[PATCH 0/4] thunderbolt: NVM fixes and consolidation

[PATCH 0/4] thunderbolt: NVM fixes and consolidation

[Mika Westerberg]

Hi all,

This series includes two fixes from Mathias on read side of NVM. These will
go to stable trees as well.

The rest will consolidate NVM read/write functions to get rid of the
duplication.

Mathias Nyman (2):
  thunderbolt: dma_port: Fix NVM read buffer bounds and offset issue
  thunderbolt: usb4: Fix NVM read buffer bounds and offset issue

Mika Westerberg (2):
  thunderbolt: Split NVM read/write generic functions out from usb4.c
  thunderbolt: Use generic tb_nvm_[read|write]_data() for Thunderbolt 2/3 devices

 drivers/thunderbolt/dma_port.c |  93 +++++-----------------------
 drivers/thunderbolt/nvm.c      |  95 ++++++++++++++++++++++++++++
 drivers/thunderbolt/tb.h       |  11 ++++
 drivers/thunderbolt/usb4.c     | 109 ++++++---------------------------
 4 files changed, 139 insertions(+), 169 deletions(-)

-- 
2.30.2

[PATCH 1/4] thunderbolt: dma_port: Fix NVM read buffer bounds and offset issue

[Mika Westerberg]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Up to 64 bytes of data can be read from NVM in one go. Read address
must be dword aligned. Data is read into a local buffer.

If caller asks to read data starting at an unaligned address then full
dword is anyway read from NVM into a local buffer. Data is then copied
from the local buffer starting at the unaligned offset to the caller
buffer.

In cases where asked data length + unaligned offset is over 64 bytes
we need to make sure we don't read past the 64 bytes in the local
buffer when copying to caller buffer, and make sure that we don't
skip copying unaligned offset bytes from local buffer anymore after
the first round of 64 byte NVM data read.

Fixes: 3e13676862f9 ("thunderbolt: Add support for DMA configuration based mailbox")
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/dma_port.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/thunderbolt/dma_port.c b/drivers/thunderbolt/dma_port.c
index 7288aaf01ae6..5631319f7b20 100644
--- a/drivers/thunderbolt/dma_port.c
+++ b/drivers/thunderbolt/dma_port.c
@@ -366,15 +366,15 @@ int dma_port_flash_read(struct tb_dma_port *dma, unsigned int address,
 			void *buf, size_t size)
 {
 	unsigned int retries = DMA_PORT_RETRIES;
-	unsigned int offset;
-
-	offset = address & 3;
-	address = address & ~3;
 
 	do {
-		u32 nbytes = min_t(u32, size, MAIL_DATA_DWORDS * 4);
+		unsigned int offset;
+		size_t nbytes;
 		int ret;
 
+		offset = address & 3;
+		nbytes = min_t(size_t, size + offset, MAIL_DATA_DWORDS * 4);
+
 		ret = dma_port_flash_read_block(dma, address, dma->buf,
 						ALIGN(nbytes, 4));
 		if (ret) {
@@ -386,6 +386,7 @@ int dma_port_flash_read(struct tb_dma_port *dma, unsigned int address,
 			return ret;
 		}
 
+		nbytes -= offset;
 		memcpy(buf, dma->buf + offset, nbytes);
 
 		size -= nbytes;
-- 
2.30.2

Re: [PATCH 1/4] thunderbolt: dma_port: Fix NVM read buffer bounds and offset issue

[Mika Westerberg]

On Mon, May 17, 2021 at 02:59:04PM +0300, Mika Westerberg wrote:
> From: Mathias Nyman <mathias.nyman@linux.intel.com>
> 
> Up to 64 bytes of data can be read from NVM in one go. Read address
> must be dword aligned. Data is read into a local buffer.
> 
> If caller asks to read data starting at an unaligned address then full
> dword is anyway read from NVM into a local buffer. Data is then copied
> from the local buffer starting at the unaligned offset to the caller
> buffer.
> 
> In cases where asked data length + unaligned offset is over 64 bytes
> we need to make sure we don't read past the 64 bytes in the local
> buffer when copying to caller buffer, and make sure that we don't
> skip copying unaligned offset bytes from local buffer anymore after
> the first round of 64 byte NVM data read.
> 
> Fixes: 3e13676862f9 ("thunderbolt: Add support for DMA configuration based mailbox")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Applied to thunderbolt.git/fixes.

