[PATCH 0/4] Cleanup vmlinux.lds.S

[PATCH 0/4] Cleanup vmlinux.lds.S

[Wei Yang]

To support 32/64 bits system, we have some definition conditionally. while
some definition is duplicated:

* __PHYSICAL_START has the same definition as LOAD_PHYSICAL_ADDR
* LOAD_OFFSET could be defined directly to __START_KERNEL_map 

After these cleanup, we could reduce some complexity of vmlinux.lds.S.

Wei Yang (4):
  vmlinux.lds.h: fix a typo in comment
  x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR
  x86/vmlinux.lds.S: remove conditional definition of LOAD_OFFSET
  x86/vmlinux.lds.S: take __START_KERNEL out conditional definition

 arch/x86/include/asm/boot.h       | 5 -----
 arch/x86/include/asm/page_types.h | 8 +++++---
 arch/x86/kernel/vmlinux.lds.S     | 7 +------
 include/asm-generic/vmlinux.lds.h | 2 +-
 4 files changed, 7 insertions(+), 15 deletions(-)

-- 
2.34.1

[PATCH 1/4] vmlinux.lds.h: fix a typo in comment

[Wei Yang]

One extra 'i' is used.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 include/asm-generic/vmlinux.lds.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 5dd3a61d673d..514d3002ad8a 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -3,7 +3,7 @@
  * linker scripts.
  *
  * A minimal linker scripts has following content:
- * [This is a sample, architectures may have special requiriements]
+ * [This is a sample, architectures may have special requirements]
  *
  * OUTPUT_FORMAT(...)
  * OUTPUT_ARCH(...)
-- 
2.34.1

[PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
which is only used to define __START_KERNEL.

Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
<asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
<asm/page_types.h>.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 arch/x86/include/asm/boot.h       | 5 -----
 arch/x86/include/asm/page_types.h | 8 +++++---
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
index a38cc0afc90a..12cbc57d0128 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -6,11 +6,6 @@
 #include <asm/pgtable_types.h>
 #include <uapi/asm/boot.h>
 
-/* Physical address where kernel should be loaded. */
-#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
-				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
-				& ~(CONFIG_PHYSICAL_ALIGN - 1))
-
 /* Minimum kernel alignment, as a power of two */
 #ifdef CONFIG_X86_64
 # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index 86bd4311daf8..acc1620fd121 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -31,10 +31,12 @@
 
 #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
-#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
-				      CONFIG_PHYSICAL_ALIGN)
+/* Physical address where kernel should be loaded. */
+#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
+				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
+				& ~(CONFIG_PHYSICAL_ALIGN - 1))
 
-#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
+#define __START_KERNEL		(__START_KERNEL_map + LOAD_PHYSICAL_ADDR)
 
 #ifdef CONFIG_X86_64
 #include <asm/page_64_types.h>
-- 
2.34.1

[PATCH 3/4] x86/vmlinux.lds.S: remove conditional definition of LOAD_OFFSET

[Wei Yang]

In vmlinux.lds.S, we define LOAD_OFFSET conditionally to __PAGE_OFFSET
or __START_KERNEL_map. While __START_KERNEL_map is already defined to
the same value with the same condition.

So it is fine to define LOAD_OFFSET to __START_KERNEL_map directly.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 arch/x86/kernel/vmlinux.lds.S | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 56451fd2099e..88dcf9366949 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -15,11 +15,7 @@
  * put it inside the section definition.
  */
 
-#ifdef CONFIG_X86_32
-#define LOAD_OFFSET __PAGE_OFFSET
-#else
 #define LOAD_OFFSET __START_KERNEL_map
-#endif
 
 #define RUNTIME_DISCARD_EXIT
 #define EMITS_PT_NOTE
-- 
2.34.1

[PATCH 4/4] x86/vmlinux.lds.S: take __START_KERNEL out conditional definition

[Wei Yang]

If CONFIG_X86_32, the section start address is defined to be
"LOAD_OFFSET + LOAD_PHYSICAL_ADDR", which is the same as
__START_KERNEL_map.

Let's take it out to remove the complexity.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 arch/x86/kernel/vmlinux.lds.S | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 88dcf9366949..a20409b0a3f2 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -110,11 +110,10 @@ PHDRS {
 
 SECTIONS
 {
+	. = __START_KERNEL;
 #ifdef CONFIG_X86_32
-	. = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
 	phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET);
 #else
-	. = __START_KERNEL;
 	phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET);
 #endif
 
-- 
2.34.1

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Ingo Molnar]

* Wei Yang <richard.weiyang@gmail.com> wrote:

> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
> which is only used to define __START_KERNEL.
> 
> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
> <asm/page_types.h>.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> ---
>  arch/x86/include/asm/boot.h       | 5 -----
>  arch/x86/include/asm/page_types.h | 8 +++++---
>  2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
> index a38cc0afc90a..12cbc57d0128 100644
> --- a/arch/x86/include/asm/boot.h
> +++ b/arch/x86/include/asm/boot.h
> @@ -6,11 +6,6 @@
>  #include <asm/pgtable_types.h>
>  #include <uapi/asm/boot.h>
>  
> -/* Physical address where kernel should be loaded. */
> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
> -
>  /* Minimum kernel alignment, as a power of two */
>  #ifdef CONFIG_X86_64
>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
> index 86bd4311daf8..acc1620fd121 100644
> --- a/arch/x86/include/asm/page_types.h
> +++ b/arch/x86/include/asm/page_types.h
> @@ -31,10 +31,12 @@
>  
>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>  
> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
> -				      CONFIG_PHYSICAL_ALIGN)
> +/* Physical address where kernel should be loaded. */
> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))

I agree with this simplification, but the ALIGN() expression is far easier 
to read, so please keep that one instead of the open-coded version.

Thanks,

	Ingo

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Nikolay Borisov]

On 13.03.24 г. 9:58 ч., Wei Yang wrote:
> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
> which is only used to define __START_KERNEL.
> 
> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
> <asm/page_types.h>.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> ---
>   arch/x86/include/asm/boot.h       | 5 -----
>   arch/x86/include/asm/page_types.h | 8 +++++---
>   2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
> index a38cc0afc90a..12cbc57d0128 100644
> --- a/arch/x86/include/asm/boot.h
> +++ b/arch/x86/include/asm/boot.h
> @@ -6,11 +6,6 @@
>   #include <asm/pgtable_types.h>
>   #include <uapi/asm/boot.h>
>   
> -/* Physical address where kernel should be loaded. */
> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
> -
>   /* Minimum kernel alignment, as a power of two */
>   #ifdef CONFIG_X86_64
>   # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
> index 86bd4311daf8..acc1620fd121 100644
> --- a/arch/x86/include/asm/page_types.h
> +++ b/arch/x86/include/asm/page_types.h
> @@ -31,10 +31,12 @@
>   
>   #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>   
> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
> -				      CONFIG_PHYSICAL_ALIGN)
> +/* Physical address where kernel should be loaded. */
> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))

Why don't you simply define LOAD_PHYSICAL_ADDR via 
ALIGN(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALING) it's way more readable.

>   
> -#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
> +#define __START_KERNEL		(__START_KERNEL_map + LOAD_PHYSICAL_ADDR)
>   
>   #ifdef CONFIG_X86_64
>   #include <asm/page_64_types.h>

[tip: x86/build] x86/vmlinux.lds.S: Take __START_KERNEL out conditional definition

[tip-bot2 for Wei Yang]

The following commit has been merged into the x86/build branch of tip:

Commit-ID:     9b67ce2c121fbf11c0c7b6216c08200fda23c9af
Gitweb:        https://git.kernel.org/tip/9b67ce2c121fbf11c0c7b6216c08200fda23c9af
Author:        Wei Yang <richard.weiyang@gmail.com>
AuthorDate:    Wed, 13 Mar 2024 07:58:39 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 13 Mar 2024 11:29:11 +01:00

x86/vmlinux.lds.S: Take __START_KERNEL out conditional definition

If CONFIG_X86_32=y, the section start address is defined to be
"LOAD_OFFSET + LOAD_PHYSICAL_ADDR", which is the same as
__START_KERNEL_map.

Unify it with the 64-bit definition to simplify the code.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240313075839.8321-5-richard.weiyang@gmail.com
---
 arch/x86/kernel/vmlinux.lds.S | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 88dcf93..a20409b 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -110,11 +110,10 @@ PHDRS {
 
 SECTIONS
 {
+	. = __START_KERNEL;
 #ifdef CONFIG_X86_32
-	. = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
 	phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET);
 #else
-	. = __START_KERNEL;
 	phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET);
 #endif
 

[tip: x86/build] x86/vmlinux.lds.S: Remove conditional definition of LOAD_OFFSET

[tip-bot2 for Wei Yang]

The following commit has been merged into the x86/build branch of tip:

Commit-ID:     a5cffd056ef52280c07a7f6a3b3faacf6b318e8e
Gitweb:        https://git.kernel.org/tip/a5cffd056ef52280c07a7f6a3b3faacf6b318e8e
Author:        Wei Yang <richard.weiyang@gmail.com>
AuthorDate:    Wed, 13 Mar 2024 07:58:38 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 13 Mar 2024 11:29:10 +01:00

x86/vmlinux.lds.S: Remove conditional definition of LOAD_OFFSET

In vmlinux.lds.S, we define LOAD_OFFSET conditionally to __PAGE_OFFSET
or __START_KERNEL_map. While __START_KERNEL_map is already defined to
the same value with the same condition.

