linux-kernel - [PATCH v2 20/25] mtd: nand: qcom: erased codeword detection configuration

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 19 Jul 2017 17:18:08 +0530
From:   Abhishek Sahu <absahu@...eaurora.org>
To:     dwmw2@...radead.org, computersforpeace@...il.com,
        boris.brezillon@...e-electrons.com, marek.vasut@...il.com,
        richard@....at, cyrille.pitchen@...ev4u.fr, robh+dt@...nel.org,
        mark.rutland@....com
Cc:     linux-mtd@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        andy.gross@...aro.org, architt@...eaurora.org,
        sricharan@...eaurora.org, Abhishek Sahu <absahu@...eaurora.org>
Subject: [PATCH v2 20/25] mtd: nand: qcom: erased codeword detection configuration

The NAND controller returns ECC failure during read of completely
erased codeword. The NAND controller has hardware functionality
to detect erased codeword in case of BCH ECC algorithm. The
NAND_ERASED_CW_DETECT_CFG register controls the Erased
Codeword/Page detection controller. This register should be reset
before every page read by setting and clearing bit 0 of
NAND_ERASED_CW_DETECT_CFG.

Signed-off-by: Abhishek Sahu <absahu@...eaurora.org>
---
 drivers/mtd/nand/qcom_nandc.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index b9e0eec..89f6a89 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -196,6 +196,11 @@
 #define NAND_BAM_NWD			BIT(1)
 /* Finish writing in the current sgl and start writing in another sgl */
 #define NAND_BAM_NEXT_SGL		BIT(2)
+/*
+ * Erased codeword status is being used two times in single transfer so this
+ * flag will determine the current value of erased codeword status register
+ */
+#define NAND_ERASED_CW_SET		BIT(4)
 
 /*
  * This data type corresponds to the BAM transaction which will be used for all
@@ -279,6 +284,8 @@ struct nandc_regs {
 	__le32 read_location2;
 	__le32 read_location3;
 
+	__le32 erased_cw_detect_cfg_clr;
+	__le32 erased_cw_detect_cfg_set;
 };
 
 /*
@@ -815,6 +822,13 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
 	if (first == NAND_FLASH_CMD)
 		flow_control = true;
 
+	if (first == NAND_ERASED_CW_DETECT_CFG) {
+		if (flags & NAND_ERASED_CW_SET)
+			vaddr = &regs->erased_cw_detect_cfg_set;
+		else
+			vaddr = &regs->erased_cw_detect_cfg_clr;
+	}
+
 	if (first == NAND_EXEC_CMD)
 		flags |= NAND_BAM_NWD;
 
@@ -867,6 +881,9 @@ static void config_nand_page_read(struct qcom_nand_controller *nandc)
 	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
 	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
 	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
+		      NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
 }
 
 /*
@@ -2268,9 +2285,13 @@ static int qcom_nand_host_setup(struct qcom_nand_host *host)
 
 	host->clrflashstatus = FS_READY_BSY_N;
 	host->clrreadstatus = 0xc0;
+	nandc->regs->erased_cw_detect_cfg_clr =
+		cpu_to_le32(CLR_ERASED_PAGE_DET);
+	nandc->regs->erased_cw_detect_cfg_set =
+		cpu_to_le32(SET_ERASED_PAGE_DET);
 
 	dev_dbg(nandc->dev,
-		"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data %d strength %d parity_bytes %d steps %d\n",
+	"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data %d strength %d parity_bytes %d steps %d\n",
 		host->cfg0, host->cfg1, host->ecc_buf_cfg, host->ecc_bch_cfg,
 		host->cw_size, host->cw_data, ecc->strength, ecc->bytes,
 		cwperpage);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation