linux-mips
[Top] [All Lists]

Re: [PATCH v2] mips: delete __cpuinit/__CPUINIT usage from MIPS code

To: Paul Gortmaker <paul.gortmaker@windriver.com>
Subject: Re: [PATCH v2] mips: delete __cpuinit/__CPUINIT usage from MIPS code
From: Ralf Baechle <ralf@linux-mips.org>
Date: Thu, 20 Jun 2013 04:15:50 +0200
Cc: David Daney <ddaney.cavm@gmail.com>, linux-mips@linux-mips.org
In-reply-to: <20130620002806.GA15693@windriver.com>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <1371566339-18336-1-git-send-email-paul.gortmaker@windriver.com> <51C22E75.3020001@gmail.com> <20130620002806.GA15693@windriver.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.5.21 (2010-09-15)
On Wed, Jun 19, 2013 at 08:28:07PM -0400, Paul Gortmaker wrote:

> I am literally in the middle of typing up a mail to linux-arch that
> explains this, and that the no-op step comes in at the beginning of the
> merge window, and that the big purge comes at the end.
> 
> However, I do not want that process to be set in stone ; as Ralf indicated,
> he expected some changes to the mips tree and wanted to deal with the
> conflicts himself (which is fine by me!) and so we can do that at the
> expense of some temporary section warnings.  This is why I explicitly
> called them out in the above commit log.
> 
> > Once that is working, we would make a second pass and remove the
> > symbols themselves.
> 
> Yep, thanks for looking at things; it sounds like we are in alignment
> with how to proceed here -- only that I wasn't quick enough in getting
> the steps published and the no-op phase into linux-next.

And I having come to the same conclusion have spent the last few hours
running a test build with the following patch applied.  It does

 - make __cpuinit, __cpuinitdata, __cpuinitconst, __cpuexit, __cpuexitdata
   and __cpuexitconst nops.
 - with .cpuinit.* and .cpuexit.* sections now being unused support for
   these sections in linker scripts and modpost is no longer required.

  Ralf

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 include/asm-generic/vmlinux.lds.h | 20 ---------------
 include/linux/init.h              | 18 +++++++-------
 scripts/mod/modpost.c             | 52 +++++++--------------------------------
 3 files changed, 18 insertions(+), 72 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h 
b/include/asm-generic/vmlinux.lds.h
index eb58d2d..eab362e 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -76,14 +76,6 @@
 #define DEV_DISCARD(sec) *(.dev##sec)
 #endif
 
-#ifdef CONFIG_HOTPLUG_CPU
-#define CPU_KEEP(sec)    *(.cpu##sec)
-#define CPU_DISCARD(sec)
-#else
-#define CPU_KEEP(sec)
-#define CPU_DISCARD(sec) *(.cpu##sec)
-#endif
-
 #if defined(CONFIG_MEMORY_HOTPLUG)
 #define MEM_KEEP(sec)    *(.mem##sec)
 #define MEM_DISCARD(sec)
@@ -184,8 +176,6 @@
        *(.data..shared_aligned) /* percpu related */                   \
        DEV_KEEP(init.data)                                             \
        DEV_KEEP(exit.data)                                             \
-       CPU_KEEP(init.data)                                             \
-       CPU_KEEP(exit.data)                                             \
        MEM_KEEP(init.data)                                             \
        MEM_KEEP(exit.data)                                             \
        *(.data.unlikely)                                               \
@@ -374,8 +364,6 @@
                *(.ref.rodata)                                          \
                DEV_KEEP(init.rodata)                                   \
                DEV_KEEP(exit.rodata)                                   \
-               CPU_KEEP(init.rodata)                                   \
-               CPU_KEEP(exit.rodata)                                   \
                MEM_KEEP(init.rodata)                                   \
                MEM_KEEP(exit.rodata)                                   \
        }                                                               \
@@ -418,8 +406,6 @@
                *(.ref.text)                                            \
        DEV_KEEP(init.text)                                             \
        DEV_KEEP(exit.text)                                             \
-       CPU_KEEP(init.text)                                             \
-       CPU_KEEP(exit.text)                                             \
        MEM_KEEP(init.text)                                             \
        MEM_KEEP(exit.text)                                             \
                *(.text.unlikely)
@@ -504,7 +490,6 @@
 #define INIT_DATA                                                      \
        *(.init.data)                                                   \
        DEV_DISCARD(init.data)                                          \
-       CPU_DISCARD(init.data)                                          \
        MEM_DISCARD(init.data)                                          \
        KERNEL_CTORS()                                                  \
        MCOUNT_REC()                                                    \
@@ -512,7 +497,6 @@
        FTRACE_EVENTS()                                                 \
        TRACE_SYSCALLS()                                                \
        DEV_DISCARD(init.rodata)                                        \
-       CPU_DISCARD(init.rodata)                                        \
        MEM_DISCARD(init.rodata)                                        \
        CLK_OF_TABLES()                                                 \
        CLKSRC_OF_TABLES()                                              \
@@ -522,22 +506,18 @@
 #define INIT_TEXT                                                      \
        *(.init.text)                                                   \
        DEV_DISCARD(init.text)                                          \
-       CPU_DISCARD(init.text)                                          \
        MEM_DISCARD(init.text)
 
 #define EXIT_DATA                                                      \
        *(.exit.data)                                                   \
        DEV_DISCARD(exit.data)                                          \
        DEV_DISCARD(exit.rodata)                                        \
-       CPU_DISCARD(exit.data)                                          \
-       CPU_DISCARD(exit.rodata)                                        \
        MEM_DISCARD(exit.data)                                          \
        MEM_DISCARD(exit.rodata)
 
 #define EXIT_TEXT                                                      \
        *(.exit.text)                                                   \
        DEV_DISCARD(exit.text)                                          \
-       CPU_DISCARD(exit.text)                                          \
        MEM_DISCARD(exit.text)
 
 #define EXIT_CALL                                                      \
diff --git a/include/linux/init.h b/include/linux/init.h
index 8618147..a4eefc1 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -94,12 +94,12 @@
 #define __exit          __section(.exit.text) __exitused __cold notrace
 
 /* Used for HOTPLUG_CPU */
-#define __cpuinit        __section(.cpuinit.text) __cold notrace
-#define __cpuinitdata    __section(.cpuinit.data)
-#define __cpuinitconst   __constsection(.cpuinit.rodata)
-#define __cpuexit        __section(.cpuexit.text) __exitused __cold notrace
-#define __cpuexitdata    __section(.cpuexit.data)
-#define __cpuexitconst   __constsection(.cpuexit.rodata)
+#define __cpuinit
+#define __cpuinitdata
+#define __cpuinitconst
+#define __cpuexit
+#define __cpuexitdata
+#define __cpuexitconst
 
 /* Used for MEMORY_HOTPLUG */
 #define __meminit        __section(.meminit.text) __cold notrace
@@ -118,9 +118,9 @@
 #define __INITRODATA   .section        ".init.rodata","a",%progbits
 #define __FINITDATA    .previous
 
-#define __CPUINIT        .section      ".cpuinit.text", "ax"
-#define __CPUINITDATA    .section      ".cpuinit.data", "aw"
-#define __CPUINITRODATA  .section      ".cpuinit.rodata", "a"
+#define __CPUINIT
+#define __CPUINITDATA
+#define __CPUINITRODATA
 
 #define __MEMINIT        .section      ".meminit.text", "ax"
 #define __MEMINITDATA    .section      ".meminit.data", "aw"
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index a4be8e1..3acbf080 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -861,24 +861,23 @@ static void check_section(const char *modname, struct 
elf_info *elf,
 
 
 #define ALL_INIT_DATA_SECTIONS \
-       ".init.setup$", ".init.rodata$", \
-       ".cpuinit.rodata$", ".meminit.rodata$", \
-       ".init.data$", ".cpuinit.data$", ".meminit.data$"
+       ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
+       ".init.data$", ".meminit.data$"
 #define ALL_EXIT_DATA_SECTIONS \
-       ".exit.data$", ".cpuexit.data$", ".memexit.data$"
+       ".exit.data$", ".memexit.data$"
 
