From 768019030ab58e9622caeb6c5a06553260609327 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 23 Feb 2017 14:50:24 +0000 Subject: MIPS: End spinlocks with .insn commit 4b5347a24a0f2d3272032c120664b484478455de upstream. When building for microMIPS we need to ensure that the assembler always knows that there is code at the target of a branch or jump. Recent toolchains will fail to link a microMIPS kernel when this isn't the case due to what it thinks is a branch to non-microMIPS code. mips-mti-linux-gnu-ld kernel/built-in.o: .spinlock.text+0x2fc: Unsupported branch between ISA modes. mips-mti-linux-gnu-ld final link failed: Bad value This is due to inline assembly labels in spinlock.h not being followed by an instruction mnemonic, either due to a .subsection pseudo-op or the end of the inline asm block. Fix this with a .insn direction after such labels. Signed-off-by: Paul Burton Signed-off-by: James Hogan Reviewed-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: Peter Zijlstra Cc: Ingo Molnar Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15325/ Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/spinlock.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/mips/include') diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h index 40196bebe849..2365ce0ad8f2 100644 --- a/arch/mips/include/asm/spinlock.h +++ b/arch/mips/include/asm/spinlock.h @@ -112,7 +112,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) " andi %[ticket], %[ticket], 0xffff \n" " bne %[ticket], %[my_ticket], 4f \n" " subu %[ticket], %[my_ticket], %[ticket] \n" - "2: \n" + "2: .insn \n" " .subsection 2 \n" "4: andi %[ticket], %[ticket], 0xffff \n" " sll %[ticket], 5 \n" @@ -187,7 +187,7 @@ static inline unsigned int arch_spin_trylock(arch_spinlock_t *lock) " sc %[ticket], %[ticket_ptr] \n" " beqz %[ticket], 1b \n" " li %[ticket], 1 \n" - "2: \n" + "2: .insn \n" " .subsection 2 \n" "3: b 2b \n" " li %[ticket], 0 \n" @@ -367,7 +367,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) " .set reorder \n" __WEAK_LLSC_MB " li %2, 1 \n" - "2: \n" + "2: .insn \n" : "=" GCC_OFF_SMALL_ASM() (rw->lock), "=&r" (tmp), "=&r" (ret) : GCC_OFF_SMALL_ASM() (rw->lock) : "memory"); @@ -407,7 +407,7 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) " lui %1, 0x8000 \n" " sc %1, %0 \n" " li %2, 1 \n" - "2: \n" + "2: .insn \n" : "=" GCC_OFF_SMALL_ASM() (rw->lock), "=&r" (tmp), "=&r" (ret) : GCC_OFF_SMALL_ASM() (rw->lock) -- cgit v1.2.3 From d8b8b5528ea5a394074a91e37571bcca081b27e1 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Mon, 19 Dec 2016 14:20:56 +0000 Subject: MIPS: Introduce irq_stack commit fe8bd18ffea5327344d4ec2bf11f47951212abd0 upstream. Allocate a per-cpu irq stack for use within interrupt handlers. Also add a utility function on_irq_stack to determine if a given stack pointer is within the irq stack for that cpu. Signed-off-by: Matt Redfearn Acked-by: Jason A. Donenfeld Cc: Thomas Gleixner Cc: Paolo Bonzini Cc: Chris Metcalf Cc: Petr Mladek Cc: James Hogan Cc: Paul Burton Cc: Aaron Tomlin Cc: Andrew Morton Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14740/ Signed-off-by: Ralf Baechle Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/irq.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/mips/include') diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h index 15e0fecbc300..ebb9efb02502 100644 --- a/arch/mips/include/asm/irq.h +++ b/arch/mips/include/asm/irq.h @@ -17,6 +17,18 @@ #include +#define IRQ_STACK_SIZE THREAD_SIZE + +extern void *irq_stack[NR_CPUS]; + +static inline bool on_irq_stack(int cpu, unsigned long sp) +{ + unsigned long low = (unsigned long)irq_stack[cpu]; + unsigned long high = low + IRQ_STACK_SIZE; + + return (low <= sp && sp <= high); +} + #ifdef CONFIG_I8259 static inline int irq_canonicalize(int irq) { -- cgit v1.2.3 From 93a82f8dbef8ee421fac80a1bd0564124a8ac41c Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Mon, 19 Dec 2016 14:20:58 +0000 Subject: MIPS: Only change $28 to thread_info if coming from user mode commit 510d86362a27577f5ee23f46cfb354ad49731e61 upstream. The SAVE_SOME macro is used to save the execution context on all exceptions. If an exception occurs while executing user code, the stack is switched to the kernel's stack for the current task, and register $28 is switched to point to the current_thread_info, which is at the bottom of the stack region. If the exception occurs while executing kernel code, the stack is left, and this change ensures that register $28 is not updated. This is the correct behaviour when the kernel can be executing on the separate irq stack, because the thread_info will not be at the base of it. With this change, register $28 is only switched to it's kernel conventional usage of the currrent thread info pointer at the point at which execution enters kernel space. Doing it on every exception was redundant, but OK without an IRQ stack, but will be erroneous once that is introduced. Signed-off-by: Matt Redfearn Acked-by: Jason A. Donenfeld Cc: Thomas Gleixner Cc: James Hogan Cc: Paul Burton Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14742/ Signed-off-by: Ralf Baechle Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/stackframe.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/mips/include') diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h index a71da576883c..5347f130f536 100644 --- a/arch/mips/include/asm/stackframe.h +++ b/arch/mips/include/asm/stackframe.h @@ -216,12 +216,19 @@ LONG_S $25, PT_R25(sp) LONG_S $28, PT_R28(sp) LONG_S $31, PT_R31(sp) + + /* Set thread_info if we're coming from user mode */ + mfc0 k0, CP0_STATUS + sll k0, 3 /* extract cu0 bit */ + bltz k0, 9f + ori $28, sp, _THREAD_MASK xori $28, _THREAD_MASK #ifdef CONFIG_CPU_CAVIUM_OCTEON .set mips64 pref 0, 0($28) /* Prefetch the current pointer */ #endif +9: .set pop .endm -- cgit v1.2.3