From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 675DAC352A1 for ; Thu, 24 Nov 2022 20:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=NPnTcKp/lsTMqD9XIE+KTJ91oC7uSG4Ek1bIOS/WL+I=; b=NqLbxygKgdID6U jR+j6le5Oow1JWma4qMmmduSwob6a1Yn8Wc9efWnH4cL3YgLzckBj39m9Te1//4FI0ycMFPn6ziaK fgIeN1AH/8l5paHhmIU2uCCQA89vMQ9GVXM22AGQ+8X8uELf8lIgV0B9GjCMqmUWmjvr/ppMR8HaS 1JMFm0Br7bk1AdauE+q7PNTJkqi9/RX8F9WrNmU1Kms4+NsLH0JHNGJrBaBHnDaN5WXepf64b9/WC 6XYQRGcmfH0u2mu3OHu/sUzAjK75sYi35+Y4Q6usjo2gwlAotohe76POt1EtQRsfSYtKATGZBITo7 WMTV9gp3KzhEFXsTslLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oyJ8P-00BWMP-ES; Thu, 24 Nov 2022 20:47:49 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oyJ8M-00BWLU-BB for linux-riscv@lists.infradead.org; Thu, 24 Nov 2022 20:47:48 +0000 Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oyJ8D-0007r7-PG; Thu, 24 Nov 2022 21:47:37 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: "Lad, Prabhakar" Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Geert Uytterhoeven , Magnus Damm , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Guo Ren , Jisheng Zhang , Atish Patra , Anup Patel , Andrew Jones , Nathan Chancellor , Philipp Tomsich , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-renesas-soc@vger.kernel.org, Biju Das , Lad Prabhakar Subject: Re: [PATCH v4 7/7] soc: renesas: Add L2 cache management for RZ/Five SoC Date: Thu, 24 Nov 2022 21:47:36 +0100 Message-ID: <5258334.1IzOArtZ34@diego> In-Reply-To: References: <20221124172207.153718-1-prabhakar.mahadev-lad.rj@bp.renesas.com> <5382916.ejJDZkT8p0@diego> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221124_124746_577534_A33DD0C5 X-CRM114-Status: GOOD ( 52.36 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Am Donnerstag, 24. November 2022, 20:56:39 CET schrieb Lad, Prabhakar: > Hi Heiko, > = > Thank you for the review. > = > On Thu, Nov 24, 2022 at 6:30 PM Heiko St=FCbner wrote: > > > > Am Donnerstag, 24. November 2022, 18:22:07 CET schrieb Prabhakar: > > > From: Lad Prabhakar > > > > > > On the AX45MP core, cache coherency is a specification option so it m= ay > > > not be supported. In this case DMA will fail. As a workaround, firstl= y we > > > allocate a global dma coherent pool from which DMA allocations are ta= ken > > > and marked as non-cacheable + bufferable using the PMA region as spec= ified > > > in the device tree. Synchronization callbacks are implemented to > > > synchronize when doing DMA transactions. > > > > > > The Andes AX45MP core has a Programmable Physical Memory Attributes (= PMA) > > > block that allows dynamic adjustment of memory attributes in the runt= ime. > > > It contains a configurable amount of PMA entries implemented as CSR > > > registers to control the attributes of memory locations in interest. > > > > > > Below are the memory attributes supported: > > > * Device, Non-bufferable > > > * Device, bufferable > > > * Memory, Non-cacheable, Non-bufferable > > > * Memory, Non-cacheable, Bufferable > > > * Memory, Write-back, No-allocate > > > * Memory, Write-back, Read-allocate > > > * Memory, Write-back, Write-allocate > > > * Memory, Write-back, Read and Write-allocate > > > > > > This patch adds support to configure the memory attributes of the mem= ory > > > regions as passed from the l2 cache node and exposes the cache manage= ment > > > ops. > > > > > > More info about PMA (section 10.3): > > > Link: http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.