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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2005, Paul Mackerras, IBM Corporation.
* Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
*/
#include <linux/sched.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/dma.h>
#include <asm/code-patching.h>
#include <mm/mmu_decl.h>
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* On Book3E CPUs, the vmemmap is currently mapped in the top half of
* the vmalloc space using normal page tables, though the size of
* pages encoded in the PTEs can be different
*/
int __meminit vmemmap_create_mapping(unsigned long start,
unsigned long page_size,
unsigned long phys)
{
/* Create a PTE encoding without page size */
unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
_PAGE_KERNEL_RW;
/* PTEs only contain page size encodings up to 32M */
BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
/* Encode the size in the PTE */
flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
/* For each PTE for that area, map things. Note that we don't
* increment phys because all PTEs are of the large size and
* thus must have the low bits clear
*/
for (i = 0; i < page_size; i += PAGE_SIZE)
BUG_ON(map_kernel_page(start + i, phys, __pgprot(flags)));
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
void vmemmap_remove_mapping(unsigned long start,
unsigned long page_size)
{
}
#endif
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
static void __init *early_alloc_pgtable(unsigned long size)
{
void *ptr;
ptr = memblock_alloc_try_nid(size, size, MEMBLOCK_LOW_LIMIT,
__pa(MAX_DMA_ADDRESS), NUMA_NO_NODE);
if (!ptr)
panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%lx\n",
__func__, size, size, __pa(MAX_DMA_ADDRESS));
return ptr;
}
/*
* map_kernel_page currently only called by __ioremap
* map_kernel_page adds an entry to the ioremap page table
* and adds an entry to the HPT, possibly bolting it
*/
int __ref map_kernel_page(unsigned long ea, phys_addr_t pa, pgprot_t prot)
{
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
if (slab_is_available()) {
pgdp = pgd_offset_k(ea);
p4dp = p4d_offset(pgdp, ea);
pudp = pud_alloc(&init_mm, p4dp, ea);
if (!pudp)
return -ENOMEM;
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
} else {
pgdp = pgd_offset_k(ea);
p4dp = p4d_offset(pgdp, ea);
if (p4d_none(*p4dp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
p4d_populate(&init_mm, p4dp, pudp);
}
pudp = pud_offset(p4dp, ea);
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PTE_TABLE_SIZE);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
}
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
smp_wmb();
return 0;
}
void __patch_exception(int exc, unsigned long addr)
{
unsigned int *ibase = &interrupt_base_book3e;
/*
* Our exceptions vectors start with a NOP and -then- a branch
* to deal with single stepping from userspace which stops on
* the second instruction. Thus we need to patch the second
* instruction of the exception, not the first one.
*/
patch_branch(ibase + (exc / 4) + 1, addr, 0);
}
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