linux_dsm_epyc7002/arch/arm64/include/asm/mmu.h
James Morse 79e9aa59dc arm64: sdei: Add trampoline code for remapping the kernel
When CONFIG_UNMAP_KERNEL_AT_EL0 is set the SDEI entry point and the rest
of the kernel may be unmapped when we take an event. If this may be the
case, use an entry trampoline that can switch to the kernel page tables.

We can't use the provided PSTATE to determine whether to switch page
tables as we may have interrupted the kernel's entry trampoline, (or a
normal-priority event that interrupted the kernel's entry trampoline).
Instead test for a user ASID in ttbr1_el1.

Save a value in regs->addr_limit to indicate whether we need to restore
the original ASID when returning from this event. This value is only used
by do_page_fault(), which we don't call with the SDEI regs.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-14 18:49:50 +00:00

94 lines
2.6 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_MMU_H
#define __ASM_MMU_H
#define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */
#define USER_ASID_BIT 48
#define USER_ASID_FLAG (UL(1) << USER_ASID_BIT)
#define TTBR_ASID_MASK (UL(0xffff) << 48)
#ifndef __ASSEMBLY__
typedef struct {
atomic64_t id;
void *vdso;
unsigned long flags;
} mm_context_t;
/*
* This macro is only used by the TLBI code, which cannot race with an
* ASID change and therefore doesn't need to reload the counter using
* atomic64_read.
*/
#define ASID(mm) ((mm)->context.id.counter & 0xffff)
static inline bool arm64_kernel_unmapped_at_el0(void)
{
return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0) &&
cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);
}
typedef void (*bp_hardening_cb_t)(void);
struct bp_hardening_data {
int hyp_vectors_slot;
bp_hardening_cb_t fn;
};
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
extern char __bp_harden_hyp_vecs_start[], __bp_harden_hyp_vecs_end[];
DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
{
return this_cpu_ptr(&bp_hardening_data);
}
static inline void arm64_apply_bp_hardening(void)
{
struct bp_hardening_data *d;
if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR))
return;
d = arm64_get_bp_hardening_data();
if (d->fn)
d->fn();
}
#else
static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
{
return NULL;
}
static inline void arm64_apply_bp_hardening(void) { }
#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
extern void paging_init(void);
extern void bootmem_init(void);
extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt);
extern void init_mem_pgprot(void);
extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
unsigned long virt, phys_addr_t size,
pgprot_t prot, bool page_mappings_only);
extern void *fixmap_remap_fdt(phys_addr_t dt_phys);
extern void mark_linear_text_alias_ro(void);
#endif /* !__ASSEMBLY__ */
#endif