2014-04-08 08:56:13

by Paul Bolle

[permalink] [raw]
Subject: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

The Kconfig symbol ARC_HAS_COH_RTSC was removed in v3.13. The Kconfig
entry for ISS_SMP_EXTN still had a select for that symbol. That select
was just removed in commit d345ea2892ae ("ARC: Remove
ARC_HAS_COH_RTSC").

But selecting ARC_HAS_COH_RTSC was the only thing ISS_SMP_EXTN ever
did. That means that since v3.13 setting ISS_SMP_EXTN was effectively a
nop anyhow. So ISS_SMP_EXTN can as well be removed entirely.

Signed-off-by: Paul Bolle <[email protected]>
---
Tested wit "git grep" only.

arch/arc/plat-arcfpga/Kconfig | 13 -------------
1 file changed, 13 deletions(-)

diff --git a/arch/arc/plat-arcfpga/Kconfig b/arch/arc/plat-arcfpga/Kconfig
index 33058aa40e77..fde2a3fb604d 100644
--- a/arch/arc/plat-arcfpga/Kconfig
+++ b/arch/arc/plat-arcfpga/Kconfig
@@ -8,7 +8,6 @@

menuconfig ARC_PLAT_FPGA_LEGACY
bool "\"Legacy\" ARC FPGA dev Boards"
- select ISS_SMP_EXTN if SMP
help
Support for ARC development boards, provided by Synopsys.
These are based on FPGA or ISS. e.g.
@@ -29,18 +28,6 @@ config ARC_BOARD_ML509
help
ARC ML509 FPGA Ref Platform (Xilinx Virtex-5 Based)

-config ISS_SMP_EXTN
- bool "ARC SMP Extensions (ISS Models only)"
- default n
- depends on SMP
- help
- SMP Extensions to ARC700, in a "simulation only" Model, supported in
- ARC ISS (Instruction Set Simulator).
- The SMP extensions include:
- -IDU (Interrupt Distribution Unit)
- -XTL (To enable CPU start/stop/set-PC for another CPU)
- It doesn't provide coherent Caches and/or Atomic Ops (LLOCK/SCOND)
-
config ARC_SERIAL_BAUD
int "UART Baud rate"
default "115200"
--
1.9.0


2014-04-08 09:24:44

by Vineet Gupta

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

Hi Paul,

On Tuesday 08 April 2014 02:26 PM, Paul Bolle wrote:
> The Kconfig symbol ARC_HAS_COH_RTSC was removed in v3.13. The Kconfig
> entry for ISS_SMP_EXTN still had a select for that symbol. That select
> was just removed in commit d345ea2892ae ("ARC: Remove
> ARC_HAS_COH_RTSC").
>
> But selecting ARC_HAS_COH_RTSC was the only thing ISS_SMP_EXTN ever
> did. That means that since v3.13 setting ISS_SMP_EXTN was effectively a
> nop anyhow. So ISS_SMP_EXTN can as well be removed entirely.

There's obvious bitrot here - however this code is not dead yet !
I have a unpushed fix which uses this Kconfig item.

diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
index a44e22ebc1b7..4d1bddc34b5b 100644
--- a/arch/arc/plat-arcfpga/Makefile
+++ b/arch/arc/plat-arcfpga/Makefile
@@ -9,4 +9,4 @@
KBUILD_CFLAGS += -Iarch/arc/plat-arcfpga/include

obj-y := platform.o irq.o
-obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_ISS_SMP_EXTN) += smp.o

-Vineet

2014-04-08 09:36:12

by Paul Bolle

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

Vineet,

On Tue, 2014-04-08 at 09:18 +0000, Vineet Gupta wrote:
> There's obvious bitrot here - however this code is not dead yet !
> I have a unpushed fix which uses this Kconfig item.

I see. Would it bother you if I send you a reminder if that fix (or
something equivalent) hasn't been added in some future release?

