[PATCH] makedumpfile/arm64: Add support for ARMv8.2-LVA (52-bit user-space VA support)

[PATCH] makedumpfile/arm64: Add support for ARMv8.2-LVA (52-bit user-space VA support)

[Bhupesh Sharma]

With ARMv8.2-LVA architecture extension availability, arm64 hardware
which supports this extension can support upto 52-bit virtual
addresses. It is specially useful for having a 52-bit user-space virtual
address space while the kernel can still retain 48-bit virtual
addresses.

Since at the moment we enable the support of this extensions in the
kernel via a CONFIG flags (CONFIG_ARM64_USER_VA_BITS_52), so there are
no clear mechanisms in user-space to determine this CONFIG
flag value and use it to determine the PA address range values.

'makedumpfile' can instead use 'MAX_USER_VA_BITS' value to
determine the maximum virtual physical address supported by user-space.
If 'MAX_USER_VA_BITS' value is greater than 'VA_BITS' than we might be
running a use-case where user-space is 52-bit and underlying kernel is
still 48-bit. The increased 'PTRS_PER_PGD' value for such cases can then
be calculated as is done by the underlying kernel (see kernel file
'arch/arm64/include/asm/pgtable-hwdef.h' for details):

I have sent a kernel patch upstream to add 'MAX_USER_VA_BITS' to
vmcoreinfo for arm64 (see [0]).

This patch is in accordance with ARMv8 Architecture Reference Manual
version D.a

[0].
http://lists.infradead.org/pipermail/kexec/2019-February/022411.html

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
---
 arch/arm64.c   | 105 +++++++++++++++++++++++++++++++++++++++++----------------
 makedumpfile.c |   2 ++
 makedumpfile.h |   1 +
 3 files changed, 79 insertions(+), 29 deletions(-)

diff --git a/arch/arm64.c b/arch/arm64.c
index a1db7dc63107..b522e93f4e80 100644
--- a/arch/arm64.c
+++ b/arch/arm64.c
@@ -47,6 +47,7 @@ typedef struct {
 static int lpa_52_bit_support_available;
 static int pgtable_level;
 static int va_bits;
+static int max_user_va_bits;
 static unsigned long kimage_voffset;
 
 #define SZ_4K			4096
@@ -145,7 +146,7 @@ get_page_table_level_arm64(void)
 #define PGDIR_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - (get_page_table_level_arm64()))
 #define PGDIR_SIZE		(_AC(1, UL) << PGDIR_SHIFT)
 #define PGDIR_MASK		(~(PGDIR_SIZE-1))
-#define PTRS_PER_PGD		(1 << ((va_bits) - PGDIR_SHIFT))
+#define PTRS_PER_PGD		(1 << ((max_user_va_bits) - PGDIR_SHIFT))
 
 /*
  * Section address mask and size definitions.
@@ -478,6 +479,46 @@ get_stext_symbol(void)
 	return(found ? kallsym : FALSE);
 }
 
+static int
+get_va_bits_from_stext_arm64(void)
+{
+	ulong _stext;
+
+	_stext = get_stext_symbol();
+	if (!_stext) {
+		ERRMSG("Can't get the symbol of _stext.\n");
+		return FALSE;
+	}
+
+	/* Derive va_bits as per arch/arm64/Kconfig */
+	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
+		va_bits = 36;
+	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
+		va_bits = 39;
+	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
+		va_bits = 42;
+	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
+		va_bits = 47;
+	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
+		va_bits = 48;
+	} else {
+		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
+		return FALSE;
+	}
+
+	DEBUG_MSG("va_bits      : %d\n", va_bits);
+
+	return TRUE;
+}
+
+static void
+get_page_offset_arm64(void)
+{
+	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
+
+	DEBUG_MSG("page_offset  : %lx\n", info->page_offset);
+}
+
 int
 get_machdep_info_arm64(void)
 {
@@ -493,8 +534,37 @@ get_machdep_info_arm64(void)
 	/* Check if va_bits is still not initialized. If still 0, call
 	 * get_versiondep_info() to initialize the same.
 	 */
+	if (NUMBER(VA_BITS) != NOT_FOUND_NUMBER) {
+		va_bits = NUMBER(VA_BITS);
+		DEBUG_MSG("va_bits    : %d (vmcoreinfo)\n",
+				va_bits);
+	}
+
+	/* Check if va_bits is still not initialized. If still 0, call
+	 * get_versiondep_info() to initialize the same from _stext
+	 * symbol.
+	 */
 	if (!va_bits)
-		get_versiondep_info_arm64();
+		if (get_va_bits_from_stext_arm64() == ERROR)
+			return ERROR;
+
+	get_page_offset_arm64();
+
+	if (NUMBER(MAX_USER_VA_BITS) != NOT_FOUND_NUMBER) {
+		max_user_va_bits = NUMBER(MAX_USER_VA_BITS);
+		DEBUG_MSG("max_user_va_bits : %d (vmcoreinfo)\n",
+				max_user_va_bits);
+	}
+
+	/* Check if max_user_va_bits is still not initialized.
+	 * If still 0, its not available in vmcoreinfo and its
+	 * safe to initialize it with va_bits.
+	 */
+	if (!max_user_va_bits) {
+		max_user_va_bits = va_bits;
+		DEBUG_MSG("max_user_va_bits : %d (default = va_bits)\n",
+				max_user_va_bits);
+	}
 
