[PATCH v3 0/5] kernel hacking: GCC optimization for better debug experience (-Og)

[PATCH v3 0/5] kernel hacking: GCC optimization for better debug experience (-Og)

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

Hi all,
I know some kernel developers was searching for a method to dissable GCC
optimizations, probably they want to apply GCC '-O0' option. But since Linux
kernel replys on GCC optimization to remove some dead code, so '-O0' just
breaks the build. They do need this because they want to debug kernel with
qemu, simics, kgtp or kgdb.

Thanks for the GCC '-Og' optimization level introduced in GCC 4.8, which
offers a reasonable level of optimization while maintaining fast compilation
and a good debugging experience. It is similar to '-O1' while perferring to
keep debug ability over runtime speed. With '-Og', we can build a kernel with
better debug ability and little performance drop after some simple change.

In this series, firstly introduce a new config CONFIG_NO_AUTO_INLINE after two
fixes for this new option. With this option, only functions explicitly marked
with "inline" will  be inlined. This will allow the function tracer to trace
more functions because it only traces functions that the compiler has not
inlined.

Then introduce new config CC_OPTIMIZE_FOR_DEBUGGING which apply '-Og'
optimization level for whole kernel, with a simple fix in fix_to_virt().
Currently I have only tested this option on x86 and ARM platform. Other
platforms should also work but probably need some compiling fixes as what
having done in this series. I leave that to who want to try this debug
option.

Comparison of vmlinux size: a bit smaller.

    w/o CONFIG_DEBUG_EXPERIENCE
    $ size vmlinux
       text    data     bss     dec     hex filename
    22665554   9709674  2920908 35296136        21a9388 vmlinux

    w/ CONFIG_DEBUG_EXPERIENCE
    $ size vmlinux
       text    data     bss     dec     hex filename
    21499032   10102758 2920908 34522698        20ec64a vmlinux


Comparison of system performance: a bit drop (~6%).
    This benchmark of kernel compilation is suggested by Ingo Molnar.
    https://lkml.org/lkml/2018/5/2/74

    Preparation: Set cpufreq to 'performance'.
    for ((cpu=0; cpu<120; cpu++)); do
      G=/sys/devices/system/cpu/cpu$cpu/cpufreq/scaling_governor
      [ -f $G ] && echo performance > $G
    done

    w/o CONFIG_DEBUG_EXPERIENCE
    $ perf stat --repeat 5 --null --pre                 '\
        cp -a kernel ../kernel.copy.$(date +%s);         \
        rm -rf *;                                        \
        git checkout .;                                  \
        echo 1 > /proc/sys/vm/drop_caches;               \
        find ../kernel* -type f | xargs cat >/dev/null;  \
        make -j kernel >/dev/null;                       \
        make clean >/dev/null 2>&1;                      \
        sync                                            '\
                                                         \
        make -j8 >/dev/null

     Performance counter stats for 'make -j8' (5 runs):

        219.764246652 seconds time elapsed                   ( +-  0.78% )

    w/ CONFIG_DEBUG_EXPERIENCE
    $ perf stat --repeat 5 --null --pre                 '\
        cp -a kernel ../kernel.copy.$(date +%s);         \
        rm -rf *;                                        \
        git checkout .;                                  \
        echo 1 > /proc/sys/vm/drop_caches;               \
        find ../kernel* -type f | xargs cat >/dev/null;  \
        make -j kernel >/dev/null;                       \
        make clean >/dev/null 2>&1;                      \
        sync                                            '\
                                                         \
        make -j8 >/dev/null

    Performance counter stats for 'make -j8' (5 runs):

         233.574187771 seconds time elapsed                  ( +-  0.19% )

Changbin Du (5):
  x86/mm: surround level4_kernel_pgt with #ifdef
    CONFIG_X86_5LEVEL...#endif
  regulator: add dummy function of_find_regulator_by_node
  kernel hacking: new config NO_AUTO_INLINE to disable compiler
    auto-inline optimizations
  kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og
    optimization
  asm-generic: fix build error in fix_to_virt with
    CONFIG_CC_OPTIMIZE_FOR_DEBUGGING

 Makefile                          | 10 ++++++++++
 arch/arm/mm/mmu.c                 |  2 +-
 arch/x86/include/asm/pgtable_64.h |  2 ++
 arch/x86/kernel/head64.c          | 13 ++++++-------
 drivers/regulator/internal.h      |  9 +++++++--
 include/linux/compiler-gcc.h      |  2 +-
 include/linux/compiler.h          |  2 +-
 init/Kconfig                      | 19 +++++++++++++++++++
 lib/Kconfig.debug                 | 17 +++++++++++++++++
 9 files changed, 64 insertions(+), 12 deletions(-)

-- 
2.7.4

[PATCH v3 1/5] x86/mm: surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

The level4_kernel_pgt is only defined when X86_5LEVEL is enabled. So
surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif to
make code correct.

