1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun #include <linux/io.h>
4*4882a593Smuzhiyun #include <linux/slab.h>
5*4882a593Smuzhiyun #include <linux/vmalloc.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <mm/mmu_decl.h>
8*4882a593Smuzhiyun
ioremap_wt(phys_addr_t addr,unsigned long size)9*4882a593Smuzhiyun void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size)
10*4882a593Smuzhiyun {
11*4882a593Smuzhiyun pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
14*4882a593Smuzhiyun }
15*4882a593Smuzhiyun EXPORT_SYMBOL(ioremap_wt);
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun void __iomem *
__ioremap_caller(phys_addr_t addr,unsigned long size,pgprot_t prot,void * caller)18*4882a593Smuzhiyun __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun unsigned long v;
21*4882a593Smuzhiyun phys_addr_t p, offset;
22*4882a593Smuzhiyun int err;
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun /*
25*4882a593Smuzhiyun * Choose an address to map it to.
26*4882a593Smuzhiyun * Once the vmalloc system is running, we use it.
27*4882a593Smuzhiyun * Before then, we use space going down from IOREMAP_TOP
28*4882a593Smuzhiyun * (ioremap_bot records where we're up to).
29*4882a593Smuzhiyun */
30*4882a593Smuzhiyun p = addr & PAGE_MASK;
31*4882a593Smuzhiyun offset = addr & ~PAGE_MASK;
32*4882a593Smuzhiyun size = PAGE_ALIGN(addr + size) - p;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun /*
35*4882a593Smuzhiyun * If the address lies within the first 16 MB, assume it's in ISA
36*4882a593Smuzhiyun * memory space
37*4882a593Smuzhiyun */
38*4882a593Smuzhiyun if (p < 16 * 1024 * 1024)
39*4882a593Smuzhiyun p += _ISA_MEM_BASE;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun #ifndef CONFIG_CRASH_DUMP
42*4882a593Smuzhiyun /*
43*4882a593Smuzhiyun * Don't allow anybody to remap normal RAM that we're using.
44*4882a593Smuzhiyun * mem_init() sets high_memory so only do the check after that.
45*4882a593Smuzhiyun */
46*4882a593Smuzhiyun if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
47*4882a593Smuzhiyun page_is_ram(__phys_to_pfn(p))) {
48*4882a593Smuzhiyun pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__,
49*4882a593Smuzhiyun (unsigned long long)p, __builtin_return_address(0));
50*4882a593Smuzhiyun return NULL;
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun #endif
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun if (size == 0)
55*4882a593Smuzhiyun return NULL;
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun /*
58*4882a593Smuzhiyun * Is it already mapped? Perhaps overlapped by a previous
59*4882a593Smuzhiyun * mapping.
60*4882a593Smuzhiyun */
61*4882a593Smuzhiyun v = p_block_mapped(p);
62*4882a593Smuzhiyun if (v)
63*4882a593Smuzhiyun return (void __iomem *)v + offset;
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun if (slab_is_available())
66*4882a593Smuzhiyun return do_ioremap(p, offset, size, prot, caller);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /*
69*4882a593Smuzhiyun * Should check if it is a candidate for a BAT mapping
70*4882a593Smuzhiyun */
71*4882a593Smuzhiyun pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun err = early_ioremap_range(ioremap_bot - size, p, size, prot);
74*4882a593Smuzhiyun if (err)
75*4882a593Smuzhiyun return NULL;
76*4882a593Smuzhiyun ioremap_bot -= size;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun return (void __iomem *)ioremap_bot + offset;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
iounmap(volatile void __iomem * addr)81*4882a593Smuzhiyun void iounmap(volatile void __iomem *addr)
82*4882a593Smuzhiyun {
83*4882a593Smuzhiyun /*
84*4882a593Smuzhiyun * If mapped by BATs then there is nothing to do.
85*4882a593Smuzhiyun * Calling vfree() generates a benign warning.
86*4882a593Smuzhiyun */
87*4882a593Smuzhiyun if (v_block_mapped((unsigned long)addr))
88*4882a593Smuzhiyun return;
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun if (addr > high_memory && (unsigned long)addr < ioremap_bot)
91*4882a593Smuzhiyun vunmap((void *)(PAGE_MASK & (unsigned long)addr));
92*4882a593Smuzhiyun }
93*4882a593Smuzhiyun EXPORT_SYMBOL(iounmap);
94