arch/powerpc/platforms/cell/spider-pci.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * IO workarounds for PCI on Celleb/Cell platform
   4  *
   5  * (C) Copyright 2006-2007 TOSHIBA CORPORATION
   6  */
   7
   8 #undef DEBUG
   9
  10 #include <linux/kernel.h>
  11 #include <linux/of_address.h>
  12 #include <linux/slab.h>
  13 #include <linux/io.h>
  14
  15 #include <asm/ppc-pci.h>
  16 #include <asm/pci-bridge.h>
  17 #include <asm/io-workarounds.h>
  18
  19 #define SPIDER_PCI_DISABLE_PREFETCH
  20
  21 struct spiderpci_iowa_private {
  22         void __iomem *regs;
  23 };
  24
  25 static void spiderpci_io_flush(struct iowa_bus *bus)
  26 {
  27         struct spiderpci_iowa_private *priv;
  28
  29         priv = bus->private;
  30         in_be32(priv->regs + SPIDER_PCI_DUMMY_READ);
  31         iosync();
  32 }
  33
  34 #define SPIDER_PCI_MMIO_READ(name, ret)                                 \
  35 static ret spiderpci_##name(const PCI_IO_ADDR addr)                     \
  36 {                                                                       \
  37         ret val = __do_##name(addr);                                    \
  38         spiderpci_io_flush(iowa_mem_find_bus(addr));                    \
  39         return val;                                                     \
  40 }
  41
  42 #define SPIDER_PCI_MMIO_READ_STR(name)                                  \
  43 static void spiderpci_##name(const PCI_IO_ADDR addr, void *buf,         \
  44                              unsigned long count)                       \
  45 {                                                                       \
  46         __do_##name(addr, buf, count);                                  \
  47         spiderpci_io_flush(iowa_mem_find_bus(addr));                    \
  48 }
  49
  50 SPIDER_PCI_MMIO_READ(readb, u8)
  51 SPIDER_PCI_MMIO_READ(readw, u16)
  52 SPIDER_PCI_MMIO_READ(readl, u32)
  53 SPIDER_PCI_MMIO_READ(readq, u64)
  54 SPIDER_PCI_MMIO_READ(readw_be, u16)
  55 SPIDER_PCI_MMIO_READ(readl_be, u32)
  56 SPIDER_PCI_MMIO_READ(readq_be, u64)
  57 SPIDER_PCI_MMIO_READ_STR(readsb)
  58 SPIDER_PCI_MMIO_READ_STR(readsw)
  59 SPIDER_PCI_MMIO_READ_STR(readsl)
  60
  61 static void spiderpci_memcpy_fromio(void *dest, const PCI_IO_ADDR src,
  62                                     unsigned long n)
  63 {
  64         __do_memcpy_fromio(dest, src, n);
  65         spiderpci_io_flush(iowa_mem_find_bus(src));
  66 }
  67
  68 static int __init spiderpci_pci_setup_chip(struct pci_controller *phb,
  69                                            void __iomem *regs)
  70 {
  71         void *dummy_page_va;
  72         dma_addr_t dummy_page_da;
  73
  74 #ifdef SPIDER_PCI_DISABLE_PREFETCH
  75         u32 val = in_be32(regs + SPIDER_PCI_VCI_CNTL_STAT);
  76         pr_debug("SPIDER_IOWA:PVCI_Control_Status was 0x%08x\n", val);
  77         out_be32(regs + SPIDER_PCI_VCI_CNTL_STAT, val | 0x8);
  78 #endif /* SPIDER_PCI_DISABLE_PREFETCH */
  79
  80         /* setup dummy read */
  81         /*
  82          * On CellBlade, we can't know that which XDR memory is used by
  83          * kmalloc() to allocate dummy_page_va.
  84          * In order to improve the performance, the XDR which is used to
  85          * allocate dummy_page_va is the nearest the spider-pci.
  86          * We have to select the CBE which is the nearest the spider-pci
  87          * to allocate memory from the best XDR, but I don't know that
  88          * how to do.
  89          *
  90          * Celleb does not have this problem, because it has only one XDR.
  91          */
  92         dummy_page_va = kmalloc(PAGE_SIZE, GFP_KERNEL);
  93         if (!dummy_page_va) {
  94                 pr_err("SPIDERPCI-IOWA:Alloc dummy_page_va failed.\n");
  95                 return -1;
  96         }
  97
  98         dummy_page_da = dma_map_single(phb->parent, dummy_page_va,
  99                                        PAGE_SIZE, DMA_FROM_DEVICE);
 100         if (dma_mapping_error(phb->parent, dummy_page_da)) {
 101                 pr_err("SPIDER-IOWA:Map dummy page filed.\n");
 102                 kfree(dummy_page_va);
 103                 return -1;
 104         }
 105
 106         out_be32(regs + SPIDER_PCI_DUMMY_READ_BASE, dummy_page_da);
 107
 108         return 0;
 109 }
 110
 111 int __init spiderpci_iowa_init(struct iowa_bus *bus, void *data)
 112 {
 113         void __iomem *regs = NULL;
 114         struct spiderpci_iowa_private *priv;
 115         struct device_node *np = bus->phb->dn;
 116         struct resource r;
 117         unsigned long offset = (unsigned long)data;
 118
 119         pr_debug("SPIDERPCI-IOWA:Bus initialize for spider(%pOF)\n",
 120                  np);
 121
 122         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 123         if (!priv) {
 124                 pr_err("SPIDERPCI-IOWA:"
 125                        "Can't allocate struct spiderpci_iowa_private");
 126                 return -1;
 127         }
 128
 129         if (of_address_to_resource(np, 0, &r)) {
 130                 pr_err("SPIDERPCI-IOWA:Can't get resource.\n");
 131                 goto error;
 132         }
 133
 134         regs = ioremap(r.start + offset, SPIDER_PCI_REG_SIZE);
 135         if (!regs) {
 136                 pr_err("SPIDERPCI-IOWA:ioremap failed.\n");
 137                 goto error;
 138         }
 139         priv->regs = regs;
 140         bus->private = priv;
 141
 142         if (spiderpci_pci_setup_chip(bus->phb, regs))
 143                 goto error;
 144
 145         return 0;
 146
 147 error:
 148         kfree(priv);
 149         bus->private = NULL;
 150
 151         if (regs)
 152                 iounmap(regs);
 153
 154         return -1;
 155 }
 156
 157 struct ppc_pci_io spiderpci_ops = {
 158         .readb = spiderpci_readb,
 159         .readw = spiderpci_readw,
 160         .readl = spiderpci_readl,
 161         .readq = spiderpci_readq,
 162         .readw_be = spiderpci_readw_be,
 163         .readl_be = spiderpci_readl_be,
 164         .readq_be = spiderpci_readq_be,
 165         .readsb = spiderpci_readsb,
 166         .readsw = spiderpci_readsw,
 167         .readsl = spiderpci_readsl,
 168         .memcpy_fromio = spiderpci_memcpy_fromio,
 169 };
 170