Signed-off-by: Changbin Du <changbin.du@intel.com>
---
 arch/x86/include/asm/pgtable_64.h |  2 ++
 arch/x86/kernel/head64.c          | 13 ++++++-------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 877bc27..9e7f667 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -15,7 +15,9 @@
 #include <linux/bitops.h>
 #include <linux/threads.h>
 
+#ifdef CONFIG_X86_5LEVEL
 extern p4d_t level4_kernel_pgt[512];
+#endif
 extern p4d_t level4_ident_pgt[512];
 extern pud_t level3_kernel_pgt[512];
 extern pud_t level3_ident_pgt[512];
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 0c408f8..775d7a6 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -143,16 +143,15 @@ unsigned long __head __startup_64(unsigned long physaddr,
 
 	pgd = fixup_pointer(&early_top_pgt, physaddr);
 	p = pgd + pgd_index(__START_KERNEL_map);
-	if (la57)
-		*p = (unsigned long)level4_kernel_pgt;
-	else
-		*p = (unsigned long)level3_kernel_pgt;
-	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
-
+#ifdef CONFIG_X86_5LEVEL
 	if (la57) {
+		*p = (unsigned long)level4_kernel_pgt;
 		p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
 		p4d[511] += load_delta;
-	}
+	} else
+#endif
+		*p = (unsigned long)level3_kernel_pgt;
+	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
 
 	pud = fixup_pointer(&level3_kernel_pgt, physaddr);
 	pud[510] += load_delta;
-- 
2.7.4

[PATCH v3 2/5] regulator: add dummy function of_find_regulator_by_node

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

If device tree is not enabled, of_find_regulator_by_node() should have
a dummy function since the function call is still there.

This is to fix build error after CONFIG_NO_AUTO_INLINE is introduced.
If this option is enabled, GCC will not auto-inline functions that are
not explicitly marked as inline.

In this case (no CONFIG_OF), the copmiler will report error in function
regulator_dev_lookup().

W/O NO_AUTO_INLINE, function of_get_regulator() is auto-inlined and then
the call to of_find_regulator_by_node() is optimized out since
of_get_regulator() always return NULL.

W/ NO_AUTO_INLINE, the return value of of_get_regulator() is a variable
so the call to of_find_regulator_by_node() cannot be optimized out. So
we need a stub of_find_regulator_by_node().

static struct regulator_dev *regulator_dev_lookup(struct device *dev,
						  const char *supply)
{
	struct regulator_dev *r = NULL;
	struct device_node *node;
	struct regulator_map *map;
	const char *devname = NULL;

	regulator_supply_alias(&dev, &supply);

	/* first do a dt based lookup */
	if (dev && dev->of_node) {
		node = of_get_regulator(dev, supply);
		if (node) {
			r = of_find_regulator_by_node(node);
			if (r)
				return r;
	...

Signed-off-by: Changbin Du <changbin.du@intel.com>
---
 drivers/regulator/internal.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index abfd56e..24fde1e 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -56,14 +56,19 @@ static inline struct regulator_dev *dev_to_rdev(struct device *dev)
 	return container_of(dev, struct regulator_dev, dev);
 }
 
-struct regulator_dev *of_find_regulator_by_node(struct device_node *np);
-
 #ifdef CONFIG_OF
+struct regulator_dev *of_find_regulator_by_node(struct device_node *np);
 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 			         const struct regulator_desc *desc,
 				 struct regulator_config *config,
 				 struct device_node **node);
 #else
+static inline struct regulator_dev *
+of_find_regulator_by_node(struct device_node *np)
+{
+	return NULL;
+}
+
 static inline struct regulator_init_data *
 regulator_of_get_init_data(struct device *dev,
 			   const struct regulator_desc *desc,
-- 
2.7.4

[PATCH v3 3/5] kernel hacking: new config NO_AUTO_INLINE to disable compiler auto-inline optimizations

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

This patch add a new kernel hacking option NO_AUTO_INLINE. Selecting
this option will prevent the compiler from optimizing the kernel by
auto-inlining functions not marked with the inline keyword.

