From patchwork Tue May 3 22:50:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 12836495 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 793FCC433F5 for ; Tue, 3 May 2022 22:52:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244043AbiECWzh (ORCPT ); Tue, 3 May 2022 18:55:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244002AbiECWzY (ORCPT ); Tue, 3 May 2022 18:55:24 -0400 Received: from mail.baikalelectronics.ru (mail.baikalelectronics.com [87.245.175.226]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 55D4942EF3; Tue, 3 May 2022 15:51:29 -0700 (PDT) Received: from mail.baikalelectronics.ru (unknown [192.168.51.25]) by mail.baikalelectronics.ru (Postfix) with ESMTP id A00FEC04; Wed, 4 May 2022 01:52:02 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.ru A00FEC04 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1651618322; bh=3NGnV4L3yKRDq8qTZRBdv9UvE+k6BF7hNy1V0ERo/1M=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=iaSxaLncR2RpDxfKCoCI5GYgeyYV2dppRHjwrbV4/XIP5jRfVSzAQofBN/8IxwozF 3uxakFetZx0y36/aGR1btXwcR2YZME9cEX31NrtM1z8qANb2TAZVNEIZhtiSGh4AMP BriLbcddP86zZDhys0ECaaj87omCLQzygIVD5HQA= Received: from localhost (192.168.53.207) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 4 May 2022 01:51:28 +0300 From: Serge Semin To: Gustavo Pimentel , Vinod Koul , Jingoo Han , Bjorn Helgaas , Lorenzo Pieralisi , Frank Li , Manivannan Sadhasivam CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Rob Herring , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , , , Subject: [PATCH v2 16/26] dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure Date: Wed, 4 May 2022 01:50:54 +0300 Message-ID: <20220503225104.12108-17-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru> References: <20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org DW eDMA v4.70a and older have the read and write channels context CSRs indirectly accessible. It means the CSRs like Channel Control, Xfer size, SAR, DAR and LLP address are accessed over at a fixed MMIO address, but their reference to the corresponding channel is determined by the Viewport CSR. In order to have a coherent access to these registers the CSR IOs are supposed to be protected with a spin-lock. DW eDMA v4.80a and newer normally have unrolled Read/Write channel context registers. That is all CSRs denoted before are directly mapped in the controller MMIO space. Since both normal and viewport-based registers are exposed via the DebugFS nodes, the original code author decided to implement an algorithm based on the unrolled CSRs mapping with the viewport addresses recalculation if it's required. The problem is that such implementation turned to be first unscalable (supports a platform with only single eDMA available since a base address statically preserved) and second needlessly overcomplicated (it loops over all Rd/Wr context addresses and re-calculates the viewport base address on each DebugFS node access). The algorithm can be greatly simplified just by adding the channel ID and it's direction fields in the eDMA DebugFS node descriptor. These new parameters can be used to find a CSR offset within the corresponding channel registers space. The DW eDMA DebugFS node getter afterwards will also use them in order to activate the respective context CSRs viewport before reading data from the specified register. In case of the unrolled version of the CSRs mapping there won't be any spin-lock taken/released, no viewport activation as before this modification. Note this modification fixes the REGISTER() macros using an externally defined local variable. The same problem with the rest of the macro will be fixed in the next commit. Signed-off-by: Serge Semin Reviewed-by: Manivannan Sadhasivam --- drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 84 +++++++++++------------- 1 file changed, 38 insertions(+), 46 