Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <e9a5f27effa12a058fa944034ee581817f2e7928.camel@physik.fu-berlin.de>
Subject: Re: [PATCH v5] sh: avoid using IRQ0 on SH3/4
From:   John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
To:     Sergey Shtylyov <s.shtylyov@omp.ru>, Rich Felker <dalias@libc.org>,
        linux-sh@vger.kernel.org
Cc:     Yoshinori Sato <ysato@users.sourceforge.jp>,
        linux-kernel@vger.kernel.org
Date:   Thu, 01 Jun 2023 08:38:01 +0200
In-Reply-To: <197b4ccb-2dc8-add6-02a5-2e241b15a5f9@omp.ru>
References: <197b4ccb-2dc8-add6-02a5-2e241b15a5f9@omp.ru>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8BIT
User-Agent: Evolution 3.48.1 
MIME-Version: 1.0
Precedence: bulk

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 <s.shtylyov@omp.ru>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
> 
> ---
> 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