From b5872db4a2ebe7dbc7a5e4013ae8ee37f3de3b97 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 10 Jan 2008 19:16:17 +0100 Subject: [PATCH] [ARM] 4584/2: ARMv7: Add Advanced SIMD (NEON) extension support This patch enables the use of the Advanced SIMD (NEON) extension on ARMv7. The NEON technology is a 64/128-bit hybrid SIMD architecture for accelerating the performance of multimedia and signal processing applications. The extension shares the registers with the VFP unit and enabling/disabling and saving/restoring follow the same rules. In addition, there are instructions that do not have the appropriate CP number encoded, the checks being made in the call_fpe function. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/Kconfig | 7 +++++++ arch/arm/kernel/entry-armv.S | 38 ++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index f4eeb03bc6a9..709f9d383c87 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -966,6 +966,13 @@ config VFPv3 depends on VFP default y if CPU_V7 +config NEON + bool "Advanced SIMD (NEON) Extension support" + depends on VFPv3 && CPU_V7 + help + Say Y to include support code for NEON, the ARMv7 Advanced SIMD + Extension. + endmenu menu "Userspace binary formats" diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 29dec080a604..8de21f51e48c 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -480,6 +480,13 @@ __und_usr: * co-processor instructions. However, we have to watch out * for the ARM6/ARM7 SWI bug. * + * NEON is a special case that has to be handled here. Not all + * NEON instructions are co-processor instructions, so we have + * to make a special case of checking for them. Plus, there's + * five groups of them, so we have a table of mask/opcode pairs + * to check against, and if any match then we branch off into the + * NEON handler code. + * * Emulators may wish to make use of the following registers: * r0 = instruction opcode. * r2 = PC+4 @@ -488,6 +495,23 @@ __und_usr: * lr = unrecognised instruction return address */ call_fpe: +#ifdef CONFIG_NEON + adr r6, .LCneon_opcodes +2: + ldr r7, [r6], #4 @ mask value + cmp r7, #0 @ end mask? + beq 1f + and r8, r0, r7 + ldr r7, [r6], #4 @ opcode bits matching in mask + cmp r8, r7 @ NEON instruction? + bne 2b + get_thread_info r10 + mov r7, #1 + strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used + strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used + b do_vfp @ let VFP handler handle this +1: +#endif tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 #if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710) and r8, r0, #0x0f000000 @ mask out op-code bits @@ -537,6 +561,20 @@ call_fpe: mov pc, lr @ CP#14 (Debug) mov pc, lr @ CP#15 (Control) +#ifdef CONFIG_NEON + .align 6 + +.LCneon_opcodes: + .word 0xfe000000 @ mask + .word 0xf2000000 @ opcode + + .word 0xff100000 @ mask + .word 0xf4000000 @ opcode + + .word 0x00000000 @ mask + .word 0x00000000 @ opcode +#endif + do_fpe: enable_irq ldr r4, .LCfp -- 2.34.1