diff mbox series

[v4,06/14] xen/asm-generic: introduce generic header percpu.h

Message ID 7f10cbda3885a91e108e1a303fe74ffc21d1025c.1701093907.git.oleksii.kurochko@gmail.com (mailing list archive)
State Superseded
Headers show
Series Introduce generic headers | expand

Commit Message

Oleksii Nov. 27, 2023, 2:13 p.m. UTC 
The patch introduces generic percpu.h which was based on Arm's version
with the following changes:
 * makes __per_cpu_data_end[] constant
 * introduce get_per_cpu_offset() for macros this_cpu() and this_cpu_ptr()
 * add inclustion of <asm/current.h> as get_per_cpu_offset() is located there.

Also it was changed a place where <asm/percpu.h> is included in <xen/percpu.h>
because asm-generic version of percpu.h started to include <asm/current.h> which
requires definition of DECLARE_PER_CPU.

As well the patch switches Arm, PPC and x86 architectures to use asm-generic
version of percpu.h.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Julien Grall <jgrall@amazon.com>
---
Changes in V4:
 - Added FIXME comment in ppc/current.h for get_per_cpu_offset()
 - Added Acked-by: Julien Grall <jgrall@amazon.com>.
---
Changes in V3:
 - switch all architectures to asm-generic version of percpu.h
 - introduce get_per_cpu_offset() and implement it architectures.
 - make __per_cpu_data_end constamt.
 - update the commit message.
---
Changes in V2:
	- use smp_processor_id() instead of get_processor_id().
 	- update commit message .
---
 xen/arch/arm/include/asm/Makefile             |  1 +
 xen/arch/arm/include/asm/current.h            |  3 +++
 xen/arch/ppc/include/asm/Makefile             |  1 +
 xen/arch/ppc/include/asm/current.h            |  6 +++++
 xen/arch/ppc/include/asm/percpu.h             | 24 -------------------
 xen/arch/x86/include/asm/Makefile             |  2 ++
 xen/arch/x86/include/asm/current.h            |  2 ++
 xen/arch/x86/include/asm/percpu.h             | 22 -----------------
 .../asm => include/asm-generic}/percpu.h      | 18 ++++++++------
 xen/include/xen/percpu.h                      |  4 ++--
 10 files changed, 28 insertions(+), 55 deletions(-)
 delete mode 100644 xen/arch/ppc/include/asm/percpu.h
 create mode 100644 xen/arch/x86/include/asm/Makefile
 delete mode 100644 xen/arch/x86/include/asm/percpu.h
 rename xen/{arch/arm/include/asm => include/asm-generic}/percpu.h (57%)

Comments

Jan Beulich Nov. 27, 2023, 2:33 p.m. UTC | #1 
On 27.11.2023 15:13, Oleksii Kurochko wrote:
> The patch introduces generic percpu.h which was based on Arm's version
> with the following changes:
>  * makes __per_cpu_data_end[] constant
>  * introduce get_per_cpu_offset() for macros this_cpu() and this_cpu_ptr()
>  * add inclustion of <asm/current.h> as get_per_cpu_offset() is located there.
> 
> Also it was changed a place where <asm/percpu.h> is included in <xen/percpu.h>
> because asm-generic version of percpu.h started to include <asm/current.h> which
> requires definition of DECLARE_PER_CPU.
> 
> As well the patch switches Arm, PPC and x86 architectures to use asm-generic
> version of percpu.h.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> Acked-by: Julien Grall <jgrall@amazon.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
Shawn Anastasio Nov. 28, 2023, 9:58 p.m. UTC | #2 
Hi Oleksii,

On 11/27/23 8:13 AM, Oleksii Kurochko wrote:
> The patch introduces generic percpu.h which was based on Arm's version
> with the following changes:
>  * makes __per_cpu_data_end[] constant
>  * introduce get_per_cpu_offset() for macros this_cpu() and this_cpu_ptr()
>  * add inclustion of <asm/current.h> as get_per_cpu_offset() is located there.
> 
> Also it was changed a place where <asm/percpu.h> is included in <xen/percpu.h>
> because asm-generic version of percpu.h started to include <asm/current.h> which
> requires definition of DECLARE_PER_CPU.
> 
> As well the patch switches Arm, PPC and x86 architectures to use asm-generic
> version of percpu.h.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> Acked-by: Julien Grall <jgrall@amazon.com>
> ---
> Changes in V4:
>  - Added FIXME comment in ppc/current.h for get_per_cpu_offset()

Sorry I missed the discussion on this in v3, but yes, the PPC
implementation of this will need to be fixed (this was also the case
before your patch in PPC's current percpu.h but it was conspicuously
missing a TODO comment).