 	if (!calculate_plat_config()) {
 		ERRMSG("Can't determine platform config values\n");
@@ -533,34 +603,11 @@ get_xen_info_arm64(void)
 int
 get_versiondep_info_arm64(void)
 {
-	ulong _stext;
-
-	_stext = get_stext_symbol();
-	if (!_stext) {
-		ERRMSG("Can't get the symbol of _stext.\n");
-		return FALSE;
-	}
-
-	/* Derive va_bits as per arch/arm64/Kconfig */
-	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
-		va_bits = 36;
-	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
-		va_bits = 39;
-	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
-		va_bits = 42;
-	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
-		va_bits = 47;
-	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
-		va_bits = 48;
-	} else {
-		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
-		return FALSE;
-	}
-
-	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
+	if (!va_bits)
+		if (get_va_bits_from_stext_arm64() == ERROR)
+			return ERROR;
 
-	DEBUG_MSG("va_bits      : %d\n", va_bits);
-	DEBUG_MSG("page_offset  : %lx\n", info->page_offset);
+	get_page_offset_arm64();
 
 	return TRUE;
 }
diff --git a/makedumpfile.c b/makedumpfile.c
index b7c1c01251bf..ccf7eb4408ba 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -2291,6 +2291,7 @@ write_vmcoreinfo_data(void)
 
 	WRITE_NUMBER("HUGETLB_PAGE_DTOR", HUGETLB_PAGE_DTOR);
 #ifdef __aarch64__
+	WRITE_NUMBER("MAX_USER_VA_BITS", MAX_USER_VA_BITS);
 	WRITE_NUMBER("VA_BITS", VA_BITS);
 	WRITE_NUMBER_UNSIGNED("PHYS_OFFSET", PHYS_OFFSET);
 	WRITE_NUMBER_UNSIGNED("kimage_voffset", kimage_voffset);
@@ -2694,6 +2695,7 @@ read_vmcoreinfo(void)
 	READ_NUMBER("PAGE_BUDDY_MAPCOUNT_VALUE", PAGE_BUDDY_MAPCOUNT_VALUE);
 	READ_NUMBER("phys_base", phys_base);
 #ifdef __aarch64__
+	READ_NUMBER("MAX_USER_VA_BITS", MAX_USER_VA_BITS);
 	READ_NUMBER("VA_BITS", VA_BITS);
 	READ_NUMBER_UNSIGNED("PHYS_OFFSET", PHYS_OFFSET);
 	READ_NUMBER_UNSIGNED("kimage_voffset", kimage_voffset);
diff --git a/makedumpfile.h b/makedumpfile.h
index d49f1f1fc1a9..3fa810e0bb40 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -1933,6 +1933,7 @@ struct number_table {
 	long    HUGETLB_PAGE_DTOR;
 	long	phys_base;
 #ifdef __aarch64__
+	long 	MAX_USER_VA_BITS;
 	long 	VA_BITS;
 	unsigned long	PHYS_OFFSET;
 	unsigned long	kimage_voffset;
-- 
2.7.4


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

RE: [PATCH] makedumpfile/arm64: Add support for ARMv8.2-LVA (52-bit user-space VA support)

