From cb170a45d69b573a08247acfbbff3b9d6e6e2f8f Mon Sep 17 00:00:00 2001 From: Paul Brook Date: Fri, 18 Apr 2008 22:43:08 +0100 Subject: Linux Thumb-2 support for user-space applications This patch implements Thumb-2 application support in Linux. Original implementation by Paul Brook with fixes for VFP and Neon by Catalin Marinas. Signed-off-by: Paul Brook Signed-off-by: Catalin Marinas --- arch/arm/kernel/entry-armv.S | 53 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 9 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 5e647eb6b3b..6fd1460111e 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -462,10 +462,6 @@ __irq_usr: __und_usr: usr_entry - tst r3, #PSR_T_BIT @ Thumb mode? - bne __und_usr_unknown @ ignore FP - sub r4, r2, #4 - @ @ fall through to the emulation code, which returns using r9 if @ it has emulated the instruction, or the more conventional lr @@ -475,7 +471,24 @@ __und_usr: @ adr r9, ret_from_exception adr lr, __und_usr_unknown -1: ldrt r0, [r4] + tst r3, #PSR_T_BIT @ Thumb mode? + subeq r4, r2, #4 @ ARM instr at LR - 4 + subne r4, r2, #2 @ Thumb instr at LR - 2 +1: ldreqt r0, [r4] + beq call_fpe + @ Thumb instruction +#if __LINUX_ARM_ARCH__ >= 7 +2: ldrht r5, [r4], #2 + and r0, r5, #0xf800 @ mask bits 111x x... .... .... + cmp r0, #0xe800 @ 32bit instruction if xx != 0 + blo __und_usr_unknown +3: ldrht r0, [r4] + add r2, r2, #2 @ r2 is PC + 2, make it PC + 4 + orr r0, r0, r5, lsl #16 +#else + b __und_usr_unknown +#endif + @ @ fallthrough to call_fpe @ @@ -484,10 +497,14 @@ __und_usr: * The out of line fixup for the ldrt above. */ .section .fixup, "ax" -2: mov pc, r9 +4: mov pc, r9 .previous .section __ex_table,"a" - .long 1b, 2b + .long 1b, 4b +#if __LINUX_ARM_ARCH__ >= 7 + .long 2b, 4b + .long 3b, 4b +#endif .previous /* @@ -514,9 +531,16 @@ __und_usr: * r10 = this threads thread_info structure. * lr = unrecognised instruction return address */ + @ + @ Fall-through from Thumb-2 __und_usr + @ +#ifdef CONFIG_NEON + adr r6, .LCneon_thumb_opcodes + b 2f +#endif call_fpe: #ifdef CONFIG_NEON - adr r6, .LCneon_opcodes + adr r6, .LCneon_arm_opcodes 2: ldr r7, [r6], #4 @ mask value cmp r7, #0 @ end mask? @@ -533,6 +557,7 @@ call_fpe: 1: #endif tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 + tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2 #if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710) and r8, r0, #0x0f000000 @ mask out op-code bits teqne r8, #0x0f000000 @ SWI (ARM6/7 bug)? @@ -584,13 +609,23 @@ call_fpe: #ifdef CONFIG_NEON .align 6 -.LCneon_opcodes: +.LCneon_arm_opcodes: .word 0xfe000000 @ mask .word 0xf2000000 @ opcode .word 0xff100000 @ mask .word 0xf4000000 @ opcode + .word 0x00000000 @ mask + .word 0x00000000 @ opcode + +.LCneon_thumb_opcodes: + .word 0xef000000 @ mask + .word 0xef000000 @ opcode + + .word 0xff100000 @ mask + .word 0xf9000000 @ opcode + .word 0x00000000 @ mask .word 0x00000000 @ opcode #endif -- cgit v1.2.3