linux/arch/powerpc/mm/kasan/8xx.c
Christophe Leroy 0549e76663 powerpc/8xx: rework support for 8M pages using contiguous PTE entries
In order to fit better with standard Linux page tables layout, add support
for 8M pages using contiguous PTE entries in a standard page table.  Page
tables will then be populated with 1024 similar entries and two PMD
entries will point to that page table.

The PMD entries also get a flag to tell it is addressing an 8M page, this
is required for the HW tablewalk assistance.

Link: https://lkml.kernel.org/r/8693d9a0408371043ca63bf9e4a9c140667af63e.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:17 -07:00

79 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#define DISABLE_BRANCH_PROFILING
#include <linux/kasan.h>
#include <linux/memblock.h>
#include <linux/hugetlb.h>
#include <asm/pgalloc.h>
static int __init
kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
{
pmd_t *pmd = pmd_off_k(k_start);
unsigned long k_cur, k_next;
for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++, block += SZ_4M) {
pte_t *ptep;
int i;
k_next = pgd_addr_end(k_cur, k_end);
if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
continue;
ptep = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
if (!ptep)
return -ENOMEM;
for (i = 0; i < PTRS_PER_PTE; i++) {
pte_t pte = pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block + i * PAGE_SIZE)), PAGE_KERNEL));
__set_pte_at(&init_mm, k_cur, ptep + i, pte, 1);
}
pmd_populate_kernel(&init_mm, pmd, ptep);
*pmd = __pmd(pmd_val(*pmd) | _PMD_PAGE_8M);
}
return 0;
}
int __init kasan_init_region(void *start, size_t size)
{
unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
unsigned long k_cur;
int ret;
void *block;
block = memblock_alloc(k_end - k_start, SZ_8M);
if (!block)
return -ENOMEM;
if (IS_ALIGNED(k_start, SZ_8M)) {
kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
k_cur = ALIGN_DOWN(k_end, SZ_8M);
if (k_cur == k_end)
goto finish;
} else {
k_cur = k_start;
}
ret = kasan_init_shadow_page_tables(k_start, k_end);
if (ret)
return ret;
for (; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_off_k(k_cur);
void *va = block + k_cur - k_start;
pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
pte = pte_mkhuge(pte);
__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
}
finish:
flush_tlb_kernel_range(k_start, k_end);
return 0;
}