[PATCH 2/4] thunderbolt: usb4: Fix NVM read buffer bounds and offset issue

[Mika Westerberg]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Up to 64 bytes of data can be read from NVM in one go.
Read address must be dword aligned. Data is read into a local buffer.

If caller asks to read data starting at an unaligned address then full
dword is anyway read from NVM into a local buffer. Data is then copied
from the local buffer starting at the unaligned offset to the caller
buffer.

In cases where asked data length + unaligned offset is over 64 bytes
we need to make sure we don't read past the 64 bytes in the local
buffer when copying to caller buffer, and make sure that we don't
skip copying unaligned offset bytes from local buffer anymore after
the first round of 64 byte NVM data read.

Fixes: b04079837b20 ("thunderbolt: Add initial support for USB4")
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/usb4.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 680bc738dd66..671d72af8ba1 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -68,15 +68,15 @@ static int usb4_do_read_data(u16 address, void *buf, size_t size,
 	unsigned int retries = USB4_DATA_RETRIES;
 	unsigned int offset;
 
-	offset = address & 3;
-	address = address & ~3;
-
 	do {
-		size_t nbytes = min_t(size_t, size, USB4_DATA_DWORDS * 4);
 		unsigned int dwaddress, dwords;
 		u8 data[USB4_DATA_DWORDS * 4];
+		size_t nbytes;
 		int ret;
 
+		offset = address & 3;
+		nbytes = min_t(size_t, size + offset, USB4_DATA_DWORDS * 4);
+
 		dwaddress = address / 4;
 		dwords = ALIGN(nbytes, 4) / 4;
 
@@ -87,6 +87,7 @@ static int usb4_do_read_data(u16 address, void *buf, size_t size,
 			return ret;
 		}
 
+		nbytes -= offset;
 		memcpy(buf, data + offset, nbytes);
 
 		size -= nbytes;
-- 
2.30.2

Re: [PATCH 2/4] thunderbolt: usb4: Fix NVM read buffer bounds and offset issue

[Mika Westerberg]

On Mon, May 17, 2021 at 02:59:05PM +0300, Mika Westerberg wrote:
> From: Mathias Nyman <mathias.nyman@linux.intel.com>
> 
> Up to 64 bytes of data can be read from NVM in one go.
> Read address must be dword aligned. Data is read into a local buffer.
> 
> If caller asks to read data starting at an unaligned address then full
> dword is anyway read from NVM into a local buffer. Data is then copied
> from the local buffer starting at the unaligned offset to the caller
> buffer.
> 
> In cases where asked data length + unaligned offset is over 64 bytes
> we need to make sure we don't read past the 64 bytes in the local
> buffer when copying to caller buffer, and make sure that we don't
> skip copying unaligned offset bytes from local buffer anymore after
> the first round of 64 byte NVM data read.
> 
> Fixes: b04079837b20 ("thunderbolt: Add initial support for USB4")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Applied to thunderbolt.git/fixes.

[PATCH 3/4] thunderbolt: Split NVM read/write generic functions out from usb4.c

[Mika Westerberg]

We do this for Thunderbolt 2/3 devices through DMA port, USB4 devices
and retimers pretty much the same way. Only the actual block read/write
is different. For this reason split out the NVM read/write functions
from usb4.c to nvm.c and make USB4 device code call these when needed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/nvm.c  |  95 ++++++++++++++++++++++++++++++++
 drivers/thunderbolt/tb.h   |  11 ++++
 drivers/thunderbolt/usb4.c | 110 ++++++-------------------------------
 3 files changed, 124 insertions(+), 92 deletions(-)

diff --git a/drivers/thunderbolt/nvm.c b/drivers/thunderbolt/nvm.c
index 29de6d95c6e7..3a5336913cca 100644
--- a/drivers/thunderbolt/nvm.c
+++ b/drivers/thunderbolt/nvm.c
@@ -164,6 +164,101 @@ void tb_nvm_free(struct tb_nvm *nvm)
 	kfree(nvm);
 }
 
