[RFC PATCH 02/17] powerpc: Split up PHYS_64BIT config option to fix "select" issues

Kyle Moffett Kyle.D.Moffett at boeing.com
Thu Nov 10 11:07:00 EST 2011


The "CONFIG_PHYS_64BIT" option violates the Kconfig best-practices in
various colorful ways.  It has explicit dependencies, but it is also
"select"ed by various CPUs and platforms.  It is not set on 64-bit
systems, but it is used by a number of pieces of powerpc code to enable
or disable 64-bit physical address support.

To resolve these issues, the option has now been split into 3:

  CONFIG_PHYS_64BIT_SUPPORTED:
    This hidden option should be selected by any CPU type which supports
    64-bit physical addresses.  This will enable the PHYS_64BIT option
    to be selected.  It is (obviously) always set on PPC64.

  CONFIG_PHYS_64BIT_DT_REQUIRED:
    This hidden option should be selected by any board or platform which
    has >32-bit physical devices present in hardware.  If this is set
    then the CONFIG_PHYS_64BIT option will be forcibly enabled and
    hidden from the user.  It is (obviously) always set on PPC64.

  CONFIG_PHYS_64BIT:
    This option is user-controllable, where allowed by CPU and platform
    settings, and should never be pointed at with a "select" statement.
    Due to the values of the above two options, this is never visible on
    PPC64.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett at boeing.com>
---
 arch/powerpc/Kconfig                   |    4 ++--
 arch/powerpc/platforms/82xx/Kconfig    |    2 +-
 arch/powerpc/platforms/83xx/Kconfig    |    2 +-
 arch/powerpc/platforms/85xx/Kconfig    |   12 ++++++------
 arch/powerpc/platforms/86xx/Kconfig    |    1 +
 arch/powerpc/platforms/Kconfig.cputype |   25 ++++++++++++++++++-------
 6 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b177caa..27e31c5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -18,10 +18,10 @@ config WORD_SIZE
 	default 32 if !PPC64
 
 config ARCH_PHYS_ADDR_T_64BIT
-       def_bool PPC64 || PHYS_64BIT
+	def_bool PHYS_64BIT
 
 config ARCH_DMA_ADDR_T_64BIT
-	def_bool ARCH_PHYS_ADDR_T_64BIT
+	def_bool PHYS_64BIT
 
 config MMU
 	bool
diff --git a/arch/powerpc/platforms/82xx/Kconfig b/arch/powerpc/platforms/82xx/Kconfig
index 7c7df40..849d403 100644
--- a/arch/powerpc/platforms/82xx/Kconfig
+++ b/arch/powerpc/platforms/82xx/Kconfig
@@ -1,6 +1,6 @@
 menuconfig PPC_82xx
 	bool "82xx-based boards (PQ II)"
-	depends on 6xx
+	depends on 6xx && !PHYS_64BIT
 
 if PPC_82xx
 
diff --git a/arch/powerpc/platforms/83xx/Kconfig b/arch/powerpc/platforms/83xx/Kconfig
index 670a033..1ed8877 100644
--- a/arch/powerpc/platforms/83xx/Kconfig
+++ b/arch/powerpc/platforms/83xx/Kconfig
@@ -1,6 +1,6 @@
 menuconfig PPC_83xx
 	bool "83xx-based boards"
-	depends on 6xx
+	depends on 6xx && !PHYS_64BIT
 	select PPC_UDBG_16550
 	select PPC_PCI_CHOICE
 	select FSL_PCI if PCI
diff --git a/arch/powerpc/platforms/85xx/Kconfig b/arch/powerpc/platforms/85xx/Kconfig
index 9088381..37f9de7 100644
--- a/arch/powerpc/platforms/85xx/Kconfig
+++ b/arch/powerpc/platforms/85xx/Kconfig
@@ -80,7 +80,7 @@ config P1010_RDB
 config P1022_DS
 	bool "Freescale P1022 DS"
 	select DEFAULT_UIMAGE
-	select PHYS_64BIT	# The DTS has 36-bit addresses
+	select PHYS_64BIT_DT_REQUIRED # The DTS has 36-bit addresses
 	select SWIOTLB
 	help
 	  This option enables support for the Freescale P1022DS reference board.
@@ -175,7 +175,7 @@ config P2041_RDB
 	bool "Freescale P2041 RDB"
 	select DEFAULT_UIMAGE
 	select PPC_E500MC
-	select PHYS_64BIT
+	select PHYS_64BIT_DT_REQUIRED
 	select SWIOTLB
 	select ARCH_REQUIRE_GPIOLIB
 	select GPIO_MPC8XXX
@@ -189,7 +189,7 @@ config P3041_DS
 	bool "Freescale P3041 DS"
 	select DEFAULT_UIMAGE
 	select PPC_E500MC
-	select PHYS_64BIT
+	select PHYS_64BIT_DT_REQUIRED
 	select SWIOTLB
 	select ARCH_REQUIRE_GPIOLIB
 	select GPIO_MPC8XXX
@@ -203,7 +203,7 @@ config P3060_QDS
 	bool "Freescale P3060 QDS"
 	select DEFAULT_UIMAGE
 	select PPC_E500MC
-	select PHYS_64BIT
+	select PHYS_64BIT_DT_REQUIRED
 	select SWIOTLB
 	select MPC8xxx_GPIO
 	select HAS_RAPIDIO
@@ -216,7 +216,7 @@ config P4080_DS
 	bool "Freescale P4080 DS"
 	select DEFAULT_UIMAGE
 	select PPC_E500MC
-	select PHYS_64BIT
+	select PHYS_64BIT_DT_REQUIRED
 	select SWIOTLB
 	select ARCH_REQUIRE_GPIOLIB
 	select GPIO_MPC8XXX
@@ -233,7 +233,7 @@ config P5020_DS
 	select DEFAULT_UIMAGE
 	select E500
 	select PPC_E500MC
-	select PHYS_64BIT
+	select PHYS_64BIT_DT_REQUIRED
 	select SWIOTLB
 	select ARCH_REQUIRE_GPIOLIB
 	select GPIO_MPC8XXX
diff --git a/arch/powerpc/platforms/86xx/Kconfig b/arch/powerpc/platforms/86xx/Kconfig
index 8d6599d..576eb43 100644
--- a/arch/powerpc/platforms/86xx/Kconfig
+++ b/arch/powerpc/platforms/86xx/Kconfig
@@ -5,6 +5,7 @@ menuconfig PPC_86xx
 	select FSL_SOC
 	select ALTIVEC
 	select ARCH_WANT_OPTIONAL_GPIOLIB
+	select PHYS_64BIT_SUPPORTED
 	help
 	  The Freescale E600 SoCs have 74xx cores.
 
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 9210e94..0ab01b0 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -26,6 +26,7 @@ config PPC_BOOK3S_32
 
 config PPC_85xx
 	bool "Freescale 85xx"
+	select PHYS_64BIT_SUPPORTED
 	select E500
 
 config PPC_8xx
@@ -47,7 +48,8 @@ config 44x
 	select PPC_UDBG_16550
 	select 4xx_SOC
 	select PPC_PCI_CHOICE
-	select PHYS_64BIT
+	select PHYS_64BIT_SUPPORTED
+	select PHYS_64BIT_DT_REQUIRED
 
 config E200
 	bool "Freescale e200"
@@ -187,14 +189,20 @@ config PPC_FSL_BOOK3E
 	select PPC_SMP_MUXED_IPI
 	default y if FSL_BOOKE
 
-config PTE_64BIT
-	bool
-	depends on 44x || E500 || PPC_86xx
-	default y if PHYS_64BIT
+## Only some 32-bit CPUs support 64-bit physical addresses
+config PHYS_64BIT_SUPPORTED
+	def_bool PPC64
+
+## Some 32-bit system device trees have >32-bit physical addresses, and so
+## the kernel won't boot unless those are supported.
+config PHYS_64BIT_DT_REQUIRED
+	def_bool PPC64
 
+## DO NOT "select" this user-visible symbol, select the two above instead!
 config PHYS_64BIT
-	bool 'Large physical address support' if E500 || PPC_86xx
-	depends on (44x || E500 || PPC_86xx) && !PPC_83xx && !PPC_82xx
+	def_bool PHYS_64BIT_DT_REQUIRED
+	prompt 'Large physical address support' if !PHYS_64BIT_DT_REQUIRED
+	depends on PHYS_64BIT_SUPPORTED
 	---help---
 	  This option enables kernel support for larger than 32-bit physical
 	  addresses.  This feature may not be available on all cores.
@@ -205,6 +213,9 @@ config PHYS_64BIT
 
 	  If in doubt, say N here.
 
+config PTE_64BIT
+	def_bool PHYS_64BIT
+
 config ALTIVEC
 	bool "AltiVec Support"
 	depends on 6xx || POWER4
-- 
1.7.2.5



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