So it is fine to define LOAD_OFFSET to __START_KERNEL_map directly.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240313075839.8321-4-richard.weiyang@gmail.com
---
 arch/x86/kernel/vmlinux.lds.S | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 56451fd..88dcf93 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -15,11 +15,7 @@
  * put it inside the section definition.
  */
 
-#ifdef CONFIG_X86_32
-#define LOAD_OFFSET __PAGE_OFFSET
-#else
 #define LOAD_OFFSET __START_KERNEL_map
-#endif
 
 #define RUNTIME_DISCARD_EXIT
 #define EMITS_PT_NOTE

[tip: x86/build] vmlinux.lds.h: Fix a typo in comment

[tip-bot2 for Wei Yang]

The following commit has been merged into the x86/build branch of tip:

Commit-ID:     1793f69326266269a8117d3f5324ac78db18931c
Gitweb:        https://git.kernel.org/tip/1793f69326266269a8117d3f5324ac78db18931c
Author:        Wei Yang <richard.weiyang@gmail.com>
AuthorDate:    Wed, 13 Mar 2024 07:58:36 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 13 Mar 2024 11:29:10 +01:00

vmlinux.lds.h: Fix a typo in comment

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240313075839.8321-2-richard.weiyang@gmail.com
---
 include/asm-generic/vmlinux.lds.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 5dd3a61..514d300 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -3,7 +3,7 @@
  * linker scripts.
  *
  * A minimal linker scripts has following content:
- * [This is a sample, architectures may have special requiriements]
+ * [This is a sample, architectures may have special requirements]
  *
  * OUTPUT_FORMAT(...)
  * OUTPUT_ARCH(...)

Re: [tip: x86/build] x86/vmlinux.lds.S: Remove conditional definition of LOAD_OFFSET

[Borislav Petkov]

On Wed, Mar 13, 2024 at 10:39:58AM -0000, tip-bot2 for Wei Yang wrote:
> -#ifdef CONFIG_X86_32
> -#define LOAD_OFFSET __PAGE_OFFSET
> -#else
>  #define LOAD_OFFSET __START_KERNEL_map
> -#endif

And, as a next step, you can get rid of LOAD_OFFSET completely and use
__START_KERNEL_map everywhere.

Even less ifdeffery.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

On Wed, Mar 13, 2024 at 11:29:33AM +0100, Ingo Molnar wrote:
>
>* Wei Yang <richard.weiyang@gmail.com> wrote:
>
>> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
>> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
>> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
>> which is only used to define __START_KERNEL.
>> 
>> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
>> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
>> <asm/page_types.h>.
>> 
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> ---
>>  arch/x86/include/asm/boot.h       | 5 -----
>>  arch/x86/include/asm/page_types.h | 8 +++++---
>>  2 files changed, 5 insertions(+), 8 deletions(-)
>> 
>> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
>> index a38cc0afc90a..12cbc57d0128 100644
>> --- a/arch/x86/include/asm/boot.h
>> +++ b/arch/x86/include/asm/boot.h
>> @@ -6,11 +6,6 @@
>>  #include <asm/pgtable_types.h>
>>  #include <uapi/asm/boot.h>
>>  
>> -/* Physical address where kernel should be loaded. */
>> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>> -
>>  /* Minimum kernel alignment, as a power of two */
>>  #ifdef CONFIG_X86_64
>>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> index 86bd4311daf8..acc1620fd121 100644
>> --- a/arch/x86/include/asm/page_types.h
>> +++ b/arch/x86/include/asm/page_types.h
>> @@ -31,10 +31,12 @@
>>  
>>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>>  
>> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
>> -				      CONFIG_PHYSICAL_ALIGN)
>> +/* Physical address where kernel should be loaded. */
>> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>
>I agree with this simplification, but the ALIGN() expression is far easier 
>to read, so please keep that one instead of the open-coded version.

Sure, will send v2.

>
>Thanks,
>
>	Ingo

-- 
Wei Yang
Help you, Help me

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

On Wed, Mar 13, 2024 at 12:29:37PM +0200, Nikolay Borisov wrote:
>
>
>On 13.03.24 г. 9:58 ч., Wei Yang wrote:
>> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
>> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
>> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
>> which is only used to define __START_KERNEL.
>> 
>> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
>> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
>> <asm/page_types.h>.
>> 
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> ---
>>   arch/x86/include/asm/boot.h       | 5 -----
>>   arch/x86/include/asm/page_types.h | 8 +++++---
>>   2 files changed, 5 insertions(+), 8 deletions(-)
>> 
>> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
>> index a38cc0afc90a..12cbc57d0128 100644
>> --- a/arch/x86/include/asm/boot.h
>> +++ b/arch/x86/include/asm/boot.h
>> @@ -6,11 +6,6 @@
>>   #include <asm/pgtable_types.h>
>>   #include <uapi/asm/boot.h>
>> -/* Physical address where kernel should be loaded. */
>> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>> -
>>   /* Minimum kernel alignment, as a power of two */
>>   #ifdef CONFIG_X86_64
>>   # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> index 86bd4311daf8..acc1620fd121 100644
>> --- a/arch/x86/include/asm/page_types.h
>> +++ b/arch/x86/include/asm/page_types.h
>> @@ -31,10 +31,12 @@
>>   #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
>> -				      CONFIG_PHYSICAL_ALIGN)
>> +/* Physical address where kernel should be loaded. */
>> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>
>Why don't you simply define LOAD_PHYSICAL_ADDR via
>ALIGN(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALING) it's way more readable.
>

Sure, will do it.

