linux-kernel - [PATCH 14/16] spi: bcm63xx-hsspi: prepend: Disable spi mem dual io read op support

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]

Message-Id: <20230106200809.330769-15-william.zhang@broadcom.com>
Date:   Fri,  6 Jan 2023 12:08:06 -0800
From:   William Zhang <william.zhang@...adcom.com>
To:     Linux SPI List <linux-spi@...r.kernel.org>,
        Broadcom Kernel List <bcm-kernel-feedback-list@...adcom.com>
Cc:     anand.gore@...adcom.com, tomer.yacoby@...adcom.com,
        dan.beygelman@...adcom.com, joel.peshkin@...adcom.com,
        f.fainelli@...il.com, jonas.gorski@...il.com,
        kursad.oney@...adcom.com, dregan@...l.com,
        William Zhang <william.zhang@...adcom.com>,
        Mark Brown <broonie@...nel.org>, linux-kernel@...r.kernel.org
Subject: [PATCH 14/16] spi: bcm63xx-hsspi: prepend: Disable spi mem dual io read op support

In general the controller supports SPI dual mode operation but the
particular SPI flash dual io read op switches from single mode in cmd
phase to dual mode in address and data phase. This is not compatible
with prepend operation where cmd and address are sent out through the
prepend buffer and they must use same the number of io pins.

This patch disables these SPI flash dual io read ops through the mem_ops
supports_op interface when prepend mode is used. This makes sure the SPI
flash driver selects the compatible read ops at run time.

Signed-off-by: William Zhang <william.zhang@...adcom.com>
---

 drivers/spi/spi-bcm63xx-hsspi.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
index be4ca01f332a..7ede7f02ba2c 100644
--- a/drivers/spi/spi-bcm63xx-hsspi.c
+++ b/drivers/spi/spi-bcm63xx-hsspi.c
@@ -20,6 +20,7 @@
 #include <linux/spi/spi.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/spi/spi-mem.h>
 #include <linux/reset.h>
 #include <linux/pm_runtime.h>
 
@@ -596,6 +597,26 @@ static int bcm63xx_hsspi_transfer_one(struct spi_master *master,
 	return 0;
 }
 
+static bool bcm63xx_hsspi_mem_supports_op(struct spi_mem *mem,
+			    const struct spi_mem_op *op)
+{
+	struct bcm63xx_hsspi *bs = spi_master_get_devdata(mem->spi->master);
+
+	if (!spi_mem_default_supports_op(mem, op))
+		return false;
+
+	/* Controller doesn't support spi mem dual/quad read cmd in prepend mode */
+	if (!bs->use_cs_workaround &&
+		  ((op->cmd.opcode == 0xbb) || (op->cmd.opcode == 0xeb)))
+		return false;
+
+	return true;
+}
+
+static const struct spi_controller_mem_ops bcm63xx_hsspi_mem_ops = {
+	.supports_op = bcm63xx_hsspi_mem_supports_op,
+};
+
 static irqreturn_t bcm63xx_hsspi_interrupt(int irq, void *dev_id)
 {
 	struct bcm63xx_hsspi *bs = (struct bcm63xx_hsspi *)dev_id;
@@ -692,6 +713,7 @@ static int bcm63xx_hsspi_probe(struct platform_device *pdev)
 	mutex_init(&bs->bus_mutex);
 	init_completion(&bs->done);
 
+	master->mem_ops = &bcm63xx_hsspi_mem_ops;
 	master->dev.of_node = dev->of_node;
 	if (!dev->of_node) {
 		master->bus_num = HSSPI_BUS_NUM;
-- 
2.37.3