path: root/arch/sparc/kernel/irq_64.c

// SPDX-License-Identifier: GPL-2.0
/* irq.c: UltraSparc IRQ handling/init/registry.
 *
 * Copyright (C) 1997, 2007, 2008 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1998  Eddie C. Dost    (ecd@skynet.be)
 * Copyright (C) 1998  Jakub Jelinek    (jj@ultra.linux.cz)
 */

#include <linux/sched.h>
#include <linux/linkage.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/ftrace.h>
#include <linux/irq.h>

#include <asm/ptrace.h>
#include <asm/processor.h>
#include <linux/atomic.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/upa.h>
#include <asm/oplib.h>
#include <asm/prom.h>
#include <asm/timer.h>
#include <asm/smp.h>
#include <asm/starfire.h>
#include <linux/uaccess.h>
#include <asm/cache.h>
#include <asm/cpudata.h>
#include <asm/auxio.h>
#include <asm/head.h>
#include <asm/hypervisor.h>
#include <asm/cacheflush.h>
#include <asm/softirq_stack.h>

#include "entry.h"
#include "cpumap.h"
#include "kstack.h"

struct ino_bucket *ivector_table;
unsigned long ivector_table_pa;

/* On several sun4u processors, it is illegal to mix bypass and
 * non-bypass accesses.  Therefore we access all INO buckets
 * using bypass accesses only.
 */
static unsigned long bucket_get_chain_pa(unsigned long bucket_pa)
{
	unsigned long ret;

	__asm__ __volatile__("ldxa	[%1] %2, %0"
			     : "=&r" (ret)
			     : "r" (bucket_pa +
				    offsetof(struct ino_bucket,
					     __irq_chain_pa)),
			       "i" (ASI_PHYS_USE_EC));

	return ret;
}

static void bucket_clear_chain_pa(unsigned long bucket_pa)
{
	__asm__ __volatile__("stxa	%%g0, [%0] %1"
			     : /* no outputs */
			     : "r" (bucket_pa +
				    offsetof(struct ino_bucket,
					     __irq_chain_pa)),
			       "i" (ASI_PHYS_USE_EC));
}

static unsigned int bucket_get_irq(unsigned long bucket_pa)
{
	unsigned int ret;

	__asm__ __volatile__("lduwa	[%1] %2, %0"
			     : "=&r" (ret)
			     : "r" (bucket_pa +
				    offsetof(struct ino_bucket,
					     __irq)),
			       "i" (ASI_PHYS_USE_EC));

	return ret;
}

static void bucket_set_irq(unsigned long bucket_pa, unsigned int irq)
{
	__asm__ __volatile__("stwa	%0, [%1] %2"
			     : /* no outputs */
			     : "r" (irq),
			       "r" (bucket_pa +
				    offsetof(struct ino_bucket,
					     __irq)),
			       "i" (ASI_PHYS_USE_EC));
}

#define irq_work_pa(__cpu)	&(trap_block[(__cpu)].irq_worklist_pa)

static unsigned long hvirq_major __initdata;
static int __init early_hvirq_major(char *p)
{
	int rc = kstrtoul(p, 10, &hvirq_major);

	return rc;
}
early_param("hvirq", early_hvirq_major);

static int hv_irq_version;

/* Major version 2.0 of HV_GRP_INTR added support for the VIRQ cookie
 * based interfaces, but:
 *
 * 1) Several OSs, Solaris and Linux included, use them even when only
 *    negotiating version 1.0 (or failing to negotiate at all).  So the
 *    hypervisor has a workaround that provides the VIRQ interfaces even
 *    when only verion 1.0 of the API is in use.
 *
 * 2) Second, and more importantly, with major version 2.0 these VIRQ
 *    interfaces only were actually hooked up for LDC interrupts, even
 *    though the Hypervisor specification clearly stated:
 *
 *	The new interrupt API functions will be available to a guest
 *	when it negotiates version 2.0 in the interrupt API group 0x2. When
 *	a guest negotiates version 2.0, all interrupt sources will only
 *	support using the cookie interface, and any attempt to use the
 *	version 1.0 interrupt APIs numbered 0xa0 to 0xa6 will result in the
 *	ENOTSUPPORTED error being returned.
 *
 *   with an emphasis on "all interrupt sources".
 *
 * To correct this, major version 3.0 was created which does actually
 * support VIRQs for all interrupt sources (not just LDC devices).  So
 * if we want to move completely over the cookie based VIRQs we must
 * negotiate major version 3.0 or later of HV_GRP_INTR.
 */
static bool sun4v_cookie_only_virqs(void)
{
	if (hv_irq_version >= 3)
		return true;
	return false;
}

static void __init irq_init_hv(void)
{
	unsigned long hv_error, major, minor = 0;

	if (tlb_type != hypervisor)
		return;

	if (hvirq_major)
		major = hvirq_major;
	else
		major = 3;

	hv_error = sun4v_hvapi_register(HV_GRP_INTR, major, &minor);
	if (!hv_error)
		hv_irq_version = major;
	else
		hv_irq_version = 1;

	pr_info("SUN4V: Using IRQ API major %d, cookie only virqs %s\n",
		hv_irq_version,
		sun4v_cookie_only_virqs() ? "enabled" : "disabled");
}

/* This function is for the timer interrupt.*/
int __init arch_probe_nr_irqs(void)
{
	return 1;
}

#define DEFAULT_NUM_IVECS	(0xfffU)
static unsigned int nr_ivec = DEFAULT_NUM_IVECS;
#define NUM_IVECS (nr_ivec)

static unsigned int __init