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
pci_dev_base(unsigned int seg,unsigned int bus,unsigned int devfn)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
pci_mmcfg_read_numachip(unsigned int seg,unsigned int bus,unsigned int devfn,int reg,int len,u32 * value)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
pci_mmcfg_write_numachip(unsigned int seg,unsigned int bus,unsigned int devfn,int reg,int len,u32 value)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 const struct pci_raw_ops pci_mmcfg_numachip = {
107 .read = pci_mmcfg_read_numachip,
108 .write = pci_mmcfg_write_numachip,
109 };
110
pci_numachip_init(void)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