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Commit f13ae30e authored by Alex Chiang's avatar Alex Chiang Committed by Tony Luck
Browse files

[IA64] allow user to force_pal_cache_flush 



The sequence executed in check_sal_cache_flush:

	- pend a timer interrupt
	- call SAL_CACHE_FLUSH
	- see if interrupt is still pending

can hang HP machines with buggy SAL_CACHE_FLUSH implementations.

Provide a kernel command-line argument to allow users skip this
check if desired. Using this parameter will force ia64_sal_cache_flush
to call ia64_pal_cache_flush() instead of SAL_CACHE_FLUSH.

Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 8a3360f0

Documentation/kernel-parameters.txt

+6 −0
Original line number Diff line number Diff line
@@ -689,6 +689,12 @@ and is between 256 and 4096 characters. It is defined in the file 
	floppy=		[HW]

			See Documentation/floppy.txt.



	force_pal_cache_flush

			[IA-64] Avoid check_sal_cache_flush which may hang on

			buggy SAL_CACHE_FLUSH implementations. Using this

			parameter will force ia64_sal_cache_flush to call

			ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.



	gamecon.map[2|3]=

			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad

			support via parallel port (up to 5 devices per port)

arch/ia64/kernel/sal.c

+11 −0
Original line number Diff line number Diff line
@@ -229,6 +229,14 @@ static void __init sal_desc_ap_wakeup(void *p) { } 
 */

static int sal_cache_flush_drops_interrupts;



static int __init

force_pal_cache_flush(char *str)

{

	sal_cache_flush_drops_interrupts = 1;

	return 0;

}

early_param("force_pal_cache_flush", force_pal_cache_flush);



void __init

check_sal_cache_flush (void)

{
@@ -237,6 +245,9 @@ check_sal_cache_flush (void) 
	u64 vector, cache_type = 3;

	struct ia64_sal_retval isrv;



	if (sal_cache_flush_drops_interrupts)

		return;



	cpu = get_cpu();

	local_irq_save(flags);