In any case,

Acked-by: Shawn Anastasio <sanastasio@raptorengineering.com>

Thanks,
Shawn
diff mbox series

Patch

diff --git a/xen/arch/arm/include/asm/Makefile b/xen/arch/arm/include/asm/Makefile
index 7593c4e8ee..60bb78fc09 100644
--- a/xen/arch/arm/include/asm/Makefile
+++ b/xen/arch/arm/include/asm/Makefile
@@ -2,5 +2,6 @@ 
 generic-y += device.h
 generic-y += iocap.h
 generic-y += paging.h
+generic-y += percpu.h
 generic-y += random.h
 generic-y += vm_event.h
diff --git a/xen/arch/arm/include/asm/current.h b/xen/arch/arm/include/asm/current.h
index 51d1c8efa8..0be7ad6ef9 100644
--- a/xen/arch/arm/include/asm/current.h
+++ b/xen/arch/arm/include/asm/current.h
@@ -5,6 +5,7 @@ 
 #include <xen/percpu.h>
 
 #include <asm/processor.h>
+#include <asm/sysregs.h>
 
 /* Tell whether the guest vCPU enabled Workaround 2 (i.e variant 4) */
 #define CPUINFO_WORKAROUND_2_FLAG_SHIFT   0
@@ -60,6 +61,8 @@  do {                                                    \
     this_cpu(cpu_id) = (id);                            \
 } while ( 0 )
 
+#define get_per_cpu_offset()  READ_SYSREG(TPIDR_EL2)
+
 #endif
 
 #endif /* __ARM_CURRENT_H__ */
diff --git a/xen/arch/ppc/include/asm/Makefile b/xen/arch/ppc/include/asm/Makefile
index 039b0eb5ee..edef0fab78 100644
--- a/xen/arch/ppc/include/asm/Makefile
+++ b/xen/arch/ppc/include/asm/Makefile
@@ -3,5 +3,6 @@  generic-y += device.h
 generic-y += hypercall.h
 generic-y += iocap.h
 generic-y += paging.h
+generic-y += percpu.h
 generic-y += random.h
 generic-y += vm_event.h
diff --git a/xen/arch/ppc/include/asm/current.h b/xen/arch/ppc/include/asm/current.h
index 0ca06033f9..e329a548e6 100644
--- a/xen/arch/ppc/include/asm/current.h
+++ b/xen/arch/ppc/include/asm/current.h
@@ -4,6 +4,8 @@ 
 
 #include <xen/percpu.h>
 
+#include <asm/processor.h>
+
 #ifndef __ASSEMBLY__
 
 struct vcpu;
@@ -38,6 +40,10 @@  static inline struct cpu_info *get_cpu_info(void)
 
 #define guest_cpu_user_regs() (&get_cpu_info()->guest_cpu_user_regs)
 
+#define smp_processor_id()      0 /* TODO: Fix this */
+
+#define get_per_cpu_offset()    smp_processor_id() /* TODO: Fix this */
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASM_PPC_CURRENT_H__ */
diff --git a/xen/arch/ppc/include/asm/percpu.h b/xen/arch/ppc/include/asm/percpu.h
deleted file mode 100644
index e7c40c0f03..0000000000
--- a/xen/arch/ppc/include/asm/percpu.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-#ifndef __PPC_PERCPU_H__
-#define __PPC_PERCPU_H__
-
-#ifndef __ASSEMBLY__
-
-extern char __per_cpu_start[], __per_cpu_data_end[];
-extern unsigned long __per_cpu_offset[NR_CPUS];
-void percpu_init_areas(void);
-
-#define smp_processor_id() 0 /* TODO: Fix this */
-
-#define per_cpu(var, cpu)  \
-    (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))
-#define this_cpu(var) \
-    (*RELOC_HIDE(&per_cpu__##var, smp_processor_id()))
-
-#define per_cpu_ptr(var, cpu)  \
-    (*RELOC_HIDE(var, __per_cpu_offset[cpu]))
-#define this_cpu_ptr(var) \
-    (*RELOC_HIDE(var, smp_processor_id()))
-
-#endif
-
-#endif /* __PPC_PERCPU_H__ */
diff --git a/xen/arch/x86/include/asm/Makefile b/xen/arch/x86/include/asm/Makefile
new file mode 100644
index 0000000000..874429ed30
--- /dev/null
+++ b/xen/arch/x86/include/asm/Makefile
@@ -0,0 +1,2 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+generic-y += percpu.h
diff --git a/xen/arch/x86/include/asm/current.h b/xen/arch/x86/include/asm/current.h
index 35cca5cbe4..10950f36cc 100644
--- a/xen/arch/x86/include/asm/current.h
+++ b/xen/arch/x86/include/asm/current.h
@@ -102,6 +102,8 @@  static inline struct cpu_info *get_cpu_info(void)
 #define smp_processor_id()    (get_cpu_info()->processor_id)
 #define guest_cpu_user_regs() (&get_cpu_info()->guest_cpu_user_regs)
 
