From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/openrisc/mm/ioremap.c | 130 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 arch/openrisc/mm/ioremap.c (limited to 'arch/openrisc/mm/ioremap.c') diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c new file mode 100644 index 000000000..8ec0dafec --- /dev/null +++ b/arch/openrisc/mm/ioremap.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * OpenRISC ioremap.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +extern int mem_init_done; + +static unsigned int fixmaps_used __initdata; + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access high addresses + * directly. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size) +{ + phys_addr_t p; + unsigned long v; + unsigned long offset, last_addr; + struct vm_struct *area = NULL; + + /* Don't allow wraparound or zero size */ + last_addr = addr + size - 1; + if (!size || last_addr < addr) + return NULL; + + /* + * Mappings have to be page-aligned + */ + offset = addr & ~PAGE_MASK; + p = addr & PAGE_MASK; + size = PAGE_ALIGN(last_addr + 1) - p; + + if (likely(mem_init_done)) { + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + v = (unsigned long)area->addr; + } else { + if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS) + return NULL; + v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used); + fixmaps_used += (size >> PAGE_SHIFT); + } + + if (ioremap_page_range(v, v + size, p, + __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) { + if (likely(mem_init_done)) + vfree(area->addr); + else + fixmaps_used -= (size >> PAGE_SHIFT); + return NULL; + } + + return (void __iomem *)(offset + (char *)v); +} +EXPORT_SYMBOL(ioremap); + +void iounmap(volatile void __iomem *addr) +{ + /* If the page is from the fixmap pool then we just clear out + * the fixmap mapping. + */ + if (unlikely((unsigned long)addr > FIXADDR_START)) { + /* This is a bit broken... we don't really know + * how big the area is so it's difficult to know + * how many fixed pages to invalidate... + * just flush tlb and hope for the best... + * consider this a FIXME + * + * Really we should be clearing out one or more page + * table entries for these virtual addresses so that + * future references cause a page fault... for now, we + * rely on two things: + * i) this code never gets called on known boards + * ii) invalid accesses to the freed areas aren't made + */ + flush_tlb_all(); + return; + } + + return vfree((void *)(PAGE_MASK & (unsigned long)addr)); +} +EXPORT_SYMBOL(iounmap); + +/** + * OK, this one's a bit tricky... ioremap can get called before memory is + * initialized (early serial console does this) and will want to alloc a page + * for its mapping. No userspace pages will ever get allocated before memory + * is initialized so this applies only to kernel pages. In the event that + * this is called before memory is initialized we allocate the page using + * the memblock infrastructure. + */ + +pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm) +{ + pte_t *pte; + + if (likely(mem_init_done)) { + pte = (pte_t *)get_zeroed_page(GFP_KERNEL); + } else { + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!pte) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE); + } + + return pte; +} -- cgit v1.2.3