Thanks,


Paul Bolle

2014-04-08 10:42:26

by Paul Bolle

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

Vineet,

On Tue, 2014-04-08 at 09:18 +0000, Vineet Gupta wrote:
> There's obvious bitrot here - however this code is not dead yet !
> I have a unpushed fix which uses this Kconfig item.
>
> diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
> index a44e22ebc1b7..4d1bddc34b5b 100644
> --- a/arch/arc/plat-arcfpga/Makefile
> +++ b/arch/arc/plat-arcfpga/Makefile
> @@ -9,4 +9,4 @@
> KBUILD_CFLAGS += -Iarch/arc/plat-arcfpga/include
>
> obj-y := platform.o irq.o
> -obj-$(CONFIG_SMP) += smp.o
> +obj-$(CONFIG_ISS_SMP_EXTN) += smp.o

I just realized that this means you're only using ISS_SMP_EXTN as an
alias for SMP, aren't you? Ie, smp.o will now be built if both
ARC_PLAT_FPGA_LEGACY and SMP are set. That will not change by this
patch.

So unless you're planning to do something else too if ISS_SMP_EXTN is
set there seems to be little value in using this symbol like that.


Paul Bolle

2014-04-08 10:51:56

by Vineet Gupta

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

On Tuesday 08 April 2014 04:12 PM, Paul Bolle wrote:
> Vineet,
>
> On Tue, 2014-04-08 at 09:18 +0000, Vineet Gupta wrote:
>> There's obvious bitrot here - however this code is not dead yet !
>> I have a unpushed fix which uses this Kconfig item.
>>
>> diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
>> index a44e22ebc1b7..4d1bddc34b5b 100644
>> --- a/arch/arc/plat-arcfpga/Makefile
>> +++ b/arch/arc/plat-arcfpga/Makefile
>> @@ -9,4 +9,4 @@
>> KBUILD_CFLAGS += -Iarch/arc/plat-arcfpga/include
>>
>> obj-y := platform.o irq.o
>> -obj-$(CONFIG_SMP) += smp.o
>> +obj-$(CONFIG_ISS_SMP_EXTN) += smp.o
> I just realized that this means you're only using ISS_SMP_EXTN as an
> alias for SMP, aren't you? Ie, smp.o will now be built if both
> ARC_PLAT_FPGA_LEGACY and SMP are set. That will not change by this
> patch.
>
> So unless you're planning to do something else too if ISS_SMP_EXTN is
> set there seems to be little value in using this symbol like that.

Indeed so - I just sent u one hunk to give an idea. There's other code too where
CONFIG_SMP will be replaced by CONFIG_ISS_SMP_EXTN as I'm decoupling SMP support
from this SMP extension.

I'll push a patch later today - which will hopefully hit mainline within this
merge window - if not in one of the rcs.

-Vineet

2014-04-08 10:52:07

by Paul Bolle

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

On Tue, 2014-04-08 at 12:42 +0200, Paul Bolle wrote:
> I just realized that this means you're only using ISS_SMP_EXTN as an
> alias for SMP, aren't you? Ie, smp.o will now be built if both
> ARC_PLAT_FPGA_LEGACY and SMP are set. That will not change by this
> patch.

Of course, the patch does add the ability to set both
ARC_PLAT_FPGA_LEGACY and SMP but still disable building smp.o. Would
that be a useful ability?

> So unless you're planning to do something else too if ISS_SMP_EXTN is
> set there seems to be little value in using this symbol like that.


Paul Bolle

2014-04-08 11:20:06

by Vineet Gupta

[permalink] [raw]
Subject: Re: [PATCH] ARC: Remove ISS_SMP_EXTN entirely

On Tuesday 08 April 2014 04:19 PM, Vineet Gupta wrote:
>
> I'll push a patch later today - which will hopefully hit mainline within this
> merge window - if not in one of the rcs.


Here's the patch I want to push - care to take a look.

