[PATCH 0/2] arm64: Cut rebuild time when changing CONFIG_BLK_DEV_INITRD

[PATCH 0/2] arm64: Cut rebuild time when changing CONFIG_BLK_DEV_INITRD

[Florian Fainelli]

Hi all,

While investigating why ARM64 required a ton of objects to be rebuilt
when toggling CONFIG_DEV_BLK_INITRD, it became clear that this was
because we define __early_init_dt_declare_initrd() differently and we do
that in arch/arm64/include/asm/memory.h which gets included by a fair
amount of other header files, and translation units as well.

This patch series proposes adding an empty initrd.h to satisfy the need
for drivers/of/fdt.c to unconditionally include that file, and moves the
custom __early_init_dt_declare_initrd() definition away from
asm/memory.h

This cuts the number of objects rebuilds from 1920 down to 26, so a
factor 73 approximately.

Apologies for the long CC list, please let me know how you would go
about merging that and if another approach would be preferable, e.g:
introducing a CONFIG_ARCH_INITRD_BELOW_START_OK Kconfig option or
something like that.

Florian Fainelli (2):
  arch: Add asm-generic/initrd.h and make use of it for most
    architectures
  arm64: Create asm/initrd.h

 arch/alpha/include/asm/Kbuild      |  1 +
 arch/arc/include/asm/Kbuild        |  1 +
 arch/arm/include/asm/Kbuild        |  1 +
 arch/arm64/include/asm/initrd.h    | 13 +++++++++++++
 arch/arm64/include/asm/memory.h    |  8 --------
 arch/c6x/include/asm/Kbuild        |  1 +
 arch/h8300/include/asm/Kbuild      |  1 +
 arch/hexagon/include/asm/Kbuild    |  1 +
 arch/ia64/include/asm/Kbuild       |  1 +
 arch/m68k/include/asm/Kbuild       |  1 +
 arch/microblaze/include/asm/Kbuild |  1 +
 arch/mips/include/asm/Kbuild       |  1 +
 arch/nds32/include/asm/Kbuild      |  1 +
 arch/nios2/include/asm/Kbuild      |  1 +
 arch/openrisc/include/asm/Kbuild   |  1 +
 arch/parisc/include/asm/Kbuild     |  1 +
 arch/powerpc/include/asm/Kbuild    |  1 +
 arch/riscv/include/asm/Kbuild      |  1 +
 arch/s390/include/asm/Kbuild       |  1 +
 arch/sh/include/asm/Kbuild         |  1 +
 arch/sparc/include/asm/Kbuild      |  1 +
 arch/um/include/asm/Kbuild         |  1 +
 arch/unicore32/include/asm/Kbuild  |  1 +
 arch/x86/include/asm/Kbuild        |  1 +
 arch/xtensa/include/asm/Kbuild     |  1 +
 drivers/of/fdt.c                   |  1 +
 include/asm-generic/initrd.h       |  1 +
 27 files changed, 38 insertions(+), 8 deletions(-)
 create mode 100644 arch/arm64/include/asm/initrd.h
 create mode 100644 include/asm-generic/initrd.h

-- 
2.17.1

[PATCH 1/2] arch: Add asm-generic/initrd.h and make use of it for most architectures

[Florian Fainelli]

In preparation for separating the definition of
__early_init_dt_declare_initrd() on ARM64 in order to cut the amount of
files that require a rebuild when CONFIG_BLK_DEV_INITRD value is
changed, introduce an empty asm-generic initrd.h file and update all
architectures but arm64 to make use of it.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/alpha/include/asm/Kbuild      | 1 +
 arch/arc/include/asm/Kbuild        | 1 +
 arch/arm/include/asm/Kbuild        | 1 +
 arch/c6x/include/asm/Kbuild        | 1 +
 arch/h8300/include/asm/Kbuild      | 1 +
 arch/hexagon/include/asm/Kbuild    | 1 +
 arch/ia64/include/asm/Kbuild       | 1 +
 arch/m68k/include/asm/Kbuild       | 1 +
 arch/microblaze/include/asm/Kbuild | 1 +
 arch/mips/include/asm/Kbuild       | 1 +
 arch/nds32/include/asm/Kbuild      | 1 +
 arch/nios2/include/asm/Kbuild      | 1 +
 arch/openrisc/include/asm/Kbuild   | 1 +
 arch/parisc/include/asm/Kbuild     | 1 +
 arch/powerpc/include/asm/Kbuild    | 1 +
 arch/riscv/include/asm/Kbuild      | 1 +
 arch/s390/include/asm/Kbuild       | 1 +
 arch/sh/include/asm/Kbuild         | 1 +
 arch/sparc/include/asm/Kbuild      | 1 +
 arch/um/include/asm/Kbuild         | 1 +
 arch/unicore32/include/asm/Kbuild  | 1 +
 arch/x86/include/asm/Kbuild        | 1 +
 arch/xtensa/include/asm/Kbuild     | 1 +
 include/asm-generic/initrd.h       | 1 +
 24 files changed, 24 insertions(+)
 create mode 100644 include/asm-generic/initrd.h

diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index 0580cb8c84b2..cd6f723aed1b 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += compat.h
 generic-y += exec.h
 generic-y += export.h
 generic-y += fb.h
+generic-y += initrd.h
 generic-y += irq_work.h
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index feed50ce89fa..ba18632aa493 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -10,6 +10,7 @@ generic-y += fb.h
 generic-y += ftrace.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kmap_types.h
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index 1d66db9c9db5..b91d5b32e64f 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -4,6 +4,7 @@ generic-y += early_ioremap.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += kdebug.h
 generic-y += local.h
diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild
index 33a2c94fed0d..9e14cf6e89b4 100644
--- a/arch/c6x/include/asm/Kbuild
+++ b/arch/c6x/include/asm/Kbuild
@@ -13,6 +13,7 @@ generic-y += extable.h
 generic-y += fb.h
 generic-y += futex.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += io.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild
index a5d0b2991f47..7d4e06a757c8 100644
--- a/arch/h8300/include/asm/Kbuild
+++ b/arch/h8300/include/asm/Kbuild
@@ -19,6 +19,7 @@ generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hash.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild
index 47c4da3d64a4..0be62abf2123 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -13,6 +13,7 @@ generic-y += fb.h
 generic-y += ftrace.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += iomap.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild
index 557bbc8ba9f5..1a1f1e4ba0d5 100644
--- a/arch/ia64/include/asm/Kbuild
+++ b/arch/ia64/include/asm/Kbuild
@@ -1,5 +1,6 @@
 generic-y += compat.h
 generic-y += exec.h
+generic-y += initrd.h
 generic-y += irq_work.h
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild
index a4b8d3331a9e..9903551e0c9c 100644
--- a/arch/m68k/include/asm/Kbuild
+++ b/arch/m68k/include/asm/Kbuild
@@ -7,6 +7,7 @@ generic-y += exec.h
 generic-y += extable.h
 generic-y += futex.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild
index 569ba9e670c1..ec37e6304be5 100644
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -11,6 +11,7 @@ generic-y += exec.h
 generic-y += extable.h
 generic-y += fb.h
 generic-y += hardirq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild
index 9a81e72119da..005ef04a4c73 100644
--- a/arch/mips/include/asm/Kbuild
+++ b/arch/mips/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += device.h
 generic-y += dma-contiguous.h
 generic-y += emergency-restart.h
 generic-y += export.h
+generic-y += initrd.h
 generic-y += irq_work.h
 generic-y += local64.h
 generic-y += mcs_spinlock.h
diff --git a/arch/nds32/include/asm/Kbuild b/arch/nds32/include/asm/Kbuild
index dbc4e5422550..1400aaf0c840 100644
--- a/arch/nds32/include/asm/Kbuild
+++ b/arch/nds32/include/asm/Kbuild
@@ -25,6 +25,7 @@ generic-y += ftrace.h
 generic-y += gpio.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += irq.h
diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild
index 8fde4fa2c34f..d89de02549ee 100644
--- a/arch/nios2/include/asm/Kbuild
+++ b/arch/nios2/include/asm/Kbuild
@@ -18,6 +18,7 @@ generic-y += ftrace.h
 generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild
index eb87cd8327c8..296fd55e8473 100644
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -15,6 +15,7 @@ generic-y += fb.h
 generic-y += ftrace.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild
index 2013d639e735..1382d78a2477 100644
--- a/arch/parisc/include/asm/Kbuild
+++ b/arch/parisc/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += div64.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index 3196d227e351..e3ea67c30605 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -1,5 +1,6 @@
 generic-y += div64.h
 generic-y += export.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += local64.h
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index efdbe311e936..0e67ed69c423 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -17,6 +17,7 @@ generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hash.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index e3239772887a..dc618745d427 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -13,6 +13,7 @@ generic-y += div64.h
 generic-y += emergency-restart.h
 generic-y += export.h
 generic-y += fb.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kmap_types.h
diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild
index 6a5609a55965..c006a7cf3a43 100644
--- a/arch/sh/include/asm/Kbuild
+++ b/arch/sh/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += div64.h
 generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += exec.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += local.h
diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild
index 410b263ef5c8..a5772c2a96c8 100644
--- a/arch/sparc/include/asm/Kbuild
+++ b/arch/sparc/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += div64.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += export.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += linkage.h
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index b10dde6cb793..032cfe1b530b 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -12,6 +12,7 @@ generic-y += ftrace.h
 generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += io.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild
index 1372553dc0a9..32e7dea45fcd 100644
--- a/arch/unicore32/include/asm/Kbuild
+++ b/arch/unicore32/include/asm/Kbuild
@@ -13,6 +13,7 @@ generic-y += ftrace.h
 generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild
index a0ab9ab61c75..290bd1c3ee2d 100644
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -9,5 +9,6 @@ generated-y += xen-hypercalls.h
 generic-y += dma-contiguous.h
 generic-y += early_ioremap.h
 generic-y += export.h
+generic-y += initrd.h
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index 82c756431b49..f2c363f2d22a 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -9,6 +9,7 @@ generic-y += exec.h
 generic-y += extable.h
 generic-y += fb.h
 generic-y += hardirq.h
+generic-y += initrd.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
diff --git a/include/asm-generic/initrd.h b/include/asm-generic/initrd.h
new file mode 100644
index 000000000000..b1a49677fe25
--- /dev/null
+++ b/include/asm-generic/initrd.h
@@ -0,0 +1 @@
+/* no content, but patch(1) dislikes empty files */
-- 
2.17.1

