xref: /openbmc/linux/arch/alpha/kernel/pci-noop.c (revision 82e6fdd6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/pci-noop.c
4  *
5  * Stub PCI interfaces for Jensen-specific kernels.
6  */
7 
8 #include <linux/pci.h>
9 #include <linux/init.h>
10 #include <linux/bootmem.h>
11 #include <linux/gfp.h>
12 #include <linux/capability.h>
13 #include <linux/mm.h>
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/scatterlist.h>
18 
19 #include "proto.h"
20 
21 
22 /*
23  * The PCI controller list.
24  */
25 
26 struct pci_controller *hose_head, **hose_tail = &hose_head;
27 struct pci_controller *pci_isa_hose;
28 
29 
30 struct pci_controller * __init
31 alloc_pci_controller(void)
32 {
33 	struct pci_controller *hose;
34 
35 	hose = alloc_bootmem(sizeof(*hose));
36 
37 	*hose_tail = hose;
38 	hose_tail = &hose->next;
39 
40 	return hose;
41 }
42 
43 struct resource * __init
44 alloc_resource(void)
45 {
46 	return alloc_bootmem(sizeof(struct resource));
47 }
48 
49 asmlinkage long
50 sys_pciconfig_iobase(long which, unsigned long bus, unsigned long dfn)
51 {
52 	struct pci_controller *hose;
53 
54 	/* from hose or from bus.devfn */
55 	if (which & IOBASE_FROM_HOSE) {
56 		for (hose = hose_head; hose; hose = hose->next)
57 			if (hose->index == bus)
58 				break;
59 		if (!hose)
60 			return -ENODEV;
61 	} else {
62 		/* Special hook for ISA access.  */
63 		if (bus == 0 && dfn == 0)
64 			hose = pci_isa_hose;
65 		else
66 			return -ENODEV;
67 	}
68 
69 	switch (which & ~IOBASE_FROM_HOSE) {
70 	case IOBASE_HOSE:
71 		return hose->index;
72 	case IOBASE_SPARSE_MEM:
73 		return hose->sparse_mem_base;
74 	case IOBASE_DENSE_MEM:
75 		return hose->dense_mem_base;
76 	case IOBASE_SPARSE_IO:
77 		return hose->sparse_io_base;
78 	case IOBASE_DENSE_IO:
79 		return hose->dense_io_base;
80 	case IOBASE_ROOT_BUS:
81 		return hose->bus->number;
82 	}
83 
84 	return -EOPNOTSUPP;
85 }
86 
87 asmlinkage long
88 sys_pciconfig_read(unsigned long bus, unsigned long dfn,
89 		   unsigned long off, unsigned long len, void *buf)
90 {
91 	if (!capable(CAP_SYS_ADMIN))
92 		return -EPERM;
93 	else
94 		return -ENODEV;
95 }
96 
97 asmlinkage long
98 sys_pciconfig_write(unsigned long bus, unsigned long dfn,
99 		    unsigned long off, unsigned long len, void *buf)
100 {
101 	if (!capable(CAP_SYS_ADMIN))
102 		return -EPERM;
103 	else
104 		return -ENODEV;
105 }
106 
107 static void *alpha_noop_alloc_coherent(struct device *dev, size_t size,
108 				       dma_addr_t *dma_handle, gfp_t gfp,
109 				       unsigned long attrs)
110 {
111 	void *ret;
112 
113 	if (!dev || *dev->dma_mask >= 0xffffffffUL)
114 		gfp &= ~GFP_DMA;
115 	ret = (void *)__get_free_pages(gfp, get_order(size));
116 	if (ret) {
117 		memset(ret, 0, size);
118 		*dma_handle = virt_to_phys(ret);
119 	}
120 	return ret;
121 }
122 
123 static int alpha_noop_supported(struct device *dev, u64 mask)
124 {
125 	return mask < 0x00ffffffUL ? 0 : 1;
126 }
127 
128 const struct dma_map_ops alpha_noop_ops = {
129 	.alloc			= alpha_noop_alloc_coherent,
130 	.free			= dma_noop_free_coherent,
131 	.map_page		= dma_noop_map_page,
132 	.map_sg			= dma_noop_map_sg,
133 	.mapping_error		= dma_noop_mapping_error,
134 	.dma_supported		= alpha_noop_supported,
135 };
136 
137 const struct dma_map_ops *dma_ops = &alpha_noop_ops;
138 EXPORT_SYMBOL(dma_ops);
139