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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53521C83006 for ; Thu, 30 Apr 2020 06:11:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CE7D2173E for ; Thu, 30 Apr 2020 06:11:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726453AbgD3GLz (ORCPT ); Thu, 30 Apr 2020 02:11:55 -0400 Received: from mail-il1-f193.google.com ([209.85.166.193]:38737 "EHLO mail-il1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726180AbgD3GLz (ORCPT ); Thu, 30 Apr 2020 02:11:55 -0400 Received: by mail-il1-f193.google.com with SMTP id c18so243625ile.5; Wed, 29 Apr 2020 23:11:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=H/Z/NG3xt+7eYef3fmAdT1EwVOP1RXMi/3PpMayvfSE=; b=G1CyT6kxjGG7Q7pshAUsV+gDfqxj9o0Fj9b174+yQHi4IfBSR6RtHSI3JXfAyAbtxH 1w5clOPh3EfH1+L4JqBMR6PVAINNwtqC7Th5HokfSvs0keUv7RvWeMnu0PXPmCdUukqL zl3lbCFkMLkq6vE4kSKo03QUeEFzs1/hD9TKeYg7Mc8OTIUtmQP8a4xaRh9bhjhMShxA +zj2Ypd/cJw+19JSlEX9oB8UT21U2/1j/6uMBqoD3POQeR0Jv2S6g/uVoEY9FmIViYbY P5oDINXNOPR2vPBlDQsR86HZNDwY9nRyvwjwIWLBn1Y+wXu6zM8x5DUcHPJaki6R+3nv xRXg== X-Gm-Message-State: AGi0PuYYJVgpunHAcuehj3yXDUfHf2B1nMCWSt7iu1xXp/nAlCt9WHUu 4ZHuQ3zfCp07RQeosqtMpAmNcB7iklwxe28ypRQ= X-Google-Smtp-Source: APiQypL4QKDFwnemYhat/ReVkS9zXaIb/KMeKVVjiMkBPx0BuX2CER+6pj9ZLeSFvHmD1X46WjFXfNzB9ELgeT6ope4= X-Received: by 2002:a92:c52a:: with SMTP id m10mr410035ili.208.1588227114118; Wed, 29 Apr 2020 23:11:54 -0700 (PDT) MIME-Version: 1.0 References: <1588213867-32274-1-git-send-email-yangtiezhu@loongson.cn> In-Reply-To: <1588213867-32274-1-git-send-email-yangtiezhu@loongson.cn> From: Huacai Chen Date: Thu, 30 Apr 2020 14:19:25 +0800 Message-ID: Subject: Re: [PATCH v6] MIPS: Loongson: Add DMA support for LS7A To: Tiezhu Yang Cc: Thomas Bogendoerfer , Christoph Hellwig , Jiaxun Yang , "open list:MIPS" , LKML , Xuefeng Li Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, On Thu, Apr 30, 2020 at 10:31 AM Tiezhu Yang wrote: > > In the current market, the most used bridge chip on the Loongson > platform are RS780E and LS7A, the RS780E bridge chip is already > supported by the mainline kernel. > > In order to use the default implementation of __phys_to_dma() and > __dma_to_phys() in dma-direct.h, remove CONFIG_ARCH_HAS_PHYS_TO_DMA > and then set the bus's DMA limit to 36 bit for RS780E to maintain > downward compatibility. I know that you want use the default implementation of __phys_to_dma() and __dma_to_phys() as more as possible. But, if that is "impossible" on Loongson-3, should we still be forced to use the default? Yes, this patch makes the default version work, but it limit the device's DMA capability, which is not what we want. > > Signed-off-by: Tiezhu Yang > --- > > Hi Christoph and Jiaxun, > > Thank you very much for your suggestions. > > v5: > - use the default implementation of __phys_to_dma() > and __dma_to_phys() in dma-direct.h > > v6: > - make loongson_dma_config() static > - put ls7a things before rs780 things > > arch/mips/Kconfig | 1 - > arch/mips/include/asm/mach-loongson64/boot_param.h | 5 +++++ > arch/mips/loongson64/dma.c | 22 +++++++++++----------- > arch/mips/loongson64/env.c | 2 ++ > 4 files changed, 18 insertions(+), 12 deletions(-) > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index 9f15539..12b6bdb 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -1454,7 +1454,6 @@ choice > config CPU_LOONGSON64 > bool "Loongson 64-bit CPU" > depends on SYS_HAS_CPU_LOONGSON64 > - select ARCH_HAS_PHYS_TO_DMA > select CPU_MIPSR2 > select CPU_HAS_PREFETCH > select CPU_SUPPORTS_64BIT_KERNEL > diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h > index f082d87..0c07a96 100644 > --- a/arch/mips/include/asm/mach-loongson64/boot_param.h > +++ b/arch/mips/include/asm/mach-loongson64/boot_param.h > @@ -197,6 +197,7 @@ enum loongson_bridge_type { > RS780E = 2 > }; > > +struct pci_dev; > struct loongson_system_configuration { > u32 nr_cpus; > u32 nr_nodes; > @@ -221,9 +222,13 @@ struct loongson_system_configuration { > u32 nr_sensors; > struct sensor_device sensors[MAX_SENSORS]; > u64 workarounds; > + void (*dma_config)(struct pci_dev *pdev); > }; > > extern struct efi_memory_map_loongson *loongson_memmap; > extern struct loongson_system_configuration loongson_sysconf; > > +extern void ls7a_dma_config(struct pci_dev *pdev); > +extern void rs780e_dma_config(struct pci_dev *pdev); > + > #endif > diff --git a/arch/mips/loongson64/dma.c b/arch/mips/loongson64/dma.c > index 5e86635..ef40b0d 100644 > --- a/arch/mips/loongson64/dma.c > +++ b/arch/mips/loongson64/dma.c > @@ -1,24 +1,24 @@ > // SPDX-License-Identifier: GPL-2.0 > -#include > +#include > #include > #include > > -dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) > +void ls7a_dma_config(struct pci_dev *pdev) > { > - /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from > - * Loongson-3's 48bit address space and embed it into 40bit */ > - long nid = (paddr >> 44) & 0x3; > - return ((nid << 44) ^ paddr) | (nid << 37); > } > > -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr) > +void rs780e_dma_config(struct pci_dev *pdev) > { > - /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from > - * Loongson-3's 48bit address space and embed it into 40bit */ > - long nid = (daddr >> 37) & 0x3; > - return ((nid << 37) ^ daddr) | (nid << 44); > + pdev->dev.bus_dma_limit = DMA_BIT_MASK(36); > } > > +static void loongson_dma_config(struct pci_dev *pdev) > +{ > + loongson_sysconf.dma_config(pdev); > +} > + > +DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, loongson_dma_config); > + > void __init plat_swiotlb_setup(void) > { > swiotlb_init(1); > diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c > index 71f4aaf..496f401 100644 > --- a/arch/mips/loongson64/env.c > +++ b/arch/mips/loongson64/env.c > @@ -192,8 +192,10 @@ void __init prom_init_env(void) > if (vendor == PCI_VENDOR_ID_LOONGSON && device == 0x7a00) { > pr_info("The bridge chip is LS7A\n"); > loongson_sysconf.bridgetype = LS7A; > + loongson_sysconf.dma_config = ls7a_dma_config; > } else { > pr_info("The bridge chip is RS780E or SR5690\n"); > loongson_sysconf.bridgetype = RS780E; > + loongson_sysconf.dma_config = rs780e_dma_config; > } > } > -- > 2.1.0 >