+/**
+ * tb_nvm_read_data() - Read data from NVM
+ * @address: Start address on the flash
+ * @buf: Buffer where the read data is copied
+ * @size: Size of the buffer in bytes
+ * @retries: Number of retries if block read fails
+ * @read_block: Function that reads block from the flash
+ * @read_block_data: Data passsed to @read_block
+ *
+ * This is a generic function that reads data from NVM or NVM like
+ * device.
+ *
+ * Returns %0 on success and negative errno otherwise.
+ */
+int tb_nvm_read_data(unsigned int address, void *buf, size_t size,
+		     unsigned int retries, read_block_fn read_block,
+		     void *read_block_data)
+{
+	do {
+		unsigned int dwaddress, dwords, offset;
+		u8 data[NVM_DATA_DWORDS * 4];
+		size_t nbytes;
+		int ret;
+
+		offset = address & 3;
+		nbytes = min_t(size_t, size + offset, NVM_DATA_DWORDS * 4);
+
+		dwaddress = address / 4;
+		dwords = ALIGN(nbytes, 4) / 4;
+
+		ret = read_block(read_block_data, dwaddress, data, dwords);
+		if (ret) {
+			if (ret != -ENODEV && retries--)
+				continue;
+			return ret;
+		}
+
+		nbytes -= offset;
+		memcpy(buf, data + offset, nbytes);
+
+		size -= nbytes;
+		address += nbytes;
+		buf += nbytes;
+	} while (size > 0);
+
+	return 0;
+}
+
+/**
+ * tb_nvm_write_data() - Write data to NVM
+ * @address: Start address on the flash
+ * @buf: Buffer where the data is copied from
+ * @size: Size of the buffer in bytes
+ * @retries: Number of retries if the block write fails
+ * @write_block: Function that writes block to the flash
+ * @write_block_data: Data passwd to @write_block
+ *
+ * This is generic function that writes data to NVM or NVM like device.
+ *
+ * Returns %0 on success and negative errno otherwise.
+ */
+int tb_nvm_write_data(unsigned int address, const void *buf, size_t size,
+		      unsigned int retries, write_block_fn write_block,
+		      void *write_block_data)
+{
+	do {
+		unsigned int offset, dwaddress;
+		u8 data[NVM_DATA_DWORDS * 4];
+		size_t nbytes;
+		int ret;
+
+		offset = address & 3;
+		nbytes = min_t(u32, size + offset, NVM_DATA_DWORDS * 4);
+
+		memcpy(data + offset, buf, nbytes);
+
+		dwaddress = address / 4;
+		ret = write_block(write_block_data, dwaddress, data, nbytes / 4);
+		if (ret) {
+			if (ret == -ETIMEDOUT) {
+				if (retries--)
+					continue;
+				ret = -EIO;
+			}
+			return ret;
+		}
+
+		size -= nbytes;
+		address += nbytes;
+		buf += nbytes;
+	} while (size > 0);
+
+	return 0;
+}
+
 void tb_nvm_exit(void)
 {
 	ida_destroy(&nvm_ida);
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 9790e9f13d2b..d9d1adc4cfd3 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -20,6 +20,7 @@
 
 #define NVM_MIN_SIZE		SZ_32K
 #define NVM_MAX_SIZE		SZ_512K
+#define NVM_DATA_DWORDS		16
 
 /* Intel specific NVM offsets */
 #define NVM_DEVID		0x05
@@ -674,6 +675,16 @@ int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
 void tb_nvm_free(struct tb_nvm *nvm);
 void tb_nvm_exit(void);
 
+typedef int (*read_block_fn)(void *, unsigned int, void *, size_t);
+typedef int (*write_block_fn)(void *, unsigned int, const void *, size_t);
+
+int tb_nvm_read_data(unsigned int address, void *buf, size_t size,
+		     unsigned int retries, read_block_fn read_block,
+		     void *read_block_data);
+int tb_nvm_write_data(unsigned int address, const void *buf, size_t size,
+		      unsigned int retries, write_block_fn write_next_block,
+		      void *write_block_data);
+
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 				  u64 route);
 struct tb_switch *tb_switch_alloc_safe_mode(struct tb *tb,
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 671d72af8ba1..c0a14bfa36d4 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -13,7 +13,6 @@
 #include "sb_regs.h"
 #include "tb.h"
 
