From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 02 Mar 2021 09:39:08 +0100 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1lH0Ye-0005nC-Jl for lore@lore.pengutronix.de; Tue, 02 Mar 2021 09:39:08 +0100 Received: from merlin.infradead.org ([2001:8b0:10b:1231::1]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lH0Yd-0000Fi-Ff for lore@pengutronix.de; Tue, 02 Mar 2021 09:39:08 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JnDTxvPtzXJs37UUd7esaYaTavpzH/nfbjzcezB5DA4=; b=MReRij7n+Yyc83Z9eHexwTQwv 1Ydn2Xo78KmRVxVEHw9hNxds+DHU+sQ+Y4kjZeojZP1IS4Alcs+jLjdVoc1zGcad0IV+ThLFxV3RJ PDzSiQ0ME0K1HIfFJ2S+PnK/Sozh5TzGc+wuuzkpzhOTArllC/Mv/5auo/st/Q2uSOLwy/wUog1DE dl371rC4ja82+UHUcsGsENE7xZubXpQT8Oo9BD6pQQE5vp+X1qqqDBoGUlfvifyD5bzz8r7b2U1KA lj9WuEzASF1I1kWrk0B/qP8ocU12nwbfwXndEvH63Fj4FHXBymViEy5gGjRSmq4IJJK3ZcMxNRMbT S3G0YAW+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lH0X7-0003ES-5X; Tue, 02 Mar 2021 08:37:33 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lH0X3-0003Dv-VL for barebox@lists.infradead.org; Tue, 02 Mar 2021 08:37:31 +0000 Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=[IPv6:::1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1lH0X1-0008T4-84; Tue, 02 Mar 2021 09:37:27 +0100 To: Jules Maselbas , barebox@lists.infradead.org References: <20210301155851.12463-1-jmaselbas@kalray.eu> <20210301155851.12463-3-jmaselbas@kalray.eu> From: Ahmad Fatoum Message-ID: <04c18498-970c-9a69-ebf7-97bf85d2f961@pengutronix.de> Date: Tue, 2 Mar 2021 09:37:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210301155851.12463-3-jmaselbas@kalray.eu> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210302_033730_049752_4C1B492E X-CRM114-Status: GOOD ( 24.38 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Yann Sionneau Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" X-SA-Exim-Connect-IP: 2001:8b0:10b:1231::1 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-3.4 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 3/5] kvx: Implement dma handling primitives X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) Hello Jules, Yann, On 01.03.21 16:58, Jules Maselbas wrote: > From: Yann Sionneau Some comments inline. I am not a cache cohereny expert, so take it with a grain of salt. > > Signed-off-by: Yann Sionneau > Signed-off-by: Jules Maselbas > --- > --- /dev/null > +++ b/arch/kvx/include/asm/dma.h > @@ -0,0 +1,35 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* SPDX-FileCopyrightText: 2021 Yann Sionneau , Kalray Inc. */ > + > +#ifndef __ASM_DMA_H > +#define __ASM_DMA_H > + > +#include > + > +#define KVX_DDR_32BIT_RAM_WINDOW_BA (0x80000000ULL) > +#define KVX_DDR_64BIT_RAM_WINDOW_BA (0x100000000ULL) > +#define MAX_32BIT_ADDR (0xffffffffULL) > + > +#define dma_alloc dma_alloc > +static inline void *dma_alloc(size_t size) > +{ > + return xmemalign(64, ALIGN(size, 64)); > +} > + > +static inline void *dma_alloc_coherent(size_t size, dma_addr_t *dma_handle) > +{ > + void *ret = xmemalign(PAGE_SIZE, size); > + > + if (dma_handle) > + *dma_handle = (dma_addr_t)(uintptr_t)ret; > + > + return ret; > +} This would imply that the CPU barebox is booting is coherent with all devices that barebox needs to access. Is that the case? (See below) > + > +static inline void dma_free_coherent(void *mem, dma_addr_t dma_handle, > + size_t size) > +{ > + free(mem); > +} > + > +#endif /* __ASM_DMA_H */ > diff --git a/arch/kvx/include/asm/sys_arch.h b/arch/kvx/include/asm/sys_arch.h > index 