cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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imask.c (1974B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * arch/sh/kernel/cpu/irq/imask.c
      4 *
      5 * Copyright (C) 1999, 2000  Niibe Yutaka
      6 *
      7 * Simple interrupt handling using IMASK of SR register.
      8 *
      9 */
     10/* NOTE: Will not work on level 15 */
     11#include <linux/ptrace.h>
     12#include <linux/errno.h>
     13#include <linux/kernel_stat.h>
     14#include <linux/signal.h>
     15#include <linux/sched.h>
     16#include <linux/interrupt.h>
     17#include <linux/init.h>
     18#include <linux/bitops.h>
     19#include <linux/spinlock.h>
     20#include <linux/cache.h>
     21#include <linux/irq.h>
     22#include <linux/bitmap.h>
     23#include <asm/irq.h>
     24
     25/* Bitmap of IRQ masked */
     26#define IMASK_PRIORITY	15
     27
     28static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
     29static int interrupt_priority;
     30
     31static inline void set_interrupt_registers(int ip)
     32{
     33	unsigned long __dummy;
     34
     35	asm volatile(
     36#ifdef CONFIG_CPU_HAS_SR_RB
     37		     "ldc	%2, r6_bank\n\t"
     38#endif
     39		     "stc	sr, %0\n\t"
     40		     "and	#0xf0, %0\n\t"
     41		     "shlr2	%0\n\t"
     42		     "cmp/eq	#0x3c, %0\n\t"
     43		     "bt/s	1f	! CLI-ed\n\t"
     44		     " stc	sr, %0\n\t"
     45		     "and	%1, %0\n\t"
     46		     "or	%2, %0\n\t"
     47		     "ldc	%0, sr\n"
     48		     "1:"
     49		     : "=&z" (__dummy)
     50		     : "r" (~0xf0), "r" (ip << 4)
     51		     : "t");
     52}
     53
     54static void mask_imask_irq(struct irq_data *data)
     55{
     56	unsigned int irq = data->irq;
     57
     58	clear_bit(irq, imask_mask);
     59	if (interrupt_priority < IMASK_PRIORITY - irq)
     60		interrupt_priority = IMASK_PRIORITY - irq;
     61	set_interrupt_registers(interrupt_priority);
     62}
     63
     64static void unmask_imask_irq(struct irq_data *data)
     65{
     66	unsigned int irq = data->irq;
     67
     68	set_bit(irq, imask_mask);
     69	interrupt_priority = IMASK_PRIORITY -
     70		find_first_zero_bit(imask_mask, IMASK_PRIORITY);
     71	set_interrupt_registers(interrupt_priority);
     72}
     73
     74static struct irq_chip imask_irq_chip = {
     75	.name		= "SR.IMASK",
     76	.irq_mask	= mask_imask_irq,
     77	.irq_unmask	= unmask_imask_irq,
     78	.irq_mask_ack	= mask_imask_irq,
     79};
     80
     81void make_imask_irq(unsigned int irq)
     82{
     83	irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
     84				      "level");
     85}