105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <mm/mmu_decl.h>
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void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size)
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{
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pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
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return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap_wt);
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void __iomem *
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__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
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{
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unsigned long v, i;
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phys_addr_t p;
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int err;
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/*
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* Choose an address to map it to.
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* Once the vmalloc system is running, we use it.
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* Before then, we use space going down from IOREMAP_TOP
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* (ioremap_bot records where we're up to).
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*/
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p = addr & PAGE_MASK;
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size = PAGE_ALIGN(addr + size) - p;
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/*
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* If the address lies within the first 16 MB, assume it's in ISA
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* memory space
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*/
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if (p < 16 * 1024 * 1024)
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p += _ISA_MEM_BASE;
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#ifndef CONFIG_CRASH_DUMP
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/*
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* Don't allow anybody to remap normal RAM that we're using.
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* mem_init() sets high_memory so only do the check after that.
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*/
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if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
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page_is_ram(__phys_to_pfn(p))) {
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pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__,
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(unsigned long long)p, __builtin_return_address(0));
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return NULL;
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}
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#endif
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if (size == 0)
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return NULL;
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/*
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* Is it already mapped? Perhaps overlapped by a previous
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* mapping.
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*/
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v = p_block_mapped(p);
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if (v)
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goto out;
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if (slab_is_available()) {
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struct vm_struct *area;
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area = get_vm_area_caller(size, VM_IOREMAP, caller);
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if (area == 0)
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return NULL;
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area->phys_addr = p;
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v = (unsigned long)area->addr;
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} else {
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v = (ioremap_bot -= size);
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}
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/*
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* Should check if it is a candidate for a BAT mapping
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*/
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err = 0;
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for (i = 0; i < size && err == 0; i += PAGE_SIZE)
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err = map_kernel_page(v + i, p + i, prot);
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if (err) {
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if (slab_is_available())
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vunmap((void *)v);
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return NULL;
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}
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out:
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return (void __iomem *)(v + ((unsigned long)addr & ~PAGE_MASK));
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}
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void iounmap(volatile void __iomem *addr)
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{
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/*
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* If mapped by BATs then there is nothing to do.
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* Calling vfree() generates a benign warning.
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*/
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if (v_block_mapped((unsigned long)addr))
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return;
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if (addr > high_memory && (unsigned long)addr < ioremap_bot)
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vunmap((void *)(PAGE_MASK & (unsigned long)addr));
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}
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EXPORT_SYMBOL(iounmap);
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