[PATCH v2 1/2] powerpc: add Book E support to 64-bit hibernation

Wang Dongsheng dongsheng.wang at freescale.com
Sun Jun 9 15:21:26 EST 2013


Update the 64-bit hibernation code to support Book E CPUs.
Some registers and instructions are not defined for Book3e
(SDR reg, tlbia instruction).

SDR: Storage Description Register. Book3S and Book3E have different
address translation mode, we do not need HTABORG & HTABSIZE to
translate virtual address to real address.

More registers are saved in BookE-64bit.(TCR, SPRGx, ...)

Signed-off-by: Wang Dongsheng <dongsheng.wang at freescale.com>
---
v2:
* Add: _tlbil_all
*
* The boot core get a virtual address, when the boot process,
* the virtual address corresponds to a physical address. After
* hibernation resume memory snapshots, The corresponding
* relationship between the virtual memory and physical memory
* might change again. We need to get a new page table. So we
* need to invalidate TLB after resume pages.
*
* Invalidations TLB Using tlbilx/tlbivax/MMUCSR0.
* tlbilx used here.
*
* Add: save/restore PID
*
* We must restore PID register, because TLB will use PID. The
* hibernation suspend flow is trapped from user space to kernel
* space, the PID register is user thread pid.
*
* The hibernation resume is begin in kernel start flow, the PID
* alway 0. After the kernel thread back to user thread, there is
* not have context switch and the pid can not update, because the
* kernel thread is trapped form user space. So if we did't restore
* PID the user space of thread will be addressing in the kernel
* space.
*
* There are two ways to restore PID:
* 1/ In this file save/resotre PID register.
* 2/ Form restore_processor_state to restore. this function will
*    do context switch.
*    switch_mmu_context(current->active_mm, current->active_mm)
*
* PPC32 Using the second method. For consistency reason, PPC64
* using the same way.
*
* History:
* Wood Scott(A): Please investigate the issue of whether we are loading
*                kernel module code in this step
* R: Kernel will allocate the memory for module code segment and data
*    segment. First allocate a memory, and copy the umod to hdr members
*    of the struct load_info. Due to the temporary assigned module belongs
*    to the kernel space, so it belongs to the kernel data.
*
*    The kernel of all data will be saved when hibernation suspend. So
*    the module which has already been inserted will be saved.

 arch/powerpc/kernel/swsusp_asm64.S | 102 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 100 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/swsusp_asm64.S b/arch/powerpc/kernel/swsusp_asm64.S
index 86ac1d9..c7e2b4a 100644
--- a/arch/powerpc/kernel/swsusp_asm64.S
+++ b/arch/powerpc/kernel/swsusp_asm64.S
@@ -46,10 +46,30 @@
 #define SL_r29		0xe8
 #define SL_r30		0xf0
 #define SL_r31		0xf8
-#define SL_SIZE		SL_r31+8
+#define SL_SPRG0	0x100
+#define SL_SPRG1	0x108
+#define SL_SPRG2	0x110
+#define SL_SPRG3	0x118
+#define SL_SPRG4	0x120
+#define SL_SPRG5	0x128
+#define SL_SPRG6	0x130
+#define SL_SPRG7	0x138
+#define SL_TCR		0x140
+#define SL_PID		0x148
+#define SL_SIZE		SL_PID+8
 
 /* these macros rely on the save area being
  * pointed to by r11 */
+
+#define SAVE_SPR(register)		\
+	mfspr	r0,SPRN_##register	;\
+	std	r0,SL_##register(r11)
+#define RESTORE_SPR(register)		\
+	ld	r0,SL_##register(r11)	;\
+	mtspr	SPRN_##register,r0
+#define RESTORE_SPRG(n)			\
+	ld	r0,SL_SPRG##n(r11)	;\
+	mtsprg	n,r0
 #define SAVE_SPECIAL(special)		\
 	mf##special	r0		;\
 	std	r0, SL_##special(r11)
@@ -103,8 +123,22 @@ _GLOBAL(swsusp_arch_suspend)
 	SAVE_REGISTER(r30)
 	SAVE_REGISTER(r31)
 	SAVE_SPECIAL(MSR)
-	SAVE_SPECIAL(SDR1)
 	SAVE_SPECIAL(XER)
+#ifdef CONFIG_PPC_BOOK3S_64
+	SAVE_SPECIAL(SDR1)
+#else
+	SAVE_SPR(TCR)
+	/* Save SPRGs */
+	SAVE_SPR(SPRG0)
+	SAVE_SPR(SPRG1)
+	SAVE_SPR(SPRG2)
+	SAVE_SPR(SPRG3)
+	SAVE_SPR(SPRG4)
+	SAVE_SPR(SPRG5)
+	SAVE_SPR(SPRG6)
+	SAVE_SPR(SPRG7)
+	SAVE_SPR(PID);
+#endif
 
