2023-05-31 20:55:03

by Sergey Shtylyov

[permalink] [raw]
Subject: [PATCH v5] sh: avoid using IRQ0 on SH3/4

Now that IRQ0 is no longer returned by platform_get_irq() and its ilk (they
now return -EINVAL instead). However, the code supporting SH3/4 SoCs still
maps the IRQ #s starting at 0 -- modify that code to start the IRQ #s from
16 instead.

The patch should mostly affect the AP-SH4A-3A/AP-SH4AD-0A boards as they
indeed use IRQ0 for the SMSC911x compatible Ethernet chip...

Fixes: ce753ad1549c ("platform: finally disallow IRQ0 in platform_get_irq() and its ilk")
Signed-off-by: Sergey Shtylyov <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Tested-by: John Paul Adrian Glaubitz <[email protected]>

---
The patch is against Linus Torvalds' 'linux.git' repo.

Changes in version 5:
- updated the patch description and the "Fixes:" tag as the patch disallowing
the use of IRQ0 was merged meanwhile.

Changes in version 4:
- fixed up the off-chip base IRQ #s for the Dreamcast/Highlander/R2D/SE7724
boards.

Changes in version 3:
- added an appropriate Fixes: tag and added a passage about it to the patch
description;
- added actual cases of the boards using IRQ0 to the patch description;
- added Geert Uytterhoeven's and John Paul Adrian Glaubitz's tags;
- updated the link to point to the version 2 of the patch.

Changes in version 2:
- changed cmp/ge to cmp/hs in the assembly code.

arch/sh/include/mach-common/mach/highlander.h | 2 +-
arch/sh/include/mach-common/mach/r2d.h | 2 +-
arch/sh/include/mach-dreamcast/mach/sysasic.h | 2 +-
arch/sh/include/mach-se/mach/se7724.h | 2 +-
arch/sh/kernel/cpu/sh3/entry.S | 4 ++--
include/linux/sh_intc.h | 6 +++---
6 files changed, 9 insertions(+), 9 deletions(-)

Index: linux/arch/sh/include/mach-common/mach/highlander.h
===================================================================
--- linux.orig/arch/sh/include/mach-common/mach/highlander.h
+++ linux/arch/sh/include/mach-common/mach/highlander.h
@@ -176,7 +176,7 @@
#define IVDR_CK_ON 4 /* iVDR Clock ON */
#endif

-#define HL_FPGA_IRQ_BASE 200
+#define HL_FPGA_IRQ_BASE (200 + 16)
#define HL_NR_IRL 15

#define IRQ_AX88796 (HL_FPGA_IRQ_BASE + 0)
Index: linux/arch/sh/include/mach-common/mach/r2d.h
===================================================================
--- linux.orig/arch/sh/include/mach-common/mach/r2d.h
+++ linux/arch/sh/include/mach-common/mach/r2d.h
@@ -47,7 +47,7 @@

#define IRLCNTR1 (PA_BCR + 0) /* Interrupt Control Register1 */

-#define R2D_FPGA_IRQ_BASE 100
+#define R2D_FPGA_IRQ_BASE (100 + 16)

#define IRQ_VOYAGER (R2D_FPGA_IRQ_BASE + 0)
#define IRQ_EXT (R2D_FPGA_IRQ_BASE + 1)
Index: linux/arch/sh/include/mach-dreamcast/mach/sysasic.h
===================================================================
--- linux.orig/arch/sh/include/mach-dreamcast/mach/sysasic.h
+++ linux/arch/sh/include/mach-dreamcast/mach/sysasic.h
@@ -22,7 +22,7 @@
takes.
*/

-#define HW_EVENT_IRQ_BASE 48
+#define HW_EVENT_IRQ_BASE (48 + 16)

/* IRQ 13 */
#define HW_EVENT_VSYNC (HW_EVENT_IRQ_BASE + 5) /* VSync */
Index: linux/arch/sh/include/mach-se/mach/se7724.h
===================================================================
--- linux.orig/arch/sh/include/mach-se/mach/se7724.h
+++ linux/arch/sh/include/mach-se/mach/se7724.h
@@ -37,7 +37,7 @@
#define IRQ2_IRQ evt2irq(0x640)

/* Bits in IRQ012 registers */
-#define SE7724_FPGA_IRQ_BASE 220
+#define SE7724_FPGA_IRQ_BASE (220 + 16)