9df32c4e7..ce07a5598 100644 > --- a/arch/kvx/include/asm/sys_arch.h > +++ b/arch/kvx/include/asm/sys_arch.h > @@ -11,6 +11,9 @@ > #define EXCEPTION_STRIDE 0x40 > #define EXCEPTION_ALIGNMENT 0x100 > > +#define kvx_cluster_id() ((int) \ > + ((kvx_sfr_get(PCR) & KVX_SFR_PCR_CID_MASK) \ > + >> KVX_SFR_PCR_CID_SHIFT)) > #define KVX_SFR_START(__sfr_reg) \ > (KVX_SFR_## __sfr_reg ## _SHIFT) > > diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile > index d271ebccf..c730e1c23 100644 > --- a/arch/kvx/lib/Makefile > +++ b/arch/kvx/lib/Makefile > @@ -3,4 +3,4 @@ > # Copyright (C) 2019 Kalray Inc. > # > > -obj-y += cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o > +obj-y += cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o dma-default.o > diff --git a/arch/kvx/lib/dma-default.c b/arch/kvx/lib/dma-default.c > new file mode 100644 > index 000000000..755a8c66f > --- /dev/null > +++ b/arch/kvx/lib/dma-default.c > @@ -0,0 +1,91 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// SPDX-FileCopyrightText: 2021 Yann Sionneau , Kalray Inc. > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* > + * The implementation of arch should follow the following rules: > + * map for_cpu for_device unmap > + * TO_DEV writeback none writeback none > + * FROM_DEV invalidate invalidate(*) invalidate invalidate(*) > + * BIDIR writeback invalidate writeback invalidate > + * > + * (*) - only necessary if the CPU speculatively prefetches. > + * > + * (see https://lkml.org/lkml/2018/5/18/979) > + */ > + > +void dma_sync_single_for_device(dma_addr_t addr, size_t size, > + enum dma_data_direction dir) > +{ > + switch (dir) { > + case DMA_FROM_DEVICE: > + kvx_dcache_invalidate_mem_area(addr, size); > + break; > + case DMA_TO_DEVICE: > + case DMA_BIDIRECTIONAL: > + /* allow device to read buffer written by CPU */ > + wmb(); If the interconnect was indeed coherent, like dma_alloc_coherent above hints, you wouldn't need any barriers here..? > + break; > + default: > + BUG(); > + } > +} > + > +void dma_sync_single_for_cpu(dma_addr_t addr, size_t size, > + enum dma_data_direction dir) > +{ > + switch (dir) { > + case DMA_FROM_DEVICE: > + case DMA_TO_DEVICE: > + break; > + case DMA_BIDIRECTIONAL: > + kvx_dcache_invalidate_mem_area(addr, size); > + break; > + default: > + BUG(); > + } > +} > + > +#define KVX_DDR_ALIAS_OFFSET \ > + (KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA) > +#define KVX_DDR_ALIAS_WINDOW \ > + (KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET) > + > +/* Local smem is aliased between 0 and 16MB */ > +#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL > + > +dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size, > + enum dma_data_direction dir) > +{ > + uintptr_t addr = (uintptr_t) ptr; > + > + dma_sync_single_for_device(addr, size, dir); > + > + /* Local smem alias should never be used for dma */ > + if (addr < KVX_SMEM_LOCAL_ALIAS) > + return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS; > + > + if (dev->dma_mask && addr <= dev->dma_mask) > + return addr; > + > + if (addr >= KVX_DDR_ALIAS_WINDOW) > + return DMA_ERROR_CODE; > + > + addr -= KVX_DDR_ALIAS_OFFSET; > + if (dev->dma_mask && addr > dev->dma_mask) > + return DMA_ERROR_CODE; > + > + return addr; > +} > + > +void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size, > + enum dma_data_direction dir) > +{ > + dma_sync_single_for_cpu(addr, size, dir); > +} > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox