From dd7c983e78a28ff0b22f8bcf32a303b4f79cb318 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 31 Mar 2020 22:15:42 +0800 Subject: csky/ftrace: Fixup ftrace_modify_code deadlock without CPU_HAS_ICACHE_INS If ICACHE_INS is not supported, we use IPI to sync icache on each core. But ftrace_modify_code is called from stop_machine from default implementation of arch_ftrace_update_code and stop_machine callback is irq_disabled. When you call ipi with irq_disabled, a deadlock will happen. We couldn't use icache_flush with irq_disabled, but startup make_nop is specific case and it needn't ipi other cores. Signed-off-by: Guo Ren --- arch/csky/mm/cachev2.c | 45 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 6 deletions(-) (limited to 'arch/csky/mm') diff --git a/arch/csky/mm/cachev2.c b/arch/csky/mm/cachev2.c index bc419f8039d3..7a9664adce43 100644 --- a/arch/csky/mm/cachev2.c +++ b/arch/csky/mm/cachev2.c @@ -7,8 +7,12 @@ #include #include +/* for L1-cache */ #define INS_CACHE (1 << 0) +#define DATA_CACHE (1 << 1) #define CACHE_INV (1 << 4) +#define CACHE_CLR (1 << 5) +#define CACHE_OMS (1 << 6) void local_icache_inv_all(void *priv) { @@ -16,11 +20,6 @@ void local_icache_inv_all(void *priv) sync_is(); } -void icache_inv_all(void) -{ - on_each_cpu(local_icache_inv_all, NULL, 1); -} - #ifdef CONFIG_CPU_HAS_ICACHE_INS void icache_inv_range(unsigned long start, unsigned long end) { @@ -31,9 +30,43 @@ void icache_inv_range(unsigned long start, unsigned long end) sync_is(); } #else +struct cache_range { + unsigned long start; + unsigned long end; +}; + +static DEFINE_SPINLOCK(cache_lock); + +static inline void cache_op_line(unsigned long i, unsigned int val) +{ + mtcr("cr22", i); + mtcr("cr17", val); +} + +void local_icache_inv_range(void *priv) +{ + struct cache_range *param = priv; + unsigned long i = param->start & ~(L1_CACHE_BYTES - 1); + unsigned long flags; + + spin_lock_irqsave(&cache_lock, flags); + + for (; i < param->end; i += L1_CACHE_BYTES) + cache_op_line(i, INS_CACHE | CACHE_INV | CACHE_OMS); + + spin_unlock_irqrestore(&cache_lock, flags); + + sync_is(); +} + void icache_inv_range(unsigned long start, unsigned long end) { - icache_inv_all(); + struct cache_range param = { start, end }; + + if (irqs_disabled()) + local_icache_inv_range(¶m); + else + on_each_cpu(local_icache_inv_range, ¶m, 1); } #endif -- cgit