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: Will Schmidt <will_schm...@vnet.ibm.com> cc: Olof Johansson <o...@lixom.net> cc: Anton Blanchard <an...@samba.org> cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> --- v2 - Per feedback from Olof, the code is reworked to utilize kernel parameter runtime checks, rather than CONFIG options. - Added relevant change to kernel-parameters.txt diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e2c7487..5c40801 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -426,6 +426,10 @@ 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. + BusLogic= [HW,SCSI] See drivers/scsi/BusLogic.c, comment before function BusLogic_ParseDriverOptions(). @@ -1499,6 +1503,10 @@ 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] diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 902987d..e174a2f 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -625,3 +625,19 @@ 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) { + if (firmware_has_feature(FW_FEATURE_LPAR)) { + if (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); diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 0707653..82d15e7 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -599,6 +599,19 @@ 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) { + if (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; _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev