diff mbox

[v7,07/17] ARM64 / ACPI: Disable ACPI if FADT revision is less than 5.1

Message ID 1421247905-3749-8-git-send-email-hanjun.guo@linaro.org
State New
Headers show

Commit Message

Hanjun Guo Jan. 14, 2015, 3:04 p.m. UTC 
FADT Major.Minor version was introduced in ACPI 5.1, it is the same
as ACPI version.

In ACPI 5.1, some major gaps are fixed for ARM, such as updates in
MADT table for GIC and SMP init, without those updates, we can not
get the MPIDR for SMP init, and GICv2/3 related init information, so
we can't boot arm64 ACPI properly with table versions predating 5.1.

If firmware provides ACPI tables with ACPI version less than 5.1,
OS will be messed up with those information and have no way to init
smp and GIC, so disable ACPI if we get an FADT table with version
less that 5.1.

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 arch/arm64/kernel/acpi.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

Comments

Hanjun Guo Jan. 18, 2015, 5:49 a.m. UTC | #1 
On 2015年01月16日 22:33, Lorenzo Pieralisi wrote:
> On Wed, Jan 14, 2015 at 03:04:55PM +0000, Hanjun Guo wrote:
>> FADT Major.Minor version was introduced in ACPI 5.1, it is the same
>> as ACPI version.
>>
>> In ACPI 5.1, some major gaps are fixed for ARM, such as updates in
>> MADT table for GIC and SMP init, without those updates, we can not
>> get the MPIDR for SMP init, and GICv2/3 related init information, so
>> we can't boot arm64 ACPI properly with table versions predating 5.1.
>>
>> If firmware provides ACPI tables with ACPI version less than 5.1,
>> OS will be messed up with those information and have no way to init
>
> Nit: "that information"
>
> or
>
> "...OS has no way to retrieve the configuration data that is necessary
> to init SMP boot protocol and the GIC properly, so.."
>
>> smp and GIC, so disable ACPI if we get an FADT table with version
>> less that 5.1.
>>
>
> Patch should be reordered in the series and must be sequenced before
> patch 5 for bisectability (that patch implements DT unflattening if ACPI
> is disabled), or squashed with previous patches.

OK, I will reorder this patch set and update the change log above.

Thanks
Hanjun
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Hanjun Guo Jan. 20, 2015, 3:05 a.m. UTC | #2 
On 2015年01月19日 19:50, Catalin Marinas wrote:
> On Wed, Jan 14, 2015 at 03:04:55PM +0000, Hanjun Guo wrote:
>> --- a/arch/arm64/kernel/acpi.c
>> +++ b/arch/arm64/kernel/acpi.c
> [...]
>> @@ -64,8 +88,13 @@ void __init acpi_boot_table_init(void)
>>   		return;
>>
>>   	/* Initialize the ACPI boot-time table parser. */
>> -	if (acpi_table_init())
>> +	if (acpi_table_init()) {
>>   		disable_acpi();
>> +		return;
>> +	}
>> +
>> +	if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt))
>> +		pr_err("Can't find FADT or error happened during parsing FADT\n");
>>   }
>
> Do you need a disable_acpi() call here as well?

Yes, if we can not find the FADT table, we should disable ACPI, I will
update it in next version, thanks for pointing this out :)

Thanks
Hanjun
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diff mbox

Patch

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 39a1655..4177758 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -13,6 +13,8 @@ 
  *  published by the Free Software Foundation.
  */
 
+#define pr_fmt(fmt) "ACPI: " fmt
+
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/cpumask.h>
@@ -49,10 +51,32 @@  void __init __acpi_unmap_table(char *map, unsigned long size)
 	early_memunmap(map, size);
 }
 
+static int __init acpi_parse_fadt(struct acpi_table_header *table)
+{
+	struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
+
+	/*
+	 * Revision in table header is the FADT Major revision,
+	 * and there is a minor revision of FADT which was introduced
+	 * by ACPI 5.1, we only deal with ACPI 5.1 or newer revision
+	 * to get arm boot flags, or we will disable ACPI.
+	 */
+	if (table->revision > 5 ||
+	    (table->revision == 5 && fadt->minor_revision >= 1))
+		return 0;
+
+	pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
+		table->revision, fadt->minor_revision);
+	disable_acpi();
+
+	return -EINVAL;
+}
+
 /*
  * 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
+ *	3. check ACPI FADT revision
  *
  * We can parse ACPI boot-time tables such as MADT after
  * this function is called.
@@ -64,8 +88,13 @@  void __init acpi_boot_table_init(void)
 		return;
 
 	/* Initialize the ACPI boot-time table parser. */
-	if (acpi_table_init())
+	if (acpi_table_init()) {
 		disable_acpi();
+		return;
+	}
+
+	if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt))
+		pr_err("Can't find FADT or error happened during parsing FADT\n");
 }
 
 static int __init parse_acpi(char *arg)