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Commit 4e89a2d8 authored by Will Schmidt's avatar Will Schmidt Committed by Benjamin Herrenschmidt
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powerpc/pseries: Add kernel parameter to disable batched hcalls 



This introduces a pair of kernel parameters that can be used to disable
the MULTITCE and BULK_REMOVE h-calls.

By default, those hcalls are enabled, active, and good for throughput
and performance.  The ability to disable them will be useful for some of
the PREEMPT_RT related investigation and work occurring on Power.

Signed-off-by: default avatarWill Schmidt <will_schmidt@vnet.ibm.com>
cc: Olof Johansson <olof@lixom.net>
cc: Anton Blanchard <anton@samba.org>
cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 475fc7c0

Documentation/kernel-parameters.txt

+8 −0
Original line number Diff line number Diff line
@@ -403,6 +403,10 @@ and is between 256 and 4096 characters. It is defined in the file 
	bttv.pll=	See Documentation/video4linux/bttv/Insmod-options

	bttv.tuner=	and Documentation/video4linux/bttv/CARDLIST



	bulk_remove=off	[PPC]  This parameter disables the use of the pSeries

			firmware feature for flushing multiple hpte entries

			at a time.



	c101=		[NET] Moxa C101 synchronous serial card



	cachesize=	[BUGS=X86-32] Override level 2 CPU cache size detection.
@@ -1490,6 +1494,10 @@ and is between 256 and 4096 characters. It is defined in the file 
	mtdparts=	[MTD]

			See drivers/mtd/cmdlinepart.c.



	multitce=off	[PPC]  This parameter disables the use of the pSeries

			firmware feature for updating multiple TCE entries

			at a time.



	onenand.bdry=	[HW,MTD] Flex-OneNAND Boundary Configuration



			Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]

arch/powerpc/platforms/pseries/iommu.c

+14 −0
Original line number Diff line number Diff line
@@ -622,3 +622,17 @@ void iommu_init_early_pSeries(void) 
	set_pci_dma_ops(&dma_iommu_ops);

}



static int __init disable_multitce(char *str)

{

	if (strcmp(str, "off") == 0 &&

	    firmware_has_feature(FW_FEATURE_LPAR) &&

	    firmware_has_feature(FW_FEATURE_MULTITCE)) {

		printk(KERN_INFO "Disabling MULTITCE firmware feature\n");

		ppc_md.tce_build = tce_build_pSeriesLP;

		ppc_md.tce_free	 = tce_free_pSeriesLP;

		powerpc_firmware_features &= ~FW_FEATURE_MULTITCE;

	}

	return 1;

}



__setup("multitce=", disable_multitce);

arch/powerpc/platforms/pseries/lpar.c

+12 −0
Original line number Diff line number Diff line
@@ -627,6 +627,18 @@ static void pSeries_lpar_flush_hash_range(unsigned long number, int local) 
		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);

}



static int __init disable_bulk_remove(char *str)

{

	if (strcmp(str, "off") == 0 &&

	    firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {

			printk(KERN_INFO "Disabling BULK_REMOVE firmware feature");

			powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;

	}

	return 1;

}



__setup("bulk_remove=", disable_bulk_remove);



void __init hpte_init_lpar(void)

{

	ppc_md.hpte_invalidate	= pSeries_lpar_hpte_invalidate;