[Kazuhito Hagio]

Hi Bhupesh,

On 2/7/2019 2:52 PM, Bhupesh Sharma wrote:
> With ARMv8.2-LVA architecture extension availability, arm64 hardware
> which supports this extension can support upto 52-bit virtual
> addresses. It is specially useful for having a 52-bit user-space virtual
> address space while the kernel can still retain 48-bit virtual
> addresses.
> 
> Since at the moment we enable the support of this extensions in the
> kernel via a CONFIG flags (CONFIG_ARM64_USER_VA_BITS_52), so there are
> no clear mechanisms in user-space to determine this CONFIG
> flag value and use it to determine the PA address range values.
> 
> 'makedumpfile' can instead use 'MAX_USER_VA_BITS' value to
> determine the maximum virtual physical address supported by user-space.
> If 'MAX_USER_VA_BITS' value is greater than 'VA_BITS' than we might be
> running a use-case where user-space is 52-bit and underlying kernel is
> still 48-bit. The increased 'PTRS_PER_PGD' value for such cases can then
> be calculated as is done by the underlying kernel (see kernel file
> 'arch/arm64/include/asm/pgtable-hwdef.h' for details):

Thank you for the patch.
I can't test the config yet, but this looks necessary.

> 
> I have sent a kernel patch upstream to add 'MAX_USER_VA_BITS' to
> vmcoreinfo for arm64 (see [0]).
> 
> This patch is in accordance with ARMv8 Architecture Reference Manual
> version D.a
> 
> [0].
> http://lists.infradead.org/pipermail/kexec/2019-February/022411.html
> 
> Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
> ---
>  arch/arm64.c   | 105 +++++++++++++++++++++++++++++++++++++++++----------------
>  makedumpfile.c |   2 ++
>  makedumpfile.h |   1 +
>  3 files changed, 79 insertions(+), 29 deletions(-)
> 
> diff --git a/arch/arm64.c b/arch/arm64.c
> index a1db7dc63107..b522e93f4e80 100644
> --- a/arch/arm64.c
> +++ b/arch/arm64.c
> @@ -47,6 +47,7 @@ typedef struct {
>  static int lpa_52_bit_support_available;
>  static int pgtable_level;
>  static int va_bits;
> +static int max_user_va_bits;
>  static unsigned long kimage_voffset;
> 
>  #define SZ_4K			4096
> @@ -145,7 +146,7 @@ get_page_table_level_arm64(void)
>  #define PGDIR_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - (get_page_table_level_arm64()))
>  #define PGDIR_SIZE		(_AC(1, UL) << PGDIR_SHIFT)
>  #define PGDIR_MASK		(~(PGDIR_SIZE-1))
> -#define PTRS_PER_PGD		(1 << ((va_bits) - PGDIR_SHIFT))
> +#define PTRS_PER_PGD		(1 << ((max_user_va_bits) - PGDIR_SHIFT))
> 
>  /*
>   * Section address mask and size definitions.
> @@ -478,6 +479,46 @@ get_stext_symbol(void)
>  	return(found ? kallsym : FALSE);
>  }
> 
> +static int
> +get_va_bits_from_stext_arm64(void)
> +{
> +	ulong _stext;
> +
> +	_stext = get_stext_symbol();
> +	if (!_stext) {
> +		ERRMSG("Can't get the symbol of _stext.\n");
> +		return FALSE;
> +	}
> +
> +	/* Derive va_bits as per arch/arm64/Kconfig */
> +	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
> +		va_bits = 36;
> +	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
> +		va_bits = 39;
> +	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
> +		va_bits = 42;
> +	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
> +		va_bits = 47;
> +	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
> +		va_bits = 48;
> +	} else {
> +		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
> +		return FALSE;
> +	}
> +
> +	DEBUG_MSG("va_bits      : %d\n", va_bits);

Please add "(_stext)" to the end of line for debugging.