/* IRQ0 */
#define IRQ0_BASE SE7724_FPGA_IRQ_BASE
Index: linux/arch/sh/kernel/cpu/sh3/entry.S
===================================================================
--- linux.orig/arch/sh/kernel/cpu/sh3/entry.S
+++ linux/arch/sh/kernel/cpu/sh3/entry.S
@@ -470,9 +470,9 @@ ENTRY(handle_interrupt)
mov r4, r0 ! save vector->jmp table offset for later

shlr2 r4 ! vector to IRQ# conversion
- add #-0x10, r4

- cmp/pz r4 ! is it a valid IRQ?
+ mov #0x10, r5
+ cmp/hs r5, r4 ! is it a valid IRQ?
bt 10f

/*
Index: linux/include/linux/sh_intc.h
===================================================================
--- linux.orig/include/linux/sh_intc.h
+++ linux/include/linux/sh_intc.h
@@ -13,9 +13,9 @@
/*
* Convert back and forth between INTEVT and IRQ values.
*/
-#ifdef CONFIG_CPU_HAS_INTEVT
-#define evt2irq(evt) (((evt) >> 5) - 16)
-#define irq2evt(irq) (((irq) + 16) << 5)
+#ifdef CONFIG_CPU_HAS_INTEVT /* Avoid IRQ0 (invalid for platform devices) */
+#define evt2irq(evt) ((evt) >> 5)
+#define irq2evt(irq) ((irq) << 5)
#else
#define evt2irq(evt) (evt)
#define irq2evt(irq) (irq)


Subject: Re: [PATCH v5] sh: avoid using IRQ0 on SH3/4

Hi Sergey!

On Wed, 2023-05-31 at 23:34 +0300, Sergey Shtylyov wrote:
> Now that IRQ0 is no longer returned by platform_get_irq() and its ilk (they
> now return -EINVAL instead). However, the code supporting SH3/4 SoCs still
> maps the IRQ #s starting at 0 -- modify that code to start the IRQ #s from
> 16 instead.
>
> The patch should mostly affect the AP-SH4A-3A/AP-SH4AD-0A boards as they
> indeed use IRQ0 for the SMSC911x compatible Ethernet chip...

I'm not sure I understand. Does that mean that the Ethernet controller on
the AP-SH4A-3A/AP-SH4AD-0A boards will no longer work after this patch
has been applied?

