kernel: fix mac-address-increment patch

Fix mac address increment patch. Permit to overflow to the next
byte and correctly calculate the incremented mac.

Reported-by: Chen Minqiang <ptpt52@gmail.com>
Fixes: d284e6ef0f ("treewide: convert mtd-mac-address-increment* to generic implementation")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
This commit is contained in:
Ansuel Smith 2021-11-04 14:36:50 +01:00 committed by Hauke Mehrtens
parent c9536520bd
commit 63ce6fcd20
4 changed files with 48 additions and 28 deletions

View File

@ -1,7 +1,7 @@
From 639dba857aa554f2a78572adc4cf3c32de9ec2e2 Mon Sep 17 00:00:00 2001
From 844c273286f328acf0dab5fbd5d864366b4904dc Mon Sep 17 00:00:00 2001
From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Tue, 30 Mar 2021 18:21:14 +0200
Subject: [PATCH 2/2] of_net: add mac-address-increment support
Subject: [PATCH] of_net: add mac-address-increment support
Lots of embedded devices use the mac-address of other interface
extracted from nvmem cells and increments it by one or two. Add two
@ -15,12 +15,12 @@ early has to be increased.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
drivers/of/of_net.c | 59 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 45 insertions(+), 14 deletions(-)
drivers/of/of_net.c | 43 +++++++++++++++++++++++++++++++++++++++----
1 file changed, 39 insertions(+), 4 deletions(-)
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -115,27 +115,52 @@ static int of_get_mac_addr_nvmem(struct
@@ -115,27 +115,62 @@ static int of_get_mac_addr_nvmem(struct
* this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
* but is all zeros.
*
@ -28,15 +28,17 @@ Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
+ * using:
+ * - mac-address-increment-byte to decide what byte to increase
+ * (if not defined is increased the last byte)
+ * - mac-address-increment to decide how much to increase. The value will
+ * not overflow to other bytes if the increment is over 255.
+ * (example 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00)
+ * - mac-address-increment to decide how much to increase. The value WILL
+ * overflow to other bytes if the increment is over 255 or the total
+ * increment will exceed 255 of the current byte.
+ * (example 00:01:02:03:04:ff + 1 == 00:01:02:03:05:00)
+ * (example 00:01:02:03:04:fe + 5 == 00:01:02:03:05:03)
+ *
* Return: 0 on success and errno in case of error.
*/
int of_get_mac_address(struct device_node *np, u8 *addr)
{
+ u32 inc_idx, mac_inc;
+ u32 inc_idx, mac_inc, mac_val;
int ret;
+ /* Check first if the increment byte is present and valid.
@ -70,8 +72,16 @@ Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
+ return ret;
+
+found:
+ if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
+ addr[inc_idx] += mac_inc;
+ if (!of_property_read_u32(np, "mac-address-increment", &mac_inc)) {
+ /* Convert to a contiguous value */
+ mac_val = (addr[3] << 16) + (addr[4] << 8) + addr[5];
+ mac_val += mac_inc << 8 * (5-inc_idx);
+
+ /* Apply the incremented value handling overflow case */
+ addr[3] = (mac_val >> 16) & 0xff;
+ addr[4] = (mac_val >> 8) & 0xff;
+ addr[5] = (mac_val >> 0) & 0xff;
+ }
- return of_get_mac_addr_nvmem(np, addr);
+ return ret;

View File

@ -28,9 +28,9 @@
/**
* Search the device tree for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
@@ -161,6 +182,7 @@ found:
if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
addr[inc_idx] += mac_inc;
@@ -171,6 +192,7 @@ found:
addr[5] = (mac_val >> 0) & 0xff;
}
+ of_add_mac_address(np, addr);
return ret;

View File

@ -1,7 +1,7 @@
From 639dba857aa554f2a78572adc4cf3c32de9ec2e2 Mon Sep 17 00:00:00 2001
From 844c273286f328acf0dab5fbd5d864366b4904dc Mon Sep 17 00:00:00 2001
From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Tue, 30 Mar 2021 18:21:14 +0200
Subject: [PATCH 2/2] of_net: add mac-address-increment support
Subject: [PATCH] of_net: add mac-address-increment support
Lots of embedded devices use the mac-address of other interface
extracted from nvmem cells and increments it by one or two. Add two
@ -15,12 +15,12 @@ early has to be increased.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
drivers/of/of_net.c | 59 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 45 insertions(+), 14 deletions(-)
drivers/of/of_net.c | 43 +++++++++++++++++++++++++++++++++++++++----
1 file changed, 39 insertions(+), 4 deletions(-)
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -109,27 +109,52 @@ static int of_get_mac_addr_nvmem(struct
@@ -109,27 +109,62 @@ static int of_get_mac_addr_nvmem(struct
* this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
* but is all zeros.
*
@ -28,15 +28,17 @@ Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
+ * using:
+ * - mac-address-increment-byte to decide what byte to increase
+ * (if not defined is increased the last byte)
+ * - mac-address-increment to decide how much to increase. The value will
+ * not overflow to other bytes if the increment is over 255.
+ * (example 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00)
+ * - mac-address-increment to decide how much to increase. The value WILL
+ * overflow to other bytes if the increment is over 255 or the total
+ * increment will exceed 255 of the current byte.
+ * (example 00:01:02:03:04:ff + 1 == 00:01:02:03:05:00)
+ * (example 00:01:02:03:04:fe + 5 == 00:01:02:03:05:03)
+ *
* Return: 0 on success and errno in case of error.
*/
int of_get_mac_address(struct device_node *np, u8 *addr)
{
+ u32 inc_idx, mac_inc;
+ u32 inc_idx, mac_inc, mac_val;
int ret;
+ /* Check first if the increment byte is present and valid.
@ -70,8 +72,16 @@ Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
+ return ret;
+
+found:
+ if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
+ addr[inc_idx] += mac_inc;
+ if (!of_property_read_u32(np, "mac-address-increment", &mac_inc)) {
+ /* Convert to a contiguous value */
+ mac_val = (addr[3] << 16) + (addr[4] << 8) + addr[5];
+ mac_val += mac_inc << 8 * (5-inc_idx);
+
+ /* Apply the incremented value handling overflow case */
+ addr[3] = (mac_val >> 16) & 0xff;
+ addr[4] = (mac_val >> 8) & 0xff;
+ addr[5] = (mac_val >> 0) & 0xff;
+ }
- return of_get_mac_addr_nvmem(np, addr);
+ return ret;

View File

@ -28,9 +28,9 @@
/**
* Search the device tree for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
@@ -155,6 +176,7 @@ found:
if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
addr[inc_idx] += mac_inc;
@@ -165,6 +186,7 @@ found:
addr[5] = (mac_val >> 0) & 0xff;
}
+ of_add_mac_address(np, addr);
return ret;