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From: Will Deacon <will@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com,
	james.morse@arm.com, joey.gouly@arm.com, maz@kernel.org
Subject: Re: [PATCH v3 14/20] arm64: entry: handle all vectors with C
Date: Fri, 4 Jun 2021 18:13:09 +0100	[thread overview]
Message-ID: <20210604171309.GD3416@willie-the-truck> (raw)
In-Reply-To: <20210525183302.56293-15-mark.rutland@arm.com>

On Tue, May 25, 2021 at 07:32:56PM +0100, Mark Rutland wrote:
> We have 16 architectural exception vectors, and depending on kernel
> configuration we handle 8 or 12 of these with C code, and we handle 8 or
> 4 of these as sepcial cases in the entry assembly.
> 
> It would be nicer if the entry assembly were uniform for all exceptions,
> and we deferred any specific handling of the exceptions to C code. This
> way the entry assembly can be more easily templated without ifdeffery or
> special cases, and it's easier to modify the handling of these cases in
> future (e.g. to dump additional registers other context).
> 
> This patch reworks the entry code so that we always have a C handler for
> every architectural exception vector, with the entry assembly being
> completely uniform. We now have to handle exceptions from EL1t and EL1h,
> and also have to handle exceptions from AArch32 even when the kernel is
> built without CONFIG_COMPAT. To make this clear and to simplify
> templating, we rename the top-level exception handlers with a consistent
> naming scheme:
> 
>   asm: <el+sp>_<regsize>_<type>
>   c:   <el+sp>_<regsize>_<type>_handler
> 
> .. where:
> 
>   <el+sp> is `el1t`, `el1h`, or `el0t`
>   <regsize> is `64` or `32`
>   <type> is `sync`, `irq`, `fiq`, or `error`
> 
> ... e.g.
> 
>   asm: el1h_64_sync
>   c:   el1h_64_sync_handler
> 
> ... with lower-level handlers simply using "el1" and "compat" as today.
> 
> For unexpected exceptions, this information is passed to
> panic_unandled(), so it can report the specific vector an unexpected

panic_unandled()? Cor blimey, guv'nor!

> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index b4e9860a2227..d9a2625168aa 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -45,16 +45,7 @@
>  	.endr
>  	.endm
>  
> -/*
> - * Bad Abort numbers
> - *-----------------
> - */
> -#define BAD_SYNC	0
> -#define BAD_IRQ		1
> -#define BAD_FIQ		2
> -#define BAD_ERROR	3
> -
> -	.macro kernel_ventry, el:req, regsize:req, label:req
> +	.macro kernel_ventry, el:req, ht, regsize:req, label:req

Might as well have ht:req given that you did it for the others earlier on?

> -	.macro entry_handler el:req, regsize:req, label:req
> +	.macro entry_handler el:req, ht, regsize:req, label:req

Same here.

Will

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  reply	other threads:[~2021-06-04 17:15 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-25 18:32 [PATCH v3 00/20] arm64: entry: migrate more code to C Mark Rutland
2021-05-25 18:32 ` [PATCH v3 01/20] arm64: remove redundant local_daif_mask() in bad_mode() Mark Rutland
2021-05-27 12:34   ` Marc Zyngier
2021-05-25 18:32 ` [PATCH v3 02/20] arm64: entry: unmask IRQ+FIQ after EL0 handling Mark Rutland
2021-06-04 16:47   ` Will Deacon
2021-05-25 18:32 ` [PATCH v3 03/20] arm64: entry: convert SError handlers to C Mark Rutland
2021-05-25 18:32 ` [PATCH v3 04/20] arm64: entry: move arm64_preempt_schedule_irq to entry-common.c Mark Rutland
2021-05-25 18:32 ` [PATCH v3 05/20] arm64: entry: move preempt logic to C Mark Rutland
2021-06-04 15:43   ` Will Deacon
2021-06-04 16:54     ` Mark Rutland
2021-05-25 18:32 ` [PATCH v3 06/20] arm64: entry: add a call_on_irq_stack helper Mark Rutland
2021-05-25 18:32 ` [PATCH v3 07/20] arm64: entry: convert IRQ+FIQ handlers to C Mark Rutland
2021-05-25 18:32 ` [PATCH v3 08/20] arm64: entry: organise entry handlers consistently Mark Rutland
2021-06-04 16:51   ` Will Deacon
2021-06-04 17:39     ` Mark Rutland
2021-06-04 17:44       ` Will Deacon
2021-06-04 18:01         ` Mark Rutland
2021-05-25 18:32 ` [PATCH v3 09/20] arm64: entry: organise entry vectors consistently Mark Rutland
2021-05-25 18:32 ` [PATCH v3 10/20] arm64: entry: consolidate EL1 exception returns Mark Rutland
2021-05-25 18:32 ` [PATCH v3 11/20] arm64: entry: move bad_mode() to entry-common.c Mark Rutland
2021-06-04 16:57   ` Will Deacon
2021-06-04 17:42     ` Mark Rutland
2021-06-04 17:43       ` Will Deacon
2021-05-25 18:32 ` [PATCH v3 12/20] arm64: entry: improve bad_mode() Mark Rutland
2021-05-25 18:32 ` [PATCH v3 13/20] arm64: entry: template the entry asm functions Mark Rutland
2021-05-25 18:32 ` [PATCH v3 14/20] arm64: entry: handle all vectors with C Mark Rutland
2021-06-04 17:13   ` Will Deacon [this message]
2021-05-25 18:32 ` [PATCH v3 15/20] arm64: entry: fold el1_inv() into el1h_64_sync_handler() Mark Rutland
2021-05-25 18:32 ` [PATCH v3 16/20] arm64: entry: split bad stack entry Mark Rutland
2021-05-25 18:32 ` [PATCH v3 17/20] arm64: entry: split SDEI entry Mark Rutland
2021-05-25 18:33 ` [PATCH v3 18/20] arm64: entry: make NMI entry/exit functions static Mark Rutland
2021-05-25 18:33 ` [PATCH v3 19/20] arm64: entry: don't instrument entry code with KCOV Mark Rutland
2021-06-04 17:16   ` Will Deacon
2021-06-04 17:49     ` Mark Rutland
2021-05-25 18:33 ` [PATCH v3 20/20] arm64: idle: don't instrument idle " Mark Rutland
2021-05-27 14:06 ` [PATCH v3 00/20] arm64: entry: migrate more code to C Catalin Marinas
2021-05-27 15:31 ` Marc Zyngier

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