> +
> +	return TRUE;
> +}
> +
> +static void
> +get_page_offset_arm64(void)
> +{
> +	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
> +
> +	DEBUG_MSG("page_offset  : %lx\n", info->page_offset);
> +}
> +
>  int
>  get_machdep_info_arm64(void)
>  {
> @@ -493,8 +534,37 @@ get_machdep_info_arm64(void)
>  	/* Check if va_bits is still not initialized. If still 0, call
>  	 * get_versiondep_info() to initialize the same.
>  	 */
> +	if (NUMBER(VA_BITS) != NOT_FOUND_NUMBER) {
> +		va_bits = NUMBER(VA_BITS);
> +		DEBUG_MSG("va_bits    : %d (vmcoreinfo)\n",
> +				va_bits);
> +	}
> +
> +	/* Check if va_bits is still not initialized. If still 0, call
> +	 * get_versiondep_info() to initialize the same from _stext
> +	 * symbol.
> +	 */
>  	if (!va_bits)
> -		get_versiondep_info_arm64();
> +		if (get_va_bits_from_stext_arm64() == ERROR)
> +			return ERROR;

These ERRORs should be FALSE.

> +
> +	get_page_offset_arm64();
> +
> +	if (NUMBER(MAX_USER_VA_BITS) != NOT_FOUND_NUMBER) {
> +		max_user_va_bits = NUMBER(MAX_USER_VA_BITS);
> +		DEBUG_MSG("max_user_va_bits : %d (vmcoreinfo)\n",
> +				max_user_va_bits);
> +	}
> +
> +	/* Check if max_user_va_bits is still not initialized.
> +	 * If still 0, its not available in vmcoreinfo and its
> +	 * safe to initialize it with va_bits.
> +	 */
> +	if (!max_user_va_bits) {
> +		max_user_va_bits = va_bits;
> +		DEBUG_MSG("max_user_va_bits : %d (default = va_bits)\n",
> +				max_user_va_bits);
> +	}
> 
>  	if (!calculate_plat_config()) {
>  		ERRMSG("Can't determine platform config values\n");
> @@ -533,34 +603,11 @@ get_xen_info_arm64(void)
>  int
>  get_versiondep_info_arm64(void)
>  {
> -	ulong _stext;
> -
> -	_stext = get_stext_symbol();
> -	if (!_stext) {
> -		ERRMSG("Can't get the symbol of _stext.\n");
> -		return FALSE;
> -	}
> -
> -	/* Derive va_bits as per arch/arm64/Kconfig */
> -	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
> -		va_bits = 36;
> -	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
> -		va_bits = 39;
> -	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
> -		va_bits = 42;
> -	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
> -		va_bits = 47;
> -	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
> -		va_bits = 48;
> -	} else {
> -		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
> -		return FALSE;
> -	}
> -
> -	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
> +	if (!va_bits)
> +		if (get_va_bits_from_stext_arm64() == ERROR)
> +			return ERROR;

Same as above.

And, it would be helpful if you would rebase this after fixing the
52-bit PA patch.

Thanks,
Kazu

> 
> -	DEBUG_MSG("va_bits      : %d\n", va_bits);
> -	DEBUG_MSG("page_offset  : %lx\n", info->page_offset);
> +	get_page_offset_arm64();
> 
>  	return TRUE;
>  }
> diff --git a/makedumpfile.c b/makedumpfile.c
> index b7c1c01251bf..ccf7eb4408ba 100644
> --- a/makedumpfile.c
> +++ b/makedumpfile.c
> @@ -2291,6 +2291,7 @@ write_vmcoreinfo_data(void)
> 
>  	WRITE_NUMBER("HUGETLB_PAGE_DTOR", HUGETLB_PAGE_DTOR);
>  #ifdef __aarch64__
> +	WRITE_NUMBER("MAX_USER_VA_BITS", MAX_USER_VA_BITS);
>  	WRITE_NUMBER("VA_BITS", VA_BITS);
>  	WRITE_NUMBER_UNSIGNED("PHYS_OFFSET", PHYS_OFFSET);
>  	WRITE_NUMBER_UNSIGNED("kimage_voffset", kimage_voffset);
> @@ -2694,6 +2695,7 @@ read_vmcoreinfo(void)
>  	READ_NUMBER("PAGE_BUDDY_MAPCOUNT_VALUE", PAGE_BUDDY_MAPCOUNT_VALUE);
>  	READ_NUMBER("phys_base", phys_base);
>  #ifdef __aarch64__
> +	READ_NUMBER("MAX_USER_VA_BITS", MAX_USER_VA_BITS);
>  	READ_NUMBER("VA_BITS", VA_BITS);
>  	READ_NUMBER_UNSIGNED("PHYS_OFFSET", PHYS_OFFSET);
>  	READ_NUMBER_UNSIGNED("kimage_voffset", kimage_voffset);
> diff --git a/makedumpfile.h b/makedumpfile.h
> index d49f1f1fc1a9..3fa810e0bb40 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -1933,6 +1933,7 @@ struct number_table {
>  	long    HUGETLB_PAGE_DTOR;
>  	long	phys_base;
>  #ifdef __aarch64__
> +	long 	MAX_USER_VA_BITS;
>  	long 	VA_BITS;
>  	unsigned long	PHYS_OFFSET;
>  	unsigned long	kimage_voffset;
> --
> 2.7.4
> 



_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH] makedumpfile/arm64: Add support for ARMv8.2-LVA (52-bit user-space VA support)

[Bhupesh Sharma]

Hi Kazu,

On 02/12/2019 03:33 AM, Kazuhito Hagio wrote:
> Hi Bhupesh,
> 
> On 2/7/2019 2:52 PM, Bhupesh Sharma wrote:
>> With ARMv8.2-LVA architecture extension availability, arm64 hardware
>> which supports this extension can support upto 52-bit virtual
>> addresses. It is specially useful for having a 52-bit user-space virtual
>> address space while the kernel can still retain 48-bit virtual
>> addresses.
>>
>> Since at the moment we enable the support of this extensions in the
>> kernel via a CONFIG flags (CONFIG_ARM64_USER_VA_BITS_52), so there are
>> no clear mechanisms in user-space to determine this CONFIG
>> flag value and use it to determine the PA address range values.
>>
>> 'makedumpfile' can instead use 'MAX_USER_VA_BITS' value to
>> determine the maximum virtual physical address supported by user-space.
>> If 'MAX_USER_VA_BITS' value is greater than 'VA_BITS' than we might be
>> running a use-case where user-space is 52-bit and underlying kernel is
>> still 48-bit. The increased 'PTRS_PER_PGD' value for such cases can then
>> be calculated as is done by the underlying kernel (see kernel file
>> 'arch/arm64/include/asm/pgtable-hwdef.h' for details):
> 
> Thank you for the patch.
> I can't test the config yet, but this looks necessary.

I am sorry, this review email somehow did not show up in my inbox.

>>
>> I have sent a kernel patch upstream to add 'MAX_USER_VA_BITS' to
>> vmcoreinfo for arm64 (see [0]).
>>
>> This patch is in accordance with ARMv8 Architecture Reference Manual
>> version D.a
>>
>> [0].
>> http://lists.infradead.org/pipermail/kexec/2019-February/022411.html
>>
>> Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
>> ---
>>   arch/arm64.c   | 105 +++++++++++++++++++++++++++++++++++++++++----------------
>>   makedumpfile.c |   2 ++
>>   makedumpfile.h |   1 +
>>   3 files changed, 79 insertions(+), 29 deletions(-)
>>
>> diff --git a/arch/arm64.c b/arch/arm64.c
>> index a1db7dc63107..b522e93f4e80 100644
>> --- a/arch/arm64.c
>> +++ b/arch/arm64.c
>> @@ -47,6 +47,7 @@ typedef struct {
>>   static int lpa_52_bit_support_available;
>>   static int pgtable_level;
>>   static int va_bits;
>> +static int max_user_va_bits;
>>   static unsigned long kimage_voffset;
>>
>>   #define SZ_4K			4096
>> @@ -145,7 +146,7 @@ get_page_table_level_arm64(void)
>>   #define PGDIR_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - (get_page_table_level_arm64()))
>>   #define PGDIR_SIZE		(_AC(1, UL) << PGDIR_SHIFT)
>>   #define PGDIR_MASK		(~(PGDIR_SIZE-1))
>> -#define PTRS_PER_PGD		(1 << ((va_bits) - PGDIR_SHIFT))
>> +#define PTRS_PER_PGD		(1 << ((max_user_va_bits) - PGDIR_SHIFT))
>>
>>   /*
>>    * Section address mask and size definitions.
>> @@ -478,6 +479,46 @@ get_stext_symbol(void)
>>   	return(found ? kallsym : FALSE);
>>   }
>>
>> +static int
>> +get_va_bits_from_stext_arm64(void)
>> +{
>> +	ulong _stext;
>> +
>> +	_stext = get_stext_symbol();
>> +	if (!_stext) {
>> +		ERRMSG("Can't get the symbol of _stext.\n");
>> +		return FALSE;
>> +	}
>> +
>> +	/* Derive va_bits as per arch/arm64/Kconfig */
>> +	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
>> +		va_bits = 36;
>> +	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
>> +		va_bits = 39;
>> +	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
>> +		va_bits = 42;
>> +	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
>> +		va_bits = 47;
>> +	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
>> +		va_bits = 48;
>> +	} else {
>> +		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
>> +		return FALSE;
>> +	}
>> +
>> +	DEBUG_MSG("va_bits      : %d\n", va_bits);
> 
> Please add "(_stext)" to the end of line for debugging.

