[PATCH v2 1/2] xen: introduce common macros for per-CPU sections defintion

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

Introduce PERCPU_BSS macro which manages:
 * Alignment of the section start
 * Insertion of per-CPU data sections
 * Alignment and start/end markers for per-CPU data
This change simplifies the linker script maintenance and ensures a unified
approach for per-CPU sections across different architectures.

Refactor the linker scripts for Arm, PPC, and x86 architectures by using
the common macro PERCPU_BSS defined in xen/xen.lds.h to handle per-CPU
data sections.

No functional changes.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Changes in V2:
 - rename PERCPU_SECTION to PERCPU_BSS
 - update the commit message
 - add Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
 - add Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---

 xen/arch/arm/xen.lds.S    |  9 +--------
 xen/arch/ppc/xen.lds.S    |  9 +--------
 xen/arch/x86/xen.lds.S    |  9 +--------
 xen/include/xen/xen.lds.h | 10 ++++++++++
 4 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
index bd884664ad..0987052f1a 100644
--- a/xen/arch/arm/xen.lds.S
+++ b/xen/arch/arm/xen.lds.S
@@ -198,14 +198,7 @@ SECTIONS
        __bss_start = .;
        *(.bss.stack_aligned)
        *(.bss.page_aligned)
-       . = ALIGN(PAGE_SIZE);
-       __per_cpu_start = .;
-       *(.bss.percpu.page_aligned)
-       *(.bss.percpu)
-       . = ALIGN(SMP_CACHE_BYTES);
-       *(.bss.percpu.read_mostly)
-       . = ALIGN(SMP_CACHE_BYTES);
-       __per_cpu_data_end = .;
+       PERCPU_BSS
        *(.bss .bss.*)
        . = ALIGN(POINTER_ALIGN);
        __bss_end = .;
diff --git a/xen/arch/ppc/xen.lds.S b/xen/arch/ppc/xen.lds.S
index 38cd857187..0c4b94814b 100644
--- a/xen/arch/ppc/xen.lds.S
+++ b/xen/arch/ppc/xen.lds.S
@@ -148,14 +148,7 @@ SECTIONS
         __bss_start = .;
         *(.bss.stack_aligned)
         *(.bss.page_aligned)
-        . = ALIGN(PAGE_SIZE);
-        __per_cpu_start = .;
-        *(.bss.percpu.page_aligned)
-        *(.bss.percpu)
-        . = ALIGN(SMP_CACHE_BYTES);
-        *(.bss.percpu.read_mostly)
-        . = ALIGN(SMP_CACHE_BYTES);
-        __per_cpu_data_end = .;
+        PERCPU_BSS
         *(.bss .bss.*)
         . = ALIGN(POINTER_ALIGN);
         __bss_end = .;
diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index d48de67cfd..b60d2f0d82 100644
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -321,14 +321,7 @@ SECTIONS
   DECL_SECTION(.bss) {
        __bss_start = .;
        *(.bss.page_aligned*)
-       . = ALIGN(PAGE_SIZE);
-       __per_cpu_start = .;
-       *(.bss.percpu.page_aligned)
-       *(.bss.percpu)
-       . = ALIGN(SMP_CACHE_BYTES);
-       *(.bss.percpu.read_mostly)
-       . = ALIGN(SMP_CACHE_BYTES);
-       __per_cpu_data_end = .;
+       PERCPU_BSS
        *(.bss .bss.*)
        . = ALIGN(POINTER_ALIGN);
        __bss_end = .;
diff --git a/xen/include/xen/xen.lds.h b/xen/include/xen/xen.lds.h
index a17810bb28..24b8900ffe 100644
--- a/xen/include/xen/xen.lds.h
+++ b/xen/include/xen/xen.lds.h
@@ -151,6 +151,16 @@
 #define LOCK_PROFILE_DATA
 #endif
 
+#define PERCPU_BSS                 \
+       . = ALIGN(PAGE_SIZE);       \
+       __per_cpu_start = .;        \
+       *(.bss.percpu.page_aligned) \
+       *(.bss.percpu)              \
+       . = ALIGN(SMP_CACHE_BYTES); \
+       *(.bss.percpu.read_mostly)  \
+       . = ALIGN(SMP_CACHE_BYTES); \
+       __per_cpu_data_end = .;     \
+
 #ifdef CONFIG_HAS_VPCI
 #define VPCI_ARRAY               \
        . = ALIGN(POINTER_ALIGN); \
-- 
2.46.1