arch/sh/drivers/pci/common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/pci.h>
   3 #include <linux/interrupt.h>
   4 #include <linux/timer.h>
   5 #include <linux/kernel.h>
   6
   7 /*
   8  * These functions are used early on before PCI scanning is done
   9  * and all of the pci_dev and pci_bus structures have been created.
  10  */
  11 static struct pci_dev *fake_pci_dev(struct pci_channel *hose,
  12         int top_bus, int busnr, int devfn)
  13 {
  14         static struct pci_dev dev;
  15         static struct pci_bus bus;
  16
  17         dev.bus = &bus;
  18         dev.sysdata = hose;
  19         dev.devfn = devfn;
  20         bus.number = busnr;
  21         bus.sysdata = hose;
  22         bus.ops = hose->pci_ops;
  23
  24         if(busnr != top_bus)
  25                 /* Fake a parent bus structure. */
  26                 bus.parent = &bus;
  27         else
  28                 bus.parent = NULL;
  29
  30         return &dev;
  31 }
  32
  33 #define EARLY_PCI_OP(rw, size, type)                                    \
  34 int __init early_##rw##_config_##size(struct pci_channel *hose,         \
  35         int top_bus, int bus, int devfn, int offset, type value)        \
  36 {                                                                       \
  37         return pci_##rw##_config_##size(                                \
  38                 fake_pci_dev(hose, top_bus, bus, devfn),                \
  39                 offset, value);                                         \
  40 }
  41
  42 EARLY_PCI_OP(read, byte, u8 *)
  43 EARLY_PCI_OP(read, word, u16 *)
  44 EARLY_PCI_OP(read, dword, u32 *)
  45 EARLY_PCI_OP(write, byte, u8)
  46 EARLY_PCI_OP(write, word, u16)
  47 EARLY_PCI_OP(write, dword, u32)
  48
  49 int __init pci_is_66mhz_capable(struct pci_channel *hose,
  50                                 int top_bus, int current_bus)
  51 {
  52         u32 pci_devfn;
  53         u16 vid;
  54         int cap66 = -1;
  55         u16 stat;
  56         int ret;
  57
  58         pr_info("PCI: Checking 66MHz capabilities...\n");
  59
  60         for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
  61                 if (PCI_FUNC(pci_devfn))
  62                         continue;
  63                 ret = early_read_config_word(hose, top_bus, current_bus,
  64                                              pci_devfn, PCI_VENDOR_ID, &vid);
  65                 if (ret != PCIBIOS_SUCCESSFUL)
  66                         continue;
  67                 if (PCI_POSSIBLE_ERROR(vid))
  68                         continue;
  69
  70                 /* check 66MHz capability */
  71                 if (cap66 < 0)
  72                         cap66 = 1;
  73                 if (cap66) {
  74                         early_read_config_word(hose, top_bus, current_bus,
  75                                                pci_devfn, PCI_STATUS, &stat);
  76                         if (!(stat & PCI_STATUS_66MHZ)) {
  77                                 printk(KERN_DEBUG
  78                                        "PCI: %02x:%02x not 66MHz capable.\n",
  79                                        current_bus, pci_devfn);
  80                                 cap66 = 0;
  81                                 break;
  82                         }
  83                 }
  84         }
  85
  86         return cap66 > 0;
  87 }
  88
  89 static void pcibios_enable_err(struct timer_list *t)
  90 {
  91         struct pci_channel *hose = from_timer(hose, t, err_timer);
  92
  93         del_timer(&hose->err_timer);
  94         printk(KERN_DEBUG "PCI: re-enabling error IRQ.\n");
  95         enable_irq(hose->err_irq);
  96 }
  97
  98 static void pcibios_enable_serr(struct timer_list *t)
  99 {
 100         struct pci_channel *hose = from_timer(hose, t, serr_timer);
 101
 102         del_timer(&hose->serr_timer);
 103         printk(KERN_DEBUG "PCI: re-enabling system error IRQ.\n");
 104         enable_irq(hose->serr_irq);
 105 }
 106
 107 void pcibios_enable_timers(struct pci_channel *hose)
 108 {
 109         if (hose->err_irq) {
 110                 timer_setup(&hose->err_timer, pcibios_enable_err, 0);
 111         }
 112
 113         if (hose->serr_irq) {
 114                 timer_setup(&hose->serr_timer, pcibios_enable_serr, 0);
 115         }
 116 }
 117
 118 /*
 119  * A simple handler for the regular PCI status errors, called from IRQ
 120  * context.
 121  */
 122 unsigned int pcibios_handle_status_errors(unsigned long addr,
 123                                           unsigned int status,
 124                                           struct pci_channel *hose)
 125 {
 126         unsigned int cmd = 0;
 127
 128         if (status & PCI_STATUS_REC_MASTER_ABORT) {
 129                 printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n", addr);
 130                 cmd |= PCI_STATUS_REC_MASTER_ABORT;
 131         }
 132
 133         if (status & PCI_STATUS_REC_TARGET_ABORT) {
 134                 printk(KERN_DEBUG "PCI: target abort: ");
 135                 pcibios_report_status(PCI_STATUS_REC_TARGET_ABORT |
 136                                       PCI_STATUS_SIG_TARGET_ABORT |
 137                                       PCI_STATUS_REC_MASTER_ABORT, 1);
 138                 pr_cont("\n");
 139
 140                 cmd |= PCI_STATUS_REC_TARGET_ABORT;
 141         }
 142
 143         if (status & (PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY)) {
 144                 printk(KERN_DEBUG "PCI: parity error detected: ");
 145                 pcibios_report_status(PCI_STATUS_PARITY |
 146                                       PCI_STATUS_DETECTED_PARITY, 1);
 147                 pr_cont("\n");
 148
 149                 cmd |= PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY;
 150
 151                 /* Now back off of the IRQ for awhile */
 152                 if (hose->err_irq) {
 153                         disable_irq_nosync(hose->err_irq);
 154                         hose->err_timer.expires = jiffies + HZ;
 155                         add_timer(&hose->err_timer);
 156                 }
 157         }
 158
 159         return cmd;
 160 }