[Skiboot] [RFC PATCH 1/4] asm/head: move unnecessary code out of head

Nicholas Piggin npiggin at gmail.com
Sun Mar 3 00:06:23 AEDT 2019 

head.S should be for things that must be located in low memory, like
boot and interrupt entry.

Move some code from there into misc.S that is not called from entry
routines. The motivation for this patch is work to run skiboot in
virtual memory mode, which does not map head.S code. Even without that
motivation, it's still good to keep head.S clean.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 asm/head.S | 135 +--------------------------------------------------
 asm/misc.S | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+), 134 deletions(-)

diff --git a/asm/head.S b/asm/head.S
index 5e7dc896c..0ed1acddd 100644
--- a/asm/head.S
+++ b/asm/head.S
@@ -23,13 +23,6 @@
 
 #define EPAPR_MAGIC	0x65504150
 
-/* Power management instructions */
-#define PPC_INST_NAP		.long 0x4c000364
-#define PPC_INST_SLEEP		.long 0x4c0003a4
-#define PPC_INST_RVWINKLE	.long 0x4c0003e4
-
-#define PPC_INST_STOP		.long 0x4c0002e4
-
 #define GET_STACK(stack_reg,pir_reg)					\
 	sldi	stack_reg,pir_reg,STACK_SHIFT;				\
 	addis	stack_reg,stack_reg,CPU_STACKS_OFFSET at ha;		\
@@ -565,133 +558,6 @@ call_relocate:
 1:	/* Fatal relocate failure */
 	attn
 
-.global enable_machine_check
-enable_machine_check:
-	mflr	%r0
-	bcl	20,31,$+4
-0:	mflr	%r3
-	addi	%r3,%r3,(1f - 0b)
-	mtspr	SPR_HSRR0,%r3
-	mfmsr	%r3
-	ori	%r3,%r3,MSR_ME
-	mtspr	SPR_HSRR1,%r3
-	hrfid
-1:	mtlr	%r0
-	blr
-
-.global disable_machine_check
-disable_machine_check:
-	mflr	%r0
-	bcl	20,31,$+4
-0:	mflr	%r3
-	addi	%r3,%r3,(1f - 0b)
-	mtspr	SPR_HSRR0,%r3
-	mfmsr	%r3
-	li	%r4,MSR_ME
-	andc	%r3,%r3,%r4
-	mtspr	SPR_HSRR1,%r3
-	hrfid
-1:	mtlr	%r0
-	blr
-
-pm_save_regs:
-	SAVE_GPR(2,%r1)
-	SAVE_GPR(14,%r1)
-	SAVE_GPR(15,%r1)
-	SAVE_GPR(16,%r1)
-	SAVE_GPR(17,%r1)
-	SAVE_GPR(18,%r1)
-	SAVE_GPR(19,%r1)
-	SAVE_GPR(20,%r1)
-	SAVE_GPR(21,%r1)
-	SAVE_GPR(22,%r1)
-	SAVE_GPR(23,%r1)
-	SAVE_GPR(24,%r1)
-	SAVE_GPR(25,%r1)
-	SAVE_GPR(26,%r1)
-	SAVE_GPR(27,%r1)
-	SAVE_GPR(28,%r1)
-	SAVE_GPR(29,%r1)
-	SAVE_GPR(30,%r1)
-	SAVE_GPR(31,%r1)
-	mfcr	%r4
-	mfxer	%r5
-	mfspr	%r6,SPR_HSPRG0
-	mfspr	%r7,SPR_HSPRG1
-	stw	%r4,STACK_CR(%r1)
-	stw	%r5,STACK_XER(%r1)
-	std	%r6,STACK_GPR0(%r1)
-	std	%r7,STACK_GPR1(%r1)
-	blr
-
-.global enter_p8_pm_state
-enter_p8_pm_state:
-	/* Before entering map or rvwinkle, we create a stack frame
-	 * and save our non-volatile registers.
-	 *
-	 * We also save these SPRs:
-	 *
-	 *  - HSPRG0	in GPR0 slot
-	 *  - HSPRG1	in GPR1 slot
-	 *
-	 *  - xxx TODO: HIDs
-	 *  - TODO: Mask MSR:ME during the process
-	 *
-	 * On entry, r3 indicates:
-	 *
-	 *    0 = nap
-	 *    1 = rvwinkle
-	 */
-	mflr	%r0
-	std	%r0,16(%r1)
-	stdu	%r1,-STACK_FRAMESIZE(%r1)
-
-	bl	pm_save_regs
-
-	/* Save stack pointer in struct cpu_thread */
-	std	%r1,CPUTHREAD_SAVE_R1(%r13)
-
-	/* Winkle or nap ? */
-	cmpli	%cr0,0,%r3,0
-	bne	1f
-
-	/* nap sequence */
-	ptesync
-0:	ld	%r0,CPUTHREAD_SAVE_R1(%r13)
-	cmpd	cr0,%r0,%r0
-	bne	0b
-	PPC_INST_NAP
-	b	.
-
-	/* rvwinkle sequence */
-1:	ptesync
-0:	ld	%r0,CPUTHREAD_SAVE_R1(%r13)
-	cmpd	cr0,%r0,%r0
-	bne	0b
-	PPC_INST_RVWINKLE
-	b	.
-
-.global enter_p9_pm_lite_state
-enter_p9_pm_lite_state:
-	mtspr	SPR_PSSCR,%r3
-	PPC_INST_STOP
-	blr
-
-.global enter_p9_pm_state
-enter_p9_pm_state:
-	mflr	%r0
-	std	%r0,16(%r1)
-	stdu	%r1,-STACK_FRAMESIZE(%r1)
-
-	bl	pm_save_regs
-
-	/* Save stack pointer in struct cpu_thread */
-	std	%r1,CPUTHREAD_SAVE_R1(%r13)
-
-	mtspr	SPR_PSSCR,%r3
-	PPC_INST_STOP
-	b	.
-
 /* This is a little piece of code that is copied down to
  * 0x100 for handling sresets and power management wakeups.
  * This matches the 0x200 handler closely.
@@ -725,6 +591,7 @@ reset_patch_start:
 reset_patch_end:
 