= 0-Datasheet.pdf > > > > > > Signed-off-by: Lad Prabhakar > > > --- > > > RFC v3 -> v4 > > > * Made use of runtime patching instead of compile time > > > * Now just exposing single function ax45mp_no_iocp_cmo() for CMO hand= ling > > > * Added a check to make sure cache line size is always 64 bytes > > > * Renamed folder rzf -> rzfive > > > * Improved Kconfig description > > > * Dropped L2 cache configuration > > > * Dropped unnecessary casts > > > * Fixed comments pointed by Geert, apart from use of PTR_ALIGN_XYZ() = macros. > > > --- > > > arch/riscv/include/asm/cacheflush.h | 8 + > > > arch/riscv/include/asm/errata_list.h | 32 +- > > > drivers/soc/renesas/Kconfig | 7 + > > > drivers/soc/renesas/Makefile | 2 + > > > drivers/soc/renesas/rzfive/Kconfig | 6 + > > > drivers/soc/renesas/rzfive/Makefile | 3 + > > > drivers/soc/renesas/rzfive/ax45mp_cache.c | 415 ++++++++++++++++++++= ++ > > > drivers/soc/renesas/rzfive/ax45mp_sbi.h | 29 ++ > > > 8 files changed, 496 insertions(+), 6 deletions(-) > > > create mode 100644 drivers/soc/renesas/rzfive/Kconfig > > > create mode 100644 drivers/soc/renesas/rzfive/Makefile > > > create mode 100644 drivers/soc/renesas/rzfive/ax45mp_cache.c > > > create mode 100644 drivers/soc/renesas/rzfive/ax45mp_sbi.h > > > > > > diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include= /asm/cacheflush.h > > > index 4a04d1be7c67..3226f3aceafe 100644 > > > --- a/arch/riscv/include/asm/cacheflush.h > > > +++ b/arch/riscv/include/asm/cacheflush.h > > > @@ -61,6 +61,14 @@ static inline void riscv_noncoherent_supported(voi= d) {} > > > #define SYS_RISCV_FLUSH_ICACHE_LOCAL 1UL > > > #define SYS_RISCV_FLUSH_ICACHE_ALL (SYS_RISCV_FLUSH_ICACHE_LOCAL) > > > > > > +#ifdef CONFIG_AX45MP_L2_CACHE > > > +extern asmlinkage void ax45mp_no_iocp_cmo(unsigned int cache_size, v= oid *vaddr, > > > + size_t size, int dir, int ops= ); > > > +#else > > > +inline void ax45mp_no_iocp_cmo(unsigned int cache_size, void *vaddr, > > > + size_t size, int dir, int ops) {} > > > +#endif > > > + > > > #include > > > > > > #endif /* _ASM_RISCV_CACHEFLUSH_H */ > > > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/includ= e/asm/errata_list.h > > > index 48e899a8e7a9..300fed3bfd80 100644 > > > --- a/arch/riscv/include/asm/errata_list.h > > > +++ b/arch/riscv/include/asm/errata_list.h > > > @@ -125,8 +125,8 @@ asm volatile(ALTERNATIVE( = \ > > > #define THEAD_SYNC_S ".long 0x0190000b" > > > > > > #define ALT_CMO_OP(_op, _start, _size, _cachesize, _dir, _ops) = \ > > > -asm volatile(ALTERNATIVE_2( = \ > > > - __nops(6), = \ > > > +asm volatile(ALTERNATIVE_3( = \ > > > + __nops(14), = \ > > > "mv a0, %1\n\t" = \ > > > "j 2f\n\t" = \ > > > "3:\n\t" = \ > > > @@ -134,7 +134,7 @@ asm volatile(ALTERNATIVE_2( = \ > > > "add a0, a0, %0\n\t" = \ > > > "2:\n\t" = \ > > > "bltu a0, %2, 3b\n\t" = \ > > > - "nop", 0, CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, = \ > > > + __nops(8), 0, CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, = \ > > > "mv a0, %1\n\t" = \ > > > "j 2f\n\t" = \ > > > "3:\n\t" = \ > > > @@ -142,8 +142,28 @@ asm volatile(ALTERNATIVE_2( = \ > > > "add a0, a0, %0\n\t" = \ > > > "2:\n\t" = \ > > > "bltu a0, %2, 3b\n\t" = \ > > > - THEAD_SYNC_S, THEAD_VENDOR_ID, = \ > > > - ERRATA_THEAD_CMO, CONFIG_ERRATA_THEAD_CMO) = \ > > > + THEAD_SYNC_S "\n\t" = \ > > > + __nops(8), THEAD_VENDOR_ID, = \ > > > + ERRATA_THEAD_CMO, CONFIG_ERRATA_THEAD_CMO, = \ > > > + ".option push\n\t\n\t" = \ > > > + ".option norvc\n\t" = \ > > > + ".option norelax\n\t"> = \ > > > > alternatives already do the norvc + norelax options anyway for old and = new instructions, > > so the .option stuff shouldn't be necessary I guess? > > > I did a quick run with .option stuff and all seems to be OK. I'll do > some rigorous testing and get rid of it in the next version. > > > > > + "addi sp,sp,-16\n\t" = \ > > > + "sd s0,0(sp)\n\t" = \ > > > + "sd ra,8(sp)\n\t" = \ > > > + "addi s0,sp,16\n\t" = \ > > > + "mv a4,%6\n\t" = \ > > > + "mv a3,%5\n\t" = \ > > > + "mv a2,%4\n\t" = \ > > > + "mv a1,%3\n\t" = \ > > > + "mv a0,%0\n\t" = \ > > > + "call ax45mp_no_iocp_cmo\n\t" = \ > > > + "ld ra,8(sp)\n\t" = \ > > > + "ld s0,0(sp)\n\t" = \ > > > + "addi sp,sp,16\n\t" = \ > > > + ".option pop\n\t", = \ > > > + ANDESTECH_VENDOR_ID, ERRATA_ANDESTECH_NO_IOCP, = \ > > > + CONFIG_ERRATA_ANDES_CMO) = \ > > > : : "r"(_cachesize), = \ > > > "r"((unsigned long)(_start) & ~((_cachesize) - 1UL)), = \ > > > "r"((unsigned long)(_start) + (_size)), = \ > > > @@ -151,7 +171,7 @@ asm volatile(ALTERNATIVE_2( = \ > > > "r"((unsigned long)(_size)), = \ > > > "r"((unsigned long)(_dir)), = \ > > > "r"((unsigned long)(_ops)) = \ > > > - : "a0") > > > + : "a0", "a1", "a2", "a3", "a4", "memory") > > > > > > #define THEAD_C9XX_RV_IRQ_PMU 17 > > > #define THEAD_C9XX_CSR_SCOUNTEROF 0x5c5 > > > > +static int ax45mp_l2c_probe(struct platform_device *pdev) > > > +{ > > > + struct device_node *np =3D pdev->dev.of_node; > > > + int ret; > > > + > > > + ax45mp_priv =3D devm_kzalloc(&pdev->dev, sizeof(*ax45mp_priv), = GFP_KERNEL); > > > + if (!ax45mp_priv) > > > + return -ENOMEM; > > > + > > > + ax45mp_priv->l2c_base =3D devm_of_iomap(&pdev->dev, pdev->dev.o= f_node, 0, NULL); > > > + if (!ax45mp_priv->l2c_base) { > > > + ret =3D -ENOMEM; > > > + goto l2c_err; > > > + } > > > + > > > + ret =3D ax45mp_configure_l2_cache(np); > > > + if (ret) > > > + goto l2c_err; > > > + > > > + ret =3D ax45mp_configure_pma_regions(np); > > > + if (ret) > > > + goto l2c_err; > > > + > > > + static_branch_disable(&ax45mp_l2c_configured); > > > + > > > + return 0; > > > + > > > +l2c_err: > > > + devm_kfree(&pdev->dev, ax45mp_priv); > > > + ax45mp_priv =3D NULL; > > > + return ret; > > > +} > > > + > > > +static const struct of_device_id ax45mp_cache_ids[] =3D { > > > + { .compatible =3D "andestech,ax45mp-cache" }, > > > + { /* sentinel */ } > > > +}; > > > + > > > +static struct platform_driver ax45mp_l2c_driver =3D { > > > + .driver =3D { > > > + .name =3D "ax45mp-l2c", > > > + .of_match_table =3D ax45mp_cache_ids, > > > + }, > > > + .probe =3D ax45mp_l2c_probe, > > > +}; > > > + > > > +static int __init ax45mp_cache_init(void) > > > +{ > > > + static_branch_enable(&ax45mp_l2c_configured); > > > + return platform_driver_register(&ax45mp_l2c_driver); > > > > the ordering is racy I think. > > > > I.e. in the function called from the cmo operations (ax45mp*_range) > > you need to access ax45mp_priv and its line-size element. > > > > But when you enable the static branch the driver is not yet registered > > but even more important, also not probed yet. > > > > So I guess the static-branch-enable should be living at the end of > > ax45mp_l2c_probe() > > > Hmm so my understanding is incorrect. > = > static_branch_unlikely() - evaluates to false when > static_branch_enable() is called > static_branch_unlikely() - evaluates to true when > static_branch_disable() is called > > Is that what you meant? That is an issue as well :-) I.e. static_branch_* will always return true when enabled and false when disabled. The likely / unlikely suffix is a mechanism for runtime performance, i.e. unlikely means that you expect the static-key to be false in _most_ cases, where likely means you expect it to be true in most cases. But also - arch_initcall(ax45mp_cache_init); - does static-branch enable - registers platform_driver - platform_driver probes - kzalloc(priv) ... [1] - priv->line_size from dt at [1] your condition could already be fullfilled but you don't have a cache-line-size yet. Heiko _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv