1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
4*4882a593Smuzhiyun * Bjorn Helgaas <bjorn.helgaas@hp.com>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/compiler.h>
8*4882a593Smuzhiyun #include <linux/module.h>
9*4882a593Smuzhiyun #include <linux/efi.h>
10*4882a593Smuzhiyun #include <linux/io.h>
11*4882a593Smuzhiyun #include <linux/mm.h>
12*4882a593Smuzhiyun #include <linux/vmalloc.h>
13*4882a593Smuzhiyun #include <asm/io.h>
14*4882a593Smuzhiyun #include <asm/meminit.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun static inline void __iomem *
__ioremap_uc(unsigned long phys_addr)17*4882a593Smuzhiyun __ioremap_uc(unsigned long phys_addr)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
20*4882a593Smuzhiyun }
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun void __iomem *
early_ioremap(unsigned long phys_addr,unsigned long size)23*4882a593Smuzhiyun early_ioremap (unsigned long phys_addr, unsigned long size)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun u64 attr;
26*4882a593Smuzhiyun attr = kern_mem_attribute(phys_addr, size);
27*4882a593Smuzhiyun if (attr & EFI_MEMORY_WB)
28*4882a593Smuzhiyun return (void __iomem *) phys_to_virt(phys_addr);
29*4882a593Smuzhiyun return __ioremap_uc(phys_addr);
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun void __iomem *
ioremap(unsigned long phys_addr,unsigned long size)33*4882a593Smuzhiyun ioremap (unsigned long phys_addr, unsigned long size)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun void __iomem *addr;
36*4882a593Smuzhiyun struct vm_struct *area;
37*4882a593Smuzhiyun unsigned long offset;
38*4882a593Smuzhiyun pgprot_t prot;
39*4882a593Smuzhiyun u64 attr;
40*4882a593Smuzhiyun unsigned long gran_base, gran_size;
41*4882a593Smuzhiyun unsigned long page_base;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /*
44*4882a593Smuzhiyun * For things in kern_memmap, we must use the same attribute
45*4882a593Smuzhiyun * as the rest of the kernel. For more details, see
46*4882a593Smuzhiyun * Documentation/ia64/aliasing.rst.
47*4882a593Smuzhiyun */
48*4882a593Smuzhiyun attr = kern_mem_attribute(phys_addr, size);
49*4882a593Smuzhiyun if (attr & EFI_MEMORY_WB)
50*4882a593Smuzhiyun return (void __iomem *) phys_to_virt(phys_addr);
51*4882a593Smuzhiyun else if (attr & EFI_MEMORY_UC)
52*4882a593Smuzhiyun return __ioremap_uc(phys_addr);
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun /*
55*4882a593Smuzhiyun * Some chipsets don't support UC access to memory. If
56*4882a593Smuzhiyun * WB is supported for the whole granule, we prefer that.
57*4882a593Smuzhiyun */
58*4882a593Smuzhiyun gran_base = GRANULEROUNDDOWN(phys_addr);
59*4882a593Smuzhiyun gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
60*4882a593Smuzhiyun if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
61*4882a593Smuzhiyun return (void __iomem *) phys_to_virt(phys_addr);
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun /*
64*4882a593Smuzhiyun * WB is not supported for the whole granule, so we can't use
65*4882a593Smuzhiyun * the region 7 identity mapping. If we can safely cover the
66*4882a593Smuzhiyun * area with kernel page table mappings, we can use those
67*4882a593Smuzhiyun * instead.
68*4882a593Smuzhiyun */
69*4882a593Smuzhiyun page_base = phys_addr & PAGE_MASK;
70*4882a593Smuzhiyun size = PAGE_ALIGN(phys_addr + size) - page_base;
71*4882a593Smuzhiyun if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
72*4882a593Smuzhiyun prot = PAGE_KERNEL;
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun /*
75*4882a593Smuzhiyun * Mappings have to be page-aligned
76*4882a593Smuzhiyun */
77*4882a593Smuzhiyun offset = phys_addr & ~PAGE_MASK;
78*4882a593Smuzhiyun phys_addr &= PAGE_MASK;
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun /*
81*4882a593Smuzhiyun * Ok, go for it..
82*4882a593Smuzhiyun */
83*4882a593Smuzhiyun area = get_vm_area(size, VM_IOREMAP);
84*4882a593Smuzhiyun if (!area)
85*4882a593Smuzhiyun return NULL;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun area->phys_addr = phys_addr;
88*4882a593Smuzhiyun addr = (void __iomem *) area->addr;
89*4882a593Smuzhiyun if (ioremap_page_range((unsigned long) addr,
90*4882a593Smuzhiyun (unsigned long) addr + size, phys_addr, prot)) {
91*4882a593Smuzhiyun vunmap((void __force *) addr);
92*4882a593Smuzhiyun return NULL;
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun return (void __iomem *) (offset + (char __iomem *)addr);
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun return __ioremap_uc(phys_addr);
99*4882a593Smuzhiyun }
100*4882a593Smuzhiyun EXPORT_SYMBOL(ioremap);
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun void __iomem *
ioremap_uc(unsigned long phys_addr,unsigned long size)103*4882a593Smuzhiyun ioremap_uc(unsigned long phys_addr, unsigned long size)
104*4882a593Smuzhiyun {
105*4882a593Smuzhiyun if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
106*4882a593Smuzhiyun return NULL;
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun return __ioremap_uc(phys_addr);
109*4882a593Smuzhiyun }
110*4882a593Smuzhiyun EXPORT_SYMBOL(ioremap_uc);
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun void
early_iounmap(volatile void __iomem * addr,unsigned long size)113*4882a593Smuzhiyun early_iounmap (volatile void __iomem *addr, unsigned long size)
114*4882a593Smuzhiyun {
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun void
iounmap(volatile void __iomem * addr)118*4882a593Smuzhiyun iounmap (volatile void __iomem *addr)
119*4882a593Smuzhiyun {
120*4882a593Smuzhiyun if (REGION_NUMBER(addr) == RGN_GATE)
121*4882a593Smuzhiyun vunmap((void *) ((unsigned long) addr & PAGE_MASK));
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun EXPORT_SYMBOL(iounmap);
124