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>
---
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%)
diff --git a/xen/arch/arm/include/asm/Makefile b/xen/arch/arm/include/asm/Makefile
index cac6d5e3df..3faf1251ec 100644
--- a/xen/arch/arm/include/asm/Makefile
+++ b/xen/arch/arm/include/asm/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
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 d8f2a1453c..c0badf5717 100644
--- a/xen/arch/ppc/include/asm/Makefile
+++ b/xen/arch/ppc/include/asm/Makefile
@@ -2,5 +2,6 @@
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..3d0d316bae 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()
+
#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)
--
2.41.0Hi Oleksii, On 17/11/2023 12:24, 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> > --- > 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 +++ The changes for Arm and common looks good to me. I saw Jan thought the include movement is fragile, I don't have any strong opinion about the placement so long it compiles :). So feels free to add my ack: Acked-by: Julien Grall <jgrall@amazon.com> Cheers, -- Julien Grall
On 17.11.2023 13:24, Oleksii Kurochko wrote: > --- 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() This 2nd item can't be quite right either, so likely also wants a FIXME comment. Shawn will have the ultimate say here anyway. > --- 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) While you explain the reason for this movement, it still feels a little fragile to me. Jan
On Tue, 2023-11-21 at 16:56 +0100, Jan Beulich wrote:
> On 17.11.2023 13:24, Oleksii Kurochko wrote:
> > --- 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()
>
> This 2nd item can't be quite right either, so likely also wants a
> FIXME comment.
> Shawn will have the ultimate say here anyway.
I did so because it is how percpu stuff was implemented before
get_per_cpu_offset was introduced.
>
> > --- 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)
>
> While you explain the reason for this movement, it still feels a
> little
> fragile to me.
The reason for that is #include <asm/processor.h> was added to
<asm/percpu.h>. <asm/processor.h> uses DECLARE_PER_CPU(...) so it
should be defined before inclusion of <asm/percpu.h>. Otherwise the
following error will occur:
./arch/riscv/include/asm/current.h:13:32: error: unknown type name
'curr_vcpu'
13 | DECLARE_PER_CPU(struct vcpu *, curr_vcpu);
| ^~~~~~~~~
In file included from ././include/xen/config.h:17,
from <command-line>:
./include/xen/sched.h: In function 'rcu_unlock_domain':
./include/asm-generic/percpu.h:19:19: error: 'per_cpu__curr_vcpu'
undeclared (first use in this function)
19 | (*RELOC_HIDE(&per_cpu__##var, get_per_cpu_offset()))
| ^~~~~~~~~
./include/xen/compiler.h:146:37: note: in definition of macro
'RELOC_HIDE'
146 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
| ^~~
./arch/riscv/include/asm/current.h:15:29: note: in expansion of macro
'this_cpu'
15 | #define current (this_cpu(curr_vcpu))
| ^~~~~~~~
./include/xen/sched.h:726:15: note: in expansion of macro 'current'
726 | if ( d != current->domain )
| ^~~~~~~
./include/asm-generic/percpu.h:19:19: note: each undeclared identifier
is reported only once for each function it appears in
19 | (*RELOC_HIDE(&per_cpu__##var, get_per_cpu_offset()))
| ^~~~~~~~~
./include/xen/compiler.h:146:37: note: in definition of macro
'RELOC_HIDE'
146 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
| ^~~
./arch/riscv/include/asm/current.h:15:29: note: in expansion of macro
'this_cpu'
15 | #define current (this_cpu(curr_vcpu))
| ^~~~~~~~
./include/xen/sched.h:726:15: note: in expansion of macro 'current'
726 | if ( d != current->domain )
~ Oleksii
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