powerpc/85xx: Add AltiVec support for e6500

The e6500 core adds support for AltiVec on a Book-E class processor.
Connect up all the various exception handling code and build config
mechanisms to allow user spaces apps to utilize AltiVec.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/include/asm/cputable.h

@@ -374,7 +374,7 @@ extern const char *powerpc_base_platform;
 #define CPU_FTRS_E6500	(CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | \
 	    CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE | \
 	    CPU_FTR_DBELL | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
-	    CPU_FTR_DEBUG_LVL_EXC | CPU_FTR_EMB_HV)
+	    CPU_FTR_DEBUG_LVL_EXC | CPU_FTR_EMB_HV | CPU_FTR_ALTIVEC_COMP)
 #define CPU_FTRS_GENERIC_32	(CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
 
 /* 64-bit CPUs */

arch/powerpc/include/asm/kvm_asm.h

@@ -67,6 +67,10 @@
 #define BOOKE_INTERRUPT_HV_SYSCALL 40
 #define BOOKE_INTERRUPT_HV_PRIV 41
 
+/* altivec */
+#define BOOKE_INTERRUPT_ALTIVEC_UNAVAIL 42
+#define BOOKE_INTERRUPT_ALTIVEC_ASSIST 43
+
 /* book3s */
 
 #define BOOK3S_INTERRUPT_SYSTEM_RESET	0x100

arch/powerpc/kernel/cpu_setup_fsl_booke.S

@@ -53,6 +53,15 @@ _GLOBAL(__e500_dcache_setup)
 	isync
 	blr
 
+_GLOBAL(__setup_cpu_e6500)
+	mflr	r6
+#ifdef CONFIG_PPC64
+	bl	.setup_altivec_ivors
+#endif
+	bl	__setup_cpu_e5500
+	mtlr	r6
+	blr
+
 #ifdef CONFIG_PPC32
 _GLOBAL(__setup_cpu_e200)
 	/* enable dedicated debug exception handling resources (Debug APU) */
@@ -107,6 +116,13 @@ _GLOBAL(__setup_cpu_e5500)
 #endif
 
 #ifdef CONFIG_PPC_BOOK3E_64
+_GLOBAL(__restore_cpu_e6500)
+	mflr	r5
+	bl	.setup_altivec_ivors
+	bl	__restore_cpu_e5500
+	mtlr	r5
+	blr
+
 _GLOBAL(__restore_cpu_e5500)
 	mflr	r4
 	bl	__e500_icache_setup

arch/powerpc/kernel/cputable.c

@@ -74,7 +74,9 @@ extern void __restore_cpu_a2(void);
 #endif /* CONFIG_PPC64 */
 #if defined(CONFIG_E500)
 extern void __setup_cpu_e5500(unsigned long offset, struct cpu_spec* spec);
+extern void __setup_cpu_e6500(unsigned long offset, struct cpu_spec* spec);
 extern void __restore_cpu_e5500(void);
+extern void __restore_cpu_e6500(void);
 #endif /* CONFIG_E500 */
 
 /* This table only contains "desktop" CPUs, it need to be filled with embedded
@@ -2065,7 +2067,8 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.pvr_value		= 0x80400000,
 		.cpu_name		= "e6500",
 		.cpu_features		= CPU_FTRS_E6500,
-		.cpu_user_features	= COMMON_USER_BOOKE | PPC_FEATURE_HAS_FPU,
+		.cpu_user_features	= COMMON_USER_BOOKE | PPC_FEATURE_HAS_FPU |
+			PPC_FEATURE_HAS_ALTIVEC_COMP,
 		.mmu_features		= MMU_FTR_TYPE_FSL_E | MMU_FTR_BIG_PHYS |
 			MMU_FTR_USE_TLBILX,
 		.icache_bsize		= 64,
@@ -2073,9 +2076,9 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.num_pmcs		= 4,
 		.oprofile_cpu_type	= "ppc/e6500",
 		.oprofile_type		= PPC_OPROFILE_FSL_EMB,
-		.cpu_setup		= __setup_cpu_e5500,
+		.cpu_setup		= __setup_cpu_e6500,
 #ifndef CONFIG_PPC32
-		.cpu_restore		= __restore_cpu_e5500,
+		.cpu_restore		= __restore_cpu_e6500,
 #endif
 		.machine_check		= machine_check_e500mc,
 		.platform		= "ppce6500",

arch/powerpc/kernel/exceptions-64e.S

@@ -299,6 +299,8 @@ interrupt_base_book3e:					/* fake trap */
 	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
 	EXCEPTION_STUB(0x1c0, data_tlb_miss)
 	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
+	EXCEPTION_STUB(0x200, altivec_unavailable)	/* 0x0f20 */
+	EXCEPTION_STUB(0x220, altivec_assist)		/* 0x1700 */
 	EXCEPTION_STUB(0x260, perfmon)
 	EXCEPTION_STUB(0x280, doorbell)
 	EXCEPTION_STUB(0x2a0, doorbell_crit)
@@ -395,6 +397,45 @@ interrupt_end_book3e:
 	bl	.kernel_fp_unavailable_exception
 	b	.ret_from_except
 
+/* Altivec Unavailable Interrupt */
+	START_EXCEPTION(altivec_unavailable);
+	NORMAL_EXCEPTION_PROLOG(0x200, BOOKE_INTERRUPT_ALTIVEC_UNAVAIL,
+				PROLOG_ADDITION_NONE)
+	/* we can probably do a shorter exception entry for that one... */
+	EXCEPTION_COMMON(0x200, PACA_EXGEN, INTS_KEEP)
+#ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
+	ld	r12,_MSR(r1)
+	andi.	r0,r12,MSR_PR;
+	beq-	1f
+	bl	.load_up_altivec
+	b	fast_exception_return
+1:
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+#endif
+	INTS_DISABLE
+	bl	.save_nvgprs
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.altivec_unavailable_exception
+	b	.ret_from_except
+
+/* AltiVec Assist */
+	START_EXCEPTION(altivec_assist);
+	NORMAL_EXCEPTION_PROLOG(0x220, BOOKE_INTERRUPT_ALTIVEC_ASSIST,
+				PROLOG_ADDITION_NONE)
+	EXCEPTION_COMMON(0x220, PACA_EXGEN, INTS_DISABLE)
+	bl	.save_nvgprs
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
+	bl	.altivec_assist_exception
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+#else
+	bl	.unknown_exception
+#endif
+	b	.ret_from_except
+
+
 /* Decrementer Interrupt */
 	MASKABLE_EXCEPTION(0x900, BOOKE_INTERRUPT_DECREMENTER,
 			   decrementer, .timer_interrupt, ACK_DEC)
@@ -807,6 +848,7 @@ fast_exception_return:
 BAD_STACK_TRAMPOLINE(0x000)
 BAD_STACK_TRAMPOLINE(0x100)
 BAD_STACK_TRAMPOLINE(0x200)
+BAD_STACK_TRAMPOLINE(0x220)
 BAD_STACK_TRAMPOLINE(0x260)
 BAD_STACK_TRAMPOLINE(0x280)
 BAD_STACK_TRAMPOLINE(0x2a0)
@@ -1350,6 +1392,11 @@ _GLOBAL(__setup_base_ivors)
 
 	blr
 
+_GLOBAL(setup_altivec_ivors)
+	SET_IVOR(32, 0x200) /* AltiVec Unavailable */
+	SET_IVOR(33, 0x220) /* AltiVec Assist */
+	blr
+
 _GLOBAL(setup_perfmon_ivor)
 	SET_IVOR(35, 0x260) /* Performance Monitor */
 	blr

arch/powerpc/platforms/Kconfig.cputype

@@ -232,7 +232,7 @@ config PHYS_64BIT
 
 config ALTIVEC
 	bool "AltiVec Support"
-	depends on 6xx || POWER4
+	depends on 6xx || POWER4 || (PPC_E500MC && PPC64)
 	---help---
 	  This option enables kernel support for the Altivec extensions to the
 	  PowerPC processor. The kernel currently supports saving and restoring