tlbflush.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/tlbflush.h
*
* Copyright (C) 1999-2003 Russell King
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_TLBFLUSH_H
#define __ASM_TLBFLUSH_H
#ifndef __ASSEMBLY__
#include <linux/bitfield.h>
#include <linux/mm_types.h>
#include <linux/sched.h>
#include <asm/cputype.h>
#include <asm/mmu.h>
/*
* Raw TLBI operations.
*
* Where necessary, use the __tlbi() macro to avoid asm()
* boilerplate. Drivers and most kernel code should use the TLB
* management routines in preference to the macro below.
*
* The macro can be used as __tlbi(op) or __tlbi(op, arg), depending
* on whether a particular TLBI operation takes an argument or
* not. The macros handles invoking the asm with or without the
* register argument as appropriate.
*/
#define __TLBI_0(op, arg) asm (ARM64_ASM_PREAMBLE \
"tlbi " #op "\n" \
ALTERNATIVE("nop\n nop", \
"dsb ish\n tlbi " #op, \
ARM64_WORKAROUND_REPEAT_TLBI, \
CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \
: : )
#define __TLBI_1(op, arg) asm (ARM64_ASM_PREAMBLE \
"tlbi " #op ", %0\n" \
ALTERNATIVE("nop\n nop", \
"dsb ish\n tlbi " #op ", %0", \
ARM64_WORKAROUND_REPEAT_TLBI, \
CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \
: : "r" (arg))
#define __TLBI_N(op, arg, n, ...) __TLBI_##n(op, arg)
#define __tlbi(op, ...) __TLBI_N(op, ##__VA_ARGS__, 1, 0)
#define __tlbi_user(op, arg) do { \
if (arm64_kernel_unmapped_at_el0()) \
__tlbi(op, (arg) | USER_ASID_FLAG); \
} while (0)
/* This macro creates a properly formatted VA operand for the TLBI */
#define __TLBI_VADDR(addr, asid) \
({ \
unsigned long __ta = (addr) >> 12; \
__ta &= GENMASK_ULL(43, 0); \
__ta |= (unsigned long)(asid) << 48; \
__ta; \
})
/*
* Get translation granule of the system, which is decided by
* PAGE_SIZE. Used by TTL.
* - 4KB : 1
* - 16KB : 2
* - 64KB : 3
*/
#define TLBI_TTL_TG_4K 1
#define TLBI_TTL_TG_16K 2
#define TLBI_TTL_TG_64K 3
static inline unsigned long get_trans_granule(void)
{
switch (PAGE_SIZE) {
case SZ_4K:
return TLBI_TTL_TG_4K;
case SZ_16K:
return TLBI_TTL_TG_16K;
case SZ_64K:
return TLBI_TTL_TG_64K;
default:
return 0;
}
}
/*
* Level-based TLBI operations.
*
* When ARMv8.4-TTL exists, TLBI operations take an additional hint for
* the level at which the invalidation must take place. If the level is
* wrong, no invalidation may take place. In the case where the level
* cannot be easily determined, a 0 value for the level parameter will
* perform a non-hinted invalidation.
*
* For Stage-2 invalidation, use the level values provided to that effect
* in asm/stage2_pgtable.h.
*/
#define TLBI_TTL_MASK GENMASK_ULL(47, 44)
#define __tlbi_level(op, addr, level) do { \
u64 arg = addr; \
\
if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \
level) { \
u64 ttl = level & 3; \
ttl |= get_trans_granule() << 2; \
arg &= ~TLBI_TTL_MASK; \
arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \
} \
\
__tlbi(op, arg); \
} while(0)
#define __tlbi_user_level(op, arg, level) do { \
if (arm64_kernel_unmapped_at_el0()) \
__tlbi_level(op, (arg | USER_ASID_FLAG), level); \
} while (0)
/*
* This macro creates a properly formatted VA operand for the TLB RANGE.
