From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E471C654 for ; Sat, 21 Oct 2023 01:11:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E97B0143D; Fri, 20 Oct 2023 18:12:17 -0700 (PDT) Received: from localhost.localdomain (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 12CAC3F64C; Fri, 20 Oct 2023 18:11:35 -0700 (PDT) From: Andre Przywara To: Jagan Teki , Jernej Skrabec Cc: Gunjan Gupta , u-boot@lists.denx.de, linux-sunxi@lists.linux.dev Subject: [PATCH 4/4] sunxi: DRAM: H6: use proper MMIO accessors in mctl_set_addrmap() Date: Sat, 21 Oct 2023 02:10:25 +0100 Message-Id: <20231021011025.568-5-andre.przywara@arm.com> X-Mailer: git-send-email 2.35.8 In-Reply-To: <20231021011025.568-1-andre.przywara@arm.com> References: <20231021011025.568-1-andre.przywara@arm.com> Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit For accessing MMIO registers, we must not rely on the compiler to realise every access to a struct which we made point to some MMIO base address. From a compiler's point of view, those writes could be considered pointless, since no code consumes them later on: the compiler would actually be free to optimise them away. So we need at least the "volatile" attribute in the pointer declaration, but a better fix is of course to use the proper MMIO accessors (writel), as we do everywhere else. Since MMIO writes are already ordered within themselves (courtesy of the "device nGnRnE" memory attribures), and we don't do any DMA operation which would requrire synchronising with normal memory accesses, we can use the cheaper writel_relaxed() accessor, which have the additional advantange of saving one instruction, for each call. Signed-off-by: Andre Przywara --- arch/arm/mach-sunxi/dram_sun50i_h6.c | 69 ++++++++++++++++------------ 1 file changed, 39 insertions(+), 30 deletions(-) diff --git a/arch/arm/mach-sunxi/dram_sun50i_h6.c b/arch/arm/mach-sunxi/dram_sun50i_h6.c index 8e959f4c600..89e855c1a7d 100644 --- a/arch/arm/mach-sunxi/dram_sun50i_h6.c +++ b/arch/arm/mach-sunxi/dram_sun50i_h6.c @@ -192,77 +192,86 @@ static void mctl_set_addrmap(const struct dram_config *config) /* Ranks */ if (ranks == 2) - mctl_ctl->addrmap[0] = rows + cols - 3; + writel_relaxed(rows + cols - 3, &mctl_ctl->addrmap[0]); else - mctl_ctl->addrmap[0] = 0x1F; + writel_relaxed(0x1f, &mctl_ctl->addrmap[0]); /* Banks, hardcoded to 8 banks now */ - mctl_ctl->addrmap[1] = (cols - 2) | (cols - 2) << 8 | (cols - 2) << 16; + writel_relaxed((cols - 2) | (cols - 2) << 8 | (cols - 2) << 16, + &mctl_ctl->addrmap[1]); /* Columns */ - mctl_ctl->addrmap[2] = 0; + writel_relaxed(0, &mctl_ctl->addrmap[2]); switch (cols) { case 7: - mctl_ctl->addrmap[3] = 0x1F1F1F00; - mctl_ctl->addrmap[4] = 0x1F1F; + writel_relaxed(0x1f1f1f00, &mctl_ctl->addrmap[3]); + writel_relaxed(0x1f1f, &mctl_ctl->addrmap[4]); break; case 8: - mctl_ctl->addrmap[3] = 0x1F1F0000; - mctl_ctl->addrmap[4] = 0x1F1F; + writel_relaxed(0x1f1f0000, &mctl_ctl->addrmap[3]); + writel_relaxed(0x1f1f, &mctl_ctl->addrmap[4]); break; case 9: - mctl_ctl->addrmap[3] = 0x1F000000; - mctl_ctl->addrmap[4] = 0x1F1F; + writel_relaxed(0x1f000000, &mctl_ctl->addrmap[3]); + writel_relaxed(0x1f1f, &mctl_ctl->addrmap[4]); break; case 10: - mctl_ctl->addrmap[3] = 0; - mctl_ctl->addrmap[4] = 0x1F1F; + writel_relaxed(0, &mctl_ctl->addrmap[3]); + writel_relaxed(0x1f1f, &mctl_ctl->addrmap[4]); break; case 11: - mctl_ctl->addrmap[3] = 0; - mctl_ctl->addrmap[4] = 0x1F00; + writel_relaxed(0, &mctl_ctl->addrmap[3]); + writel_relaxed(0x1f00, &mctl_ctl->addrmap[4]); break; case 12: - mctl_ctl->addrmap[3] = 0; - mctl_ctl->addrmap[4] = 0; + writel_relaxed(0, &mctl_ctl->addrmap[3]); + writel_relaxed(0, &mctl_ctl->addrmap[4]); break; default: panic("Unsupported DRAM configuration: column number invalid\n"); } /* Rows */ - mctl_ctl->addrmap[5] = (cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24); + writel_relaxed((cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24), + &mctl_ctl->addrmap[5]); switch (rows) { case 13: - mctl_ctl->addrmap[6] = (cols - 3) | 0x0F0F0F00; - mctl_ctl->addrmap[7] = 0x0F0F; + writel_relaxed((cols - 3) | 0x0f0f0f00, &mctl_ctl->addrmap[6]); + writel_relaxed(0x0f0f, &mctl_ctl->addrmap[7]); break; case 14: - mctl_ctl->addrmap[6] = (cols - 3) | ((cols - 3) << 8) | 0x0F0F0000; - mctl_ctl->addrmap[7] = 0x0F0F; + writel_relaxed((cols - 3) | ((cols - 3) << 8) | 0x0f0f0000, + &mctl_ctl->addrmap[6]); + writel_relaxed(0x0f0f, &mctl_ctl->addrmap[7]); break; case 15: - mctl_ctl->addrmap[6] = (cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | 0x0F000000; - mctl_ctl->addrmap[7] = 0x0F0F; + writel_relaxed((cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | 0x0f000000, + &mctl_ctl->addrmap[6]); + writel_relaxed(0x0f0f, &mctl_ctl->addrmap[7]); break; case 16: - mctl_ctl->addrmap[6] = (cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24); - mctl_ctl->addrmap[7] = 0x0F0F; + writel_relaxed((cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24), + &mctl_ctl->addrmap[6]); + writel_relaxed(0x0f0f, &mctl_ctl->addrmap[7]); break; case 17: - mctl_ctl->addrmap[6] = (cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24); - mctl_ctl->addrmap[7] = (cols - 3) | 0x0F00; + writel_relaxed((cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24), + &mctl_ctl->addrmap[6]); + writel_relaxed((cols - 3) | 0x0f00, &mctl_ctl->addrmap[7]); break; case 18: - mctl_ctl->addrmap[6] = (cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24); - mctl_ctl->addrmap[7] = (cols - 3) | ((cols - 3) << 8); + writel_relaxed((cols - 3) | ((cols - 3) << 8) | ((cols - 3) << 16) | ((cols - 3) << 24), + &mctl_ctl->addrmap[6]); + writel_relaxed((cols - 3) | ((cols - 3) << 8), + &mctl_ctl->addrmap[7]); break; default: panic("Unsupported DRAM configuration: row number invalid\n"); } /* Bank groups, DDR4 only */ - mctl_ctl->addrmap[8] = 0x3F3F; + writel_relaxed(0x3f3f, &mctl_ctl->addrmap[8]); + dsb(); } static void mctl_com_init(const struct dram_para *para, -- 2.35.8