[PATCH v2 0/3] powerpc: tweak the kernel options for CRASH_DUMP and RELOCATABLE

[PATCH v2 0/3] powerpc: tweak the kernel options for CRASH_DUMP and RELOCATABLE

[Kevin Hao]

v2:
Compare to v1 [1], the main differences are:
 - Still automatically select RELOCATABLE when CRASH_DUMP is enabled.
 - Add a new patch to kill RELOCATABLE_PPC32.

v1:
The first patch fixes a build error when CRASH_DUMP=y && ADVANCED_OPTIONS=n
for ppc32. The second does some cleanup for RELOCATABLE option.

Kevin Hao (3):
  powerpc32: booke: fix the build error when CRASH_DUMP is enabled
  powerpc: merge the RELOCATABLE config entries for ppc32 and ppc64
  powerpc32: kill RELOCATABLE_PPC32

 arch/powerpc/Kconfig              | 61 +++++++++++++++------------------------
 arch/powerpc/include/asm/page.h   |  6 ++--
 arch/powerpc/kernel/Makefile      |  3 +-
 arch/powerpc/kernel/vmlinux.lds.S |  2 +-
 arch/powerpc/mm/init_32.c         |  2 +-
 5 files changed, 29 insertions(+), 45 deletions(-)

[1] http://linuxppc-dev.ozlabs.narkive.com/fKHcSZbu/patch-0-2-powerpc-tweak-the-kernel-options-for-crash-dump-and-relocatable
-- 
2.8.1

[PATCH v2 1/3] powerpc32: booke: fix the build error when CRASH_DUMP is enabled

[Kevin Hao]

In the current code, the RELOCATABLE will be forcedly enabled when
enabling CRASH_DUMP. But for ppc32, the RELOCABLE also depend on
ADVANCED_OPTIONS and select NONSTATIC_KERNEL. This will cause the
following build error when CRASH_DUMP=y && ADVANCED_OPTIONS=n
because the select of NONSTATIC_KERNEL doesn't take effect.
  arch/powerpc/include/asm/io.h: In function 'virt_to_phys':
  arch/powerpc/include/asm/page.h:113:26: error: 'virt_phys_offset' undeclared (first use in this function)
   #define VIRT_PHYS_OFFSET virt_phys_offset
                          ^
It doesn't have any strong reasons to make the RELOCATABLE depend on
ADVANCED_OPTIONS. So remove this dependency to fix this issue.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 0a4cea451cf2..cb7910b9f10f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -952,7 +952,7 @@ config DYNAMIC_MEMSTART
 
 config RELOCATABLE
 	bool "Build a relocatable kernel"
-	depends on ADVANCED_OPTIONS && FLATMEM && (44x || FSL_BOOKE)
+	depends on FLATMEM && (44x || FSL_BOOKE)
 	select NONSTATIC_KERNEL
 	help
 	  This builds a kernel image that is capable of running at the
-- 
2.8.1

[PATCH v2 2/3] powerpc: merge the RELOCATABLE config entries for ppc32 and ppc64

[Kevin Hao]

It makes no sense to keep two separate RELOCATABLE config entries for
ppc32 and ppc64 respectively. Merge them into one and move it to
a common place.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/Kconfig | 65 ++++++++++++++++++++++------------------------------
 1 file changed, 27 insertions(+), 38 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index cb7910b9f10f..a9d847c8a20d 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -458,6 +458,33 @@ config KEXEC
 	  interface is strongly in flux, so no good recommendation can be
 	  made.
 
