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

[Shannon Zhao <zhaoshenglong@xxxxxxxxxx>]

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@xxxxxxxxxx>
>>>>>>>>>>>
>>>>>>>>>>> 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@xxxxxxxxxx>
>>>>>>>>>>> Signed-off-by: Parth Dixit <parth.dixit@xxxxxxxxxx>
>>>>>>>>>>> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>>>>>>>>>>> ---
>>>>>>>>>>>  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@xxxxxxxxx>
>>>>>>>>>>> + *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@xxxxxxxxx>
>>>>>>>>>>> + *  Copyright (C) 2014, Naresh Bhat <naresh.bhat@xxxxxxxxxx>
>>>>>>>>>>> + *  Copyright (C) 2015, Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>>>>>>>>>>> + *
>>>>>>>>>>> + * 
>>>>>>>>>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>>>>>>>> + *
>>>>>>>>>>> + *  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

-- 
Shannon


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