-#define USB4_DATA_DWORDS		16
 #define USB4_DATA_RETRIES		3
 
 enum usb4_sb_target {
@@ -37,9 +36,6 @@ enum usb4_sb_target {
 
 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
 
-typedef int (*read_block_fn)(void *, unsigned int, void *, size_t);
-typedef int (*write_block_fn)(void *, const void *, size_t);
-
 static int usb4_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
 				    u32 value, int timeout_msec)
 {
@@ -62,76 +58,6 @@ static int usb4_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
 	return -ETIMEDOUT;
 }
 
-static int usb4_do_read_data(u16 address, void *buf, size_t size,
-			     read_block_fn read_block, void *read_block_data)
-{
-	unsigned int retries = USB4_DATA_RETRIES;
-	unsigned int offset;
-
-	do {
-		unsigned int dwaddress, dwords;
-		u8 data[USB4_DATA_DWORDS * 4];
-		size_t nbytes;
-		int ret;
-
-		offset = address & 3;
-		nbytes = min_t(size_t, size + offset, USB4_DATA_DWORDS * 4);
-
-		dwaddress = address / 4;
-		dwords = ALIGN(nbytes, 4) / 4;
-
-		ret = read_block(read_block_data, dwaddress, data, dwords);
-		if (ret) {
-			if (ret != -ENODEV && retries--)
-				continue;
-			return ret;
-		}
-
-		nbytes -= offset;
-		memcpy(buf, data + offset, nbytes);
-
-		size -= nbytes;
-		address += nbytes;
-		buf += nbytes;
-	} while (size > 0);
-
-	return 0;
-}
-
-static int usb4_do_write_data(unsigned int address, const void *buf, size_t size,
-	write_block_fn write_next_block, void *write_block_data)
-{
-	unsigned int retries = USB4_DATA_RETRIES;
-	unsigned int offset;
-
-	offset = address & 3;
-	address = address & ~3;
-
-	do {
-		u32 nbytes = min_t(u32, size, USB4_DATA_DWORDS * 4);
-		u8 data[USB4_DATA_DWORDS * 4];
-		int ret;
-
-		memcpy(data + offset, buf, nbytes);
-
-		ret = write_next_block(write_block_data, data, nbytes / 4);
-		if (ret) {
-			if (ret == -ETIMEDOUT) {
-				if (retries--)
-					continue;
-				ret = -EIO;
-			}
-			return ret;
-		}
-
-		size -= nbytes;
-		address += nbytes;
-		buf += nbytes;
-	} while (size > 0);
-
-	return 0;
-}
-
 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
 				 u32 *metadata, u8 *status,
 				 const void *tx_data, size_t tx_dwords,
@@ -193,7 +119,7 @@ static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
 {
 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
 
-	if (tx_dwords > USB4_DATA_DWORDS || rx_dwords > USB4_DATA_DWORDS)
+	if (tx_dwords > NVM_DATA_DWORDS || rx_dwords > NVM_DATA_DWORDS)
 		return -EINVAL;
 
 	/*
@@ -414,8 +340,8 @@ static int usb4_switch_drom_read_block(void *data,
 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
 			  size_t size)
 {
-	return usb4_do_read_data(address, buf, size,
-				 usb4_switch_drom_read_block, sw);
+	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
+				usb4_switch_drom_read_block, sw);
 }
 
 /**
@@ -595,8 +521,8 @@ static int usb4_switch_nvm_read_block(void *data,
 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
 			 size_t size)
 {
-	return usb4_do_read_data(address, buf, size,
-				 usb4_switch_nvm_read_block, sw);
+	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
+				usb4_switch_nvm_read_block, sw);
 }
 
 static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
@@ -618,8 +544,8 @@ static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
 	return status ? -EIO : 0;
 }
 
-static int usb4_switch_nvm_write_next_block(void *data, const void *buf,
-					    size_t dwords)
+static int usb4_switch_nvm_write_next_block(void *data, unsigned int dwaddress,
+					    const void *buf, size_t dwords)
 {
 	struct tb_switch *sw = data;
 	u8 status;
@@ -652,8 +578,8 @@ int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
 	if (ret)
 		return ret;
 
-	return usb4_do_write_data(address, buf, size,
-				  usb4_switch_nvm_write_next_block, sw);
+	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
+				 usb4_switch_nvm_write_next_block, sw);
 }
 