 /* Wakeup vector in r3 */
+.global reset_wakeup
 reset_wakeup:
 	/* Get PIR */
 	mfspr	%r31,SPR_PIR
diff --git a/asm/misc.S b/asm/misc.S
index 6ef11a35c..223fd3d59 100644
--- a/asm/misc.S
+++ b/asm/misc.S
@@ -24,6 +24,35 @@
 	.section ".text","ax"
 	.balign	0x10
 
+.global enable_machine_check
+enable_machine_check:
+	mflr	%r0
+	bcl	20,31,$+4
+0:	mflr	%r3
+	addi	%r3,%r3,(1f - 0b)
+	mtspr	SPR_HSRR0,%r3
+	mfmsr	%r3
+	ori	%r3,%r3,MSR_ME
+	mtspr	SPR_HSRR1,%r3
+	hrfid
+1:	mtlr	%r0
+	blr
+
+.global disable_machine_check
+disable_machine_check:
+	mflr	%r0
+	bcl	20,31,$+4
+0:	mflr	%r3
+	addi	%r3,%r3,(1f - 0b)
+	mtspr	SPR_HSRR0,%r3
+	mfmsr	%r3
+	li	%r4,MSR_ME
+	andc	%r3,%r3,%r4
+	mtspr	SPR_HSRR1,%r3
+	hrfid
+1:	mtlr	%r0
+	blr
+
 	/* void set_hid0(unsigned long hid0) */
 .global set_hid0
 set_hid0:
@@ -126,3 +155,112 @@ cleanup_global_tlb:
 	ptesync
 