>> -#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
>> +#define __START_KERNEL		(__START_KERNEL_map + LOAD_PHYSICAL_ADDR)
>>   #ifdef CONFIG_X86_64
>>   #include <asm/page_64_types.h>

-- 
Wei Yang
Help you, Help me

Re: [tip: x86/build] x86/vmlinux.lds.S: Remove conditional definition of LOAD_OFFSET

[Wei Yang]

On Wed, Mar 13, 2024 at 02:18:33PM +0100, Borislav Petkov wrote:
>On Wed, Mar 13, 2024 at 10:39:58AM -0000, tip-bot2 for Wei Yang wrote:
>> -#ifdef CONFIG_X86_32
>> -#define LOAD_OFFSET __PAGE_OFFSET
>> -#else
>>  #define LOAD_OFFSET __START_KERNEL_map
>> -#endif
>
>And, as a next step, you can get rid of LOAD_OFFSET completely and use
>__START_KERNEL_map everywhere.
>
>Even less ifdeffery.

You mean remove the definition of LOAD_OFFSET?

I have tried this, but I found this is used in vmlinux.lds.h. So I don't
figure out a way to get rid of it.

>
>-- 
>Regards/Gruss,
>    Boris.
>
>https://people.kernel.org/tglx/notes-about-netiquette

-- 
Wei Yang
Help you, Help me

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

On Wed, Mar 13, 2024 at 11:29:33AM +0100, Ingo Molnar wrote:
>
>* Wei Yang <richard.weiyang@gmail.com> wrote:
>
>> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
>> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
>> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
>> which is only used to define __START_KERNEL.
>> 
>> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
>> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
>> <asm/page_types.h>.
>> 
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> ---
>>  arch/x86/include/asm/boot.h       | 5 -----
>>  arch/x86/include/asm/page_types.h | 8 +++++---
>>  2 files changed, 5 insertions(+), 8 deletions(-)
>> 
>> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
>> index a38cc0afc90a..12cbc57d0128 100644
>> --- a/arch/x86/include/asm/boot.h
>> +++ b/arch/x86/include/asm/boot.h
>> @@ -6,11 +6,6 @@
>>  #include <asm/pgtable_types.h>
>>  #include <uapi/asm/boot.h>
>>  
>> -/* Physical address where kernel should be loaded. */
>> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>> -
>>  /* Minimum kernel alignment, as a power of two */
>>  #ifdef CONFIG_X86_64
>>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> index 86bd4311daf8..acc1620fd121 100644
>> --- a/arch/x86/include/asm/page_types.h
>> +++ b/arch/x86/include/asm/page_types.h
>> @@ -31,10 +31,12 @@
>>  
>>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>>  
>> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
>> -				      CONFIG_PHYSICAL_ALIGN)
>> +/* Physical address where kernel should be loaded. */
>> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>
>I agree with this simplification, but the ALIGN() expression is far easier 
>to read, so please keep that one instead of the open-coded version.
>

I just tried to define LOAD_PHYSICAL_ADDR by ALIGN, but face a compile error
on compressed/head_[32|64].o.

$ make arch/x86/boot/compressed/head_64.o
  CALL    scripts/checksyscalls.sh
  DESCEND objtool
  INSTALL libsubcmd_headers
  AS      arch/x86/boot/compressed/head_64.o
arch/x86/boot/compressed/head_64.S: Assembler messages:
arch/x86/boot/compressed/head_64.S:154: Error: junk (0x1000000,0x200000)' after expression
arch/x86/boot/compressed/head_64.S:154: Error: number of operands mismatch for 16' after expression
arch/x86/boot/compressed/head_64.S:157: Error: junk mov'
arch/x86/boot/compressed/head_64.S:330: Error: junk (0x1000000,0x200000)' after expression
arch/x86/boot/compressed/head_64.S:330: Error: number of operands mismatch for 16' after expression
arch/x86/boot/compressed/head_64.S:333: Error: junk movq'

If my understanding is correct, the reason is linkage.h defines ALIGN, which
is ".balign xxx". Maybe this is why original LOAD_PHYSICAL_ADDR doesn't use
ALIGN.

So is this ok to keep the open-coded definition?

