From ef59a20ba375aeb97b3150a118318884743452a8 Mon Sep 17 00:00:00 2001 From: Dmitry Eremin-Solenikov Date: Fri, 21 Nov 2014 15:29:00 +0100 Subject: [PATCH 1/3] ARM: 8216/1: xscale: correct auxiliary register in suspend/resume According to the manuals I have, XScale auxiliary register should be reached with opc_2 = 1 instead of crn = 1. cpu_xscale_proc_init correctly uses c1, c0, 1 arguments, but cpu_xscale_do_suspend and cpu_xscale_do_resume use c1, c1, 0. Correct suspend/resume functions to also use c1, c0, 1. The issue was primarily noticed thanks to qemu reporing "unsupported instruction" on the pxa suspend path. Confirmed in PXA210/250 and PXA255 XScale Core manuals and in PXA270 and PXA320 Developers Guides. Harware tested by me on tosa (pxa255). Robert confirmed on pxa270 board. Tested-by: Robert Jarzmik Signed-off-by: Dmitry Eremin-Solenikov Acked-by: Robert Jarzmik Cc: stable@vger.kernel.org Signed-off-by: Russell King --- arch/arm/mm/proc-xscale.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/proc-xscale.S b/arch/arm/mm/proc-xscale.S index 23259f104c66..afa2b3c4df4a 100644 --- a/arch/arm/mm/proc-xscale.S +++ b/arch/arm/mm/proc-xscale.S @@ -535,7 +535,7 @@ ENTRY(cpu_xscale_do_suspend) mrc p15, 0, r5, c15, c1, 0 @ CP access reg mrc p15, 0, r6, c13, c0, 0 @ PID mrc p15, 0, r7, c3, c0, 0 @ domain ID - mrc p15, 0, r8, c1, c1, 0 @ auxiliary control reg + mrc p15, 0, r8, c1, c0, 1 @ auxiliary control reg mrc p15, 0, r9, c1, c0, 0 @ control reg bic r4, r4, #2 @ clear frequency change bit stmia r0, {r4 - r9} @ store cp regs @@ -552,7 +552,7 @@ ENTRY(cpu_xscale_do_resume) mcr p15, 0, r6, c13, c0, 0 @ PID mcr p15, 0, r7, c3, c0, 0 @ domain ID mcr p15, 0, r1, c2, c0, 0 @ translation table base addr - mcr p15, 0, r8, c1, c1, 0 @ auxiliary control reg + mcr p15, 0, r8, c1, c0, 1 @ auxiliary control reg mov r0, r9 @ control register b cpu_resume_mmu ENDPROC(cpu_xscale_do_resume) From 995ab5189d1d7264e79e665dfa032a19b3ac646e Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Tue, 25 Nov 2014 18:43:15 +0100 Subject: [PATCH 2/3] ARM: 8222/1: mvebu: enable strex backoff delay Under extremely rare conditions, in an MPCore node consisting of at least 3 CPUs, two CPUs trying to perform a STREX to data on the same shared cache line can enter a livelock situation. This patch enables the HW mechanism that overcomes the bug. This fixes the incorrect setup of the STREX backoff delay bit due to a wrong description in the specification. Note that enabling the STREX backoff delay mechanism is done by leaving the bit *cleared*, while the bit was currently being set by the proc-v7.S code. [Thomas: adapt to latest mainline, slightly reword the commit log, add stable markers.] Fixes: de4901933f6d ("arm: mm: Add support for PJ4B cpu and init routines") Cc: # v3.8+ Signed-off-by: Nadav Haklai Signed-off-by: Thomas Petazzoni Acked-by: Gregory CLEMENT Acked-by: Jason Cooper Signed-off-by: Russell King --- arch/arm/mm/proc-v7.S | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index b3a947863ac7..22ac2a6fbfe3 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -270,7 +270,6 @@ __v7_pj4b_setup: /* Auxiliary Debug Modes Control 1 Register */ #define PJ4B_STATIC_BP (1 << 2) /* Enable Static BP */ #define PJ4B_INTER_PARITY (1 << 8) /* Disable Internal Parity Handling */ -#define PJ4B_BCK_OFF_STREX (1 << 5) /* Enable the back off of STREX instr */ #define PJ4B_CLEAN_LINE (1 << 16) /* Disable data transfer for clean line */ /* Auxiliary Debug Modes Control 2 Register */ @@ -293,7 +292,6 @@ __v7_pj4b_setup: /* Auxiliary Debug Modes Control 1 Register */ mrc p15, 1, r0, c15, c1, 1 orr r0, r0, #PJ4B_CLEAN_LINE - orr r0, r0, #PJ4B_BCK_OFF_STREX orr r0, r0, #PJ4B_INTER_PARITY bic r0, r0, #PJ4B_STATIC_BP mcr p15, 1, r0, c15, c1, 1 From 3f4aa45ceea5789a4aade536acc27f2e0d3da5e1 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Thu, 27 Nov 2014 11:39:04 +0100 Subject: [PATCH 3/3] ARM: 8226/1: cacheflush: get rid of restarting block We cannot restart cacheflush safely if a process provides user-defined signal handler and signal is pending. In this case -EINTR is returned and it is expected that process re-invokes syscall. However, there are a few problems with that: * looks like nobody bothers checking return value from cacheflush * but if it did, we don't provide the restart address for that, so the process has to use the same range again * ...and again, what might lead to looping forever So, remove cacheflush restarting code and terminate cache flushing as early as fatal signal is pending. Cc: stable@vger.kernel.org # 3.12+ Reported-by: Chanho Min Signed-off-by: Vladimir Murzin Acked-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/thread_info.h | 11 ----------- arch/arm/kernel/traps.c | 31 ++---------------------------- 2 files changed, 2 insertions(+), 40 deletions(-) diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index fc44d3761f9e..ce73ab635414 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -44,16 +44,6 @@ struct cpu_context_save { __u32 extra[2]; /* Xscale 'acc' register, etc */ }; -struct arm_restart_block { - union { - /* For user cache flushing */ - struct { - unsigned long start; - unsigned long end; - } cache; - }; -}; - /* * low level task data that entry.S needs immediate access to. * __switch_to() assumes cpu_context follows immediately after cpu_domain. @@ -79,7 +69,6 @@ struct thread_info { unsigned long thumbee_state; /* ThumbEE Handler Base register */ #endif struct restart_block restart_block; - struct arm_restart_block arm_restart_block; }; #define INIT_THREAD_INFO(tsk) \ diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 0c8b10801d36..9f5d81881eb6 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -533,8 +533,6 @@ static int bad_syscall(int n, struct pt_regs *regs) return regs->ARM_r0; } -static long do_cache_op_restart(struct restart_block *); - static inline int __do_cache_op(unsigned long start, unsigned long end) { @@ -543,24 +541,8 @@ __do_cache_op(unsigned long start, unsigned long end) do { unsigned long chunk = min(PAGE_SIZE, end - start); - if (signal_pending(current)) { - struct thread_info *ti = current_thread_info(); - - ti->restart_block = (struct restart_block) { - .fn = do_cache_op_restart, - }; - - ti->arm_restart_block = (struct arm_restart_block) { - { - .cache = { - .start = start, - .end = end, - }, - }, - }; - - return -ERESTART_RESTARTBLOCK; - } + if (fatal_signal_pending(current)) + return 0; ret = flush_cache_user_range(start, start + chunk); if (ret) @@ -573,15 +555,6 @@ __do_cache_op(unsigned long start, unsigned long end) return 0; } -static long do_cache_op_restart(struct restart_block *unused) -{ - struct arm_restart_block *restart_block; - - restart_block = ¤t_thread_info()->arm_restart_block; - return __do_cache_op(restart_block->cache.start, - restart_block->cache.end); -} - static inline int do_cache_op(unsigned long start, unsigned long end, int flags) {