Adrian

>
> Fixes: ce753ad1549c ("platform: finally disallow IRQ0 in platform_get_irq() and its ilk")
> Signed-off-by: Sergey Shtylyov <[email protected]>
> Reviewed-by: Geert Uytterhoeven <[email protected]>
> Tested-by: Geert Uytterhoeven <[email protected]>
> Tested-by: John Paul Adrian Glaubitz <[email protected]>
>
> ---
> The patch is against Linus Torvalds' 'linux.git' repo.
>
> Changes in version 5:
> - updated the patch description and the "Fixes:" tag as the patch disallowing
> the use of IRQ0 was merged meanwhile.
>
> Changes in version 4:
> - fixed up the off-chip base IRQ #s for the Dreamcast/Highlander/R2D/SE7724
> boards.
>
> Changes in version 3:
> - added an appropriate Fixes: tag and added a passage about it to the patch
> description;
> - added actual cases of the boards using IRQ0 to the patch description;
> - added Geert Uytterhoeven's and John Paul Adrian Glaubitz's tags;
> - updated the link to point to the version 2 of the patch.
>
> Changes in version 2:
> - changed cmp/ge to cmp/hs in the assembly code.
>
> arch/sh/include/mach-common/mach/highlander.h | 2 +-
> arch/sh/include/mach-common/mach/r2d.h | 2 +-
> arch/sh/include/mach-dreamcast/mach/sysasic.h | 2 +-
> arch/sh/include/mach-se/mach/se7724.h | 2 +-
> arch/sh/kernel/cpu/sh3/entry.S | 4 ++--
> include/linux/sh_intc.h | 6 +++---
> 6 files changed, 9 insertions(+), 9 deletions(-)
>
> Index: linux/arch/sh/include/mach-common/mach/highlander.h
> ===================================================================
> --- linux.orig/arch/sh/include/mach-common/mach/highlander.h
> +++ linux/arch/sh/include/mach-common/mach/highlander.h
> @@ -176,7 +176,7 @@
> #define IVDR_CK_ON 4 /* iVDR Clock ON */
> #endif
>
> -#define HL_FPGA_IRQ_BASE 200
> +#define HL_FPGA_IRQ_BASE (200 + 16)
> #define HL_NR_IRL 15
>
> #define IRQ_AX88796 (HL_FPGA_IRQ_BASE + 0)
> Index: linux/arch/sh/include/mach-common/mach/r2d.h
> ===================================================================
> --- linux.orig/arch/sh/include/mach-common/mach/r2d.h
> +++ linux/arch/sh/include/mach-common/mach/r2d.h
> @@ -47,7 +47,7 @@
>
> #define IRLCNTR1 (PA_BCR + 0) /* Interrupt Control Register1 */
>
> -#define R2D_FPGA_IRQ_BASE 100
> +#define R2D_FPGA_IRQ_BASE (100 + 16)
>
> #define IRQ_VOYAGER (R2D_FPGA_IRQ_BASE + 0)
> #define IRQ_EXT (R2D_FPGA_IRQ_BASE + 1)
> Index: linux/arch/sh/include/mach-dreamcast/mach/sysasic.h
> ===================================================================
> --- linux.orig/arch/sh/include/mach-dreamcast/mach/sysasic.h
> +++ linux/arch/sh/include/mach-dreamcast/mach/sysasic.h
> @@ -22,7 +22,7 @@
> takes.
> */
>
> -#define HW_EVENT_IRQ_BASE 48
> +#define HW_EVENT_IRQ_BASE (48 + 16)
>
> /* IRQ 13 */
> #define HW_EVENT_VSYNC (HW_EVENT_IRQ_BASE + 5) /* VSync */
> Index: linux/arch/sh/include/mach-se/mach/se7724.h
> ===================================================================
> --- linux.orig/arch/sh/include/mach-se/mach/se7724.h
> +++ linux/arch/sh/include/mach-se/mach/se7724.h
> @@ -37,7 +37,7 @@
> #define IRQ2_IRQ evt2irq(0x640)
>
> /* Bits in IRQ012 registers */
> -#define SE7724_FPGA_IRQ_BASE 220
> +#define SE7724_FPGA_IRQ_BASE (220 + 16)
>
> /* IRQ0 */
> #define IRQ0_BASE SE7724_FPGA_IRQ_BASE
> Index: linux/arch/sh/kernel/cpu/sh3/entry.S
> ===================================================================
> --- linux.orig/arch/sh/kernel/cpu/sh3/entry.S
> +++ linux/arch/sh/kernel/cpu/sh3/entry.S
> @@ -470,9 +470,9 @@ ENTRY(handle_interrupt)
> mov r4, r0 ! save vector->jmp table offset for later
>
> shlr2 r4 ! vector to IRQ# conversion
> - add #-0x10, r4
>
> - cmp/pz r4 ! is it a valid IRQ?
> + mov #0x10, r5
> + cmp/hs r5, r4 ! is it a valid IRQ?
> bt 10f
>
> /*
> Index: linux/include/linux/sh_intc.h
> ===================================================================
> --- linux.orig/include/linux/sh_intc.h
> +++ linux/include/linux/sh_intc.h
> @@ -13,9 +13,9 @@
> /*
> * Convert back and forth between INTEVT and IRQ values.
> */
> -#ifdef CONFIG_CPU_HAS_INTEVT
> -#define evt2irq(evt) (((evt) >> 5) - 16)
> -#define irq2evt(irq) (((irq) + 16) << 5)
> +#ifdef CONFIG_CPU_HAS_INTEVT /* Avoid IRQ0 (invalid for platform devices) */
> +#define evt2irq(evt) ((evt) >> 5)
> +#define irq2evt(irq) ((irq) << 5)
> #else
> #define evt2irq(evt) (evt)
> #define irq2evt(irq) (irq)

--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer
`. `' Physicist
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913

2023-06-01 19:19:22

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH v5] sh: avoid using IRQ0 on SH3/4

On 6/1/23 9:38 AM, John Paul Adrian Glaubitz wrote:
[...]
>> Now that IRQ0 is no longer returned by platform_get_irq() and its ilk (they
>> now return -EINVAL instead). However, the code supporting SH3/4 SoCs still
>> maps the IRQ #s starting at 0 -- modify that code to start the IRQ #s from
>> 16 instead.

Now that I'm re-reading this passage, it seems unfinished... :-/

>> The patch should mostly affect the AP-SH4A-3A/AP-SH4AD-0A boards as they
>> indeed use IRQ0 for the SMSC911x compatible Ethernet chip...
>
> I'm not sure I understand. Does that mean that the Ethernet controller on
> the AP-SH4A-3A/AP-SH4AD-0A boards will no longer work after this patch
> has been applied?

Contrariwise, they should start working again! :-)
Here's the story as I understand it:

1. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=965b2aa78fbcb831acf4f669f494da201f4bcace broke IRQ0 use in the SMSC 9111x
driver.

2. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5ef9b803a4af0f5e42012176889b40bb2a978b18 fixed IRQ0 use in that driver.

3. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce753ad1549cbe9ccaea4c06a1f5fa47432c8289 totally stopped returning IRQ0
from platform_get_irq(), thus breaking that driver again.

4. This patch remaps IRQ0 to IRQ16 and thus fixes the SMSC 911x driver again.

[...]

MBR, Sergey