>Thanks,
>
>	Ingo

-- 
Wei Yang
Help you, Help me

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Ingo Molnar]

* Wei Yang <richard.weiyang@gmail.com> wrote:

> On Wed, Mar 13, 2024 at 11:29:33AM +0100, Ingo Molnar wrote:
> >
> >* Wei Yang <richard.weiyang@gmail.com> wrote:
> >
> >> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
> >> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
> >> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
> >> which is only used to define __START_KERNEL.
> >> 
> >> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
> >> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
> >> <asm/page_types.h>.
> >> 
> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> >> ---
> >>  arch/x86/include/asm/boot.h       | 5 -----
> >>  arch/x86/include/asm/page_types.h | 8 +++++---
> >>  2 files changed, 5 insertions(+), 8 deletions(-)
> >> 
> >> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
> >> index a38cc0afc90a..12cbc57d0128 100644
> >> --- a/arch/x86/include/asm/boot.h
> >> +++ b/arch/x86/include/asm/boot.h
> >> @@ -6,11 +6,6 @@
> >>  #include <asm/pgtable_types.h>
> >>  #include <uapi/asm/boot.h>
> >>  
> >> -/* Physical address where kernel should be loaded. */
> >> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> >> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> >> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
> >> -
> >>  /* Minimum kernel alignment, as a power of two */
> >>  #ifdef CONFIG_X86_64
> >>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
> >> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
> >> index 86bd4311daf8..acc1620fd121 100644
> >> --- a/arch/x86/include/asm/page_types.h
> >> +++ b/arch/x86/include/asm/page_types.h
> >> @@ -31,10 +31,12 @@
> >>  
> >>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
> >>  
> >> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
> >> -				      CONFIG_PHYSICAL_ALIGN)
> >> +/* Physical address where kernel should be loaded. */
> >> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
> >> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
> >> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
> >
> >I agree with this simplification, but the ALIGN() expression is far easier 
> >to read, so please keep that one instead of the open-coded version.
> >
> 
> I just tried to define LOAD_PHYSICAL_ADDR by ALIGN, but face a compile error
> on compressed/head_[32|64].o.
> 
> $ make arch/x86/boot/compressed/head_64.o
>   CALL    scripts/checksyscalls.sh
>   DESCEND objtool
>   INSTALL libsubcmd_headers
>   AS      arch/x86/boot/compressed/head_64.o
> arch/x86/boot/compressed/head_64.S: Assembler messages:
> arch/x86/boot/compressed/head_64.S:154: Error: junk (0x1000000,0x200000)' after expression
> arch/x86/boot/compressed/head_64.S:154: Error: number of operands mismatch for 16' after expression
> arch/x86/boot/compressed/head_64.S:157: Error: junk mov'
> arch/x86/boot/compressed/head_64.S:330: Error: junk (0x1000000,0x200000)' after expression
> arch/x86/boot/compressed/head_64.S:330: Error: number of operands mismatch for 16' after expression
> arch/x86/boot/compressed/head_64.S:333: Error: junk movq'
> 
> If my understanding is correct, the reason is linkage.h defines ALIGN, which
> is ".balign xxx". Maybe this is why original LOAD_PHYSICAL_ADDR doesn't use
> ALIGN.

linkage.h defines __ALIGN, which is different from ALIGN().

Also, a number of .S files seem to be using some sort of ALIGN() method 
within arch/x86/, according to:

   git grep 'ALIGN(' -- 'arch/x86/*.S'

> So is this ok to keep the open-coded definition?

It would be nice to figure out why ALIGN() appears to be working in other 
cases in .S files, while not in this case.

