_SMP */
-
-static int apbt_clocksource_register(void)
-{
-	u64 start, now;
-	u64 t1;
-
-	/* Start the counter, use timer 2 as source, timer 0/1 for event */
-	dw_apb_clocksource_start(clocksource_apbt);
-
-	/* Verify whether apbt counter works */
-	t1 = dw_apb_clocksource_read(clocksource_apbt);
-	start = rdtsc();
-
-	/*
-	 * We don't know the TSC frequency yet, but waiting for
-	 * 200000 TSC cycles is safe:
-	 * 4 GHz == 50us
-	 * 1 GHz == 200us
-	 */
-	do {
-		rep_nop();
-		now = rdtsc();
-	} while ((now - start) < 200000UL);
-
-	/* APBT is the only always on clocksource, it has to work! */
-	if (t1 == dw_apb_clocksource_read(clocksource_apbt))
-		panic("APBT counter not counting. APBT disabled\n");
-
-	dw_apb_clocksource_register(clocksource_apbt);
-
-	return 0;
-}
-
-/*
- * Early setup the APBT timer, only use timer 0 for booting then switch to
- * per CPU timer if possible.
- * returns 1 if per cpu apbt is setup
- * returns 0 if no per cpu apbt is chosen
- * panic if set up failed, this is the only platform timer on Moorestown.
- */
-void __init apbt_time_init(void)
-{
-#ifdef CONFIG_SMP
-	int i;
-	struct sfi_timer_table_entry *p_mtmr;
-	struct apbt_dev *adev;
-#endif
-
-	if (apb_timer_block_enabled)
-		return;
-	apbt_set_mapping();
-	if (!apbt_virt_address)
-		goto out_noapbt;
-	/*
-	 * Read the frequency and check for a sane value, for ESL model
-	 * we extend the possible clock range to allow time scaling.
-	 */
-
-	if (apbt_freq < APBT_MIN_FREQ || apbt_freq > APBT_MAX_FREQ) {
-		pr_debug("APBT has invalid freq 0x%lx\n", apbt_freq);
-		goto out_noapbt;
-	}
-	if (apbt_clocksource_register()) {
-		pr_debug("APBT has failed to register clocksource\n");
-		goto out_noapbt;
-	}
-	if (!apbt_clockevent_register())
-		apb_timer_block_enabled = 1;
-	else {
-		pr_debug("APBT has failed to register clockevent\n");
-		goto out_noapbt;
-	}
-#ifdef CONFIG_SMP
-	/* kernel cmdline disable apb timer, so we will use lapic timers */
-	if (intel_mid_timer_options == INTEL_MID_TIMER_LAPIC_APBT) {
-		printk(KERN_INFO "apbt: disabled per cpu timer\n");
-		return;
-	}
-	pr_debug("%s: %d CPUs online\n", __func__, num_online_cpus());
-	if (num_possible_cpus() <= sfi_mtimer_num)
-		apbt_num_timers_used = num_possible_cpus();
-	else
-		apbt_num_timers_used = 1;
-	pr_debug("%s: %d APB timers used\n", __func__, apbt_num_timers_used);
-
-	/* here we set up per CPU timer data structure */
-	for (i = 0; i < apbt_num_timers_used; i++) {
-		adev = &per_cpu(cpu_apbt_dev, i);
-		adev->num = i;
-		adev->cpu = i;
-		p_mtmr = sfi_get_mtmr(i);
-		if (p_mtmr)
-			adev->irq = p_mtmr->irq;
-		else
-			printk(KERN_ERR "Failed to get timer for cpu %d\n", i);
-		snprintf(adev->name, sizeof(adev->name) - 1, "apbt%d", i);
-	}
-#endif
-
-	return;
-
-out_noapbt:
-	apbt_clear_mapping();
-	apb_timer_block_enabled = 0;
-	panic("failed to enable APB timer\n");
-}