cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ioremap.c (2573B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
      4 */
      5
      6#include <linux/vmalloc.h>
      7#include <linux/init.h>
      8#include <linux/module.h>
      9#include <linux/io.h>
     10#include <linux/mm.h>
     11#include <linux/slab.h>
     12#include <linux/cache.h>
     13
     14static inline bool arc_uncached_addr_space(phys_addr_t paddr)
     15{
     16	if (is_isa_arcompact()) {
     17		if (paddr >= ARC_UNCACHED_ADDR_SPACE)
     18			return true;
     19	} else if (paddr >= perip_base && paddr <= perip_end) {
     20		return true;
     21	}
     22
     23	return false;
     24}
     25
     26void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
     27{
     28	phys_addr_t end;
     29
     30	/* Don't allow wraparound or zero size */
     31	end = paddr + size - 1;
     32	if (!size || (end < paddr))
     33		return NULL;
     34
     35	/*
     36	 * If the region is h/w uncached, MMU mapping can be elided as optim
     37	 * The cast to u32 is fine as this region can only be inside 4GB
     38	 */
     39	if (arc_uncached_addr_space(paddr))
     40		return (void __iomem *)(u32)paddr;
     41
     42	return ioremap_prot(paddr, size,
     43			    pgprot_val(pgprot_noncached(PAGE_KERNEL)));
     44}
     45EXPORT_SYMBOL(ioremap);
     46
     47/*
     48 * ioremap with access flags
     49 * Cache semantics wise it is same as ioremap - "forced" uncached.
     50 * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
     51 * ARC hardware uncached region, this one still goes thru the MMU as caller
     52 * might need finer access control (R/W/X)
     53 */
     54void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
     55			   unsigned long flags)
     56{
     57	unsigned int off;
     58	unsigned long vaddr;
     59	struct vm_struct *area;
     60	phys_addr_t end;
     61	pgprot_t prot = __pgprot(flags);
     62
     63	/* Don't allow wraparound, zero size */
     64	end = paddr + size - 1;
     65	if ((!size) || (end < paddr))
     66		return NULL;
     67
     68	/* An early platform driver might end up here */
     69	if (!slab_is_available())
     70		return NULL;
     71
     72	/* force uncached */
     73	prot = pgprot_noncached(prot);
     74
     75	/* Mappings have to be page-aligned */
     76	off = paddr & ~PAGE_MASK;
     77	paddr &= PAGE_MASK_PHYS;
     78	size = PAGE_ALIGN(end + 1) - paddr;
     79
     80	/*
     81	 * Ok, go for it..
     82	 */
     83	area = get_vm_area(size, VM_IOREMAP);
     84	if (!area)
     85		return NULL;
     86	area->phys_addr = paddr;
     87	vaddr = (unsigned long)area->addr;
     88	if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
     89		vunmap((void __force *)vaddr);
     90		return NULL;
     91	}
     92	return (void __iomem *)(off + (char __iomem *)vaddr);
     93}
     94EXPORT_SYMBOL(ioremap_prot);
     95
     96
     97void iounmap(const void __iomem *addr)
     98{
     99	/* weird double cast to handle phys_addr_t > 32 bits */
    100	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
    101		return;
    102
    103	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
    104}
    105EXPORT_SYMBOL(iounmap);