e85e335f8f
MMUv3 comes out of reset with identity vaddr -> paddr mapping in the TLB
way 6:
Way 6 (512 MB)
Vaddr Paddr ASID Attr RWX Cache
---------- ---------- ---- ---- --- -------
0x00000000 0x00000000 0x01 0x03 RWX Bypass
0x20000000 0x20000000 0x01 0x03 RWX Bypass
0x40000000 0x40000000 0x01 0x03 RWX Bypass
0x60000000 0x60000000 0x01 0x03 RWX Bypass
0x80000000 0x80000000 0x01 0x03 RWX Bypass
0xa0000000 0xa0000000 0x01 0x03 RWX Bypass
0xc0000000 0xc0000000 0x01 0x03 RWX Bypass
0xe0000000 0xe0000000 0x01 0x03 RWX Bypass
This patch adds remapping code at the reset vector or at the kernel
_start (depending on CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) that
reconfigures MMUv3 as MMUv2:
Way 5 (128 MB)
Vaddr Paddr ASID Attr RWX Cache
---------- ---------- ---- ---- --- -------
0xd0000000 0x00000000 0x01 0x07 RWX WB
0xd8000000 0x00000000 0x01 0x03 RWX Bypass
Way 6 (256 MB)
Vaddr Paddr ASID Attr RWX Cache
---------- ---------- ---- ---- --- -------
0xe0000000 0xf0000000 0x01 0x07 RWX WB
0xf0000000 0xf0000000 0x01 0x03 RWX Bypass
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
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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/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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void __init paging_init(void)
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{
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memset(swapper_pg_dir, 0, PAGE_SIZE);
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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 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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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(PGTABLE_START);
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}
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struct kmem_cache *pgtable_cache __read_mostly;
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static void pgd_ctor(void *addr)
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{
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pte_t *ptep = (pte_t *)addr;
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int i;
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for (i = 0; i < 1024; i++, ptep++)
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pte_clear(NULL, 0, ptep);
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}
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void __init pgtable_cache_init(void)
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{
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pgtable_cache = kmem_cache_create("pgd",
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PAGE_SIZE, PAGE_SIZE,
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SLAB_HWCACHE_ALIGN,
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pgd_ctor);
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}
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