Thanks,

	Ingo

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

On Thu, Mar 14, 2024 at 10:25:53AM +0100, Ingo Molnar wrote:
>
>* Wei Yang <richard.weiyang@gmail.com> wrote:
>
>> On Wed, Mar 13, 2024 at 11:29:33AM +0100, Ingo Molnar wrote:
>> >
>> >* Wei Yang <richard.weiyang@gmail.com> wrote:
>> >
>> >> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
>> >> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
>> >> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
>> >> which is only used to define __START_KERNEL.
>> >> 
>> >> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
>> >> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
>> >> <asm/page_types.h>.
>> >> 
>> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> >> ---
>> >>  arch/x86/include/asm/boot.h       | 5 -----
>> >>  arch/x86/include/asm/page_types.h | 8 +++++---
>> >>  2 files changed, 5 insertions(+), 8 deletions(-)
>> >> 
>> >> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
>> >> index a38cc0afc90a..12cbc57d0128 100644
>> >> --- a/arch/x86/include/asm/boot.h
>> >> +++ b/arch/x86/include/asm/boot.h
>> >> @@ -6,11 +6,6 @@
>> >>  #include <asm/pgtable_types.h>
>> >>  #include <uapi/asm/boot.h>
>> >>  
>> >> -/* Physical address where kernel should be loaded. */
>> >> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> >> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> >> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>> >> -
>> >>  /* Minimum kernel alignment, as a power of two */
>> >>  #ifdef CONFIG_X86_64
>> >>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
>> >> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> >> index 86bd4311daf8..acc1620fd121 100644
>> >> --- a/arch/x86/include/asm/page_types.h
>> >> +++ b/arch/x86/include/asm/page_types.h
>> >> @@ -31,10 +31,12 @@
>> >>  
>> >>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>> >>  
>> >> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
>> >> -				      CONFIG_PHYSICAL_ALIGN)
>> >> +/* Physical address where kernel should be loaded. */
>> >> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>> >> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>> >> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>> >
>> >I agree with this simplification, but the ALIGN() expression is far easier 
>> >to read, so please keep that one instead of the open-coded version.
>> >
>> 
>> I just tried to define LOAD_PHYSICAL_ADDR by ALIGN, but face a compile error
>> on compressed/head_[32|64].o.
>> 
>> $ make arch/x86/boot/compressed/head_64.o
>>   CALL    scripts/checksyscalls.sh
>>   DESCEND objtool
>>   INSTALL libsubcmd_headers
>>   AS      arch/x86/boot/compressed/head_64.o
>> arch/x86/boot/compressed/head_64.S: Assembler messages:
>> arch/x86/boot/compressed/head_64.S:154: Error: junk (0x1000000,0x200000)' after expression
>> arch/x86/boot/compressed/head_64.S:154: Error: number of operands mismatch for 16' after expression
>> arch/x86/boot/compressed/head_64.S:157: Error: junk mov'
>> arch/x86/boot/compressed/head_64.S:330: Error: junk (0x1000000,0x200000)' after expression
>> arch/x86/boot/compressed/head_64.S:330: Error: number of operands mismatch for 16' after expression
>> arch/x86/boot/compressed/head_64.S:333: Error: junk movq'
>> 
>> If my understanding is correct, the reason is linkage.h defines ALIGN, which
>> is ".balign xxx". Maybe this is why original LOAD_PHYSICAL_ADDR doesn't use
>> ALIGN.
>
>linkage.h defines __ALIGN, which is different from ALIGN().
>

linkage.h defines ALIGN to __ALIGN which is different from what we expect.

>Also, a number of .S files seem to be using some sort of ALIGN() method 
>within arch/x86/, according to:
>
>   git grep 'ALIGN(' -- 'arch/x86/*.S'

I tried below command by append '\<' to ALIGN 

    git grep '\<ALIGN(' -- 'arch/x86/*.S'

>
>> So is this ok to keep the open-coded definition?
>
>It would be nice to figure out why ALIGN() appears to be working in other 
>cases in .S files, while not in this case.
>

Here is grep result

arch/x86/boot/compressed/vmlinux.lds.S:	.data :	ALIGN(0x1000) {
arch/x86/boot/compressed/vmlinux.lds.S:		. = ALIGN(. + 4, 0x200);
arch/x86/boot/compressed/vmlinux.lds.S:	. = ALIGN(L1_CACHE_BYTES);
arch/x86/boot/compressed/vmlinux.lds.S:		. = ALIGN(8);	/* For convenience during zeroing */
arch/x86/boot/compressed/vmlinux.lds.S:       . = ALIGN(PAGE_SIZE);
arch/x86/boot/compressed/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);	/* keep ZO size page aligned */
arch/x86/kernel/vmlinux.lds.S:#define X86_ALIGN_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(HPAGE_SIZE);				\
arch/x86/kernel/vmlinux.lds.S:#define ALIGN_ENTRY_TEXT_BEGIN	. = ALIGN(PMD_SIZE);
arch/x86/kernel/vmlinux.lds.S:#define ALIGN_ENTRY_TEXT_END	. = ALIGN(PMD_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PMD_SIZE);					\
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);					\
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PMD_SIZE);					\
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);				\
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);		/* keep VO_INIT_SIZE page aligned */
arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(HPAGE_SIZE);
arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(HPAGE_SIZE);
arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(4);
arch/x86/realmode/rm/realmode.lds.S:		. = ALIGN(16);
arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(PAGE_SIZE);
arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(128);
arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(4);
arch/x86/um/vdso/vdso-layout.lds.S:	. = ALIGN(0x100);

It looks all happens in link script, not assembly source code.

And other grep result with "ALIGN" are:

    SYM_CODE_START_NOALIGN
    SYM_CODE_START_LOCAL_NOALIGN
    SYM_FUNC_START_NOALIGN
    SYM_FUNC_START_LOCAL_NOALIGN
    SYM_INNER_LABEL_ALIGN

which are defined in linkage.h.

