Re: [PATCH v4 05/21] arm/acpi: Add basic ACPI initialization

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Thu, 28 Jan 2016, Shannon Zhao wrote:
> On 2016/1/28 19:27, Stefano Stabellini wrote:
> > On Thu, 28 Jan 2016, Shannon Zhao wrote:
> >> On 2016/1/28 18:44, Stefano Stabellini wrote:
> >>> On Thu, 28 Jan 2016, Shannon Zhao wrote:
> >>>>> On 2016/1/27 22:54, Stefano Stabellini wrote:
> >>>>>>> On Sat, 23 Jan 2016, Shannon Zhao wrote:
> >>>>>>>>>>> From: Shannon Zhao <shannon.zhao@linaro.org>
> >>>>>>>>>>>
> >>>>>>>>>>> acpi_boot_table_init() will be called in start_xen to get the RSDP and
> >>>>>>>>>>> all the table pointers. With this patch, we can get ACPI boot-time
> >>>>>>>>>>> tables from firmware on ARM64.
> >>>>>>>>>>>
> >>>>>>>>>>> Signed-off-by: Naresh Bhat <naresh.bhat@linaro.org>
> >>>>>>>>>>> Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
> >>>>>>>>>>> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> >>>>>>>>>>> ---
> >>>>>>>>>>>  xen/arch/arm/acpi/Makefile |  1 +
> >>>>>>>>>>>  xen/arch/arm/acpi/boot.c   | 58 ++++++++++++++++++++++++++++++++++++++++++++++
> >>>>>>>>>>>  xen/arch/arm/setup.c       |  4 ++++
> >>>>>>>>>>>  3 files changed, 63 insertions(+)
> >>>>>>>>>>>  create mode 100644 xen/arch/arm/acpi/boot.c
> >>>>>>>>>>>
> >>>>>>>>>>> diff --git a/xen/arch/arm/acpi/Makefile b/xen/arch/arm/acpi/Makefile
> >>>>>>>>>>> index b5be22d..196c40a 100644
> >>>>>>>>>>> --- a/xen/arch/arm/acpi/Makefile
> >>>>>>>>>>> +++ b/xen/arch/arm/acpi/Makefile
> >>>>>>>>>>> @@ -1 +1,2 @@
> >>>>>>>>>>>  obj-y += lib.o
> >>>>>>>>>>> +obj-y += boot.o
> >>>>>>>>>>> diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
> >>>>>>>>>>> new file mode 100644
> >>>>>>>>>>> index 0000000..1570f7e
> >>>>>>>>>>> --- /dev/null
> >>>>>>>>>>> +++ b/xen/arch/arm/acpi/boot.c
> >>>>>>>>>>> @@ -0,0 +1,58 @@
> >>>>>>>>>>> +/*
> >>>>>>>>>>> + *  ARM Specific Low-Level ACPI Boot Support
> >>>>>>>>>>> + *
> >>>>>>>>>>> + *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
> >>>>>>>>>>> + *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@intel.com>
> >>>>>>>>>>> + *  Copyright (C) 2014, Naresh Bhat <naresh.bhat@linaro.org>
> >>>>>>>>>>> + *  Copyright (C) 2015, Shannon Zhao <shannon.zhao@linaro.org>
> >>>>>>>>>>> + *
> >>>>>>>>>>> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>>>>>>>>>> + *
> >>>>>>>>>>> + *  This program is free software; you can redistribute it and/or modify
> >>>>>>>>>>> + *  it under the terms of the GNU General Public License as published by
> >>>>>>>>>>> + *  the Free Software Foundation; either version 2 of the License, or
> >>>>>>>>>>> + *  (at your option) any later version.
> >>>>>>>>>>> + *
> >>>>>>>>>>> + *  This program is distributed in the hope that it will be useful,
> >>>>>>>>>>> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> >>>>>>>>>>> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >>>>>>>>>>> + *  GNU General Public License for more details.
> >>>>>>>>>>> + *
> >>>>>>>>>>> + *  You should have received a copy of the GNU General Public License
> >>>>>>>>>>> + *  along with this program; if not, write to the Free Software
> >>>>>>>>>>> + *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> >>>>>>>>>>> + *
> >>>>>>>>>>> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>>>>>>>>>> + */
> >>>>>>>>>>> +
> >>>>>>>>>>> +#include <xen/init.h>
> >>>>>>>>>>> +#include <xen/acpi.h>
> >>>>>>>>>>> +
> >>>>>>>>>>> +#include <asm/acpi.h>
> >>>>>>>>>>> +
> >>>>>>>>>>> +/*
> >>>>>>>>>>> + * acpi_boot_table_init() called from setup_arch(), always.