Ok, will address in v3.

>> +
>> +	return TRUE;
>> +}
>> +
>> +static void
>> +get_page_offset_arm64(void)
>> +{
>> +	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
>> +
>> +	DEBUG_MSG("page_offset  : %lx\n", info->page_offset);
>> +}
>> +
>>   int
>>   get_machdep_info_arm64(void)
>>   {
>> @@ -493,8 +534,37 @@ get_machdep_info_arm64(void)
>>   	/* Check if va_bits is still not initialized. If still 0, call
>>   	 * get_versiondep_info() to initialize the same.
>>   	 */
>> +	if (NUMBER(VA_BITS) != NOT_FOUND_NUMBER) {
>> +		va_bits = NUMBER(VA_BITS);
>> +		DEBUG_MSG("va_bits    : %d (vmcoreinfo)\n",
>> +				va_bits);
>> +	}
>> +
>> +	/* Check if va_bits is still not initialized. If still 0, call
>> +	 * get_versiondep_info() to initialize the same from _stext
>> +	 * symbol.
>> +	 */
>>   	if (!va_bits)
>> -		get_versiondep_info_arm64();
>> +		if (get_va_bits_from_stext_arm64() == ERROR)
>> +			return ERROR;
> 
> These ERRORs should be FALSE.

Ok, will address in v3.

>> +
>> +	get_page_offset_arm64();
>> +
>> +	if (NUMBER(MAX_USER_VA_BITS) != NOT_FOUND_NUMBER) {
>> +		max_user_va_bits = NUMBER(MAX_USER_VA_BITS);
>> +		DEBUG_MSG("max_user_va_bits : %d (vmcoreinfo)\n",
>> +				max_user_va_bits);
>> +	}
>> +
>> +	/* Check if max_user_va_bits is still not initialized.
>> +	 * If still 0, its not available in vmcoreinfo and its
>> +	 * safe to initialize it with va_bits.
>> +	 */
>> +	if (!max_user_va_bits) {
>> +		max_user_va_bits = va_bits;
>> +		DEBUG_MSG("max_user_va_bits : %d (default = va_bits)\n",
>> +				max_user_va_bits);
>> +	}
>>
>>   	if (!calculate_plat_config()) {
>>   		ERRMSG("Can't determine platform config values\n");
>> @@ -533,34 +603,11 @@ get_xen_info_arm64(void)
>>   int
>>   get_versiondep_info_arm64(void)
>>   {
>> -	ulong _stext;
>> -
>> -	_stext = get_stext_symbol();
>> -	if (!_stext) {
>> -		ERRMSG("Can't get the symbol of _stext.\n");
>> -		return FALSE;
>> -	}
>> -
>> -	/* Derive va_bits as per arch/arm64/Kconfig */
>> -	if ((_stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
>> -		va_bits = 36;
>> -	} else if ((_stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
>> -		va_bits = 39;
>> -	} else if ((_stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
>> -		va_bits = 42;
>> -	} else if ((_stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
>> -		va_bits = 47;
>> -	} else if ((_stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
>> -		va_bits = 48;
>> -	} else {
>> -		ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
>> -		return FALSE;
>> -	}
>> -
>> -	info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
>> +	if (!va_bits)
>> +		if (get_va_bits_from_stext_arm64() == ERROR)
>> +			return ERROR;
> 
> Same as above.

Ok, will address in v3.

Thanks,
Bhupesh

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec