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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_TLBFLUSH_H
#define _ASM_X86_TLBFLUSH_H
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/special_insns.h>
#include <asm/smp.h>
#include <asm/invpcid.h>
#include <asm/pti.h>
#include <asm/processor-flags.h>
void __flush_tlb_all(void);
#define TLB_FLUSH_ALL -1UL
void cr4_update_irqsoff(unsigned long set, unsigned long clear);
unsigned long cr4_read_shadow(void);
/* Set in this cpu's CR4. */
static inline void cr4_set_bits_irqsoff(unsigned long mask)
{
cr4_update_irqsoff(mask, 0);
}
/* Clear in this cpu's CR4. */
static inline void cr4_clear_bits_irqsoff(unsigned long mask)
{
cr4_update_irqsoff(0, mask);
}
/* Set in this cpu's CR4. */
static inline void cr4_set_bits(unsigned long mask)
{
unsigned long flags;
local_irq_save(flags);
cr4_set_bits_irqsoff(mask);
local_irq_restore(flags);
}
/* Clear in this cpu's CR4. */
static inline void cr4_clear_bits(unsigned long mask)
{
unsigned long flags;
local_irq_save(flags);
cr4_clear_bits_irqsoff(mask);
local_irq_restore(flags);
}
#ifndef MODULE
/*
* 6 because 6 should be plenty and struct tlb_state will fit in two cache
* lines.
*/
#define TLB_NR_DYN_ASIDS 6
struct tlb_context {
u64 ctx_id;
u64 tlb_gen;
};
struct tlb_state {
/*
* cpu_tlbstate.loaded_mm should match CR3 whenever interrupts
* are on. This means that it may not match current->active_mm,
* which will contain the previous user mm when we're in lazy TLB
* mode even if we've already switched back to swapper_pg_dir.
*
* During switch_mm_irqs_off(), loaded_mm will be set to
* LOADED_MM_SWITCHING during the brief interrupts-off window
* when CR3 and loaded_mm would otherwise be inconsistent. This
* is for nmi_uaccess_okay()'s benefit.
*/
struct mm_struct *loaded_mm;
#define LOADED_MM_SWITCHING ((struct mm_struct *)1UL)
/* Last user mm for optimizing IBPB */
union {
struct mm_struct *last_user_mm;
unsigned long last_user_mm_ibpb;
};
u16 loaded_mm_asid;
u16 next_asid;
/*
* We can be in one of several states:
*
* - Actively using an mm. Our CPU's bit will be set in
* mm_cpumask(loaded_mm) and is_lazy == false;
*
* - Not using a real mm. loaded_mm == &init_mm. Our CPU's bit
* will not be set in mm_cpumask(&init_mm) and is_lazy == false.
*
* - Lazily using a real mm. loaded_mm != &init_mm, our bit
* is set in mm_cpumask(loaded_mm), but is_lazy == true.
* We're heuristically guessing that the CR3 load we
* skipped more than makes up for the overhead added by
* lazy mode.
*/
bool is_lazy;
/*
* If set we changed the page tables in such a way that we
* needed an invalidation of all contexts (aka. PCIDs / ASIDs).
* This tells us to go invalidate all the non-loaded ctxs[]
* on the next context switch.
*
* The current ctx was kept up-to-date as it ran and does not
* need to be invalidated.
*/
bool invalidate_other;
/*
* Mask that contains TLB_NR_DYN_ASIDS+1 bits to indicate
* the corresponding user PCID needs a flush next time we
* switch to it; see SWITCH_TO_USER_CR3.
*/
unsigned short user_pcid_flush_mask;
/*
* Access to this CR4 shadow and to H/W CR4 is protected by
* disabling interrupts when modifying either one.
*/
unsigned long cr4;
/*
* This is a list of all contexts that might exist in the TLB.
* There is one per ASID that we use, and the ASID (what the
* CPU calls PCID) is the index into ctxts.
*
* For each context, ctx_id indicates which mm the TLB's user
* entries came from. As an invariant, the TLB will never
* contain entries that are out-of-date as when that mm reached
* the tlb_gen in the list.
*
* To be clear, this means that it's legal for the TLB code to
* flush the TLB without updating tlb_gen. This can happen
* (for now, at least) due to paravirt remote flushes.
*
* NB: context 0 is a bit special, since it's also used by
* various bits of init code. This is fine -- code that
* isn't aware of PCID will end up harmlessly flushing
* context 0.
*/
struct tlb_context ctxs[TLB_NR_DYN_ASIDS];
};
DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate);
bool nmi_uaccess_okay(void);
#define nmi_uaccess_okay nmi_uaccess_okay
/* Initialize cr4 shadow for this CPU. */
static inline void cr4_init_shadow(void)
{
this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
}
extern unsigned long mmu_cr4_features;
extern u32 *trampoline_cr4_features;
extern void initialize_tlbstate_and_flush(void);
/*
* TLB flushing:
*
* - flush_tlb_all() flushes all processes TLBs
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(vma, start, end) flushes a range of pages
* - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
* - flush_tlb_others(cpumask, info) flushes TLBs on other cpus
*
* ..but the i386 has somewhat limited tlb flushing capabilities,
* and page-granular flushes are available only on i486 and up.
*/
struct flush_tlb_info {
/*
* We support several kinds of flushes.
*
* - Fully flush a single mm. .mm will be set, .end will be
* TLB_FLUSH_ALL, and .new_tlb_gen will be the tlb_gen to
* which the IPI sender is trying to catch us up.
*
* - Partially flush a single mm. .mm will be set, .start and
* .end will indicate the range, and .new_tlb_gen will be set
* such that the changes between generation .new_tlb_gen-1 and
* .new_tlb_gen are entirely contained in the indicated range.
*
* - Fully flush all mms whose tlb_gens have been updated. .mm
* will be NULL, .end will be TLB_FLUSH_ALL, and .new_tlb_gen
* will be zero.
*/
struct mm_struct *mm;
unsigned long start;
unsigned long end;
u64 new_tlb_gen;
unsigned int stride_shift;
bool freed_tables;
};
void flush_tlb_local(void);
void flush_tlb_one_user(unsigned long addr);
void flush_tlb_one_kernel(unsigned long addr);
void flush_tlb_others(const struct cpumask *cpumask,
const struct flush_tlb_info *info);
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#endif
#define flush_tlb_mm(mm) \
flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)
#define flush_tlb_range(vma, start, end) \
flush_tlb_mm_range((vma)->vm_mm, start, end, \
((vma)->vm_flags & VM_HUGETLB) \
? huge_page_shift(hstate_vma(vma)) \
: PAGE_SHIFT, false)
extern void flush_tlb_all(void);
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned int stride_shift,
bool freed_tables);
extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)
{
flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false);
}
static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
{
/*
* Bump the generation count. This also serves as a full barrier
* that synchronizes with switch_mm(): callers are required to order
* their read of mm_cpumask after their writes to the paging
* structures.
*/
return atomic64_inc_return(&mm->context.tlb_gen);
}
static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
struct mm_struct *mm)
{
inc_mm_tlb_gen(mm);
cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
}
extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
#endif /* !MODULE */
#endif /* _ASM_X86_TLBFLUSH_H */
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