With this option, only functions explicitly marked with "inline" will
be inlined. This will allow the function tracer to trace more functions
because it only traces functions that the compiler has not inlined.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

---
v2: Some grammar updates from Steven.
---
 Makefile          |  6 ++++++
 lib/Kconfig.debug | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/Makefile b/Makefile
index 619a85a..eb694f6 100644
--- a/Makefile
+++ b/Makefile
@@ -775,6 +775,12 @@ KBUILD_CFLAGS 	+= $(call cc-option, -femit-struct-debug-baseonly) \
 		   $(call cc-option,-fno-var-tracking)
 endif
 
+ifdef CONFIG_NO_AUTO_INLINE
+KBUILD_CFLAGS   += $(call cc-option, -fno-inline-functions) \
+		   $(call cc-option, -fno-inline-small-functions) \
+		   $(call cc-option, -fno-inline-functions-called-once)
+endif
+
 ifdef CONFIG_FUNCTION_TRACER
 ifndef CC_FLAGS_FTRACE
 CC_FLAGS_FTRACE := -pg
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c40c7b7..da52243 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -198,6 +198,23 @@ config GDB_SCRIPTS
 	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
 	  for further details.
 
+config NO_AUTO_INLINE
+	bool "Disable compiler auto-inline optimizations"
+	help
+	  This will prevent the compiler from optimizing the kernel by
+	  auto-inlining functions not marked with the inline keyword.
+	  With this option, only functions explicitly marked with
+	  "inline" will be inlined. This will allow the function tracer
+	  to trace more functions because it only traces functions that
+	  the compiler has not inlined.
+
+	  Enabling this function can help debugging a kernel if using
+	  the function tracer. But it can also change how the kernel
+	  works, because inlining functions may change the timing,
+	  which could make it difficult while debugging race conditions.
+
+	  If unsure, select N.
+
 config ENABLE_WARN_DEPRECATED
 	bool "Enable __deprecated logic"
 	default y
-- 
2.7.4

[PATCH v3 4/5] kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og optimization

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

This will apply GCC '-Og' optimization level which is supported
since GCC 4.8. This optimization level offers a reasonable level
of optimization while maintaining fast compilation and a good
debugging experience. It is similar to '-O1' while perferring
to keep debug ability over runtime speed.

If enabling this option breaks your kernel, you should either
disable this or find a fix (mostly in the arch code). Currently
this option has only been tested on x86_64 and arm platform.

This option can satisfy people who was searching for a method
to disable compiler optimizations so to achieve better kernel
debugging experience with kgdb or qemu.

The main problem of '-Og' is we must not use __attribute__((error(msg))).
The compiler will report error though the call to error function
still can be optimize out. So we must fallback to array tricky.

Comparison of vmlinux size: a bit smaller.

    w/o CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
    $ size vmlinux
       text    data     bss     dec     hex filename
    22665554   9709674  2920908 35296136        21a9388 vmlinux

    w/ CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
    $ size vmlinux
       text    data     bss     dec     hex filename
    21499032   10102758 2920908 34522698        20ec64a vmlinux

Comparison of system performance: a bit drop (~6%).
    This benchmark of kernel compilation is suggested by Ingo Molnar.
    https://lkml.org/lkml/2018/5/2/74

    Preparation: Set cpufreq to 'performance'.
    for ((cpu=0; cpu<120; cpu++)); do
      G=/sys/devices/system/cpu/cpu$cpu/cpufreq/scaling_governor
      [ -f $G ] && echo performance > $G
    done

    w/o CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
    $ perf stat --repeat 5 --null --pre                 '\
        cp -a kernel ../kernel.copy.$(date +%s);         \
        rm -rf *;                                        \
        git checkout .;                                  \
        echo 1 > /proc/sys/vm/drop_caches;               \
        find ../kernel* -type f | xargs cat >/dev/null;  \
        make -j kernel >/dev/null;                       \
        make clean >/dev/null 2>&1;                      \
        sync                                            '\
                                                         \
        make -j8 >/dev/null

    Performance counter stats for 'make -j8' (5 runs):

