| Message ID | 20240328235214.4079063-3-leitao@debian.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | allocate dummy device dynamically | expand |
On Thu, 28 Mar 2024 16:52:02 -0700 Breno Leitao wrote: > - init_dummy_netdev(&sdma->napi_dev); > + sdma->napi_dev = alloc_netdev_dummy(0); > + if (!sdma->napi_dev) { > + dev_err(dev, "not able to initialize dummy device\n"); > + goto err_alloc_dummy; > + } > + > duplicated empty line here > - netif_napi_add(&sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); > + netif_napi_add(sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); > napi_enable(&sdma->rx_napi); > > return 0; > > +err_alloc_dummy: > + prestera_hw_event_handler_unregister(sw, PRESTERA_EVENT_TYPE_RXTX, > + prestera_rxtx_handle_event); > err_evt_register: > err_tx_init: > prestera_sdma_tx_fini(sdma); > @@ -682,6 +690,7 @@ static void prestera_sdma_switch_fini(struct prestera_switch *sw) > prestera_sdma_tx_fini(sdma); > prestera_sdma_rx_fini(sdma); > dma_pool_destroy(sdma->desc_pool); > + kfree(sdma->napi_dev); Why kfree()? Let's use free_netdev() consistently, in case one day we have to undo something alloc_netdev_dummy() has done.
On Fri, Mar 29, 2024 at 08:56:33AM -0700, Jakub Kicinski wrote: > > @@ -682,6 +690,7 @@ static void prestera_sdma_switch_fini(struct prestera_switch *sw) > > prestera_sdma_tx_fini(sdma); > > prestera_sdma_rx_fini(sdma); > > dma_pool_destroy(sdma->desc_pool); > > + kfree(sdma->napi_dev); > > Why kfree()? Let's use free_netdev() consistently, in case one day > we have to undo something alloc_netdev_dummy() has done. I should have used free_netdev() in fact. I will update.
On Thu, Mar 28, 2024 at 04:52:02PM -0700, Breno Leitao wrote: > Embedding net_device into structures prohibits the usage of flexible > arrays in the net_device structure. For more details, see the discussion > at [1]. > > Un-embed the net_device from the private struct by converting it > into a pointer. Then use the leverage the new alloc_netdev_dummy() > helper to allocate and initialize dummy devices. > > [1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/ > > Signed-off-by: Breno Leitao <leitao@debian.org> > --- > .../net/ethernet/marvell/prestera/prestera_rxtx.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c ... > @@ -654,13 +654,21 @@ static int prestera_sdma_switch_init(struct prestera_switch *sw) > if (err) > goto err_evt_register; > > - init_dummy_netdev(&sdma->napi_dev); > + sdma->napi_dev = alloc_netdev_dummy(0); > + if (!sdma->napi_dev) { > + dev_err(dev, "not able to initialize dummy device\n"); > + goto err_alloc_dummy; Hi Breno, This goto will result in the function returning err. But err is 0 here. Perhaps it should be set to a negative error value instead? Flagged by Smatch. > + } > + > > - netif_napi_add(&sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); > + netif_napi_add(sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); > napi_enable(&sdma->rx_napi); > > return 0; > > +err_alloc_dummy: > + prestera_hw_event_handler_unregister(sw, PRESTERA_EVENT_TYPE_RXTX, > + prestera_rxtx_handle_event); > err_evt_register: > err_tx_init: > prestera_sdma_tx_fini(sdma); ...
On Sun, Mar 31, 2024 at 09:54:38AM +0100, Simon Horman wrote: > On Thu, Mar 28, 2024 at 04:52:02PM -0700, Breno Leitao wrote: > > Embedding net_device into structures prohibits the usage of flexible > > arrays in the net_device structure. For more details, see the discussion > > at [1]. > > > > Un-embed the net_device from the private struct by converting it > > into a pointer. Then use the leverage the new alloc_netdev_dummy() > > helper to allocate and initialize dummy devices. > > > > [1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/ > > > > Signed-off-by: Breno Leitao <leitao@debian.org> > > --- > > .../net/ethernet/marvell/prestera/prestera_rxtx.c | 15 ++++++++++++--- > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c > > ... > > > @@ -654,13 +654,21 @@ static int prestera_sdma_switch_init(struct prestera_switch *sw) > > if (err) > > goto err_evt_register; > > > > - init_dummy_netdev(&sdma->napi_dev); > > + sdma->napi_dev = alloc_netdev_dummy(0); > > + if (!sdma->napi_dev) { > > + dev_err(dev, "not able to initialize dummy device\n"); > > + goto err_alloc_dummy; > > Hi Breno, > > This goto will result in the function returning err. > But err is 0 here. Perhaps it should be set to a negative error value > instead? Definitely, that was a good catch. > Flagged by Smatch. I am curious how you are running Smatch. I tried to run it here according to[1] , and I found different and valid errors also, that I will fix soon. For instance: drivers/net/ethernet/marvell/prestera/prestera_main.c:433 prestera_port_sfp_bind() error: uninitialized symbol 'err'. drivers/net/ethernet/marvell/prestera/prestera_main.c:861 prestera_switch_set_base_mac_addr() error: uninitialized symbol 'ret'. [1] https://rajanvaja.wordpress.com/2021/02/06/how-to-run-smatch-on-linux-kernel/ Thanks
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c index cc2a9ae794be..ed33a201a0f5 100644 --- a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c +++ b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c @@ -96,7 +96,7 @@ struct prestera_sdma { struct dma_pool *desc_pool; struct work_struct tx_work; struct napi_struct rx_napi; - struct net_device napi_dev; + struct net_device *napi_dev; u32 map_addr; u64 dma_mask; /* protect SDMA with concurrent access from multiple CPUs */ @@ -654,13 +654,21 @@ static int prestera_sdma_switch_init(struct prestera_switch *sw) if (err) goto err_evt_register; - init_dummy_netdev(&sdma->napi_dev); + sdma->napi_dev = alloc_netdev_dummy(0); + if (!sdma->napi_dev) { + dev_err(dev, "not able to initialize dummy device\n"); + goto err_alloc_dummy; + } + - netif_napi_add(&sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); + netif_napi_add(sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll); napi_enable(&sdma->rx_napi); return 0; +err_alloc_dummy: + prestera_hw_event_handler_unregister(sw, PRESTERA_EVENT_TYPE_RXTX, + prestera_rxtx_handle_event); err_evt_register: err_tx_init: prestera_sdma_tx_fini(sdma); @@ -682,6 +690,7 @@ static void prestera_sdma_switch_fini(struct prestera_switch *sw) prestera_sdma_tx_fini(sdma); prestera_sdma_rx_fini(sdma); dma_pool_destroy(sdma->desc_pool); + kfree(sdma->napi_dev); } static bool prestera_sdma_is_ready(struct prestera_sdma *sdma)
Embedding net_device into structures prohibits the usage of flexible arrays in the net_device structure. For more details, see the discussion at [1]. Un-embed the net_device from the private struct by converting it into a pointer. Then use the leverage the new alloc_netdev_dummy() helper to allocate and initialize dummy devices. [1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/ Signed-off-by: Breno Leitao <leitao@debian.org> --- .../net/ethernet/marvell/prestera/prestera_rxtx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)