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

[Shannon Zhao <zhaoshenglong@huawei.com>]

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, acpi_os_zalloc_memory will call xzalloc_bytes to
malloc memory but vm_init is not called, so the ASSERT(!ptr ||
is_xmalloc_memory(ptr)) will occurs.

void *__init acpi_os_zalloc_memory(size_t sz)
{
	void *ptr;

	if (system_state != SYS_STATE_early_boot) {
		ptr = xzalloc_bytes(sz);
		ASSERT(!ptr || is_xmalloc_memory(ptr));
		return ptr;
	}
	ptr = acpi_os_alloc_memory(sz);
	return ptr ? memset(ptr, 0, sz) : NULL;
}

-- 
Shannon