[PATCH] x86/percpu: silence section mismatch warnings related to EARLY_PER_CPU variables

[PATCH] x86/percpu: silence section mismatch warnings related to EARLY_PER_CPU variables

[Marcin Slusarz]

Quoting Mike Travis in "x86: cleanup early per cpu variables/accesses v4"
(23ca4bba3e20c6c3cb11c1bb0ab4770b724d39ac):

    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.

As these variables are NULL'ed before __init sections are dropped
(in setup_per_cpu_maps), they can be safely annotated as __ref.

This change silences following section mismatch warnings:

WARNING: vmlinux.o(.data+0x46c0): Section mismatch in reference from the variable x86_cpu_to_apicid_early_ptr to the variable .init.data:x86_cpu_to_apicid_early_map
The variable x86_cpu_to_apicid_early_ptr references
the variable __initdata x86_cpu_to_apicid_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

WARNING: vmlinux.o(.data+0x46c8): Section mismatch in reference from the variable x86_bios_cpu_apicid_early_ptr to the variable .init.data:x86_bios_cpu_apicid_early_map
The variable x86_bios_cpu_apicid_early_ptr references
the variable __initdata x86_bios_cpu_apicid_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

WARNING: vmlinux.o(.data+0x46d0): Section mismatch in reference from the variable x86_cpu_to_node_map_early_ptr to the variable .init.data:x86_cpu_to_node_map_early_map
The variable x86_cpu_to_node_map_early_ptr references
the variable __initdata x86_cpu_to_node_map_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 include/asm-x86/percpu.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/asm-x86/percpu.h b/include/asm-x86/percpu.h
index 4e91ee1..f643a3a 100644
--- a/include/asm-x86/percpu.h
+++ b/include/asm-x86/percpu.h
@@ -182,7 +182,7 @@ do {							\
 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\
 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
 				{ [0 ... NR_CPUS-1] = _initvalue };	\
-	__typeof__(_type) *_name##_early_ptr = _name##_early_map
+	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 
 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
 	EXPORT_PER_CPU_SYMBOL(_name)
-- 
1.5.4.5

[PATCH] x86: silence section mismatch warning - get_local_pda

[Marcin Slusarz]

Take out part of get_local_pda referencing __init function (free_bootmem)
to new (static) function marked as __ref. It's safe to do because free_bootmem
is called before __init sections are dropped.

WARNING: vmlinux.o(.cpuinit.text+0x3cd7): Section mismatch in reference from the function get_local_pda() to the function .init.text:free_bootmem()
The function __cpuinit get_local_pda() references
a function __init free_bootmem().
If free_bootmem is only used by get_local_pda then
annotate free_bootmem with a matching annotation.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/smpboot.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 91055d7..47dbf98 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -756,6 +756,14 @@ static void __cpuinit do_fork_idle(struct work_struct *work)
 }
 
 #ifdef CONFIG_X86_64
+
+/* __ref because it's safe to call free_bootmem when after_bootmem == 0. */
+static void __ref free_bootmem_pda(struct x8664_pda *oldpda)
+{
+	if (!after_bootmem)
+		free_bootmem((unsigned long)oldpda, sizeof(*oldpda));
+}
+
 /*
  * Allocate node local memory for the AP pda.
  *
@@ -784,8 +792,7 @@ int __cpuinit get_local_pda(int cpu)
 
 	if (oldpda) {
 		memcpy(newpda, oldpda, size);
-		if (!after_bootmem)
-			free_bootmem((unsigned long)oldpda, size);
+		free_bootmem_pda(oldpda);
 	}
 
 	newpda->in_bootmem = 0;
-- 
1.5.4.5

[PATCH] x86,calgary: fix section mismatch warning - get_tce_space_from_tar

[Marcin Slusarz]

WARNING: vmlinux.o(.text+0x27032): Section mismatch in reference from the function get_tce_space_from_tar() to the function .init.text:calgary_bus_has_devices()
The function get_tce_space_from_tar() references
the function __init calgary_bus_has_devices().
This is often because get_tce_space_from_tar lacks a __init
annotation or the annotation of calgary_bus_has_devices is wrong.

get_tce_space_from_tar is called only from __init function (calgary_init)
and calls __init function (calgary_bus_has_devices).
So annotate it properly.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Chandru Siddalingappa <chandru@in.ibm.com>
---
 arch/x86/kernel/pci-calgary_64.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 02d1932..218d783 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -1350,7 +1350,7 @@ static void calgary_init_bitmap_from_tce_table(struct iommu_table *tbl)
  * Function for kdump case. Get the tce tables from first kernel
  * by reading the contents of the base adress register of calgary iommu
  */
-static void get_tce_space_from_tar(void)
+static void __init get_tce_space_from_tar(void)
 {
 	int bus;
 	void __iomem *target;
-- 
1.5.4.5

Re: [PATCH] x86,calgary: fix section mismatch warning - get_tce_space_from_tar

[Ingo Molnar]

applied these commits to tip/x86/urgent:

f710666: x86, calgary: fix section mismatch warning - get_tce_space_from_tar
d19fbfd: x86: silence section mismatch warning - get_local_pda
c6a92a2: x86, percpu: silence section mismatch warnings related to EARLY_PER_CPU

thanks Marcin!

	Ingo