[RFC PATCH v3 2/7] powerpc: Prepare for moving thread_info into task_struct

From: Christophe Leroy
Date: Mon Oct 01 2018 - 08:30:53 EST

Next message: Masahiro Yamada: "[PATCH 1/2] mmc: tmio: move MFD variant reset to a platform hook"
Previous message: Christophe Leroy: "[RFC PATCH v3 4/7] powerpc: regain entire stack space"
In reply to: Christophe LEROY: "Re: [RFC PATCH v3 4/7] powerpc: regain entire stack space"
Next in thread: Nicholas Piggin: "Re: [RFC PATCH v3 2/7] powerpc: Prepare for moving thread_info into task_struct"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This patch cleans the powerpc kernel before activating
CONFIG_THREAD_INFO_IN_TASK:
- The purpose of the pointer given to call_do_softirq() and
call_do_irq() is to point the new stack ==> change it to void*
- Don't use CURRENT_THREAD_INFO() to locate the stack.
- Fixed a few comments.
- TI_CPU is only used when CONFIG_SMP is set.
- Replace current_thread_info()->task by current
- Remove unnecessary casts to thread_info, as they'll become invalid
once thread_info is not in stack anymore.
- Ensure task_struct 'cpu' fields is not used directly out of SMP code
- Rename THREAD_INFO to TASK_STASK: As it is in fact the offset of the
pointer to the stack in task_struct, this pointer will not be impacted
by the move of THREAD_INFO.
- Makes TASK_STACK available to PPC64 which will need it to the get
stack pointer from current once the thread_info have been moved.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/irq.h | 4 ++--
arch/powerpc/include/asm/livepatch.h | 2 +-
arch/powerpc/include/asm/processor.h | 4 ++--
arch/powerpc/include/asm/reg.h | 2 +-
arch/powerpc/kernel/asm-offsets.c | 2 +-
arch/powerpc/kernel/entry_32.S | 2 +-
arch/powerpc/kernel/entry_64.S | 2 +-
arch/powerpc/kernel/head_32.S | 4 ++--
arch/powerpc/kernel/head_40x.S | 4 ++--
arch/powerpc/kernel/head_44x.S | 2 +-
arch/powerpc/kernel/head_8xx.S | 2 +-
arch/powerpc/kernel/head_booke.h | 4 ++--
arch/powerpc/kernel/head_fsl_booke.S | 6 ++++--
arch/powerpc/kernel/irq.c | 2 +-
arch/powerpc/kernel/misc_32.S | 8 ++++++--
arch/powerpc/kernel/process.c | 6 +++---
arch/powerpc/kernel/setup_32.c | 15 +++++----------
arch/powerpc/kernel/smp.c | 4 +++-
arch/powerpc/xmon/xmon.c | 2 +-
19 files changed, 40 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index ee39ce56b2a2..8108d1fe33ca 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -63,8 +63,8 @@ extern struct thread_info *hardirq_ctx[NR_CPUS];
extern struct thread_info *softirq_ctx[NR_CPUS];

extern void irq_ctx_init(void);
-extern void call_do_softirq(struct thread_info *tp);
-extern void call_do_irq(struct pt_regs *regs, struct thread_info *tp);
+extern void call_do_softirq(void *tp);
+extern void call_do_irq(struct pt_regs *regs, void *tp);
extern void do_IRQ(struct pt_regs *regs);
extern void __init init_IRQ(void);
extern void __do_irq(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 47a03b9b528b..818451bf629c 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -49,7 +49,7 @@ static inline void klp_init_thread_info(struct thread_info *ti)
ti->livepatch_sp = (unsigned long *)(ti + 1) + 1;
}
#else
-static void klp_init_thread_info(struct thread_info *ti) { }
+static inline void klp_init_thread_info(struct thread_info *ti) { }
#endif /* CONFIG_LIVEPATCH */

#endif /* _ASM_POWERPC_LIVEPATCH_H */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 353879db3e98..31873614392f 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -40,7 +40,7 @@

#ifndef __ASSEMBLY__
#include <linux/types.h>
-#include <asm/thread_info.h>
+#include <linux/thread_info.h>
#include <asm/ptrace.h>
#include <asm/hw_breakpoint.h>

@@ -333,7 +333,7 @@ struct thread_struct {

#define INIT_SP (sizeof(init_stack) + (unsigned long) &init_stack)
#define INIT_SP_LIMIT \
- (_ALIGN_UP(sizeof(init_thread_info), 16) + (unsigned long) &init_stack)
+ (_ALIGN_UP(sizeof(struct thread_info), 16) + (unsigned long) &init_stack)

#ifdef CONFIG_SPE
#define SPEFSCR_INIT \
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e5b314ed054e..f3a9cf19a986 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1053,7 +1053,7 @@
* - SPRG9 debug exception scratch
*
* All 32-bit:
- * - SPRG3 current thread_info pointer
+ * - SPRG3 current thread_struct physical addr pointer
* (virtual on BookE, physical on others)
*
* 32-bit classic:
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ba9d0fc98730..d1f161e48945 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -85,10 +85,10 @@ int main(void)
DEFINE(NMI_MASK, NMI_MASK);
OFFSET(TASKTHREADPPR, task_struct, thread.ppr);
#else
- OFFSET(THREAD_INFO, task_struct, stack);
DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16));
OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
#endif /* CONFIG_PPC64 */
+ OFFSET(TASK_STACK, task_struct, stack);

#ifdef CONFIG_LIVEPATCH
OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e58c3f467db5..12c0721f65ea 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1166,7 +1166,7 @@ ret_from_debug_exc:
mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
- lwz r9,THREAD_INFO-THREAD(r9)
+ lwz r9,TASK_STACK-THREAD(r9)
CURRENT_THREAD_INFO(r10, r1)
lwz r10,TI_PREEMPT(r10)
stw r10,TI_PREEMPT(r9)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 77a888bfcb53..697406572592 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -680,7 +680,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
2:
#endif /* CONFIG_PPC_BOOK3S_64 */

- CURRENT_THREAD_INFO(r7, r8) /* base of new stack */
+ clrrdi r7, r8, THREAD_SHIFT /* base of new stack */
/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
because we don't need to leave the 288-byte ABI gap at the
top of the kernel stack. */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 61ca27929355..dce6f2ff07e5 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -261,7 +261,7 @@ __secondary_hold_acknowledge:
tophys(r11,r1); /* use tophys(r1) if kernel */ \
beq 1f; \
mfspr r11,SPRN_SPRG_THREAD; \
- lwz r11,THREAD_INFO-THREAD(r11); \
+ lwz r11,TASK_STACK-THREAD(r11); \
addi r11,r11,THREAD_SIZE; \
tophys(r11,r11); \
1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
@@ -841,7 +841,7 @@ __secondary_start:
bl init_idle_6xx
#endif /* CONFIG_6xx */

- /* get current_thread_info and current */
+ /* get current's stack and current */
lis r1,secondary_ti@ha
tophys(r1,r1)
lwz r1,secondary_ti@l(r1)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index b19d78410511..3088c9f29f5e 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -115,7 +115,7 @@ _ENTRY(saved_ksp_limit)
andi. r11,r11,MSR_PR; \
beq 1f; \
mfspr r1,SPRN_SPRG_THREAD; /* if from user, start at top of */\
- lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\
+ lwz r1,TASK_STACK-THREAD(r1); /* this thread's kernel stack */\
addi r1,r1,THREAD_SIZE; \
1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\
tophys(r11,r1); \
@@ -158,7 +158,7 @@ _ENTRY(saved_ksp_limit)
beq 1f; \
/* COMING FROM USER MODE */ \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
- lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+ lwz r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm */\
tophys(r11,r11); \
stw r10,_CCR(r11); /* save various registers */\
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 37e4a7cf0065..15d39b2499de 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1020,7 +1020,7 @@ _GLOBAL(start_secondary_47x)

/* Now we can get our task struct and real stack pointer */

- /* Get current_thread_info and current */
+ /* Get current's stack and current */
lis r1,secondary_ti@ha
lwz r1,secondary_ti@l(r1)
lwz r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 6582f824d620..e56e36aa2b3d 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -124,7 +124,7 @@ turn_on_mmu:
tophys(r11,r1); /* use tophys(r1) if kernel */ \
beq 1f; \
mfspr r11,SPRN_SPRG_THREAD; \
- lwz r11,THREAD_INFO-THREAD(r11); \
+ lwz r11,TASK_STACK-THREAD(r11); \
addi r11,r11,THREAD_SIZE; \
tophys(r11,r11); \
1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index d0862a100d29..20fe0c93a0bd 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -44,7 +44,7 @@
mr r11, r1; \
beq 1f; \
/* if from user, start at top of this thread's kernel stack */ \
- lwz r11, THREAD_INFO-THREAD(r10); \
+ lwz r11, TASK_STACK-THREAD(r10); \
ALLOC_STACK_FRAME(r11, THREAD_SIZE); \
1 : subi r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */ \
stw r13, _CCR(r11); /* save various registers */ \
@@ -130,7 +130,7 @@
DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
andi. r11,r11,MSR_PR; \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
- lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+ lwz r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
beq 1f; \
/* COMING FROM USER MODE */ \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index e2750b856c8f..239ad8a4754e 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -243,8 +243,10 @@ set_ivor:
li r0,0
stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)

+#ifdef CONFIG_SMP
CURRENT_THREAD_INFO(r22, r1)
stw r24, TI_CPU(r22)
+#endif

bl early_init

@@ -702,7 +704,7 @@ finish_tlb_load:

/* Get the next_tlbcam_idx percpu var */
#ifdef CONFIG_SMP
- lwz r12, THREAD_INFO-THREAD(r12)
+ lwz r12, TASK_STACK-THREAD(r12)
lwz r15, TI_CPU(r12)
lis r14, __per_cpu_offset@h
ori r14, r14, __per_cpu_offset@l
@@ -1074,7 +1076,7 @@ __secondary_start:
mr r4,r24 /* Why? */
bl call_setup_cpu