> >>>>>>>>>>> + *      1. find RSDP and get its address, and then find XSDT
> >>>>>>>>>>> + *      2. extract all tables and checksums them all
> >>>>>>>>>>> + *
> >>>>>>>>>>> + * return value: (currently ignored)
> >>>>>>>>>>> + *	0: success
> >>>>>>>>>>> + *	!0: failure
> >>>>>>>>>>> + *
> >>>>>>>>>>> + * We can parse ACPI boot-time tables such as FADT, MADT after
> >>>>>>>>>>> + * this function is called.
> >>>>>>>>>>> + */
> >>>>>>>>>>> +int __init acpi_boot_table_init(void)
> >>>>>>>>>>> +{
> >>>>>>>>>>> +    int error;
> >>>>>>>>>>> +
> >>>>>>>>>>> +    /* Initialize the ACPI boot-time table parser. */
> >>>>>>>>>>> +    error = acpi_table_init();
> >>>>>>>>>>> +    if ( error )
> >>>>>>>>>>> +    {
> >>>>>>>>>>> +        disable_acpi();
> >>>>>>>>>>> +        return error;
> >>>>>>>>>>> +    }
> >>>>>>>>>>> +
> >>>>>>>>>>> +    return 0;
> >>>>>>>>>>> +}
> >>>>>>>>>>> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> >>>>>>>>>>> index 0ba601e..c15a09d 100644
> >>>>>>>>>>> --- a/xen/arch/arm/setup.c
> >>>>>>>>>>> +++ b/xen/arch/arm/setup.c
> >>>>>>>>>>> @@ -36,6 +36,7 @@
> >>>>>>>>>>>  #include <xen/pfn.h>
> >>>>>>>>>>>  #include <xen/vmap.h>
> >>>>>>>>>>>  #include <xen/libfdt/libfdt.h>
> >>>>>>>>>>> +#include <xen/acpi.h>
> >>>>>>>>>>>  #include <asm/page.h>
> >>>>>>>>>>>  #include <asm/current.h>
> >>>>>>>>>>>  #include <asm/setup.h>
> >>>>>>>>>>> @@ -749,6 +750,9 @@ void __init start_xen(unsigned long boot_phys_offset,
> >>>>>>>>>>>  
> >>>>>>>>>>>      setup_mm(fdt_paddr, fdt_size);
> >>>>>>>>>>>  
> >>>>>>>>>>> +    /* Parse the ACPI tables for possible boot-time configuration */
> >>>>>>>>>>> +    acpi_boot_table_init();
> >>>>>>> As I asked before, why do you need to call acpi_boot_table_init() before
> >>>>>>> vm_init?  If you called acpi_boot_table_init() after vm_init(), you
> >>>>>>> could implement __acpi_map_table with vmap, which would be better.
> >>>>>>>
> >>>>> Yes, if we call acpi_boot_table_init() before vm_init, it needs to move
> >>>>> end_boot_allocator after acpi_boot_table_init because it will assert in
> >>>>> acpi_os_zalloc_memory.
> >>> Why does acpi_os_zalloc_memory assert exactly?
> >>>
> >>
> >> If call acpi_boot_table_init after end_boot_allocator, system_state !=
> >> SYS_STATE_early_boot,
> > 
> > Could you please point out where end_boot_allocator changes
> > system_state?
> > 
> Oh, sorry, I see. It doesn't change the system_state. I mixed this with
> the patch[1] which change the system_state to SYS_STATE_boot, then will
> cause assert.
> 
> +    system_state = SYS_STATE_boot;
> +
>      vm_init();
> +
> +/*
> + * Parse the ACPI tables for possible boot-time configuration
> + */
> +
> +#if defined(CONFIG_ACPI) && defined(CONFIG_ARM_64)
> +    acpi_boot_table_init();
> +#endif
> 
> But current implementation doesn't do that so it won't cause assert.
> 
> While the true reason to move acpi_boot_table_init before
> end_boot_allocator is NUMA support. There is a discussion about it, see [2].
> 
> [1]http://lists.xenproject.org/archives/html/xen-devel/2015-02/msg00491.html
> [2]http://lists.xenproject.org/archives/html/xen-devel/2015-02/msg01157.html
 
All right, that's a good reason. Please fix the commit message of the
patch that moves end_boot_allocator. Also mention that it's done this
way on x86 too.