[PATCH 2/2] arm64: Create asm/initrd.h

[Florian Fainelli]

ARM64 is the only architecture that requires a re-definition of
__early_init_dt_declare_initrd(). Now that we added the infrastructure
in asm-generic to provide an asm/initrd.h file, properly break up that
definition from asm/memory.h and make use of that header in
drivers/of/fdt.c where this is used.

This significantly cuts the number of objects that need to be rebuilt on
ARM64 due to the repercusions of including asm/memory.h in several
places.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm64/include/asm/initrd.h | 13 +++++++++++++
 arch/arm64/include/asm/memory.h |  8 --------
 drivers/of/fdt.c                |  1 +
 3 files changed, 14 insertions(+), 8 deletions(-)
 create mode 100644 arch/arm64/include/asm/initrd.h

diff --git a/arch/arm64/include/asm/initrd.h b/arch/arm64/include/asm/initrd.h
new file mode 100644
index 000000000000..0c9572485810
--- /dev/null
+++ b/arch/arm64/include/asm/initrd.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_INITRD_H
+#define __ASM_INITRD_H
+
+#ifdef CONFIG_BLK_DEV_INITRD
+#define __early_init_dt_declare_initrd(__start, __end)			\
+	do {								\
+		initrd_start = (__start);				\
+		initrd_end = (__end);					\
+	} while (0)
+#endif
+
+#endif /* __ASM_INITRD_H */
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index b96442960aea..dc3ca21ba240 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -168,14 +168,6 @@
 #define IOREMAP_MAX_ORDER	(PMD_SHIFT)
 #endif
 
-#ifdef CONFIG_BLK_DEV_INITRD
-#define __early_init_dt_declare_initrd(__start, __end)			\
-	do {								\
-		initrd_start = (__start);				\
-		initrd_end = (__end);					\
-	} while (0)
-#endif
-
 #ifndef __ASSEMBLY__
 
 #include <linux/bitops.h>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 800ad252cf9c..4e4711af907b 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -28,6 +28,7 @@
 
 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
 #include <asm/page.h>
+#include <asm/initrd.h>
 
 #include "of_private.h"
 
-- 
2.17.1