* The value bit assignments are:
*
* +----------+------+-------+-------+-------+----------------------+
* | ASID | TG | SCALE | NUM | TTL | BADDR |
* +-----------------+-------+-------+-------+----------------------+
* |63 48|47 46|45 44|43 39|38 37|36 0|
*
* The address range is determined by below formula:
* [BADDR, BADDR + (NUM + 1) * 2^(5*SCALE + 1) * PAGESIZE)
*
*/
#define __TLBI_VADDR_RANGE(addr, asid, scale, num, ttl) \
({ \
unsigned long __ta = (addr) >> PAGE_SHIFT; \
__ta &= GENMASK_ULL(36, 0); \
__ta |= (unsigned long)(ttl) << 37; \
__ta |= (unsigned long)(num) << 39; \
__ta |= (unsigned long)(scale) << 44; \
__ta |= get_trans_granule() << 46; \
__ta |= (unsigned long)(asid) << 48; \
__ta; \
})
/* These macros are used by the TLBI RANGE feature. */
#define __TLBI_RANGE_PAGES(num, scale) \
((unsigned long)((num) + 1) << (5 * (scale) + 1))
#define MAX_TLBI_RANGE_PAGES __TLBI_RANGE_PAGES(31, 3)
/*
* Generate 'num' values from -1 to 30 with -1 rejected by the
* __flush_tlb_range() loop below.
*/
#define TLBI_RANGE_MASK GENMASK_ULL(4, 0)
#define __TLBI_RANGE_NUM(pages, scale) \
((((pages) >> (5 * (scale) + 1)) & TLBI_RANGE_MASK) - 1)
/*
* TLB Invalidation
* ================
*
* This header file implements the low-level TLB invalidation routines
* (sometimes referred to as "flushing" in the kernel) for arm64.
*
* Every invalidation operation uses the following template:
*
* DSB ISHST // Ensure prior page-table updates have completed
* TLBI ... // Invalidate the TLB
* DSB ISH // Ensure the TLB invalidation has completed
* if (invalidated kernel mappings)
* ISB // Discard any instructions fetched from the old mapping
*
*
* The following functions form part of the "core" TLB invalidation API,
* as documented in Documentation/core-api/cachetlb.rst:
*
* flush_tlb_all()
* Invalidate the entire TLB (kernel + user) on all CPUs
*
* flush_tlb_mm(mm)
* Invalidate an entire user address space on all CPUs.
* The 'mm' argument identifies the ASID to invalidate.
*
* flush_tlb_range(vma, start, end)
* Invalidate the virtual-address range '[start, end)' on all
* CPUs for the user address space corresponding to 'vma->mm'.
* Note that this operation also invalidates any walk-cache
* entries associated with translations for the specified address
* range.
*
* flush_tlb_kernel_range(start, end)
* Same as flush_tlb_range(..., start, end), but applies to
* kernel mappings rather than a particular user address space.
* Whilst not explicitly documented, this function is used when
* unmapping pages from vmalloc/io space.
*
* flush_tlb_page(vma, addr)
* Invalidate a single user mapping for address 'addr' in the
* address space corresponding to 'vma->mm'. Note that this
* operation only invalidates a single, last-level page-table
* entry and therefore does not affect any walk-caches.
*
*
* Next, we have some undocumented invalidation routines that you probably
* don't want to call unless you know what you're doing:
*
* local_flush_tlb_all()
* Same as flush_tlb_all(), but only applies to the calling CPU.
*
* __flush_tlb_kernel_pgtable(addr)
* Invalidate a single kernel mapping for address 'addr' on all
* CPUs, ensuring that any walk-cache entries associated with the
* translation are also invalidated.
*
* __flush_tlb_range(vma, start, end, stride, last_level)
* Invalidate the virtual-address range '[start, end)' on all
* CPUs for the user address space corresponding to 'vma->mm'.
* The invalidation operations are issued at a granularity
* determined by 'stride' and only affect any walk-cache entries
* if 'last_level' is equal to false.
*
*
* Finally, take a look at asm/tlb.h to see how tlb_flush() is implemented
* on top of these routines, since that is our interface to the mmu_gather
* API as used by munmap() and friends.
