From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C8C034FF7E; Thu, 18 Dec 2025 15:19:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766071163; cv=none; b=n/f8qcKCL/8N4CNwK5WsZr8FQfPF8xgw3QU4TeIutuErNfoqgTy/ABamhCj0JoZCH6IM+tyTMbiXmhkWQ+2s+QDqNOu5lwjLnxZxzivywqy5hBQ9rAPfy7GRnEFH8hK0sKbRLb9uu6LOMlEY+FUzmirIAPAMmSjlIhrYxjnb+TI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766071163; c=relaxed/simple; bh=lNs6h/Tn6npet126alMraOzQWAdHEXctBs9xqAtaI9M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s+a/lgjDJysMn/VQch1pPb9fnlYGqFrvgERtjbotp3iczuPQwCQRM9xuhK2e57JvmjkT7SUjlVIwZfRLw6Z75oF+dYXop2x6mKGl8uXDqorL9ceNUTsXDtvjbFFSbonI6gYe6R819bWvZLPCd+lJgHeLHq9psi6qTuCtgxau0jw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Mh9vl8cO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Mh9vl8cO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7037CC4CEFB; Thu, 18 Dec 2025 15:19:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766071163; bh=lNs6h/Tn6npet126alMraOzQWAdHEXctBs9xqAtaI9M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Mh9vl8cO8g3zNkwI0qQEywi4S51l7RjjDFD+/NdoNaLkGqyRx/m6rMMWhNUAe/f7p ayNsqjF0dga4H1hM0eBbT33xWsC3nBBDkCMb7NkPrqoSg4v74duc9/Q2XD17wHljdm yojfvvwp03tfkXiwRvLb2udPhmZpeXD5MFNHzWHzDxSj0GvUIms23wcwgZC2ISjAcM k1paKBb6BaFYcG4p5jQMYoICzy5HtZwhZLJ07d6szQNEo9aHjh1dO3uVvrc+DZy+9Z SPQMmbht7uYv8YsFigMu2U/9a4X5PAY02AWgZ98AhbxtK9EMCcOShNkr0uzeJPImFd MlBo/i78fGf2Q== Date: Thu, 18 Dec 2025 15:19:17 +0000 From: Will Deacon To: Ahmed Tiba Cc: linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, tony.luck@intel.com, bp@alien8.de, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, rafael@kernel.org, linux-doc@vger.kernel.org, Dmitry.Lamerov@arm.com, Michael.Zhao2@arm.com Subject: Re: [PATCH 11/12] ras: add DeviceTree estatus provider driver Message-ID: References: <20251218134311.2309421-1-ahmed.tiba@arm.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251218134311.2309421-1-ahmed.tiba@arm.com> On Thu, Dec 18, 2025 at 01:42:47PM +0000, Ahmed Tiba wrote: > On Thu, 18 Dec 2025 12:13:25PM +0000, Will Deacon wrote: > >> Introduce a platform driver that maps the CPER status block described > >> in DeviceTree, feeds it into the estatus core and handles either IRQ- or > >> poll-driven notifications. Arm64 gains a FIX_ESTATUS_IRQ slot so the > >> driver can safely map the shared buffer while copying records. > >> > >> Signed-off-by: Ahmed Tiba > >> --- > >> MAINTAINERS | 1 + > >> arch/arm64/include/asm/fixmap.h | 5 + > >> drivers/ras/Kconfig | 14 ++ > >> drivers/ras/Makefile | 1 + > >> drivers/ras/estatus-dt.c | 318 ++++++++++++++++++++++++++++++++ > >> include/linux/estatus.h | 3 +- > >> 6 files changed, 341 insertions(+), 1 deletion(-) > >> create mode 100644 drivers/ras/estatus-dt.c > >> > >> diff --git a/MAINTAINERS b/MAINTAINERS > >> index 6b2ef2ddc0c7..5567d5e82053 100644 > >> --- a/MAINTAINERS > >> +++ b/MAINTAINERS > >> @@ -21761,6 +21761,7 @@ RAS ERROR STATUS > >> M: Ahmed Tiba > >> S: Maintained > >> F: Documentation/devicetree/bindings/ras/arm,ras-ffh.yaml > >> +F: drivers/ras/estatus-dt.c > >> F: drivers/firmware/efi/estatus.c > >> F: include/linux/estatus.h > >> > >> diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h > >> index 65555284446e..85ffba87bab9 100644 > >> --- a/arch/arm64/include/asm/fixmap.h > >> +++ b/arch/arm64/include/asm/fixmap.h > >> @@ -64,6 +64,11 @@ enum fixed_addresses { > >> #endif > >> #endif /* CONFIG_ACPI_APEI_GHES */ > >> > >> +#ifdef CONFIG_RAS_ESTATUS_DT > >> + /* Used for ESTATUS mapping from assorted contexts */ > >> + FIX_ESTATUS_IRQ, > >> +#endif /* CONFIG_RAS_ESTATUS_DT */ > > > > Why do we need this in addition to the four existing GHES slots? The DT > > code doesn't use it and I was assuming that the ACPI code would continue > > to use the existing irq; is that not the case? > > > We still need a dedicated slot when only the DT provider is built. > All four GHES slots are defined as part of the ACPI implementation, > so they are not present in a DT-only configuration. > > The estatus core always requests a fixmap index from each provider > before copying a CPER record. As a result, the DT driver must supply > its own slot to return a valid enum value to satisfy the common code. Sorry, but I still don't follow this. The DT code doesn't use the fixmap, does it? It looks like it maps the buffer ahead of time using devm_ioremap_resource() and then the accessors don't use the fixmap index at all, hence the horrible '(void)fixmap_idx;' cast which presumably stops the compiler from complaining about an unused variable. Will