cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ioremap.c (3041B)

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