>Thanks,
>
>	Ingo

-- 
Wei Yang
Help you, Help me

Re: [PATCH 2/4] x86/boot: replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[Wei Yang]

On Fri, Mar 15, 2024 at 12:57:37AM +0000, Wei Yang wrote:
>On Thu, Mar 14, 2024 at 10:25:53AM +0100, Ingo Molnar wrote:
>>
>>* Wei Yang <richard.weiyang@gmail.com> wrote:
>>
>>> On Wed, Mar 13, 2024 at 11:29:33AM +0100, Ingo Molnar wrote:
>>> >
>>> >* Wei Yang <richard.weiyang@gmail.com> wrote:
>>> >
>>> >> Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
>>> >> CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
>>> >> LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
>>> >> which is only used to define __START_KERNEL.
>>> >> 
>>> >> Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
>>> >> <asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
>>> >> <asm/page_types.h>.
>>> >> 
>>> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>>> >> ---
>>> >>  arch/x86/include/asm/boot.h       | 5 -----
>>> >>  arch/x86/include/asm/page_types.h | 8 +++++---
>>> >>  2 files changed, 5 insertions(+), 8 deletions(-)
>>> >> 
>>> >> diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
>>> >> index a38cc0afc90a..12cbc57d0128 100644
>>> >> --- a/arch/x86/include/asm/boot.h
>>> >> +++ b/arch/x86/include/asm/boot.h
>>> >> @@ -6,11 +6,6 @@
>>> >>  #include <asm/pgtable_types.h>
>>> >>  #include <uapi/asm/boot.h>
>>> >>  
>>> >> -/* Physical address where kernel should be loaded. */
>>> >> -#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>>> >> -				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>>> >> -				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>>> >> -
>>> >>  /* Minimum kernel alignment, as a power of two */
>>> >>  #ifdef CONFIG_X86_64
>>> >>  # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
>>> >> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>>> >> index 86bd4311daf8..acc1620fd121 100644
>>> >> --- a/arch/x86/include/asm/page_types.h
>>> >> +++ b/arch/x86/include/asm/page_types.h
>>> >> @@ -31,10 +31,12 @@
>>> >>  
>>> >>  #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
>>> >>  
>>> >> -#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
>>> >> -				      CONFIG_PHYSICAL_ALIGN)
>>> >> +/* Physical address where kernel should be loaded. */
>>> >> +#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
>>> >> +				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
>>> >> +				& ~(CONFIG_PHYSICAL_ALIGN - 1))
>>> >
>>> >I agree with this simplification, but the ALIGN() expression is far easier 
>>> >to read, so please keep that one instead of the open-coded version.
>>> >
>>> 
>>> I just tried to define LOAD_PHYSICAL_ADDR by ALIGN, but face a compile error
>>> on compressed/head_[32|64].o.
>>> 
>>> $ make arch/x86/boot/compressed/head_64.o
>>>   CALL    scripts/checksyscalls.sh
>>>   DESCEND objtool
>>>   INSTALL libsubcmd_headers
>>>   AS      arch/x86/boot/compressed/head_64.o
>>> arch/x86/boot/compressed/head_64.S: Assembler messages:
>>> arch/x86/boot/compressed/head_64.S:154: Error: junk (0x1000000,0x200000)' after expression
>>> arch/x86/boot/compressed/head_64.S:154: Error: number of operands mismatch for 16' after expression
>>> arch/x86/boot/compressed/head_64.S:157: Error: junk mov'
>>> arch/x86/boot/compressed/head_64.S:330: Error: junk (0x1000000,0x200000)' after expression
>>> arch/x86/boot/compressed/head_64.S:330: Error: number of operands mismatch for 16' after expression
>>> arch/x86/boot/compressed/head_64.S:333: Error: junk movq'
>>> 
>>> If my understanding is correct, the reason is linkage.h defines ALIGN, which
>>> is ".balign xxx". Maybe this is why original LOAD_PHYSICAL_ADDR doesn't use
>>> ALIGN.
>>
>>linkage.h defines __ALIGN, which is different from ALIGN().
>>
>
>linkage.h defines ALIGN to __ALIGN which is different from what we expect.
>
>>Also, a number of .S files seem to be using some sort of ALIGN() method 
>>within arch/x86/, according to:
>>
>>   git grep 'ALIGN(' -- 'arch/x86/*.S'
>
>I tried below command by append '\<' to ALIGN 
>
>    git grep '\<ALIGN(' -- 'arch/x86/*.S'
>
>>
>>> So is this ok to keep the open-coded definition?
>>
>>It would be nice to figure out why ALIGN() appears to be working in other 
>>cases in .S files, while not in this case.
>>
>
>Here is grep result
>
>arch/x86/boot/compressed/vmlinux.lds.S:	.data :	ALIGN(0x1000) {
>arch/x86/boot/compressed/vmlinux.lds.S:		. = ALIGN(. + 4, 0x200);
>arch/x86/boot/compressed/vmlinux.lds.S:	. = ALIGN(L1_CACHE_BYTES);
>arch/x86/boot/compressed/vmlinux.lds.S:		. = ALIGN(8);	/* For convenience during zeroing */
>arch/x86/boot/compressed/vmlinux.lds.S:       . = ALIGN(PAGE_SIZE);
>arch/x86/boot/compressed/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);	/* keep ZO size page aligned */
>arch/x86/kernel/vmlinux.lds.S:#define X86_ALIGN_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(HPAGE_SIZE);				\
>arch/x86/kernel/vmlinux.lds.S:#define ALIGN_ENTRY_TEXT_BEGIN	. = ALIGN(PMD_SIZE);
>arch/x86/kernel/vmlinux.lds.S:#define ALIGN_ENTRY_TEXT_END	. = ALIGN(PMD_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PMD_SIZE);					\
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);					\
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PMD_SIZE);					\
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);				\
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(8);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(PAGE_SIZE);		/* keep VO_INIT_SIZE page aligned */
>arch/x86/kernel/vmlinux.lds.S:	. = ALIGN(HPAGE_SIZE);
>arch/x86/kernel/vmlinux.lds.S:		. = ALIGN(HPAGE_SIZE);
>arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(4);
>arch/x86/realmode/rm/realmode.lds.S:		. = ALIGN(16);
>arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(PAGE_SIZE);
>arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(128);
>arch/x86/realmode/rm/realmode.lds.S:	. = ALIGN(4);
>arch/x86/um/vdso/vdso-layout.lds.S:	. = ALIGN(0x100);
>
>It looks all happens in link script, not assembly source code.
>
>And other grep result with "ALIGN" are:
>
>    SYM_CODE_START_NOALIGN
>    SYM_CODE_START_LOCAL_NOALIGN
>    SYM_FUNC_START_NOALIGN
>    SYM_FUNC_START_LOCAL_NOALIGN
>    SYM_INNER_LABEL_ALIGN
>
>which are defined in linkage.h.
>

