[PATCH v4] sh: avoid using IRQ0 on SH3/4

From: Sergey Shtylyov
Date: Tue May 03 2022 - 16:42:42 EST


Using IRQ0 by the platform devices is going to be disallowed soon (see [1])
and even now, when IRQ0 is about to be returned by platfrom_get_irq(), you
see a big warning. The code supporting SH3/4 SoCs 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...

[1] https://lore.kernel.org/all/025679e1-1f0a-ae4b-4369-01164f691511@xxxxxx/

Fixes: a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>

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

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)