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1eb0616c2d
The conversion to the generic kmap_atomic() implementation missed the fact
that xtensa's fixmap works bottom up while all other implementations work
top down. There is no real reason why xtensa needs to work that way.
Cure it by:
- Using the generic fix_to_virt()/virt_to_fix() functions which work top
down
- Adjusting the mapping defines
- Using the generic index calculation for the non cache aliasing case
- Making the cache colour offset reverse so the effective index is correct
While at it, remove the outdated and misleading comment above the fixmap
enum which originates from the initial copy&pasta of this code from i386.
[ Max: Fixed the off by one in the index calculation ]
Fixes: 629ed3f7da ("xtensa/mm/highmem: Switch to generic kmap atomic")
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20201116193253.23875-1-jcmvbkbc@gmail.com
117 lines
3 KiB
C
117 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* xtensa mmu stuff
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*
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* Extracted from init.c
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*/
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#include <linux/memblock.h>
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#include <linux/percpu.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/cache.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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#include <asm/page.h>
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#include <asm/initialize_mmu.h>
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#include <asm/io.h>
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#if defined(CONFIG_HIGHMEM)
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static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages)
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{
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pmd_t *pmd = pmd_off_k(vaddr);
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pte_t *pte;
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unsigned long i;
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n_pages = ALIGN(n_pages, PTRS_PER_PTE);
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pr_debug("%s: vaddr: 0x%08lx, n_pages: %ld\n",
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__func__, vaddr, n_pages);
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pte = memblock_alloc_low(n_pages * sizeof(pte_t), PAGE_SIZE);
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if (!pte)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, n_pages * sizeof(pte_t), PAGE_SIZE);
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for (i = 0; i < n_pages; ++i)
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pte_clear(NULL, 0, pte + i);
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for (i = 0; i < n_pages; i += PTRS_PER_PTE, ++pmd) {
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pte_t *cur_pte = pte + i;
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BUG_ON(!pmd_none(*pmd));
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set_pmd(pmd, __pmd(((unsigned long)cur_pte) & PAGE_MASK));
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BUG_ON(cur_pte != pte_offset_kernel(pmd, 0));
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pr_debug("%s: pmd: 0x%p, pte: 0x%p\n",
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__func__, pmd, cur_pte);
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}
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return pte;
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}
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static void __init fixedrange_init(void)
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{
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BUILD_BUG_ON(FIXADDR_START < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
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init_pmd(FIXADDR_START, __end_of_fixed_addresses);
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}
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#endif
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void __init paging_init(void)
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{
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#ifdef CONFIG_HIGHMEM
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fixedrange_init();
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pkmap_page_table = init_pmd(PKMAP_BASE, LAST_PKMAP);
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kmap_init();
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#endif
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}
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/*
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* Flush the mmu and reset associated register to default values.
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*/
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void init_mmu(void)
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{
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#if !(XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY)
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/*
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* Writing zeros to the instruction and data TLBCFG special
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* registers ensure that valid values exist in the register.
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*
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* For existing PGSZID<w> fields, zero selects the first element
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* of the page-size array. For nonexistent PGSZID<w> fields,
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* zero is the best value to write. Also, when changing PGSZID<w>
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* fields, the corresponding TLB must be flushed.
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*/
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set_itlbcfg_register(0);
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set_dtlbcfg_register(0);
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#endif
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init_kio();
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local_flush_tlb_all();
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/* Set rasid register to a known value. */
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set_rasid_register(ASID_INSERT(ASID_USER_FIRST));
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/* Set PTEVADDR special register to the start of the page
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* table, which is in kernel mappable space (ie. not
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* statically mapped). This register's value is undefined on
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* reset.
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*/
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set_ptevaddr_register(XCHAL_PAGE_TABLE_VADDR);
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}
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void init_kio(void)
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{
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#if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY && defined(CONFIG_OF)
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/*
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* Update the IO area mapping in case xtensa_kio_paddr has changed
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*/
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write_dtlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
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XCHAL_KIO_CACHED_VADDR + 6);
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write_itlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
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XCHAL_KIO_CACHED_VADDR + 6);
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write_dtlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
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XCHAL_KIO_BYPASS_VADDR + 6);
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write_itlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
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XCHAL_KIO_BYPASS_VADDR + 6);
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#endif
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}
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