Hi, Ingo

Take another look into the usage.

In linkage.h, we have following definition:

    #ifdef __ASSEMBLY__
    
    #ifndef LINKER_SCRIPT
    #define ALIGN __ALIGN
    #endif
    
    #endif

We would include linkage.h from .S and .lds.S. We both define __ASSEMBLY__ in
command line when building these target, but we would define LINKER_SCRIPT
when building .lds from .lds.S. This introduces the different behavior of
ALIGN.

    * For .S, ALING is replaced by __ALIGN and then to .balign xxx
    * For .lds, ALIGN is is not expanded, which is a lds keyword

Also linkage.h may be included in .c, e.g. head64.c. But we don't define
__ASSEMBLY__ in command line, which leads the ALIGN undefined until kernel.h
is included.

>>Thanks,
>>
>>	Ingo
>
>-- 
>Wei Yang
>Help you, Help me

-- 
Wei Yang
Help you, Help me

[tip: x86/build] x86/boot: Replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

[tip-bot2 for Wei Yang]

The following commit has been merged into the x86/build branch of tip:

Commit-ID:     29b0aab841da3cade64c7e41e99e9f4645e65fb1
Gitweb:        https://git.kernel.org/tip/29b0aab841da3cade64c7e41e99e9f4645e65fb1
Author:        Wei Yang <richard.weiyang@gmail.com>
AuthorDate:    Wed, 13 Mar 2024 07:58:37 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 22 Mar 2024 11:36:45 +01:00

x86/boot: Replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR

Both __PHYSICAL_START and LOAD_PHYSICAL_ADDR are defined to get aligned
CONFIG_PHYSICAL_START, so we can replace __PHYSICAL_START with
LOAD_PHYSICAL_ADDR. And then remove the definition of __PHYSICAL_START,
which is only used to define __START_KERNEL.

Since <asm/boot.h> includes <asm/pgtable_types.h>, which includes
<asm/page_types.h>, it is fine to move definition from <asm/boot.h> to
<asm/page_types.h>.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240313075839.8321-3-richard.weiyang@gmail.com
---
 arch/x86/include/asm/boot.h       | 5 -----
 arch/x86/include/asm/page_types.h | 8 +++++---
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
index a38cc0a..12cbc57 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -6,11 +6,6 @@
 #include <asm/pgtable_types.h>
 #include <uapi/asm/boot.h>
 
-/* Physical address where kernel should be loaded. */
-#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
-				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
-				& ~(CONFIG_PHYSICAL_ALIGN - 1))
-
 /* Minimum kernel alignment, as a power of two */
 #ifdef CONFIG_X86_64
 # define MIN_KERNEL_ALIGN_LG2	PMD_SHIFT
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index 86bd431..acc1620 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -31,10 +31,12 @@
 
 #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
-#define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
-				      CONFIG_PHYSICAL_ALIGN)
+/* Physical address where kernel should be loaded. */
+#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
+				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
+				& ~(CONFIG_PHYSICAL_ALIGN - 1))
 
-#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
+#define __START_KERNEL		(__START_KERNEL_map + LOAD_PHYSICAL_ADDR)
 
 #ifdef CONFIG_X86_64
 #include <asm/page_64_types.h>