Switching to Thumb-2 mode can be done using a single 'sub' instruction so use that instead of the badr macro in various places in the code. This allows us to reimplement the macro in a way that does not allow it to be used in ARM code sequences when building a Thumb2 kernel.
Signed-off-by: Ard Biesheuvel <[email protected]> --- arch/arm/common/mcpm_head.S | 5 ++--- arch/arm/kernel/head-nommu.S | 7 +++---- arch/arm/kernel/head.S | 15 +++++++-------- arch/arm/kernel/sleep.S | 7 +++---- 4 files changed, 15 insertions(+), 19 deletions(-) diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S index 08b3bb9bc6a2..4c72314e87a3 100644 --- a/arch/arm/common/mcpm_head.S +++ b/arch/arm/common/mcpm_head.S @@ -49,10 +49,9 @@ ENTRY(mcpm_entry_point) ARM_BE8(setend be) - THUMB( badr r12, 1f ) - THUMB( bx r12 ) + THUMB( sub pc, pc, #3 ) THUMB( .thumb ) -1: + mrc p15, 0, r0, c0, c0, 5 @ MPIDR ubfx r9, r0, #0, #8 @ r9 = cpu ubfx r10, r0, #8, #8 @ r10 = cluster diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index dae8fa2f72c5..406dab0b773c 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -47,10 +47,9 @@ ENTRY(stext) .arm ENTRY(stext) - THUMB( badr r9, 1f ) @ Kernel is always entered in ARM. - THUMB( bx r9 ) @ If this is a Thumb-2 kernel, - THUMB( .thumb ) @ switch to Thumb now. - THUMB(1: ) + THUMB( sub pc, pc, #3 ) @ Kernel is always entered in ARM. + THUMB( .thumb ) @ If this is a Thumb-2 kernel, + @ switch to Thumb now. #endif setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 4b815821ec02..1e44ee9b2074 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -80,10 +80,9 @@ ENTRY(stext) ARM_BE8(setend be ) @ ensure we are in BE8 mode - THUMB( badr r9, 1f ) @ Kernel is always entered in ARM. - THUMB( bx r9 ) @ If this is a Thumb-2 kernel, - THUMB( .thumb ) @ switch to Thumb now. - THUMB(1: ) + THUMB( sub pc, pc, #3 ) @ Kernel is always entered in ARM. + THUMB( .thumb ) @ If this is a Thumb-2 kernel, + @ switch to Thumb now. #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install @@ -363,10 +362,10 @@ __turn_mmu_on_loc: .text .arm ENTRY(secondary_startup_arm) - THUMB( badr r9, 1f ) @ Kernel is entered in ARM. - THUMB( bx r9 ) @ If this is a Thumb-2 kernel, - THUMB( .thumb ) @ switch to Thumb now. - THUMB(1: ) + THUMB( sub pc, pc, #3 ) @ Kernel is entered in ARM. + THUMB( .thumb ) @ If this is a Thumb-2 kernel, + @ switch to Thumb now. + ENTRY(secondary_startup) /* * Common entry point for secondary CPUs. diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index a8257fc9cf2a..76b3d7c1c8d0 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -123,10 +123,9 @@ ENDPROC(cpu_resume_after_mmu) #ifdef CONFIG_MMU .arm ENTRY(cpu_resume_arm) - THUMB( badr r9, 1f ) @ Kernel is entered in ARM. - THUMB( bx r9 ) @ If this is a Thumb-2 kernel, - THUMB( .thumb ) @ switch to Thumb now. - THUMB(1: ) + THUMB( sub pc, pc, #3 ) @ Kernel is entered in ARM. + THUMB( .thumb ) @ If this is a Thumb-2 kernel, + @ switch to Thumb now. #endif ENTRY(cpu_resume) -- 2.17.1