Note that it might still seem that ISS_SMP_EXTN symbol is uselss (and alias for
SMP) because the code for SMP_EXTN_2 is still in works and will take some more
time to hit upstream. So you see the motivation of this change now ?

--------------------->
>From c7f4c1084d2563def0f5bc5dc2b1b857bc4b50f0 Mon Sep 17 00:00:00 2001
From: Vineet Gupta <[email protected]>
Date: Fri, 28 Feb 2014 16:13:44 +0800
Subject: [PATCH] ARC: [SMP] ISS SMP extension bitrot

* Move extension specific code out of common SMP code
* Don't enable it by default for SMP

Signed-off-by: Vineet Gupta <[email protected]>
---
arch/arc/include/asm/irq.h | 2 --
arch/arc/kernel/irq.c | 18 ------------------
arch/arc/plat-arcfpga/Makefile | 2 +-
arch/arc/plat-arcfpga/platform.c | 4 ++--
arch/arc/plat-arcfpga/smp.c | 18 ++++++++++++++++++
5 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index 291a70db68b8..781f57f25bd8 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -19,8 +19,6 @@
#include <asm-generic/irq.h>

extern void arc_init_IRQ(void);
-extern int get_hw_config_num_irq(void);
-
void arc_local_timer_setup(unsigned int cpu);

#endif
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index a4b141ee9a6a..7d653c0d0773 100644
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -150,24 +150,6 @@ void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
set_irq_regs(old_regs);
}

-int get_hw_config_num_irq(void)
-{
- uint32_t val = read_aux_reg(ARC_REG_VECBASE_BCR);
-
- switch (val & 0x03) {
- case 0:
- return 16;
- case 1:
- return 32;
- case 2:
- return 8;
- default:
- return 0;
- }
-
- return 0;
-}
-
/*
* arch_local_irq_enable - Enable interrupts.
*
diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
index a44e22ebc1b7..4d1bddc34b5b 100644
--- a/arch/arc/plat-arcfpga/Makefile
+++ b/arch/arc/plat-arcfpga/Makefile
@@ -9,4 +9,4 @@
KBUILD_CFLAGS += -Iarch/arc/plat-arcfpga/include

obj-y := platform.o irq.o
-obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_ISS_SMP_EXTN) += smp.o
diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
index 19b76b61f44b..213394a15cd2 100644
--- a/arch/arc/plat-arcfpga/platform.c
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -169,7 +169,7 @@ static void __init plat_fpga_early_init(void)

arc_fpga_serial_init();

-#ifdef CONFIG_SMP
+#ifdef CONFIG_ISS_SMP_EXTN
iss_model_init_early_smp();
#endif
}
@@ -211,7 +211,7 @@ MACHINE_START(ANGEL4, "angel4")
.init_early = plat_fpga_early_init,
.init_machine = plat_fpga_populate_dev,
.init_irq = plat_fpga_init_IRQ,
-#ifdef CONFIG_SMP
+#ifdef CONFIG_ISS_SMP_EXTN
.init_smp = iss_model_init_smp,
#endif
MACHINE_END
diff --git a/arch/arc/plat-arcfpga/smp.c b/arch/arc/plat-arcfpga/smp.c
index 8a12741f5f7a..92bad9122077 100644
--- a/arch/arc/plat-arcfpga/smp.c
+++ b/arch/arc/plat-arcfpga/smp.c
@@ -42,6 +42,24 @@ static void iss_model_smp_wakeup_cpu(int cpu, unsigned long pc)

}

+static inline int get_hw_config_num_irq(void)
+{
+ uint32_t val = read_aux_reg(ARC_REG_VECBASE_BCR);
+
+ switch (val & 0x03) {
+ case 0:
+ return 16;
+ case 1:
+ return 32;
+ case 2:
+ return 8;
+ default:
+ return 0;
+ }
+
+ return 0;
+}
+
/*
* Any SMP specific init any CPU does when it comes up.
* Here we setup the CPU to enable Inter-Processor-Interrupts
--
1.8.3.2