arch/powerpc/sysdev/fsl_mpic_err.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Freescale Semiconductor, Inc.
   4  *
   5  * Author: Varun Sethi <varun.sethi@freescale.com>
   6  */
   7
   8 #include <linux/irq.h>
   9 #include <linux/smp.h>
  10 #include <linux/interrupt.h>
  11
  12 #include <asm/io.h>
  13 #include <asm/irq.h>
  14 #include <asm/mpic.h>
  15
  16 #include "mpic.h"
  17
  18 #define MPIC_ERR_INT_BASE       0x3900
  19 #define MPIC_ERR_INT_EISR       0x0000
  20 #define MPIC_ERR_INT_EIMR       0x0010
  21
  22 static inline u32 mpic_fsl_err_read(u32 __iomem *base, unsigned int err_reg)
  23 {
  24         return in_be32(base + (err_reg >> 2));
  25 }
  26
  27 static inline void mpic_fsl_err_write(u32 __iomem *base, u32 value)
  28 {
  29         out_be32(base + (MPIC_ERR_INT_EIMR >> 2), value);
  30 }
  31
  32 static void fsl_mpic_mask_err(struct irq_data *d)
  33 {
  34         u32 eimr;
  35         struct mpic *mpic = irq_data_get_irq_chip_data(d);
  36         unsigned int src = virq_to_hw(d->irq) - mpic->err_int_vecs[0];
  37
  38         eimr = mpic_fsl_err_read(mpic->err_regs, MPIC_ERR_INT_EIMR);
  39         eimr |= (1 << (31 - src));
  40         mpic_fsl_err_write(mpic->err_regs, eimr);
  41 }
  42
  43 static void fsl_mpic_unmask_err(struct irq_data *d)
  44 {
  45         u32 eimr;
  46         struct mpic *mpic = irq_data_get_irq_chip_data(d);
  47         unsigned int src = virq_to_hw(d->irq) - mpic->err_int_vecs[0];
  48
  49         eimr = mpic_fsl_err_read(mpic->err_regs, MPIC_ERR_INT_EIMR);
  50         eimr &= ~(1 << (31 - src));
  51         mpic_fsl_err_write(mpic->err_regs, eimr);
  52 }
  53
  54 static struct irq_chip fsl_mpic_err_chip = {
  55         .irq_disable    = fsl_mpic_mask_err,
  56         .irq_mask       = fsl_mpic_mask_err,
  57         .irq_unmask     = fsl_mpic_unmask_err,
  58 };
  59
  60 int mpic_setup_error_int(struct mpic *mpic, int intvec)
  61 {
  62         int i;
  63
  64         mpic->err_regs = ioremap(mpic->paddr + MPIC_ERR_INT_BASE, 0x1000);
  65         if (!mpic->err_regs) {
  66                 pr_err("could not map mpic error registers\n");
  67                 return -ENOMEM;
  68         }
  69         mpic->hc_err = fsl_mpic_err_chip;
  70         mpic->hc_err.name = mpic->name;
  71         mpic->flags |= MPIC_FSL_HAS_EIMR;
  72         /* allocate interrupt vectors for error interrupts */
  73         for (i = MPIC_MAX_ERR - 1; i >= 0; i--)
  74                 mpic->err_int_vecs[i] = intvec--;
  75
  76         return 0;
  77 }
  78
  79 int mpic_map_error_int(struct mpic *mpic, unsigned int virq, irq_hw_number_t  hw)
  80 {
  81         if ((mpic->flags & MPIC_FSL_HAS_EIMR) &&
  82             (hw >= mpic->err_int_vecs[0] &&
  83              hw <= mpic->err_int_vecs[MPIC_MAX_ERR - 1])) {
  84                 WARN_ON(mpic->flags & MPIC_SECONDARY);
  85
  86                 pr_debug("mpic: mapping as Error Interrupt\n");
  87                 irq_set_chip_data(virq, mpic);
  88                 irq_set_chip_and_handler(virq, &mpic->hc_err,
  89                                          handle_level_irq);
  90                 return 1;
  91         }
  92
  93         return 0;
  94 }
  95
  96 static irqreturn_t fsl_error_int_handler(int irq, void *data)
  97 {
  98         struct mpic *mpic = (struct mpic *) data;
  99         u32 eisr, eimr;
 100         int errint;
 101         unsigned int cascade_irq;
 102
 103         eisr = mpic_fsl_err_read(mpic->err_regs, MPIC_ERR_INT_EISR);
 104         eimr = mpic_fsl_err_read(mpic->err_regs, MPIC_ERR_INT_EIMR);
 105
 106         if (!(eisr & ~eimr))
 107                 return IRQ_NONE;
 108
 109         while (eisr) {
 110                 errint = __builtin_clz(eisr);
 111                 cascade_irq = irq_linear_revmap(mpic->irqhost,
 112                                  mpic->err_int_vecs[errint]);
 113                 WARN_ON(!cascade_irq);
 114                 if (cascade_irq) {
 115                         generic_handle_irq(cascade_irq);
 116                 } else {
 117                         eimr |=  1 << (31 - errint);
 118                         mpic_fsl_err_write(mpic->err_regs, eimr);
 119                 }
 120                 eisr &= ~(1 << (31 - errint));
 121         }
 122
 123         return IRQ_HANDLED;
 124 }
 125
 126 void mpic_err_int_init(struct mpic *mpic, irq_hw_number_t irqnum)
 127 {
 128         unsigned int virq;
 129         int ret;
 130
 131         virq = irq_create_mapping(mpic->irqhost, irqnum);
 132         if (!virq) {
 133                 pr_err("Error interrupt setup failed\n");
 134                 return;
 135         }
 136
 137         /* Mask all error interrupts */
 138         mpic_fsl_err_write(mpic->err_regs, ~0);
 139
 140         ret = request_irq(virq, fsl_error_int_handler, IRQF_NO_THREAD,
 141                     "mpic-error-int", mpic);
 142         if (ret)
 143                 pr_err("Failed to register error interrupt handler\n");
 144 }