From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
kernel@pengutronix.de, Oliver Hartkopp <socketcan@hartkopp.net>,
Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [net-next 11/25] can: gw: support modification of Classical CAN DLCs
Date: Fri, 20 Nov 2020 14:33:04 +0100 [thread overview]
Message-ID: <20201120133318.3428231-12-mkl@pengutronix.de> (raw)
In-Reply-To: <20201120133318.3428231-1-mkl@pengutronix.de>
From: Oliver Hartkopp <socketcan@hartkopp.net>
Add support for data length code modifications for Classical CAN.
The netlink configuration interface always allowed to pass any value
that fits into a byte, therefore only the modification process had to be
extended to handle the raw DLC represenation of Classical CAN frames.
When a DLC value from 0 .. F is provided for Classical CAN frame
modifications the 'len' value is modified as-is with the exception that
potentially existing 9 .. F DLC values in the len8_dlc element are moved
to the 'len' element for the modification operation by mod_retrieve_ccdlc().
After the modification the Classical CAN frame DLC information is brought
back into the correct format by mod_store_ccdlc() which is filling 'len'
and 'len8_dlc' accordingly.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201119084921.2621-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
include/uapi/linux/can/gw.h | 4 +-
net/can/gw.c | 78 +++++++++++++++++++++++++++++++++----
2 files changed, 72 insertions(+), 10 deletions(-)
diff --git a/include/uapi/linux/can/gw.h b/include/uapi/linux/can/gw.h
index c2190bbe21d8..e4f0957554f3 100644
--- a/include/uapi/linux/can/gw.h
+++ b/include/uapi/linux/can/gw.h
@@ -98,8 +98,8 @@ enum {
/* CAN frame elements that are affected by curr. 3 CAN frame modifications */
#define CGW_MOD_ID 0x01
-#define CGW_MOD_DLC 0x02 /* contains the data length in bytes */
-#define CGW_MOD_LEN CGW_MOD_DLC /* CAN FD length representation */
+#define CGW_MOD_DLC 0x02 /* Classical CAN data length code */
+#define CGW_MOD_LEN CGW_MOD_DLC /* CAN FD (plain) data length */
#define CGW_MOD_DATA 0x04
#define CGW_MOD_FLAGS 0x08 /* CAN FD flags */
diff --git a/net/can/gw.c b/net/can/gw.c
index de5e8859ec9b..8598d9da0e5f 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -199,6 +199,68 @@ static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
}
+/* retrieve valid CC DLC value and store it into 'len' */
+static void mod_retrieve_ccdlc(struct canfd_frame *cf)
+{
+ struct can_frame *ccf = (struct can_frame *)cf;
+
+ /* len8_dlc is only valid if len == CAN_MAX_DLEN */
+ if (ccf->len != CAN_MAX_DLEN)
+ return;
+
+ /* do we have a valid len8_dlc value from 9 .. 15 ? */
+ if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC)
+ ccf->len = ccf->len8_dlc;
+}
+
+/* convert valid CC DLC value in 'len' into struct can_frame elements */
+static void mod_store_ccdlc(struct canfd_frame *cf)
+{
+ struct can_frame *ccf = (struct can_frame *)cf;
+
+ /* clear potential leftovers */
+ ccf->len8_dlc = 0;
+
+ /* plain data length 0 .. 8 - that was easy */
+ if (ccf->len <= CAN_MAX_DLEN)
+ return;
+
+ /* potentially broken values are catched in can_can_gw_rcv() */
+ if (ccf->len > CAN_MAX_RAW_DLC)
+ return;
+
+ /* we have a valid dlc value from 9 .. 15 in ccf->len */
+ ccf->len8_dlc = ccf->len;
+ ccf->len = CAN_MAX_DLEN;
+}
+
+static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ mod_retrieve_ccdlc(cf);
+ mod_and_len(cf, mod);
+ mod_store_ccdlc(cf);
+}
+
+static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ mod_retrieve_ccdlc(cf);
+ mod_or_len(cf, mod);
+ mod_store_ccdlc(cf);
+}
+
+static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ mod_retrieve_ccdlc(cf);
+ mod_xor_len(cf, mod);
+ mod_store_ccdlc(cf);
+}
+
+static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ mod_set_len(cf, mod);
+ mod_store_ccdlc(cf);
+}
+
static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
{
/* Copy the struct members separately to ensure that no uninitialized
@@ -842,8 +904,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_and_id;
- if (mb.modtype & CGW_MOD_LEN)
- mod->modfunc[modidx++] = mod_and_len;
+ if (mb.modtype & CGW_MOD_DLC)
+ mod->modfunc[modidx++] = mod_and_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_and_data;
