Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937384AbdCJNZ4 (ORCPT ); Fri, 10 Mar 2017 08:25:56 -0500 Received: from mail-wr0-f196.google.com ([209.85.128.196]:36743 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937322AbdCJNZn (ORCPT ); Fri, 10 Mar 2017 08:25:43 -0500 From: Jan Glauber To: Ulf Hansson Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, David Daney , "Steven J . Hill" , Jan Glauber , David Daney , "Steven J . Hill" Subject: [PATCH v12 4/9] mmc: cavium: Work-around hardware bug on cn6xxx and cnf7xxx Date: Fri, 10 Mar 2017 14:25:02 +0100 Message-Id: <20170310132507.32025-5-jglauber@cavium.com> X-Mailer: git-send-email 2.9.0.rc0.21.g7777322 In-Reply-To: <20170310132507.32025-1-jglauber@cavium.com> References: <20170310132507.32025-1-jglauber@cavium.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7103 Lines: 233 Prevent data corruption on cn6xxx and cnf7xxx. Due to an imperfection in the design of the MMC bus hardware, the 2nd to last cache block of a DMA read must be locked into the L2 cache. Signed-off-by: Jan Glauber Signed-off-by: David Daney Signed-off-by: Steven J. Hill --- arch/mips/cavium-octeon/Makefile | 1 + arch/mips/cavium-octeon/octeon-mmc-l2c.c | 98 ++++++++++++++++++++++++++++++++ drivers/mmc/host/cavium-mmc.c | 5 ++ drivers/mmc/host/cavium-mmc.h | 5 ++ drivers/mmc/host/cavium-pltfm-octeon.c | 30 ++++++++++ 5 files changed, 139 insertions(+) create mode 100644 arch/mips/cavium-octeon/octeon-mmc-l2c.c diff --git a/arch/mips/cavium-octeon/Makefile b/arch/mips/cavium-octeon/Makefile index 7c02e54..3329a89 100644 --- a/arch/mips/cavium-octeon/Makefile +++ b/arch/mips/cavium-octeon/Makefile @@ -19,3 +19,4 @@ obj-$(CONFIG_MTD) += flash_setup.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_OCTEON_ILM) += oct_ilm.o obj-$(CONFIG_USB) += octeon-usb.o +obj-$(CONFIG_MMC_CAVIUM_OCTEON) += octeon-mmc-l2c.o diff --git a/arch/mips/cavium-octeon/octeon-mmc-l2c.c b/arch/mips/cavium-octeon/octeon-mmc-l2c.c new file mode 100644 index 0000000..6aaaf73 --- /dev/null +++ b/arch/mips/cavium-octeon/octeon-mmc-l2c.c @@ -0,0 +1,98 @@ +/* + * Driver for MMC and SSD cards for Cavium OCTEON SOCs. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2012-2016 Cavium Inc. + */ +#include +#include + +/* + * The functions below are used for the EMMC-17978 workaround. + * + * Due to an imperfection in the design of the MMC bus hardware, + * the 2nd to last cache block of a DMA read must be locked into the L2 Cache. + * Otherwise, data corruption may occur. + */ + +static inline void *phys_to_ptr(u64 address) +{ + return (void *)(address | (1ull << 63)); /* XKPHYS */ +} + +/** + * Lock a single line into L2. The line is zeroed before locking + * to make sure no dram accesses are made. + * + * @addr Physical address to lock + */ +static void l2c_lock_line(u64 addr) +{ + char *addr_ptr = phys_to_ptr(addr); + + asm volatile ( + "cache 31, %[line]" /* Unlock the line */ + :: [line] "m" (*addr_ptr)); +} + +/** + * Unlock a single line in the L2 cache. + * + * @addr Physical address to unlock + * + * Return Zero on success + */ +static void l2c_unlock_line(u64 addr) +{ + char *addr_ptr = phys_to_ptr(addr); + + asm volatile ( + "cache 23, %[line]" /* Unlock the line */ + :: [line] "m" (*addr_ptr)); +} + +/** + * Locks a memory region in the L2 cache + * + * @start - start address to begin locking + * @len - length in bytes to lock + */ +void l2c_lock_mem_region(u64 start, u64 len) +{ + u64 end; + + /* Round start/end to cache line boundaries */ + end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE); + start = ALIGN(start, CVMX_CACHE_LINE_SIZE); + + while (start <= end) { + l2c_lock_line(start); + start += CVMX_CACHE_LINE_SIZE; + } + asm volatile("sync"); +} +EXPORT_SYMBOL_GPL(l2c_lock_mem_region); + +/** + * Unlock