*/
static inline void local_flush_tlb_all(void)
{
dsb(nshst);
__tlbi(vmalle1);
dsb(nsh);
isb();
}
static inline void flush_tlb_all(void)
{
dsb(ishst);
__tlbi(vmalle1is);
dsb(ish);
isb();
}
static inline void flush_tlb_mm(struct mm_struct *mm)
{
unsigned long asid;
dsb(ishst);
asid = __TLBI_VADDR(0, ASID(mm));
__tlbi(aside1is, asid);
__tlbi_user(aside1is, asid);
dsb(ish);
}
static inline void flush_tlb_page_nosync(struct vm_area_struct *vma,
unsigned long uaddr)
{
unsigned long addr;
dsb(ishst);
addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
__tlbi(vale1is, addr);
__tlbi_user(vale1is, addr);
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long uaddr)
{
flush_tlb_page_nosync(vma, uaddr);
dsb(ish);
}
/*
* This is meant to avoid soft lock-ups on large TLB flushing ranges and not
* necessarily a performance improvement.
*/
#define MAX_TLBI_OPS PTRS_PER_PTE
static inline void __flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long stride, bool last_level,
int tlb_level)
{
int num = 0;
int scale = 0;
unsigned long asid, addr, pages;
start = round_down(start, stride);
end = round_up(end, stride);
pages = (end - start) >> PAGE_SHIFT;
/*
* When not uses TLB range ops, we can handle up to
* (MAX_TLBI_OPS - 1) pages;
* When uses TLB range ops, we can handle up to
* (MAX_TLBI_RANGE_PAGES - 1) pages.
*/
if ((!system_supports_tlb_range() &&
(end - start) >= (MAX_TLBI_OPS * stride)) ||
pages >= MAX_TLBI_RANGE_PAGES) {
flush_tlb_mm(vma->vm_mm);
return;
}
dsb(ishst);
asid = ASID(vma->vm_mm);
/*
* When the CPU does not support TLB range operations, flush the TLB
* entries one by one at the granularity of 'stride'. If the TLB
* range ops are supported, then:
*
* 1. If 'pages' is odd, flush the first page through non-range
* operations;
*
* 2. For remaining pages: the minimum range granularity is decided
* by 'scale', so multiple range TLBI operations may be required.
* Start from scale = 0, flush the corresponding number of pages
* ((num+1)*2^(5*scale+1) starting from 'addr'), then increase it
* until no pages left.
*
* Note that certain ranges can be represented by either num = 31 and
* scale or num = 0 and scale + 1. The loop below favours the latter
* since num is limited to 30 by the __TLBI_RANGE_NUM() macro.
*/
while (pages > 0) {
if (!system_supports_tlb_range() ||
pages % 2 == 1) {
addr = __TLBI_VADDR(start, asid);
if (last_level) {
__tlbi_level(vale1is, addr, tlb_level);
__tlbi_user_level(vale1is, addr, tlb_level);
} else {
__tlbi_level(vae1is, addr, tlb_level);
__tlbi_user_level(vae1is, addr, tlb_level);
}
start += stride;
pages -= stride >> PAGE_SHIFT;
continue;
}
num = __TLBI_RANGE_NUM(pages, scale);
if (num >= 0) {
addr = __TLBI_VADDR_RANGE(start, asid, scale,
num, tlb_level);
if (last_level) {
__tlbi(rvale1is, addr);
__tlbi_user(rvale1is, addr);
} else {
__tlbi(rvae1is, addr);
__tlbi_user(rvae1is, addr);
}
start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT;
pages -= __TLBI_RANGE_PAGES(num, scale);
}
scale++;
}
dsb(ish);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
/*
* We cannot use leaf-only invalidation here, since we may be invalidating
* table entries as part of collapsing hugepages or moving page tables.
* Set the tlb_level to 0 because we can not get enough information here.
*/
__flush_tlb_range(vma, start, end, PAGE_SIZE, false, 0);
}
static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
unsigned long addr;
if ((end - start) > (MAX_TLBI_OPS * PAGE_SIZE)) {
flush_tlb_all();
return;
}
start = __TLBI_VADDR(start, 0);
end = __TLBI_VADDR(end, 0);
dsb(ishst);
for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12))
__tlbi(vaale1is, addr);
dsb(ish);
isb();
}
/*
* Used to invalidate the TLB (walk caches) corresponding to intermediate page
* table levels (pgd/pud/pmd).
*/
static inline void __flush_tlb_kernel_pgtable(unsigned long kaddr)
{
unsigned long addr = __TLBI_VADDR(kaddr, 0);
dsb(ishst);
__tlbi(vaae1is, addr);
dsb(ish);
isb();
}
#endif
#endif