deletions(-) diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c index 7bb3363b40e4..1596eedf35c5 100644 --- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c +++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c @@ -15,9 +15,27 @@ #define REGS_ADDR(name) \ ((void __iomem *)®s->name) + +#define REGS_CH_ADDR(name, _dir, _ch) \ + ({ \ + struct dw_edma_v0_ch_regs __iomem *__ch_regs; \ + \ + if ((dw)->chip->mf == EDMA_MF_EDMA_LEGACY) \ + __ch_regs = ®s->type.legacy.ch; \ + else if (_dir == EDMA_DIR_READ) \ + __ch_regs = ®s->type.unroll.ch[_ch].rd; \ + else \ + __ch_regs = ®s->type.unroll.ch[_ch].wr; \ + \ + (void __iomem *)&__ch_regs->name; \ + }) + #define REGISTER(name) \ { #name, REGS_ADDR(name) } +#define CTX_REGISTER(name, dir, ch) \ + { #name, REGS_CH_ADDR(name, dir, ch), dir, ch } + #define WR_REGISTER(name) \ { #name, REGS_ADDR(wr_##name) } #define RD_REGISTER(name) \ @@ -41,14 +59,11 @@ static struct dw_edma *dw; static struct dw_edma_v0_regs __iomem *regs; -static struct { - void __iomem *start; - void __iomem *end; -} lim[2][EDMA_V0_MAX_NR_CH]; - struct dw_edma_debugfs_entry { const char *name; void __iomem *reg; + enum dw_edma_dir dir; + u16 ch; }; static int dw_edma_debugfs_u32_get(void *data, u64 *val) @@ -58,33 +73,16 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val) if (dw->chip->mf == EDMA_MF_EDMA_LEGACY && reg >= (void __iomem *)®s->type.legacy.ch) { - void __iomem *ptr = ®s->type.legacy.ch; - u32 viewport_sel = 0; unsigned long flags; - u16 ch; - - for (ch = 0; ch < dw->wr_ch_cnt; ch++) - if (lim[0][ch].start >= reg && reg < lim[0][ch].end) { - ptr += (reg - lim[0][ch].start); - goto legacy_sel_wr; - } - - for (ch = 0; ch < dw->rd_ch_cnt; ch++) - if (lim[1][ch].start >= reg && reg < lim[1][ch].end) { - ptr += (reg - lim[1][ch].start); - goto legacy_sel_rd; - } - - return 0; -legacy_sel_rd: - viewport_sel = BIT(31); -legacy_sel_wr: - viewport_sel |= FIELD_PREP(EDMA_V0_VIEWPORT_MASK, ch); + u32 viewport_sel; + + viewport_sel = entry->dir == EDMA_DIR_READ ? BIT(31) : 0; + viewport_sel |= FIELD_PREP(EDMA_V0_VIEWPORT_MASK, entry->ch); raw_spin_lock_irqsave(&dw->lock, flags); writel(viewport_sel, ®s->type.legacy.viewport_sel); - *val = readl(ptr); + *val = readl(reg); raw_spin_unlock_irqrestore(&dw->lock, flags); } else { @@ -114,19 +112,19 @@ static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[], } } -static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs, +static void dw_edma_debugfs_regs_ch(enum dw_edma_dir dir, u16 ch, struct dentry *dent) { - const struct dw_edma_debugfs_entry debugfs_regs[] = { - REGISTER(ch_control1), - REGISTER(ch_control2), - REGISTER(transfer_size), - REGISTER(sar.lsb), - REGISTER(sar.msb), - REGISTER(dar.lsb), - REGISTER(dar.msb), - REGISTER(llp.lsb), - REGISTER(llp.msb), + struct dw_edma_debugfs_entry debugfs_regs[] = { + CTX_REGISTER(ch_control1, dir, ch), + CTX_REGISTER(ch_control2, dir, ch), + CTX_REGISTER(transfer_size, dir, ch), + CTX_REGISTER(sar.lsb, dir, ch), + CTX_REGISTER(sar.msb, dir, ch), + CTX_REGISTER(dar.lsb, dir, ch), + CTX_REGISTER(dar.msb, dir, ch), + CTX_REGISTER(llp.lsb, dir, ch), + CTX_REGISTER(llp.msb, dir, ch), }; int nr_entries; @@ -191,10 +189,7 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dent) ch_dent = debugfs_create_dir(name, regs_dent); - dw_edma_debugfs_regs_ch(®s->type.unroll.ch[i].wr, ch_dent); - - lim[0][i].start = ®s->type.unroll.ch[i].wr; - lim[0][i].end = ®s->type.unroll.ch[i].padding_1[0]; + dw_edma_debugfs_regs_ch(EDMA_DIR_WRITE, i, ch_dent); } } @@ -256,10 +251,7 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dent) ch_dent = debugfs_create_dir(name, regs_dent); - dw_edma_debugfs_regs_ch(®s->type.unroll.ch[i].rd, ch_dent); - - lim[1][i].start = ®s->type.unroll.ch[i].rd; - lim[1][i].end = ®s->type.unroll.ch[i].padding_2[0]; + dw_edma_debugfs_regs_ch(EDMA_DIR_READ, i, ch_dent); } }