 /**
@@ -1029,7 +955,7 @@ static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
 
 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
 {
-	if (dwords > USB4_DATA_DWORDS)
+	if (dwords > NVM_DATA_DWORDS)
 		return -EINVAL;
 
 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
@@ -1039,7 +965,7 @@ static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
 static int usb4_port_write_data(struct tb_port *port, const void *data,
 				size_t dwords)
 {
-	if (dwords > USB4_DATA_DWORDS)
+	if (dwords > NVM_DATA_DWORDS)
 		return -EINVAL;
 
 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
@@ -1316,8 +1242,8 @@ struct retimer_info {
 	u8 index;
 };
 
-static int usb4_port_retimer_nvm_write_next_block(void *data, const void *buf,
-						  size_t dwords)
+static int usb4_port_retimer_nvm_write_next_block(void *data,
+	unsigned int dwaddress, const void *buf, size_t dwords)
 
 {
 	const struct retimer_info *info = data;
@@ -1357,8 +1283,8 @@ int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int add
 	if (ret)
 		return ret;
 
-	return usb4_do_write_data(address, buf, size,
-			usb4_port_retimer_nvm_write_next_block, &info);
+	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
+				 usb4_port_retimer_nvm_write_next_block, &info);
 }
 
 /**
@@ -1442,7 +1368,7 @@ static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
 	int ret;
 
 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
-	if (dwords < USB4_DATA_DWORDS)
+	if (dwords < NVM_DATA_DWORDS)
 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
 
 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
@@ -1475,8 +1401,8 @@ int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
 {
 	struct retimer_info info = { .port = port, .index = index };
 
-	return usb4_do_read_data(address, buf, size,
-			usb4_port_retimer_nvm_read_block, &info);
+	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
+				usb4_port_retimer_nvm_read_block, &info);
 }
 
 /**
-- 
2.30.2

Re: [PATCH 3/4] thunderbolt: Split NVM read/write generic functions out from usb4.c

[Mika Westerberg]

On Mon, May 17, 2021 at 02:59:06PM +0300, Mika Westerberg wrote:
> We do this for Thunderbolt 2/3 devices through DMA port, USB4 devices
> and retimers pretty much the same way. Only the actual block read/write
> is different. For this reason split out the NVM read/write functions
> from usb4.c to nvm.c and make USB4 device code call these when needed.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

This and the 4/4 applied to thunderbolt.git/next.

[PATCH 4/4] thunderbolt: Use generic tb_nvm_[read|write]_data() for Thunderbolt 2/3 devices

[Mika Westerberg]

Now that we have generic functionality available in nvm.c make the DMA
port code call it instead of duplicating the functionality.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/dma_port.c | 94 ++++++----------------------------
 1 file changed, 15 insertions(+), 79 deletions(-)

diff --git a/drivers/thunderbolt/dma_port.c b/drivers/thunderbolt/dma_port.c
index 5631319f7b20..9f20c7bbf0ce 100644
--- a/drivers/thunderbolt/dma_port.c
+++ b/drivers/thunderbolt/dma_port.c
@@ -299,15 +299,13 @@ static int dma_port_request(struct tb_dma_port *dma, u32 in,
 	return status_to_errno(out);
 }
 
-static int dma_port_flash_read_block(struct tb_dma_port *dma, u32 address,
-				     void *buf, u32 size)
+static int dma_port_flash_read_block(void *data, unsigned int dwaddress,
+				     void *buf, size_t dwords)
 {
+	struct tb_dma_port *dma = data;
 	struct tb_switch *sw = dma->sw;
-	u32 in, dwaddress, dwords;
 	int ret;
-
-	dwaddress = address / 4;
-	dwords = size / 4;
+	u32 in;
 
 	in = MAIL_IN_CMD_FLASH_READ << MAIL_IN_CMD_SHIFT;
 	if (dwords < MAIL_DATA_DWORDS)
@@ -323,14 +321,13 @@ static int dma_port_flash_read_block(struct tb_dma_port *dma, u32 address,
 			     dma->base + MAIL_DATA, dwords, DMA_PORT_TIMEOUT);
 }
 