+#define get_per_cpu_offset()  (get_cpu_info()->per_cpu_offset)
+
 /*
  * Get the bottom-of-stack, as stored in the per-CPU TSS. This actually points
  * into the middle of cpu_info.guest_cpu_user_regs, at the section that
diff --git a/xen/arch/x86/include/asm/percpu.h b/xen/arch/x86/include/asm/percpu.h
deleted file mode 100644
index 2b0c29a233..0000000000
--- a/xen/arch/x86/include/asm/percpu.h
+++ /dev/null
@@ -1,22 +0,0 @@ 
-#ifndef __X86_PERCPU_H__
-#define __X86_PERCPU_H__
-
-#ifndef __ASSEMBLY__
-extern char __per_cpu_start[], __per_cpu_data_end[];
-extern unsigned long __per_cpu_offset[NR_CPUS];
-void percpu_init_areas(void);
-#endif
-
-/* var is in discarded region: offset to particular copy we want */
-#define per_cpu(var, cpu)  \
-    (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))
-#define this_cpu(var) \
-    (*RELOC_HIDE(&per_cpu__##var, get_cpu_info()->per_cpu_offset))
-
-#define this_cpu_ptr(var) \
-    (*RELOC_HIDE(var, get_cpu_info()->per_cpu_offset))
-
-#define per_cpu_ptr(var, cpu)  \
-    (*RELOC_HIDE(var, __per_cpu_offset[cpu]))
-
-#endif /* __X86_PERCPU_H__ */
diff --git a/xen/arch/arm/include/asm/percpu.h b/xen/include/asm-generic/percpu.h
similarity index 57%
rename from xen/arch/arm/include/asm/percpu.h
rename to xen/include/asm-generic/percpu.h
index f1a8768080..60af4f9ff9 100644
--- a/xen/arch/arm/include/asm/percpu.h
+++ b/xen/include/asm-generic/percpu.h
@@ -1,28 +1,32 @@ 
-#ifndef __ARM_PERCPU_H__
-#define __ARM_PERCPU_H__
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_PERCPU_H__
+#define __ASM_GENERIC_PERCPU_H__
 
 #ifndef __ASSEMBLY__
 
 #include <xen/types.h>
-#include <asm/sysregs.h>
+#include <asm/current.h>
 
-extern char __per_cpu_start[], __per_cpu_data_end[];
+extern char __per_cpu_start[];
+extern const char __per_cpu_data_end[];
 extern unsigned long __per_cpu_offset[NR_CPUS];
 void percpu_init_areas(void);
 
 #define per_cpu(var, cpu)  \
     (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))
+
 #define this_cpu(var) \
-    (*RELOC_HIDE(&per_cpu__##var, READ_SYSREG(TPIDR_EL2)))
+    (*RELOC_HIDE(&per_cpu__##var, get_per_cpu_offset()))
 
 #define per_cpu_ptr(var, cpu)  \
     (*RELOC_HIDE(var, __per_cpu_offset[cpu]))
 #define this_cpu_ptr(var) \
-    (*RELOC_HIDE(var, READ_SYSREG(TPIDR_EL2)))
+    (*RELOC_HIDE(var, get_per_cpu_offset()))
 
 #endif
 
-#endif /* __ARM_PERCPU_H__ */
+#endif /* __ASM_GENERIC_PERCPU_H__ */
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/xen/percpu.h b/xen/include/xen/percpu.h
index c7bf57cbcd..57522f346b 100644
--- a/xen/include/xen/percpu.h
+++ b/xen/include/xen/percpu.h
@@ -1,8 +1,6 @@ 
 #ifndef __XEN_PERCPU_H__
 #define __XEN_PERCPU_H__
 
-#include <asm/percpu.h>
-
 #define DECLARE_PER_CPU(type, name) \
     extern __typeof__(type) per_cpu__ ## name
 
@@ -29,6 +27,8 @@ 
 
 #define get_per_cpu_var(var)  (per_cpu__##var)
 
+#include <asm/percpu.h>
+
 /* Linux compatibility. */
 #define get_cpu_var(var) this_cpu(var)
 #define put_cpu_var(var)