1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Numascale NumaConnect-specific PCI code 7 * 8 * Copyright (C) 2012 Numascale AS. All rights reserved. 9 * 10 * Send feedback to <support@numascale.com> 11 * 12 * PCI accessor functions derived from mmconfig_64.c 13 * 14 */ 15 16 #include <linux/pci.h> 17 #include <asm/pci_x86.h> 18 19 static u8 limit __read_mostly; 20 21 static inline char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) 22 { 23 struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus); 24 25 if (cfg && cfg->virt) 26 return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12)); 27 return NULL; 28 } 29 30 static int pci_mmcfg_read_numachip(unsigned int seg, unsigned int bus, 31 unsigned int devfn, int reg, int len, u32 *value) 32 { 33 char __iomem *addr; 34 35 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */ 36 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) { 37 err: *value = -1; 38 return -EINVAL; 39 } 40 41 /* Ensure AMD Northbridges don't decode reads to other devices */ 42 if (unlikely(bus == 0 && devfn >= limit)) { 43 *value = -1; 44 return 0; 45 } 46 47 rcu_read_lock(); 48 addr = pci_dev_base(seg, bus, devfn); 49 if (!addr) { 50 rcu_read_unlock(); 51 goto err; 52 } 53 54 switch (len) { 55 case 1: 56 *value = mmio_config_readb(addr + reg); 57 break; 58 case 2: 59 *value = mmio_config_readw(addr + reg); 60 break; 61 case 4: 62 *value = mmio_config_readl(addr + reg); 63 break; 64 } 65 rcu_read_unlock(); 66 67 return 0; 68 } 69 70 static int pci_mmcfg_write_numachip(unsigned int seg, unsigned int bus, 71 unsigned int devfn, int reg, int len, u32 value) 72 { 73 char __iomem *addr; 74 75 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */ 76 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) 77 return -EINVAL; 78 79 /* Ensure AMD Northbridges don't decode writes to other devices */ 80 if (unlikely(bus == 0 && devfn >= limit)) 81 return 0; 82 83 rcu_read_lock(); 84 addr = pci_dev_base(seg, bus, devfn); 85 if (!addr) { 86 rcu_read_unlock(); 87 return -EINVAL; 88 } 89 90 switch (len) { 91 case 1: 92 mmio_config_writeb(addr + reg, value); 93 break; 94 case 2: 95 mmio_config_writew(addr + reg, value); 96 break; 97 case 4: 98 mmio_config_writel(addr + reg, value); 99 break; 100 } 101 rcu_read_unlock(); 102 103 return 0; 104 } 105 106 static const struct pci_raw_ops pci_mmcfg_numachip = { 107 .read = pci_mmcfg_read_numachip, 108 .write = pci_mmcfg_write_numachip, 109 }; 110 111 int __init pci_numachip_init(void) 112 { 113 int ret = 0; 114 u32 val; 115 116 /* For remote I/O, restrict bus 0 access to the actual number of AMD 117 Northbridges, which starts at device number 0x18 */ 118 ret = raw_pci_read(0, 0, PCI_DEVFN(0x18, 0), 0x60, sizeof(val), &val); 119 if (ret) 120 goto out; 121 122 /* HyperTransport fabric size in bits 6:4 */ 123 limit = PCI_DEVFN(0x18 + ((val >> 4) & 7) + 1, 0); 124 125 /* Use NumaChip PCI accessors for non-extended and extended access */ 126 raw_pci_ops = raw_pci_ext_ops = &pci_mmcfg_numachip; 127 out: 128 return ret; 129 } 130