@@ -858,8 +920,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_or_id;
- if (mb.modtype & CGW_MOD_LEN)
- mod->modfunc[modidx++] = mod_or_len;
+ if (mb.modtype & CGW_MOD_DLC)
+ mod->modfunc[modidx++] = mod_or_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_or_data;
@@ -874,8 +936,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_xor_id;
- if (mb.modtype & CGW_MOD_LEN)
- mod->modfunc[modidx++] = mod_xor_len;
+ if (mb.modtype & CGW_MOD_DLC)
+ mod->modfunc[modidx++] = mod_xor_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_xor_data;
@@ -890,8 +952,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_set_id;
- if (mb.modtype & CGW_MOD_LEN)
- mod->modfunc[modidx++] = mod_set_len;
+ if (mb.modtype & CGW_MOD_DLC)
+ mod->modfunc[modidx++] = mod_set_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_set_data;
--
2.29.2
next prev parent reply other threads:[~2020-11-20 13:34 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 13:32 pull-request: can-next 2020-11-20 Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 01/25] can: j1939: add tables for the CAN identifier and its fields Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 02/25] can: add optional DLC element to Classical CAN frame structure Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 03/25] can: rename get_can_dlc() macro with can_cc_dlc2len() Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 04/25] can: remove obsolete get_canfd_dlc() macro Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 05/25] can: replace can_dlc as variable/element for payload length Marc Kleine-Budde
2020-11-20 13:32 ` [net-next 06/25] can: rename CAN FD related can_len2dlc and can_dlc2len helpers Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 07/25] can: update documentation for DLC usage in Classical CAN Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 08/25] can: drivers: introduce helpers to access Classical CAN DLC values Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 09/25] can: drivers: add len8_dlc support for various CAN adapters Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 10/25] can: drivers: add len8_dlc support for esd_usb2 CAN adapter Marc Kleine-Budde
2020-11-20 13:33 ` Marc Kleine-Budde [this message]
2020-11-20 13:33 ` [net-next 12/25] dt-bindings: can: fsl,flexcan: add uint32 reference to clock-frequency property Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 13/25] dt-bindings: can: fsl,flexcan: fix fsl,clk-source property Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 14/25] dt-bindings: firmware: add IMX_SC_R_CAN(x) macro for CAN Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 15/25] can: flexcan: rename macro FLEXCAN_QUIRK_SETUP_STOP_MODE -> FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 16/25] can: flexcan: factor out enabling and disabling of interrupts into separate function Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 17/25] can: flexcan: move enabling/disabling of interrupts from flexcan_chip_{start,stop}() to callers Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 18/25] can: flexcan: flexcan_rx_offload_setup(): factor out mailbox and rx-offload setup into separate function Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 19/25] can: flexcan: flexcan_open(): completely initialize controller before requesting IRQ Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 20/25] can: flexcan: flexcan_close(): change order if commands to properly shut down the controller Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 21/25] can: kvaser_usb: Add USB_{LEAF,HYDRA}_PRODUCT_ID_END defines Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 22/25] can: kvaser_usb: Add new Kvaser Leaf v2 devices Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 23/25] can: kvaser_usb: kvaser_usb_hydra: Add support for new device variant Marc Kleine-Budde
2020-11-20 13:33 ` [net-next 24/25] can: kvaser_usb: Add new Kvaser hydra devices Marc Kleine-Budde
2020-11-20 13:44 ` [PATCH 25/25] can: mcp251xfd: remove useless code in mcp251xfd_chip_softreset Marc Kleine-Budde
2020-11-21 23:09 ` pull-request: can-next 2020-11-20 Jakub Kicinski
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