path: root/arch/powerpc/sysdev/xive/spapr.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2016,2017 IBM Corporation.
 */

#define pr_fmt(fmt) "xive: " fmt

#include <linux/types.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_fdt.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/bitmap.h>
#include <linux/cpumask.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/libfdt.h>

#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xive.h>
#include <asm/xive-regs.h>
#include <asm/hvcall.h>
#include <asm/svm.h>
#include <asm/ultravisor.h>

#include "xive-internal.h"

static u32 xive_queue_shift;

struct xive_irq_bitmap {
	unsigned long		*bitmap;
	unsigned int		base;
	unsigned int		count;
	spinlock_t		lock;
	struct list_head	list;
};

static LIST_HEAD(xive_irq_bitmaps);

static int __init xive_irq_bitmap_add(int base, int count)
{
	struct xive_irq_bitmap *xibm;

	xibm = kzalloc(sizeof(*xibm), GFP_KERNEL);
	if (!xibm)
		return -ENOMEM;

	spin_lock_init(&xibm->lock);
	xibm->base = base;
	xibm->count = count;
	xibm->bitmap = bitmap_zalloc(xibm->count, GFP_KERNEL);
	if (!xibm->bitmap) {
		kfree(xibm);
		return -ENOMEM;
	}
	list_add(&xibm->list, &xive_irq_bitmaps);

	pr_info("Using IRQ range [%x-%x]", xibm->base,
		xibm->base + xibm->count - 1);
	return 0;
}

static void xive_irq_bitmap_remove_all(void)
{
	struct xive_irq_bitmap *xibm, *tmp;

	list_for_each_entry_safe(xibm, tmp, &xive_irq_bitmaps, list) {
		list_del(&xibm->list);
		bitmap_free(xibm->bitmap);
		kfree(xibm);
	}
}

static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
{
	int irq;

	irq = find_first_zero_bit(xibm->bitmap, xibm->count);
	if (irq != xibm->count) {
		set_bit(irq, xibm->bitmap);
		irq += xibm->base;
	} else {
		irq = -ENOMEM;
	}

	return irq;
}

static int xive_irq_bitmap_alloc(void)
{
	struct xive_irq_bitmap *xibm;
	unsigned long flags;
	int irq = -ENOENT;

	list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
		spin_lock_irqsave(&xibm->lock, flags);
		irq = __xive_irq_bitmap_alloc(xibm);
		spin_unlock_irqrestore(&xibm->lock, flags);
		if (irq >= 0)
			break;
	}
	return irq;
}

static void xive_irq_bitmap_free(int irq)
{
	unsigned long flags;
	struct xive_irq_bitmap *xibm;

	list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
		if ((irq >= xibm->base) && (irq < xibm->base + xibm->count)) {
			spin_lock_irqsave(&xibm->lock, flags);
			clear_bit(irq - xibm->base, xibm->bitmap);
			spin_unlock_irqrestore(&xibm->lock, flags);
			break;
		}
	}
}


/* Based on the similar routines in RTAS */
static unsigned int plpar_busy_delay_time(long rc)
{
	unsigned int ms = 0;

	if (H_IS_LONG_BUSY(rc)) {
		ms = get_longbusy_msecs(rc);
	} else if (rc == H_BUSY) {
		ms = 10; /* seems appropriate for XIVE hcalls */
	}

	return ms;
}

static unsigned int plpar_busy_delay(int rc)
{
	unsigned int ms;

	ms = plpar_busy_delay_time(rc);
	if (ms)
		mdelay(ms);

	return ms;
}

/*
 * Note: this call has a partition wide scope and can take a while to
 * complete. If it returns H_LONG_BUSY_* it should be retried
 * periodically.
 */
static long plpar_int_reset(unsigned long flags)
{
	long rc;

	do {
		rc = plpar_hcall_norets(H_INT_RESET, flags);
	} while (plpar_busy_delay(rc));

	if (rc)
		pr_err("H_INT_RESET failed %ld\n", rc);

	return rc;
}

static long plpar_int_get_source_info(unsigned long flags,
				      unsigned long lisn,
				      unsigned long *src_flags,
				      unsigned long *eoi_page,
				      unsigned long *trig_page,
				      unsigned long *esb_shift)
{
	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
	long