+config RELOCATABLE
+	bool "Build a relocatable kernel"
+	depends on (PPC64 && !COMPILE_TEST) || (FLATMEM && (44x || FSL_BOOKE))
+	select NONSTATIC_KERNEL
+	help
+	  This builds a kernel image that is capable of running at the
+	  location the kernel is loaded at. For ppc32, there is no any
+	  alignment restrictions, and this feature is a superset of
+	  DYNAMIC_MEMSTART and hence overrides it. For ppc64, we should use
+	  16k-aligned base address. The kernel is linked as a
+	  position-independent executable (PIE) and contains dynamic relocations
+	  which are processed early in the bootup process.
+
+	  One use is for the kexec on panic case where the recovery kernel
+	  must live at a different physical address than the primary
+	  kernel.
+
+	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
+	  it has been loaded at and the compile time physical addresses
+	  CONFIG_PHYSICAL_START is ignored.  However CONFIG_PHYSICAL_START
+	  setting can still be useful to bootwrappers that need to know the
+	  load address of the kernel (eg. u-boot/mkimage).
+
+config RELOCATABLE_PPC32
+	def_bool y
+	depends on PPC32 && RELOCATABLE
+
 config CRASH_DUMP
 	bool "Build a kdump crash kernel"
 	depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
@@ -950,29 +977,6 @@ config DYNAMIC_MEMSTART
 
 	  This option is overridden by CONFIG_RELOCATABLE
 
-config RELOCATABLE
-	bool "Build a relocatable kernel"
-	depends on FLATMEM && (44x || FSL_BOOKE)
-	select NONSTATIC_KERNEL
-	help
-	  This builds a kernel image that is capable of running at the
-	  location the kernel is loaded at, without any alignment restrictions.
-	  This feature is a superset of DYNAMIC_MEMSTART and hence overrides it.
-
-	  One use is for the kexec on panic case where the recovery kernel
-	  must live at a different physical address than the primary
-	  kernel.
-
-	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
-	  it has been loaded at and the compile time physical addresses
-	  CONFIG_PHYSICAL_START is ignored.  However CONFIG_PHYSICAL_START
-	  setting can still be useful to bootwrappers that need to know the
-	  load address of the kernel (eg. u-boot/mkimage).
-
-config RELOCATABLE_PPC32
-	def_bool y
-	depends on PPC32 && RELOCATABLE
-
 config PAGE_OFFSET_BOOL
 	bool "Set custom page offset address"
 	depends on ADVANCED_OPTIONS
@@ -1063,21 +1067,6 @@ config PIN_TLB_IMMR
 endmenu
 
 if PPC64
-config RELOCATABLE
-	bool "Build a relocatable kernel"
-	depends on !COMPILE_TEST
-	select NONSTATIC_KERNEL
-	help
-	  This builds a kernel image that is capable of running anywhere
-	  in the RMA (real memory area) at any 16k-aligned base address.
-	  The kernel is linked as a position-independent executable (PIE)
-	  and contains dynamic relocations which are processed early
-	  in the bootup process.
-
-	  One use is for the kexec on panic case where the recovery kernel
-	  must live at a different physical address than the primary
-	  kernel.
-
 # This value must have zeroes in the bottom 60 bits otherwise lots will break
 config PAGE_OFFSET
 	hex
-- 
2.8.1

[PATCH v2 3/3] powerpc32: kill RELOCATABLE_PPC32

[Kevin Hao]

It is seldom used in the kernel code and can be easily replaced by
either RELOCATABLE or PPC32. So there is no reason to keep a separate
kernel option for this.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/Kconfig              | 4 ----
 arch/powerpc/include/asm/page.h   | 6 +++---
 arch/powerpc/kernel/Makefile      | 3 +--
 arch/powerpc/kernel/vmlinux.lds.S | 2 +-
 arch/powerpc/mm/init_32.c         | 2 +-
 5 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a9d847c8a20d..98f7e29e5680 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -481,10 +481,6 @@ config RELOCATABLE
 	  setting can still be useful to bootwrappers that need to know the
 	  load address of the kernel (eg. u-boot/mkimage).
 
