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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23FA4ECAAD1 for ; Thu, 1 Sep 2022 15:39:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232448AbiIAPjC (ORCPT ); Thu, 1 Sep 2022 11:39:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233249AbiIAPi7 (ORCPT ); Thu, 1 Sep 2022 11:38:59 -0400 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3050E7B2A6 for ; Thu, 1 Sep 2022 08:38:57 -0700 (PDT) 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 1oTmHO-0005mr-3g; Thu, 01 Sep 2022 17:38:54 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Palmer Dabbelt , Paul Walmsley , Anup Patel Cc: Atish Patra , Anup Patel , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Anup Patel , Mayuresh Chitale Subject: Re: [PATCH v2 3/4] RISC-V: Implement arch specific PMEM APIs Date: Thu, 01 Sep 2022 17:38:53 +0200 Message-ID: <13199249.VsHLxoZxqI@diego> In-Reply-To: <20220830044642.566769-4-apatel@ventanamicro.com> References: <20220830044642.566769-1-apatel@ventanamicro.com> <20220830044642.566769-4-apatel@ventanamicro.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Anup, Am Dienstag, 30. August 2022, 06:46:41 CEST schrieb Anup Patel: > The NVDIMM PMEM driver expects arch specific APIs for cache maintenance > and if arch does not provide these APIs then NVDIMM PMEM driver will > always use MEMREMAP_WT to map persistent memory which in-turn maps as > UC memory type defined by the RISC-V Svpbmt specification. > > Now that the Svpbmt and Zicbom support is available in RISC-V kernel, > we implement PMEM APIs using ALT_CMO_OP() macros so that the NVDIMM > PMEM driver can use MEMREMAP_WB to map persistent memory. Zicbom is detected at runtime, though that kconfig setting changes the behaviour for the memremap-type at compile-time. So what happens on systems not using zicbom (or another cmo-variant) ? Heiko > Co-developed-by: Mayuresh Chitale > Signed-off-by: Mayuresh Chitale > Signed-off-by: Anup Patel > --- > arch/riscv/Kconfig | 1 + > arch/riscv/mm/Makefile | 1 + > arch/riscv/mm/pmem.c | 21 +++++++++++++++++++++ > 3 files changed, 23 insertions(+) > create mode 100644 arch/riscv/mm/pmem.c > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0ebd8da388d8..37d6370d29c3 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -25,6 +25,7 @@ config RISCV > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_KCOV > select ARCH_HAS_MMIOWB > + select ARCH_HAS_PMEM_API > select ARCH_HAS_PTE_SPECIAL > select ARCH_HAS_SET_DIRECT_MAP if MMU > select ARCH_HAS_SET_MEMORY if MMU > diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile > index d76aabf4b94d..3b368e547f83 100644 > --- a/arch/riscv/mm/Makefile > +++ b/arch/riscv/mm/Makefile > @@ -31,3 +31,4 @@ endif > > obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o > obj-$(CONFIG_RISCV_DMA_NONCOHERENT) += dma-noncoherent.o > +obj-$(CONFIG_ARCH_HAS_PMEM_API) += pmem.o > diff --git a/arch/riscv/mm/pmem.c b/arch/riscv/mm/pmem.c > new file mode 100644 > index 000000000000..089df92ae876 > --- /dev/null > +++ b/arch/riscv/mm/pmem.c > @@ -0,0 +1,21 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2022 Ventana Micro Systems Inc. > + */ > + > +#include > +#include > + > +#include > + > +void arch_wb_cache_pmem(void *addr, size_t size) > +{ > + ALT_CMO_OP(clean, addr, size, riscv_cbom_block_size); > +} > +EXPORT_SYMBOL_GPL(arch_wb_cache_pmem); > + > +void arch_invalidate_pmem(void *addr, size_t size) > +{ > + ALT_CMO_OP(inval, addr, size, riscv_cbom_block_size); > +} > +EXPORT_SYMBOL_GPL(arch_invalidate_pmem); >