[PATCH 5/7] ARM: suspend: fix CPU suspend code for !CONFIG_MMU configurations
Jonathan Austin
jonathan.austin at arm.com
Tue May 14 07:48:55 EDT 2013
From: Will Deacon <will.deacon at arm.com>
The ARM CPU suspend code can be selected even for a !CONFIG_MMU
configuration. The resulting kernel will not compile and, even if it did,
would access undefined co-processor registers when executing.
This patch fixes the v6 and v7 CPU suspend code for the nommu case.
Signed-off-by: Will Deacon <will.deacon at arm.com>
Tested-by: Jonathan Austin <jonathan.austin at arm.com>
CC: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
CC: Santosh Shilimkar <santosh.shilimkar at ti.com>
CC: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
arch/arm/kernel/suspend.c | 64 +++++++++++++++++++++++++--------------------
arch/arm/mm/proc-v6.S | 6 ++++-
arch/arm/mm/proc-v7.S | 14 ++++++----
3 files changed, 50 insertions(+), 34 deletions(-)
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index c59c97e..38a5067 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -10,6 +10,42 @@
extern int __cpu_suspend(unsigned long, int (*)(unsigned long));
extern void cpu_resume_mmu(void);
+#ifdef CONFIG_MMU
+/*
+ * Hide the first two arguments to __cpu_suspend - these are an implementation
+ * detail which platform code shouldn't have to know about.
+ */
+int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+{
+ struct mm_struct *mm = current->active_mm;
+ int ret;
+
+ if (!idmap_pgd)
+ return -EINVAL;
+
+ /*
+ * Provide a temporary page table with an identity mapping for
+ * the MMU-enable code, required for resuming. On successful
+ * resume (indicated by a zero return code), we need to switch
+ * back to the correct page tables.
+ */
+ ret = __cpu_suspend(arg, fn);
+ if (ret == 0) {
+ cpu_switch_mm(mm->pgd, mm);
+ local_flush_bp_all();
+ local_flush_tlb_all();
+ }
+
+ return ret;
+}
+#else
+int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+{
+ return __cpu_suspend(arg, fn);
+}
+#define idmap_pgd NULL
+#endif
+
/*
* This is called by __cpu_suspend() to save the state, and do whatever
* flushing is required to ensure that when the CPU goes to sleep we have
@@ -46,31 +82,3 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
outer_clean_range(virt_to_phys(save_ptr),
virt_to_phys(save_ptr) + sizeof(*save_ptr));
}
-
-/*
- * Hide the first two arguments to __cpu_suspend - these are an implementation
- * detail which platform code shouldn't have to know about.
- */
-int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
-{
- struct mm_struct *mm = current->active_mm;
- int ret;
-
- if (!idmap_pgd)
- return -EINVAL;
-
- /*
- * Provide a temporary page table with an identity mapping for
- * the MMU-enable code, required for resuming. On successful
- * resume (indicated by a zero return code), we need to switch
- * back to the correct page tables.
- */
- ret = __cpu_suspend(arg, fn);
- if (ret == 0) {
- cpu_switch_mm(mm->pgd, mm);
- local_flush_bp_all();
- local_flush_tlb_all();
- }
-
- return ret;
-}
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 919405e..2d1ef87 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -140,8 +140,10 @@ ENTRY(cpu_v6_set_pte_ext)
ENTRY(cpu_v6_do_suspend)
stmfd sp!, {r4 - r9, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
+#ifdef CONFIG_MMU
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
+#endif
mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register
mrc p15, 0, r8, c1, c0, 2 @ co-processor access control
mrc p15, 0, r9, c1, c0, 0 @ control register
@@ -158,14 +160,16 @@ ENTRY(cpu_v6_do_resume)
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0, {r4 - r9}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
+#ifdef CONFIG_MMU
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
mcr p15, 0, r1, c2, c0, 0 @ Translation table base 0
mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
+ mcr p15, 0, ip, c2, c0, 2 @ TTB control register
+#endif
mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register
mcr p15, 0, r8, c1, c0, 2 @ co-processor access control
- mcr p15, 0, ip, c2, c0, 2 @ TTB control register
mcr p15, 0, ip, c7, c5, 4 @ ISB
mov r0, r9 @ control register
b cpu_resume_mmu
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 2c73a73..a851e34 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -98,9 +98,11 @@ ENTRY(cpu_v7_do_suspend)
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
+#ifdef CONFIG_MMU
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
mrc p15, 0, r11, c2, c0, 2 @ TTB control register
+#endif
mrc p15, 0, r8, c1, c0, 0 @ Control register
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
@@ -110,13 +112,14 @@ ENDPROC(cpu_v7_do_suspend)
ENTRY(cpu_v7_do_resume)
mov ip, #0
- mcr p15, 0, ip, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0!, {r4 - r5}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c13, c0, 3 @ User r/o thread ID
ldmia r0, {r6 - r11}
+#ifdef CONFIG_MMU
+ mcr p15, 0, ip, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
#ifndef CONFIG_ARM_LPAE
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
@@ -125,14 +128,15 @@ ENTRY(cpu_v7_do_resume)
mcr p15, 0, r1, c2, c0, 0 @ TTB 0
mcr p15, 0, r7, c2, c0, 1 @ TTB 1
mcr p15, 0, r11, c2, c0, 2 @ TTB control register
- mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
- teq r4, r9 @ Is it already set?
- mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
- mcr p15, 0, r10, c1, c0, 2 @ Co-processor access control
ldr r4, =PRRR @ PRRR
ldr r5, =NMRR @ NMRR
mcr p15, 0, r4, c10, c2, 0 @ write PRRR
mcr p15, 0, r5, c10, c2, 1 @ write NMRR
+#endif /* CONFIG_MMU */
+ mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
+ teq r4, r9 @ Is it already set?
+ mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
+ mcr p15, 0, r10, c1, c0, 2 @ Co-processor access control
isb
dsb
mov r0, r8 @ control register
--
1.7.9.5
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