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f436b2ac90
The Performance Monitors extension is an optional feature of the
AArch64 architecture, therefore, in order to access Performance
Monitors registers safely, the kernel should detect the architected
PMU unit presence through the ID_AA64DFR0_EL1 register PMUVer field
before accessing them.
This patch implements a guard by reading the ID_AA64DFR0_EL1 register
PMUVer field to detect the architected PMU presence and prevent accessing
PMU system registers if the Performance Monitors extension is not
implemented in the core.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Fixes: 60792ad349 ("arm64: kernel: enforce pmuserenr_el0 initialization and restore")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
99 lines
2.7 KiB
ArmAsm
99 lines
2.7 KiB
ArmAsm
/*
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* Based on arch/arm/mm/proc-macros.S
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*
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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/*
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* vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
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*/
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.macro vma_vm_mm, rd, rn
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ldr \rd, [\rn, #VMA_VM_MM]
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.endm
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/*
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* mmid - get context id from mm pointer (mm->context.id)
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*/
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.macro mmid, rd, rn
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ldr \rd, [\rn, #MM_CONTEXT_ID]
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.endm
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/*
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* dcache_line_size - get the minimum D-cache line size from the CTR register.
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*/
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.macro dcache_line_size, reg, tmp
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mrs \tmp, ctr_el0 // read CTR
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ubfm \tmp, \tmp, #16, #19 // cache line size encoding
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mov \reg, #4 // bytes per word
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lsl \reg, \reg, \tmp // actual cache line size
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.endm
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/*
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* icache_line_size - get the minimum I-cache line size from the CTR register.
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*/
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.macro icache_line_size, reg, tmp
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mrs \tmp, ctr_el0 // read CTR
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and \tmp, \tmp, #0xf // cache line size encoding
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mov \reg, #4 // bytes per word
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lsl \reg, \reg, \tmp // actual cache line size
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.endm
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/*
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* tcr_set_idmap_t0sz - update TCR.T0SZ so that we can load the ID map
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*/
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.macro tcr_set_idmap_t0sz, valreg, tmpreg
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#ifndef CONFIG_ARM64_VA_BITS_48
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ldr_l \tmpreg, idmap_t0sz
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bfi \valreg, \tmpreg, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH
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#endif
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.endm
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/*
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* Macro to perform a data cache maintenance for the interval
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* [kaddr, kaddr + size)
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*
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* op: operation passed to dc instruction
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* domain: domain used in dsb instruciton
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* kaddr: starting virtual address of the region
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* size: size of the region
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* Corrupts: kaddr, size, tmp1, tmp2
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*/
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.macro dcache_by_line_op op, domain, kaddr, size, tmp1, tmp2
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dcache_line_size \tmp1, \tmp2
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add \size, \kaddr, \size
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sub \tmp2, \tmp1, #1
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bic \kaddr, \kaddr, \tmp2
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9998: dc \op, \kaddr
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add \kaddr, \kaddr, \tmp1
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cmp \kaddr, \size
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b.lo 9998b
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dsb \domain
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.endm
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/*
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* reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
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*/
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.macro reset_pmuserenr_el0, tmpreg
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mrs \tmpreg, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer
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sbfx \tmpreg, \tmpreg, #8, #4
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cmp \tmpreg, #1 // Skip if no PMU present
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b.lt 9000f
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msr pmuserenr_el0, xzr // Disable PMU access from EL0
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9000:
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.endm
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