From 25b92693a1b67a47b0c64a3410009d09e9658412 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 13 Feb 2020 12:14:52 +0000 Subject: arm64: mm: convert cpu_do_switch_mm() to C There's no reason that cpu_do_switch_mm() needs to be written as an assembly function, and having it as a C function would make it easier to maintain. This patch converts cpu_do_switch_mm() to C, removing code that this change makes redundant (e.g. the mmid macro). Since the header comment was stale and the prototype now implies all the necessary information, this comment is removed. The 'pgd_phys' argument is made a phys_addr_t to match the return type of virt_to_phys(). At the same time, post_ttbr_update_workaround() is updated to use IS_ENABLED(), which allows the compiler to figure out it can elide calls for !CONFIG_CAVIUM_ERRATUM_27456 builds. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Will Deacon [catalin.marinas@arm.com: change comments from asm-style to C-style] Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/assembler.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'arch/arm64/include/asm/assembler.h') diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aca337d79d12..af03001293c6 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -256,12 +256,6 @@ alternative_endif ldr \rd, [\rn, #VMA_VM_MM] .endm -/* - * mmid - get context id from mm pointer (mm->context.id) - */ - .macro mmid, rd, rn - ldr \rd, [\rn, #MM_CONTEXT_ID] - .endm /* * read_ctr - read CTR_EL0. If the system has mismatched register fields, * provide the system wide safe value from arm64_ftr_reg_ctrel0.sys_val -- cgit v1.2.1 From 87a1f063464afd934f0f22aac710ca65bef77af3 Mon Sep 17 00:00:00 2001 From: Ionela Voinescu Date: Thu, 5 Mar 2020 09:06:22 +0000 Subject: arm64: trap to EL1 accesses to AMU counters from EL0 The activity monitors extension is an optional extension introduced by the ARMv8.4 CPU architecture. In order to access the activity monitors counters safely, if desired, the kernel should detect the presence of the extension through the feature register, and mediate the access. Therefore, disable direct accesses to activity monitors counters from EL0 (userspace) and trap them to EL1 (kernel). To be noted that the ARM64_AMU_EXTN kernel config does not have an effect on this code. Given that the amuserenr_el0 resets to an UNKNOWN value, setting the trap of EL0 accesses to EL1 is always attempted for safety and security considerations. Therefore firmware should still ensure accesses to AMU registers are not trapped in EL2/EL3 as this code cannot be bypassed if the CPU implements the Activity Monitors Unit. Signed-off-by: Ionela Voinescu Reviewed-by: James Morse Reviewed-by: Valentin Schneider Reviewed-by: Suzuki K Poulose Cc: Steve Capper Cc: Mark Rutland Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/assembler.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm64/include/asm/assembler.h') diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aca337d79d12..c5487806273f 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -430,6 +430,16 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU 9000: .endm +/* + * reset_amuserenr_el0 - reset AMUSERENR_EL0 if AMUv1 present + */ + .macro reset_amuserenr_el0, tmpreg + mrs \tmpreg, id_aa64pfr0_el1 // Check ID_AA64PFR0_EL1 + ubfx \tmpreg, \tmpreg, #ID_AA64PFR0_AMU_SHIFT, #4 + cbz \tmpreg, .Lskip_\@ // Skip if no AMU present + msr_s SYS_AMUSERENR_EL0, xzr // Disable AMU access from EL0 +.Lskip_\@: + .endm /* * copy_page - copy src to dest using temp registers t1-t8 */ -- cgit v1.2.1