        219.764246652 seconds time elapsed                   ( +-  0.78% )

    w/ CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
    $ perf stat --repeat 5 --null --pre                 '\
        cp -a kernel ../kernel.copy.$(date +%s);         \
        rm -rf *;                                        \
        git checkout .;                                  \
        echo 1 > /proc/sys/vm/drop_caches;               \
        find ../kernel* -type f | xargs cat >/dev/null;  \
        make -j kernel >/dev/null;                       \
        make clean >/dev/null 2>&1;                      \
        sync                                            '\
                                                         \
        make -j8 >/dev/null

    Performance counter stats for 'make -j8' (5 runs):

         233.574187771 seconds time elapsed                  ( +-  0.19% )

Signed-off-by: Changbin Du <changbin.du@intel.com>

---
v3:
  o Rename DEBUG_EXPERIENCE to CC_OPTIMIZE_FOR_DEBUGGING
  o Move new configuration item to "General setup->Compiler optimization level"
v2:
  o Improve performance benchmark as suggested by Ingo.
  o Grammar updates in description. (Randy Dunlap)
---
 Makefile                     |  4 ++++
 include/linux/compiler-gcc.h |  2 +-
 include/linux/compiler.h     |  2 +-
 init/Kconfig                 | 19 +++++++++++++++++++
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index eb694f6..ae1dea7 100644
--- a/Makefile
+++ b/Makefile
@@ -639,6 +639,9 @@ KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
 KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
 KBUILD_CFLAGS	+= $(call cc-disable-warning, int-in-bool-context)
 
+ifdef CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
+KBUILD_CFLAGS	+= $(call cc-option, -Og)
+else
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS	+= $(call cc-option,-Oz,-Os)
 KBUILD_CFLAGS	+= $(call cc-disable-warning,maybe-uninitialized,)
@@ -649,6 +652,7 @@ else
 KBUILD_CFLAGS   += -O2
 endif
 endif
+endif
 
 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
 			$(call cc-disable-warning,maybe-uninitialized,))
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index b4bf73f..586ed11 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -192,7 +192,7 @@
 
 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
 
-#ifndef __CHECKER__
+#if !defined(__CHECKER__) && !defined(CONFIG_CC_OPTIMIZE_FOR_DEBUGGING)
 # define __compiletime_warning(message) __attribute__((warning(message)))
 # define __compiletime_error(message) __attribute__((error(message)))
 #endif /* __CHECKER__ */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index ab4711c..e97caf4 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -301,7 +301,7 @@ unsigned long read_word_at_a_time(const void *addr)
  * sparse see a constant array size without breaking compiletime_assert on old
  * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
  */
-# ifndef __CHECKER__
+# if !defined(__CHECKER__) && !defined(CONFIG_CC_OPTIMIZE_FOR_DEBUGGING)
 #  define __compiletime_error_fallback(condition) \
 	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
 # endif
diff --git a/init/Kconfig b/init/Kconfig
index f013afc..aa52535 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1036,6 +1036,25 @@ config CC_OPTIMIZE_FOR_SIZE
 
 	  If unsure, say N.
 
+config CC_OPTIMIZE_FOR_DEBUGGING
+	bool "Optimize for better debugging experience (-Og)"
+	select NO_AUTO_INLINE
+	help
+	  This will apply GCC '-Og' optimization level which is supported
+	  since GCC 4.8. This optimization level offers a reasonable level
+	  of optimization while maintaining fast compilation and a good
+	  debugging experience. It is similar to '-O1' while preferring to
+	  keep debug ability over runtime speed. The overall performance
+	  will drop a bit (~6%).
+
+	  Use only if you want to debug the kernel, especially if you want
+	  to have better kernel debugging experience with gdb facilities
+	  like kgdb or qemu. If enabling this option breaks your kernel,
+	  you should either disable this or find a fix (mostly in the arch
+	  code).
+
+	  If unsure, select N.
+
 endchoice
 
 config SYSCTL
-- 
2.7.4

[PATCH v3 5/5] asm-generic: fix build error in fix_to_virt with CONFIG_CC_OPTIMIZE_FOR_DEBUGGING

[changbin.du]

From: Changbin Du <changbin.du@intel.com>

With '-Og' optimization level, GCC would not optimize a count for a loop
as a constant value. But BUILD_BUG_ON() only accept compile-time constant
values. Let's use __fix_to_virt() to avoid the error.