-static int dma_port_flash_write_block(struct tb_dma_port *dma, u32 address,
-				      const void *buf, u32 size)
+static int dma_port_flash_write_block(void *data, unsigned int dwaddress,
+				      const void *buf, size_t dwords)
 {
+	struct tb_dma_port *dma = data;
 	struct tb_switch *sw = dma->sw;
-	u32 in, dwaddress, dwords;
 	int ret;
-
-	dwords = size / 4;
+	u32 in;
 
 	/* Write the block to MAIL_DATA registers */
 	ret = dma_port_write(sw->tb->ctl, buf, tb_route(sw), dma->port,
@@ -341,12 +338,8 @@ static int dma_port_flash_write_block(struct tb_dma_port *dma, u32 address,
 	in = MAIL_IN_CMD_FLASH_WRITE << MAIL_IN_CMD_SHIFT;
 
 	/* CSS header write is always done to the same magic address */
-	if (address >= DMA_PORT_CSS_ADDRESS) {
-		dwaddress = DMA_PORT_CSS_ADDRESS;
+	if (dwaddress >= DMA_PORT_CSS_ADDRESS)
 		in |= MAIL_IN_CSS;
-	} else {
-		dwaddress = address / 4;
-	}
 
 	in |= ((dwords - 1) << MAIL_IN_DWORDS_SHIFT) & MAIL_IN_DWORDS_MASK;
 	in |= (dwaddress << MAIL_IN_ADDRESS_SHIFT) & MAIL_IN_ADDRESS_MASK;
@@ -365,36 +358,8 @@ static int dma_port_flash_write_block(struct tb_dma_port *dma, u32 address,
 int dma_port_flash_read(struct tb_dma_port *dma, unsigned int address,
 			void *buf, size_t size)
 {
-	unsigned int retries = DMA_PORT_RETRIES;
-
-	do {
-		unsigned int offset;
-		size_t nbytes;
-		int ret;
-
-		offset = address & 3;
-		nbytes = min_t(size_t, size + offset, MAIL_DATA_DWORDS * 4);
-
-		ret = dma_port_flash_read_block(dma, address, dma->buf,
-						ALIGN(nbytes, 4));
-		if (ret) {
-			if (ret == -ETIMEDOUT) {
-				if (retries--)
-					continue;
-				ret = -EIO;
-			}
-			return ret;
-		}
-
-		nbytes -= offset;
-		memcpy(buf, dma->buf + offset, nbytes);
-
-		size -= nbytes;
-		address += nbytes;
-		buf += nbytes;
-	} while (size > 0);
-
-	return 0;
+	return tb_nvm_read_data(address, buf, size, DMA_PORT_RETRIES,
+				dma_port_flash_read_block, dma);
 }
 
 /**
@@ -411,40 +376,11 @@ int dma_port_flash_read(struct tb_dma_port *dma, unsigned int address,
 int dma_port_flash_write(struct tb_dma_port *dma, unsigned int address,
 			 const void *buf, size_t size)
 {
-	unsigned int retries = DMA_PORT_RETRIES;
-	unsigned int offset;
-
-	if (address >= DMA_PORT_CSS_ADDRESS) {
-		offset = 0;
-		if (size > DMA_PORT_CSS_MAX_SIZE)
-			return -E2BIG;
-	} else {
-		offset = address & 3;
-		address = address & ~3;
-	}
-
-	do {
-		u32 nbytes = min_t(u32, size, MAIL_DATA_DWORDS * 4);
-		int ret;
+	if (address >= DMA_PORT_CSS_ADDRESS && size > DMA_PORT_CSS_MAX_SIZE)
+		return -E2BIG;
 
-		memcpy(dma->buf + offset, buf, nbytes);
-
-		ret = dma_port_flash_write_block(dma, address, buf, nbytes);
-		if (ret) {
-			if (ret == -ETIMEDOUT) {
-				if (retries--)
-					continue;
-				ret = -EIO;
-			}
-			return ret;
-		}
-
-		size -= nbytes;
-		address += nbytes;
-		buf += nbytes;
-	} while (size > 0);
-
-	return 0;
+	return tb_nvm_write_data(address, buf, size, DMA_PORT_RETRIES,
+				 dma_port_flash_write_block, dma);
 }
 
 /**
-- 
2.30.2