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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>
This commit is contained in:
Vineet Gupta 2013-02-17 12:51:42 +02:00
parent 7e5122190b
commit 2328af0c9c
1 changed files with 19 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
arch/arc/mm/cache_arc700.c
View File

@ -389,7 +389,7 @@ static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
/***********************************************************
* 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 @@ static inline void __ic_entire_inv(void)
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 flush_icache_range(unsigned long kstart, unsigned long kend)
*/
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 */