arch/arm/mm/mmu.o: In function `fix_to_virt':
/home/changbin/work/linux/./include/asm-generic/fixmap.h:31: undefined reference to `__compiletime_assert_31'
Makefile:1051: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

Signed-off-by: Changbin Du <changbin.du@intel.com>

---
v2: use __fix_to_virt() to fix the issue.
---
 arch/arm/mm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e46a6a4..c08d74e 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1599,7 +1599,7 @@ static void __init early_fixmap_shutdown(void)
 		pte_t *pte;
 		struct map_desc map;
 
-		map.virtual = fix_to_virt(i);
+		map.virtual = __fix_to_virt(i);
 		pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);
 
 		/* Only i/o device mappings are supported ATM */
-- 
2.7.4

Re: [PATCH v3 3/5] kernel hacking: new config NO_AUTO_INLINE to disable compiler auto-inline optimizations

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 5626 bytes --]

Hi Changbin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.17-rc3 next-20180504]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180506-110946
config: arm64-allmodconfig (attached as .config)
compiler: aarch64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm64 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers/pci/host/pci-xgene.c: In function 'xgene_pcie_setup_ib_reg':
>> drivers/pci/host/pci-xgene.c:532:2: warning: 'pim_reg' may be used uninitialized in this function [-Wmaybe-uninitialized]
     xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   drivers/scsi/ufs/ufs-qcom.c: In function 'ufs_qcom_testbus_config':
>> drivers/scsi/ufs/ufs-qcom.c:1527:6: warning: 'offset' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int offset;
         ^~~~~~
>> drivers/scsi/ufs/ufs-qcom.c:1526:6: warning: 'reg' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int reg;
         ^~~

vim +/pim_reg +532 drivers/pci/host/pci-xgene.c

5f6b6ccd Tanmay Inamdar 2014-10-01  484  
5f6b6ccd Tanmay Inamdar 2014-10-01  485  static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port,
5f6b6ccd Tanmay Inamdar 2014-10-01  486  				    struct of_pci_range *range, u8 *ib_reg_mask)
5f6b6ccd Tanmay Inamdar 2014-10-01  487  {
5f6b6ccd Tanmay Inamdar 2014-10-01  488  	void __iomem *cfg_base = port->cfg_base;
d963ab22 Bjorn Helgaas  2016-10-06  489  	struct device *dev = port->dev;
5f6b6ccd Tanmay Inamdar 2014-10-01  490  	void *bar_addr;
4ecf6b0f Bjorn Helgaas  2016-10-06  491  	u32 pim_reg;
5f6b6ccd Tanmay Inamdar 2014-10-01  492  	u64 cpu_addr = range->cpu_addr;
5f6b6ccd Tanmay Inamdar 2014-10-01  493  	u64 pci_addr = range->pci_addr;
5f6b6ccd Tanmay Inamdar 2014-10-01  494  	u64 size = range->size;
5f6b6ccd Tanmay Inamdar 2014-10-01  495  	u64 mask = ~(size - 1) | EN_REG;
5f6b6ccd Tanmay Inamdar 2014-10-01  496  	u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
5f6b6ccd Tanmay Inamdar 2014-10-01  497  	u32 bar_low;
5f6b6ccd Tanmay Inamdar 2014-10-01  498  	int region;
5f6b6ccd Tanmay Inamdar 2014-10-01  499  
5f6b6ccd Tanmay Inamdar 2014-10-01  500  	region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
5f6b6ccd Tanmay Inamdar 2014-10-01  501  	if (region < 0) {
d963ab22 Bjorn Helgaas  2016-10-06  502  		dev_warn(dev, "invalid pcie dma-range config\n");
5f6b6ccd Tanmay Inamdar 2014-10-01  503  		return;
5f6b6ccd Tanmay Inamdar 2014-10-01  504  	}
5f6b6ccd Tanmay Inamdar 2014-10-01  505  
5f6b6ccd Tanmay Inamdar 2014-10-01  506  	if (range->flags & IORESOURCE_PREFETCH)
5f6b6ccd Tanmay Inamdar 2014-10-01  507  		flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
5f6b6ccd Tanmay Inamdar 2014-10-01  508  
5f6b6ccd Tanmay Inamdar 2014-10-01  509  	bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
5f6b6ccd Tanmay Inamdar 2014-10-01  510  	switch (region) {
5f6b6ccd Tanmay Inamdar 2014-10-01  511  	case 0:
4ecf6b0f Bjorn Helgaas  2016-10-06  512  		xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size);
5f6b6ccd Tanmay Inamdar 2014-10-01  513  		bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
5f6b6ccd Tanmay Inamdar 2014-10-01  514  		writel(bar_low, bar_addr);
5f6b6ccd Tanmay Inamdar 2014-10-01  515  		writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
4ecf6b0f Bjorn Helgaas  2016-10-06  516  		pim_reg = PIM1_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01  517  		break;
5f6b6ccd Tanmay Inamdar 2014-10-01  518  	case 1:
8e93c513 Bjorn Helgaas  2016-10-06  519  		xgene_pcie_writel(port, IBAR2, bar_low);
8e93c513 Bjorn Helgaas  2016-10-06  520  		xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
4ecf6b0f Bjorn Helgaas  2016-10-06  521  		pim_reg = PIM2_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01  522  		break;
5f6b6ccd Tanmay Inamdar 2014-10-01  523  	case 2:
8e93c513 Bjorn Helgaas  2016-10-06  524  		xgene_pcie_writel(port, IBAR3L, bar_low);
8e93c513 Bjorn Helgaas  2016-10-06  525  		xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
8e93c513 Bjorn Helgaas  2016-10-06  526  		xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
8e93c513 Bjorn Helgaas  2016-10-06  527  		xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
4ecf6b0f Bjorn Helgaas  2016-10-06  528  		pim_reg = PIM3_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01  529  		break;
5f6b6ccd Tanmay Inamdar 2014-10-01  530  	}
5f6b6ccd Tanmay Inamdar 2014-10-01  531  
4ecf6b0f Bjorn Helgaas  2016-10-06 @532  	xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
5f6b6ccd Tanmay Inamdar 2014-10-01  533  }
5f6b6ccd Tanmay Inamdar 2014-10-01  534  