a memory region in the L2 cache + * + * @start - start address to unlock + * @len - length to unlock in bytes + */ +void l2c_unlock_mem_region(u64 start, u64 len) +{ + u64 end; + + /* Round start/end to cache line boundaries */ + end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE); + start = ALIGN(start, CVMX_CACHE_LINE_SIZE); + + while (start <= end) { + l2c_unlock_line(start); + start += CVMX_CACHE_LINE_SIZE; + } +} +EXPORT_SYMBOL_GPL(l2c_unlock_mem_region); diff --git a/drivers/mmc/host/cavium-mmc.c b/drivers/mmc/host/cavium-mmc.c index 11fdcfb..c1d3c65 100644 --- a/drivers/mmc/host/cavium-mmc.c +++ b/drivers/mmc/host/cavium-mmc.c @@ -468,6 +468,8 @@ irqreturn_t cvm_mmc_interrupt(int irq, void *dev_id) req->done(req); no_req_done: + if (host->dmar_fixup_done) + host->dmar_fixup_done(host); if (host_done) host->release_bus(host); out: @@ -572,6 +574,9 @@ static void cvm_mmc_dma_request(struct mmc_host *mmc, host->int_enable(host, MIO_EMM_INT_CMD_ERR | MIO_EMM_INT_DMA_DONE | MIO_EMM_INT_DMA_ERR); + if (host->dmar_fixup) + host->dmar_fixup(host, mrq->cmd, data, addr); + /* * If we have a valid SD card in the slot, we set the response * bit mask to check for CRC errors and timeouts only. diff --git a/drivers/mmc/host/cavium-mmc.h b/drivers/mmc/host/cavium-mmc.h index c3843448..3ee6dae 100644 --- a/drivers/mmc/host/cavium-mmc.h +++ b/drivers/mmc/host/cavium-mmc.h @@ -48,6 +48,7 @@ struct cvm_mmc_host { int reg_off; int reg_off_dma; u64 emm_cfg; + u64 n_minus_one; /* OCTEON II workaround location */ int last_slot; struct clk *clk; int sys_freq; @@ -63,6 +64,10 @@ struct cvm_mmc_host { void (*acquire_bus)(struct cvm_mmc_host *); void (*release_bus)(struct cvm_mmc_host *); void (*int_enable)(struct cvm_mmc_host *, u64); + /* required on some MIPS models */ + void (*dmar_fixup)(struct cvm_mmc_host *, struct mmc_command *, + struct mmc_data *, u64); + void (*dmar_fixup_done)(struct cvm_mmc_host *); }; struct cvm_mmc_slot { diff --git a/drivers/mmc/host/cavium-pltfm-octeon.c b/drivers/mmc/host/cavium-pltfm-octeon.c index e83d143..9dabfa4 100644 --- a/drivers/mmc/host/cavium-pltfm-octeon.c +++ b/drivers/mmc/host/cavium-pltfm-octeon.c @@ -18,6 +18,9 @@ #define CVMX_MIO_BOOT_CTL CVMX_ADD_IO_SEG(0x00011800000000D0ull) +extern void l2c_lock_mem_region(u64 start, u64 len); +extern void l2c_unlock_mem_region(u64 start, u64 len); + static void octeon_mmc_acquire_bus(struct cvm_mmc_host *host) { /* Switch the MMC controller onto the bus. */ @@ -36,6 +39,28 @@ static void octeon_mmc_int_enable(struct cvm_mmc_host *host, u64 val) writeq(val, host->base + MIO_EMM_INT_EN(host)); } +static void octeon_mmc_dmar_fixup(struct cvm_mmc_host *host, + struct mmc_command *cmd, + struct mmc_data *data, + u64 addr) +{ + if (cmd->opcode != MMC_WRITE_MULTIPLE_BLOCK) + return; + if (data->blksz * data->blocks <= 1024) + return; + + host->n_minus_one = addr + (data->blksz * data->blocks) - 1024; + l2c_lock_mem_region(host->n_minus_one, 512); +} + +static void octeon_mmc_dmar_fixup_done(struct cvm_mmc_host *host) +{ + if (!host->n_minus_one) + return; + l2c_unlock_mem_region(host->n_minus_one, 512); + host->n_minus_one = 0; +} + static int octeon_mmc_probe(struct platform_device *pdev) { struct device_node *cn, *node = pdev->dev.of_node; @@ -54,6 +79,11 @@ static int octeon_mmc_probe(struct platform_device *pdev) host->acquire_bus = octeon_mmc_acquire_bus; host->release_bus = octeon_mmc_release_bus; host->int_enable = octeon_mmc_int_enable; + if (OCTEON_IS_MODEL(OCTEON_CN6XXX) || + OCTEON_IS_MODEL(OCTEON_CNF7XXX)) { + host->dmar_fixup = octeon_mmc_dmar_fixup; + host->dmar_fixup_done = octeon_mmc_dmar_fixup_done; + } host->sys_freq = octeon_get_io_clock_rate(); -- 2.9.0.rc0.21.g7777322