 	blr
+
+
+/* Power management instructions */
+#define PPC_INST_NAP		.long 0x4c000364
+#define PPC_INST_SLEEP		.long 0x4c0003a4
+#define PPC_INST_RVWINKLE	.long 0x4c0003e4
+
+#define PPC_INST_STOP		.long 0x4c0002e4
+
+#define SAVE_GPR(reg,sp)	std %r##reg,STACK_GPR##reg(sp)
+#define REST_GPR(reg,sp)	ld %r##reg,STACK_GPR##reg(sp)
+
+pm_save_regs:
+	SAVE_GPR(2,%r1)
+	SAVE_GPR(14,%r1)
+	SAVE_GPR(15,%r1)
+	SAVE_GPR(16,%r1)
+	SAVE_GPR(17,%r1)
+	SAVE_GPR(18,%r1)
+	SAVE_GPR(19,%r1)
+	SAVE_GPR(20,%r1)
+	SAVE_GPR(21,%r1)
+	SAVE_GPR(22,%r1)
+	SAVE_GPR(23,%r1)
+	SAVE_GPR(24,%r1)
+	SAVE_GPR(25,%r1)
+	SAVE_GPR(26,%r1)
+	SAVE_GPR(27,%r1)
+	SAVE_GPR(28,%r1)
+	SAVE_GPR(29,%r1)
+	SAVE_GPR(30,%r1)
+	SAVE_GPR(31,%r1)
+	mfcr	%r4
+	mfxer	%r5
+	mfspr	%r6,SPR_HSPRG0
+	mfspr	%r7,SPR_HSPRG1
+	stw	%r4,STACK_CR(%r1)
+	stw	%r5,STACK_XER(%r1)
+	std	%r6,STACK_GPR0(%r1)
+	std	%r7,STACK_GPR1(%r1)
+	blr
+
+.global enter_p8_pm_state
+enter_p8_pm_state:
+	/* Before entering map or rvwinkle, we create a stack frame
+	 * and save our non-volatile registers.
+	 *
+	 * We also save these SPRs:
+	 *
+	 *  - HSPRG0	in GPR0 slot
+	 *  - HSPRG1	in GPR1 slot
+	 *
+	 *  - xxx TODO: HIDs
+	 *  - TODO: Mask MSR:ME during the process
+	 *
+	 * On entry, r3 indicates:
+	 *
+	 *    0 = nap
+	 *    1 = rvwinkle
+	 */
+	mflr	%r0
+	std	%r0,16(%r1)
+	stdu	%r1,-STACK_FRAMESIZE(%r1)
+
+	bl	pm_save_regs
+
+	/* Save stack pointer in struct cpu_thread */
+	std	%r1,CPUTHREAD_SAVE_R1(%r13)
+
+	/* Winkle or nap ? */
+	cmpli	%cr0,0,%r3,0
+	bne	1f
+
+	/* nap sequence */
+	ptesync
+0:	ld	%r0,CPUTHREAD_SAVE_R1(%r13)
+	cmpd	cr0,%r0,%r0
+	bne	0b
+	PPC_INST_NAP
+	b	.
+
+	/* rvwinkle sequence */
+1:	ptesync
+0:	ld	%r0,CPUTHREAD_SAVE_R1(%r13)
+	cmpd	cr0,%r0,%r0
+	bne	0b
+	PPC_INST_RVWINKLE
+	b	.
+
+.global enter_p9_pm_lite_state
+enter_p9_pm_lite_state:
+	mtspr	SPR_PSSCR,%r3
+	PPC_INST_STOP
+	blr
+
+.global enter_p9_pm_state
+enter_p9_pm_state:
+	mflr	%r0
+	std	%r0,16(%r1)
+	stdu	%r1,-STACK_FRAMESIZE(%r1)
+
+	bl	pm_save_regs
+
+	/* Save stack pointer in struct cpu_thread */
+	std	%r1,CPUTHREAD_SAVE_R1(%r13)
+
+	mtspr	SPR_PSSCR,%r3
+	PPC_INST_STOP
+	b	.
-- 
2.18.0

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