 #define ALL_INIT_TEXT_SECTIONS \
-       ".init.text$", ".cpuinit.text$", ".meminit.text$"
+       ".init.text$", ".meminit.text$"
 #define ALL_EXIT_TEXT_SECTIONS \
-       ".exit.text$", ".cpuexit.text$", ".memexit.text$"
+       ".exit.text$", ".memexit.text$"
 
 #define ALL_PCI_INIT_SECTIONS  \
        ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
        ".pci_fixup_enable$", ".pci_fixup_resume$", \
        ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
 
-#define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
-#define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
+#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
+#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
 
 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
@@ -887,11 +886,9 @@ static void check_section(const char *modname, struct 
elf_info *elf,
 #define TEXT_SECTIONS ".text$"
 
 #define INIT_SECTIONS      ".init.*"
-#define CPU_INIT_SECTIONS  ".cpuinit.*"
 #define MEM_INIT_SECTIONS  ".meminit.*"
 
 #define EXIT_SECTIONS      ".exit.*"
-#define CPU_EXIT_SECTIONS  ".cpuexit.*"
 #define MEM_EXIT_SECTIONS  ".memexit.*"
 
 /* init data sections */
@@ -979,48 +976,20 @@ const struct sectioncheck sectioncheck[] = {
        .mismatch = DATA_TO_ANY_EXIT,
        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 },
-/* Do not reference init code/data from cpuinit/meminit code/data */
+/* Do not reference init code/data from meminit code/data */
 {
        .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
        .tosec   = { INIT_SECTIONS, NULL },
        .mismatch = XXXINIT_TO_SOME_INIT,
        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 },
-/* Do not reference cpuinit code/data from meminit code/data */
-{
-       .fromsec = { MEM_INIT_SECTIONS, NULL },
-       .tosec   = { CPU_INIT_SECTIONS, NULL },
-       .mismatch = XXXINIT_TO_SOME_INIT,
-       .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
-},
-/* Do not reference meminit code/data from cpuinit code/data */
-{
-       .fromsec = { CPU_INIT_SECTIONS, NULL },
-       .tosec   = { MEM_INIT_SECTIONS, NULL },
-       .mismatch = XXXINIT_TO_SOME_INIT,
-       .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
-},
-/* Do not reference exit code/data from cpuexit/memexit code/data */
+/* Do not reference exit code/data from memexit code/data */
 {
        .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
        .tosec   = { EXIT_SECTIONS, NULL },
        .mismatch = XXXEXIT_TO_SOME_EXIT,
        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 },
-/* Do not reference cpuexit code/data from memexit code/data */
-{
-       .fromsec = { MEM_EXIT_SECTIONS, NULL },
-       .tosec   = { CPU_EXIT_SECTIONS, NULL },
-       .mismatch = XXXEXIT_TO_SOME_EXIT,
-       .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
-},
-/* Do not reference memexit code/data from cpuexit code/data */
-{
-       .fromsec = { CPU_EXIT_SECTIONS, NULL },
-       .tosec   = { MEM_EXIT_SECTIONS, NULL },
-       .mismatch = XXXEXIT_TO_SOME_EXIT,
-       .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
-},
 /* Do not use exit code/data from init code */
 {
        .fromsec = { ALL_INIT_SECTIONS, NULL },
@@ -1089,8 +1058,6 @@ static const struct sectioncheck *section_mismatch(
  * Pattern 2:
  *   Many drivers utilise a *driver container with references to
  *   add, remove, probe functions etc.
- *   These functions may often be marked __cpuinit and we do not want to
- *   warn here.
  *   the pattern is identified by:
  *   tosec   = init or exit section
  *   fromsec = data section
@@ -1249,7 +1216,6 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, 
Elf_Addr addr,
 /*
  * Convert a section name to the function/data attribute
  * .init.text => __init
- * .cpuinit.data => __cpudata
  * .memexitconst => __memconst
  * etc.
  *

<Prev in Thread] Current Thread [Next in Thread>