- /* get current_thread_info and current */
+ /* get current's stack and current */
lis r1,secondary_ti@ha
lwz r1,secondary_ti@l(r1)
lwz r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 916ddc4aac44..aa53db3ba6e7 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -663,7 +663,7 @@ void do_IRQ(struct pt_regs *regs)
struct thread_info *curtp, *irqtp, *sirqtp;

/* Switch to the irq stack to handle this */
- curtp = current_thread_info();
+ curtp = (void*)(current_stack_pointer() & ~(THREAD_SIZE - 1));
irqtp = hardirq_ctx[raw_smp_processor_id()];
sirqtp = softirq_ctx[raw_smp_processor_id()];

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 695b24a2d954..24a7f18ea10c 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -60,7 +60,7 @@ _GLOBAL(call_do_softirq)
blr

/*
- * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
+ * void call_do_irq(struct pt_regs *regs, void *irqtp);
*/
_GLOBAL(call_do_irq)
mflr r0
@@ -183,10 +183,14 @@ _GLOBAL(low_choose_750fx_pll)
or r4,r4,r5
mtspr SPRN_HID1,r4

+#ifdef CONFIG_SMP
/* Store new HID1 image */
CURRENT_THREAD_INFO(r6, r1)
lwz r6,TI_CPU(r6)
slwi r6,r6,2
+#else
+ li r6, 0
+#endif
addis r6,r6,nap_save_hid1@ha
stw r4,nap_save_hid1@l(r6)

@@ -599,7 +603,7 @@ EXPORT_SYMBOL(__bswapdi2)
#ifdef CONFIG_SMP
_GLOBAL(start_secondary_resume)
/* Reset stack */
- CURRENT_THREAD_INFO(r1, r1)
+ rlwinm r1, r1, 0, 0, 31 - THREAD_SHIFT
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
li r3,0
stw r3,0(r1) /* Zero the stack frame pointer */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 03c2e1f134bc..111abb4df2ec 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1240,8 +1240,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
batch->active = 1;
}

- if (current_thread_info()->task->thread.regs) {
- restore_math(current_thread_info()->task->thread.regs);
+ if (current->thread.regs) {
+ restore_math(current->thread.regs);

/*
* The copy-paste buffer can only store into foreign real
@@ -1251,7 +1251,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
* mappings, we must issue a cp_abort to clear any state and
* prevent snooping, corruption or a covert channel.
*/
- if (current_thread_info()->task->thread.used_vas)
+ if (current->thread.used_vas)
asm volatile(PPC_CP_ABORT);
}
#endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 8c507be12c3c..81ebf7d6f526 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -205,10 +205,8 @@ void __init irqstack_early_init(void)
/* interrupt stacks must be in lowmem, we get that for free on ppc32
* as the memblock is limited to lowmem by default */
for_each_possible_cpu(i) {
- softirq_ctx[i] = (struct thread_info *)
- __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
- hardirq_ctx[i] = (struct thread_info *)
- __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+ softirq_ctx[i] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+ hardirq_ctx[i] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
}
}

@@ -226,13 +224,10 @@ void __init exc_lvl_early_init(void)
hw_cpu = 0;
#endif

- critirq_ctx[hw_cpu] = (struct thread_info *)
- __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+ critirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
#ifdef CONFIG_BOOKE
- dbgirq_ctx[hw_cpu] = (struct thread_info *)
- __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
- mcheckirq_ctx[hw_cpu] = (struct thread_info *)
- __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+ dbgirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+ mcheckirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
#endif
}
}
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 61c1fadbc644..19dd0ea55714 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -20,6 +20,7 @@
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
#include <linux/sched/topology.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
@@ -812,7 +813,8 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)

#ifdef CONFIG_PPC64
paca_ptrs[cpu]->__current = idle;
- paca_ptrs[cpu]->kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
+ paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
+ THREAD_SIZE - STACK_FRAME_OVERHEAD;
#endif
ti->cpu = cpu;
secondary_ti = current_set[cpu] = ti;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 694c1d92e796..0d8d6fee892a 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2988,7 +2988,7 @@ static void show_task(struct task_struct *tsk)
printf("%px %016lx %6d %6d %c %2d %s\n", tsk,
tsk->thread.ksp,
tsk->pid, tsk->parent->pid,
- state, task_thread_info(tsk)->cpu,
+ state, task_cpu(tsk),
tsk->comm);
}

--
2.13.3

Next message: Masahiro Yamada: "[PATCH 1/2] mmc: tmio: move MFD variant reset to a platform hook"
Previous message: Christophe Leroy: "[RFC PATCH v3 4/7] powerpc: regain entire stack space"
In reply to: Christophe LEROY: "Re: [RFC PATCH v3 4/7] powerpc: regain entire stack space"
Next in thread: Nicholas Piggin: "Re: [RFC PATCH v3 2/7] powerpc: Prepare for moving thread_info into task_struct"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]