-config RELOCATABLE_PPC32
-	def_bool y
-	depends on PPC32 && RELOCATABLE
-
 config CRASH_DUMP
 	bool "Build a kdump crash kernel"
 	depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 51db3a37bced..56398e7e6100 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -96,7 +96,7 @@ extern unsigned int HPAGE_SHIFT;
 extern phys_addr_t memstart_addr;
 extern phys_addr_t kernstart_addr;
 
-#ifdef CONFIG_RELOCATABLE_PPC32
+#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32)
 extern long long virt_phys_offset;
 #endif
 
@@ -139,9 +139,9 @@ extern long long virt_phys_offset;
  * determine MEMORY_START until then.  However we can determine PHYSICAL_START
  * from information at hand (program counter, TLB lookup).
  *
- * On BookE with RELOCATABLE (RELOCATABLE_PPC32)
+ * On BookE with RELOCATABLE && PPC32
  *
- *   With RELOCATABLE_PPC32,  we support loading the kernel at any physical 
+ *   With RELOCATABLE && PPC32,  we support loading the kernel at any physical
  *   address without any restriction on the page alignment.
  *
  *   We find the runtime address of _stext and relocate ourselves based on 
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 0c7106df90e6..0719b1a3fb24 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -47,7 +47,6 @@ obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
 obj-$(CONFIG_PPC_BOOK3S_64)	+= cpu_setup_ppc970.o cpu_setup_pa6t.o
 obj-$(CONFIG_PPC_BOOK3S_64)	+= cpu_setup_power.o
 obj-$(CONFIG_PPC_BOOK3S_64)	+= mce.o mce_power.o hmi.o
-obj64-$(CONFIG_RELOCATABLE)	+= reloc_64.o
 obj-$(CONFIG_PPC_BOOK3E_64)	+= exceptions-64e.o idle_book3e.o
 obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o
@@ -92,7 +91,7 @@ extra-$(CONFIG_FSL_BOOKE)	:= head_fsl_booke.o
 extra-$(CONFIG_8xx)		:= head_8xx.o
 extra-y				+= vmlinux.lds
 
-obj-$(CONFIG_RELOCATABLE_PPC32)	+= reloc_32.o
+obj-$(CONFIG_RELOCATABLE)	+= reloc_$(CONFIG_WORD_SIZE).o
 
 obj-$(CONFIG_PPC32)		+= entry_32.o setup_32.o
 obj-$(CONFIG_PPC64)		+= dma-iommu.o iommu.o
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 2dd91f79de05..b5fba689fca6 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -165,7 +165,7 @@ SECTIONS
 	. = ALIGN(8);
 	.dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET)
 	{
-#ifdef CONFIG_RELOCATABLE_PPC32
+#ifdef CONFIG_PPC32
 		__dynamic_symtab = .;
 #endif
 		*(.dynsym)
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index e2d7ba124618..448685fbf27c 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -64,7 +64,7 @@ EXPORT_SYMBOL(memstart_addr);
 phys_addr_t kernstart_addr;
 EXPORT_SYMBOL(kernstart_addr);
 
-#ifdef CONFIG_RELOCATABLE_PPC32
+#ifdef CONFIG_RELOCATABLE
 /* Used in __va()/__pa() */
 long long virt_phys_offset;
 EXPORT_SYMBOL(virt_phys_offset);
-- 
2.8.1

Re: [v2, 1/3] powerpc32: booke: fix the build error when CRASH_DUMP is enabled

[Michael Ellerman]

On Wed, 2016-13-07 at 01:14:38 UTC, Kevin Hao wrote:
> In the current code, the RELOCATABLE will be forcedly enabled when
> enabling CRASH_DUMP. But for ppc32, the RELOCABLE also depend on
> ADVANCED_OPTIONS and select NONSTATIC_KERNEL. This will cause the
> following build error when CRASH_DUMP=y && ADVANCED_OPTIONS=n
> because the select of NONSTATIC_KERNEL doesn't take effect.
>   arch/powerpc/include/asm/io.h: In function 'virt_to_phys':
>   arch/powerpc/include/asm/page.h:113:26: error: 'virt_phys_offset' undeclared (first use in this function)
>    #define VIRT_PHYS_OFFSET virt_phys_offset
>                           ^
> It doesn't have any strong reasons to make the RELOCATABLE depend on
> ADVANCED_OPTIONS. So remove this dependency to fix this issue.
> 
> Signed-off-by: Kevin Hao <haokexin@gmail.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/da4230714662278781d007fb2b

cheers