 	/* we push the stack up 128 bytes but don't store the
 	 * stack pointer on the stack like a real stackframe */
@@ -151,6 +185,7 @@ copy_page_loop:
 	bne+	copyloop
 nothing_to_copy:
 
+#ifdef CONFIG_PPC_BOOK3S_64
 	/* flush caches */
 	lis	r3, 0x10
 	mtctr	r3
@@ -167,6 +202,7 @@ nothing_to_copy:
 	sync
 
 	tlbia
+#endif
 
 	ld	r11,swsusp_save_area_ptr at toc(r2)
 
@@ -208,16 +244,78 @@ nothing_to_copy:
 	RESTORE_REGISTER(r29)
 	RESTORE_REGISTER(r30)
 	RESTORE_REGISTER(r31)
+
+#ifdef CONFIG_PPC_BOOK3S_64
 	/* can't use RESTORE_SPECIAL(MSR) */
 	ld	r0, SL_MSR(r11)
 	mtmsrd	r0, 0
 	RESTORE_SPECIAL(SDR1)
+#else
+	/* Save SPRGs */
+	RESTORE_SPRG(0)
+	RESTORE_SPRG(1)
+	RESTORE_SPRG(2)
+	RESTORE_SPRG(3)
+	RESTORE_SPRG(4)
+	RESTORE_SPRG(5)
+	RESTORE_SPRG(6)
+	RESTORE_SPRG(7)
+
+	/*
+	 * We must restore PID register, because TLB will use PID. The
+	 * hibernation suspend flow is trapped from user space to kernel
+	 * space, the PID register is user thread pid.
+	 *
+	 * The hibernation resume is begin in kernel start flow, the PID
+	 * alway 0. After the kernel thread back to user thread, there is
+	 * not have context switch and the pid can not update, because the
+	 * kernel thread is trapped form user space. So if we did't restore
+	 * PID the user space of thread will be addressing in the kernel
+	 * space.
+	 *
+	 * There are two ways to restore PID:
+	 * 1/ In this file save/resotre PID register.
+	 * 2/ Form restore_processor_state to restore. this function will
+	 *    do context switch.
+	 *    switch_mmu_context(current->active_mm, current->active_mm)
+	 *
+	 * PPC32 Using the second method. For consistency reason, PPC64
+	 * using the same way.
+	 */
+//	RESTORE_SPR(PID)
+
+	RESTORE_SPECIAL(MSR)
+
+	/* Restore TCR and clear any pending bits in TSR. */
+	RESTORE_SPR(TCR)
+	lis	r0, (TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS)@h
+	mtspr	SPRN_TSR,r0
+
+	/* Kick decrementer */
+	li	r0,1
+	mtdec	r0
+#endif
 	RESTORE_SPECIAL(XER)
 
+	/*
+	 * The boot core get a virtual address, when the boot process,
+	 * the virtual address corresponds to a physical address. After
+	 * hibernation resume memory snapshots, The corresponding
+	 * relationship between the virtual memory and physical memory
+	 * might change again. We need to get a new page table. So we
+	 * need to invalidate TLB after resume pages.
+	 *
+	 * Invalidations TLB Using tlbilx/tlbivax/MMUCSR0.
+	 * tlbilx used here.
+	 */
+	bl	_tlbil_all
+
 	sync
 
 	addi	r1,r1,-128
+#ifdef CONFIG_PPC_BOOK3S_64
 	bl	slb_flush_and_rebolt
+#endif
 	bl	do_after_copyback
 	addi	r1,r1,128
 
-- 
1.8.0




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