ARC: [SMP] Enable icache coherency
icaches are not snooped hence not cohrent in SMP setups which means
kernel has to do cross core calls to ensure the same.
The leaf routine __ic_line_inv_vaddr() now does cross core calls.
__sync_icache_dcache() is affected due to this:
* local dcache line flushed ahead of remote icache inv requests
* can't disable interrupts anymore, since
__ic_line_inv_vaddr()->on_each_cpu() can deadlock.
| WARNING: CPU: 0 PID: 1 at kernel/smp.c:374
| smp_call_function_many+0x25a/0x2c4()
|
| init_kprobes+0x90/0xc8
| register_kprobe+0x1d6/0x510
| __sync_icache_dcache+0x28/0x80
|
| DISABLE IRQ
|
| __ic_line_inv_vaddr
| on_each_cpu
| smp_call_function_many+0x25a/0x2c4 --> WARN
| __ic_line_inv_vaddr_local
| __dc_line_op
* TODO: Needs to use mask of relevant CPUs to avoid broadcasting
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/mm/cache_arc700.c b/arch/arc/mm/cache_arc700.c
index 1f676c4..353b202 100644
--- a/arch/arc/mm/cache_arc700.c
+++ b/arch/arc/mm/cache_arc700.c
@@ -389,7 +389,7 @@
/***********************************************************
* Machine specific helper for per line I-Cache invalidate.
*/
-static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
+static void __ic_line_inv_vaddr_local(unsigned long paddr, unsigned long vaddr,
unsigned long sz)
{
unsigned long flags;
@@ -405,6 +405,23 @@
read_aux_reg(ARC_REG_IC_CTRL); /* blocks */
}
+struct ic_line_inv_vaddr_ipi {
+ unsigned long paddr, vaddr;
+ int sz;
+};
+
+static void __ic_line_inv_vaddr_helper(void *info)
+{
+ struct ic_line_inv_vaddr_ipi *ic_inv = (struct ic_line_inv_vaddr_ipi*) info;
+ __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
+}
+
+static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
+ unsigned long sz)
+{
+ struct ic_line_inv_vaddr_ipi ic_inv = { paddr, vaddr , sz};
+ on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
+}
#else
#define __ic_entire_inv()
@@ -553,12 +570,8 @@
*/
void __sync_icache_dcache(unsigned long paddr, unsigned long vaddr, int len)
{
- unsigned long flags;
-
- local_irq_save(flags);
- __ic_line_inv_vaddr(paddr, vaddr, len);
__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
- local_irq_restore(flags);
+ __ic_line_inv_vaddr(paddr, vaddr, len);
}
/* wrapper to compile time eliminate alignment checks in flush loop */