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         unsigned short vid;
  54         int cap66 = -1;
  55         u16 stat;
  56
  57         pr_info("PCI: Checking 66MHz capabilities...\n");
  58
  59         for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
  60                 if (PCI_FUNC(pci_devfn))
  61                         continue;
  62                 if (early_read_config_word(hose, top_bus, current_bus,
  63                                            pci_devfn, PCI_VENDOR_ID, &vid) !=
  64                     PCIBIOS_SUCCESSFUL)
  65                         continue;
  66                 if (vid == 0xffff)
  67                         continue;
  68
  69                 /* check 66MHz capability */
  70                 if (cap66 < 0)
  71                         cap66 = 1;
  72                 if (cap66) {
  73                         early_read_config_word(hose, top_bus, current_bus,
  74                                                pci_devfn, PCI_STATUS, &stat);
  75                         if (!(stat & PCI_STATUS_66MHZ)) {
  76                                 printk(KERN_DEBUG
  77                                        "PCI: %02x:%02x not 66MHz capable.\n",
  78                                        current_bus, pci_devfn);
  79                                 cap66 = 0;
  80                                 break;
  81                         }
  82                 }
  83         }
  84
  85         return cap66 > 0;
  86 }
  87
  88 static void pcibios_enable_err(struct timer_list *t)
  89 {
  90         struct pci_channel *hose = from_timer(hose, t, err_timer);
  91
  92         del_timer(&hose->err_timer);
  93         printk(KERN_DEBUG "PCI: re-enabling error IRQ.\n");
  94         enable_irq(hose->err_irq);
  95 }
  96
  97 static void pcibios_enable_serr(struct timer_list *t)
  98 {
  99         struct pci_channel *hose = from_timer(hose, t, serr_timer);
 100
 101         del_timer(&hose->serr_timer);
 102         printk(KERN_DEBUG "PCI: re-enabling system error IRQ.\n");
 103         enable_irq(hose->serr_irq);
 104 }
 105
 106 void pcibios_enable_timers(struct pci_channel *hose)
 107 {
 108         if (hose->err_irq) {
 109                 timer_setup(&hose->err_timer, pcibios_enable_err, 0);
 110         }
 111
 112         if (hose->serr_irq) {
 113                 timer_setup(&hose->serr_timer, pcibios_enable_serr, 0);
 114         }
 115 }
 116
 117 /*
 118  * A simple handler for the regular PCI status errors, called from IRQ
 119  * context.
 120  */
 121 unsigned int pcibios_handle_status_errors(unsigned long addr,
 122                                           unsigned int status,
 123                                           struct pci_channel *hose)
 124 {
 125         unsigned int cmd = 0;
 126
 127         if (status & PCI_STATUS_REC_MASTER_ABORT) {
 128                 printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n", addr);
 129                 cmd |= PCI_STATUS_REC_MASTER_ABORT;
 130         }
 131
 132         if (status & PCI_STATUS_REC_TARGET_ABORT) {
 133                 printk(KERN_DEBUG "PCI: target abort: ");
 134                 pcibios_report_status(PCI_STATUS_REC_TARGET_ABORT |
 135                                       PCI_STATUS_SIG_TARGET_ABORT |
 136                                       PCI_STATUS_REC_MASTER_ABORT, 1);
 137                 pr_cont("\n");
 138
 139                 cmd |= PCI_STATUS_REC_TARGET_ABORT;
 140         }
 141
 142         if (status & (PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY)) {
 143                 printk(KERN_DEBUG "PCI: parity error detected: ");
 144                 pcibios_report_status(PCI_STATUS_PARITY |
 145                                       PCI_STATUS_DETECTED_PARITY, 1);
 146                 pr_cont("\n");
 147
 148                 cmd |= PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY;
 149
 150                 /* Now back off of the IRQ for awhile */
 151                 if (hose->err_irq) {
 152                         disable_irq_nosync(hose->err_irq);
 153                         hose->err_timer.expires = jiffies + HZ;
 154                         add_timer(&hose->err_timer);
 155                 }
 156         }
 157
 158         return cmd;
 159 }