:::::: The code at line 532 was first introduced by commit
:::::: 4ecf6b0f83523fb186dd1de9e2f1d324a2a413d9 PCI: xgene: Pass struct xgene_pcie_port to setup functions

:::::: TO: Bjorn Helgaas <bhelgaas@google.com>
:::::: CC: Bjorn Helgaas <bhelgaas@google.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [PATCH v3 2/5] regulator: add dummy function of_find_regulator_by_node

[Du, Changbin]

On Wed, May 09, 2018 at 05:21:14PM +0900, Mark Brown wrote:
> On Sun, May 06, 2018 at 08:20:13AM +0800, changbin.du@intel.com wrote:
> > From: Changbin Du <changbin.du@intel.com>
> > 
> > If device tree is not enabled, of_find_regulator_by_node() should have
> > a dummy function since the function call is still there.
> 
> Please do not submit new versions of already applied patches, please
> submit incremental updates to the existing code.  Modifying existing
> commits creates problems for other users building on top of those
> commits so it's best practice to only change pubished git commits if
> absolutely essential.

Hmm, I saw your merging notification too late. Let me refresh the series. Sorry
for confusing.

-- 
Thanks,
Changbin Du

Re: [PATCH v3 2/5] regulator: add dummy function of_find_regulator_by_node

[Mark Brown]

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On Sun, May 06, 2018 at 08:20:13AM +0800, changbin.du@intel.com wrote:
> From: Changbin Du <changbin.du@intel.com>
> 
> If device tree is not enabled, of_find_regulator_by_node() should have
> a dummy function since the function call is still there.

Please do not submit new versions of already applied patches, please
submit incremental updates to the existing code.  Modifying existing
commits creates problems for other users building on top of those
commits so it's best practice to only change pubished git commits if
absolutely essential.

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Re: [PATCH v3 2/5] regulator: add dummy function of_find_regulator_by_node

[Mark Brown]

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On Wed, May 09, 2018 at 04:13:42PM +0800, Du, Changbin wrote:
> On Wed, May 09, 2018 at 05:21:14PM +0900, Mark Brown wrote:

> > Please do not submit new versions of already applied patches, please
> > submit incremental updates to the existing code.  Modifying existing
> > commits creates problems for other users building on top of those
> > commits so it's best practice to only change pubished git commits if
> > absolutely essential.

> Hmm, I saw your merging notification too late. Let me refresh the series. Sorry
> for confusing.

No problem, just wanted to make sure I wasn't missing any updates from
this new version.

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