From: Balbir Singh <bsingharora@gmail.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH for-4.8 12/12] powerpc/mm/radix: Add a kernel command line to disable radix
Date: Thu, 14 Jul 2016 15:02:59 +1000 [thread overview]
Message-ID: <20160714050259.GJ18277@balbir.ozlabs.ibm.com> (raw)
In-Reply-To: <1468402531-4914-13-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
On Wed, Jul 13, 2016 at 03:05:31PM +0530, Aneesh Kumar K.V wrote:
> This patch adds the kernel command line disable_radix which disable
> the radix MMU mode even if firmware indicates radix support via
> ibm,pa-features device tree node.
>
> This helps in testing different MMU mode easily.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> Documentation/kernel-parameters.txt | 3 +++
> arch/powerpc/kernel/prom.c | 13 +++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 738bae4a5958..bba7ef30d74e 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -929,6 +929,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> disable= [IPV6]
> See Documentation/networking/ipv6.txt.
>
> + disable_radix [PPC]
> + Disable RADIX MMU mode on POWER9
> +
> disable_cpu_apicid= [X86,APIC,SMP]
> Format: <int>
> The number of initial APIC ID for the
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 946e34ffeae9..022540b9366d 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -645,6 +645,14 @@ static void __init early_reserve_mem(void)
> #endif
> }
>
> +static bool disable_radix;
__read_mostly?
> +static int __init parse_disable_radix(char *p)
> +{
> + disable_radix = true;
> + return 0;
> +}
> +early_param("disable_radix", parse_disable_radix);
> +
> void __init early_init_devtree(void *params)
> {
> phys_addr_t limit;
> @@ -739,6 +747,11 @@ void __init early_init_devtree(void *params)
> /* Scan and build the list of machine check recoverable ranges */
> of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
> #endif
> + /*
> + * now fixup radix MMU mode based on kernel command line
> + */
> + if (disable_radix)
> + cur_cpu_spec->mmu_features &= ~MMU_FTR_RADIX;
Shouldn't this happen before prom_init() and exchanging capabilities?
next prev parent reply other threads:[~2016-07-14 5:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-13 9:35 [PATCH for-4.8_set1 00/12] Radix fixes for 4.8 Aneesh Kumar K.V
2016-07-13 9:35 ` [PATCH for-4.8 01/12] Fix .long's in mm/tlb-radix.c to more meaningful Aneesh Kumar K.V
2016-07-17 10:28 ` [for-4.8,01/12] " Michael Ellerman
2016-07-13 9:35 ` [PATCH for-4.8 02/12] powerpc/mm/radix: Update LPCR HR bit as per ISA Aneesh Kumar K.V
2016-07-14 3:30 ` Balbir Singh
2016-07-13 9:35 ` [PATCH for-4.8 03/12] powerpc/mm: use _raw variant of page table accessors Aneesh Kumar K.V
2016-07-14 3:42 ` Balbir Singh
2016-07-15 11:42 ` David Laight
2016-07-17 5:22 ` Anton Blanchard
2016-07-13 9:35 ` [PATCH for-4.8 04/12] powerpc/mm: Compile out radix related functions if RADIX_MMU is disabled Aneesh Kumar K.V
2016-07-13 9:35 ` [PATCH for-4.8 05/12] powerpc/mm: Clear top 16 bits of va only on older cpus Aneesh Kumar K.V
2016-07-14 3:50 ` Balbir Singh
2016-07-13 9:35 ` [PATCH for-4.8 06/12] powerpc/mm: Print formation regarding the the MMU mode Aneesh Kumar K.V
2016-07-14 4:03 ` Balbir Singh
2016-07-13 9:35 ` [PATCH for-4.8 07/12] powerpc/mm/hash: Update SDR1 size encoding as documented in ISA 3.0 Aneesh Kumar K.V
2016-07-14 4:29 ` Balbir Singh
2016-07-13 9:35 ` [PATCH for-4.8 08/12] powerpc/mm/radix: Update PID switch sequence Aneesh Kumar K.V
2016-07-13 9:35 ` [PATCH for-4.8 09/12] powerpc/mm/radix: Update machine call back to support new HCALL Aneesh Kumar K.V
2016-07-13 9:35 ` [PATCH for-4.8 10/12] powerpc/mm/radix: Add LPID based tlb flush helpers Aneesh Kumar K.V
2016-07-14 5:12 ` Balbir Singh
2016-07-13 9:35 ` [PATCH for-4.8 11/12] powerpc/mm: Cleanup LPCR defines Aneesh Kumar K.V
2016-07-13 9:35 ` [PATCH for-4.8 12/12] powerpc/mm/radix: Add a kernel command line to disable radix Aneesh Kumar K.V
2016-07-14 5:02 ` Balbir Singh [this message]
2016-07-14 8:43 ` Aneesh Kumar K.V
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