| Message ID | 20230316131503.738933-1-jh@henneberg-systemdesign.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,V2] net: stmmac: Fix for mismatched host/device DMA address width | expand |
On Thu, Mar 16, 2023 at 02:15:03PM +0100, Jochen Henneberg wrote: > Currently DMA address width is either read from a RO device register > or force set from the platform data. This breaks DMA when the host DMA > address width is <=32it but the device is >32bit. > > Right now the driver may decide to use a 2nd DMA descriptor for > another buffer (happens in case of TSO xmit) assuming that 32bit > addressing is used due to platform configuration but the device will > still use both descriptor addresses as one address. > > This can be observed with the Intel EHL platform driver that sets > 32bit for addr64 but the MAC reports 40bit. The TX queue gets stuck in > case of TCP with iptables NAT configuration on TSO packets. > > The logic should be like this: Whatever we do on the host side (memory > allocation GFP flags) should happen with the host DMA width, whenever > we decide how to set addresses on the device registers we must use the > device DMA address width. > > This patch renames the platform address width field from addr64 (term > used in device datasheet) to host_addr and uses this value exclusively > for host side operations while all chip operations consider the device > DMA width as read from the device register. > > Fixes: 7cfc4486e7ea ("stmmac: intel: Configure EHL PSE0 GbE and PSE1 GbE to 32 bits DMA addressing") > Signed-off-by: Jochen Henneberg <jh@henneberg-systemdesign.com> > --- > V2: Fixes from checkpatch.pl for commit message > > drivers/net/ethernet/stmicro/stmmac/common.h | 1 + > .../net/ethernet/stmicro/stmmac/dwmac-imx.c | 2 +- > .../net/ethernet/stmicro/stmmac/dwmac-intel.c | 4 +-- > .../ethernet/stmicro/stmmac/dwmac-mediatek.c | 2 +- > .../net/ethernet/stmicro/stmmac/stmmac_main.c | 30 ++++++++++--------- > include/linux/stmmac.h | 2 +- > 6 files changed, 22 insertions(+), 19 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h > index 6b5d96bced47..55a728b1b708 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/common.h > +++ b/drivers/net/ethernet/stmicro/stmmac/common.h > @@ -418,6 +418,7 @@ struct dma_features { > unsigned int frpbs; > unsigned int frpes; > unsigned int addr64; > + unsigned int host_addr; Obvious question: is host_addr an address? From the above description it sounds like this is more of a host address width indicator. Maybe call these "dev_addr_width" and "host_addr_width" so it's clear what each of these are?
"Russell King (Oracle)" <linux@armlinux.org.uk> writes: > On Thu, Mar 16, 2023 at 02:15:03PM +0100, Jochen Henneberg wrote: >> Currently DMA address width is either read from a RO device register >> or force set from the platform data. This breaks DMA when the host DMA >> address width is <=32it but the device is >32bit. >> >> Right now the driver may decide to use a 2nd DMA descriptor for >> another buffer (happens in case of TSO xmit) assuming that 32bit >> addressing is used due to platform configuration but the device will >> still use both descriptor addresses as one address. >> >> This can be observed with the Intel EHL platform driver that sets >> 32bit for addr64 but the MAC reports 40bit. The TX queue gets stuck in >> case of TCP with iptables NAT configuration on TSO packets. >> >> The logic should be like this: Whatever we do on the host side (memory >> allocation GFP flags) should happen with the host DMA width, whenever >> we decide how to set addresses on the device registers we must use the >> device DMA address width. >> >> This patch renames the platform address width field from addr64 (term >> used in device datasheet) to host_addr and uses this value exclusively >> for host side operations while all chip operations consider the device >> DMA width as read from the device register. >> >> Fixes: 7cfc4486e7ea ("stmmac: intel: Configure EHL PSE0 GbE and PSE1 GbE to 32 bits DMA addressing") >> Signed-off-by: Jochen Henneberg <jh@henneberg-systemdesign.com> >> --- >> V2: Fixes from checkpatch.pl for commit message >> >> drivers/net/ethernet/stmicro/stmmac/common.h | 1 + >> .../net/ethernet/stmicro/stmmac/dwmac-imx.c | 2 +- >> .../net/ethernet/stmicro/stmmac/dwmac-intel.c | 4 +-- >> .../ethernet/stmicro/stmmac/dwmac-mediatek.c | 2 +- >> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 30 ++++++++++--------- >> include/linux/stmmac.h | 2 +- >> 6 files changed, 22 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h >> index 6b5d96bced47..55a728b1b708 100644 >> --- a/drivers/net/ethernet/stmicro/stmmac/common.h >> +++ b/drivers/net/ethernet/stmicro/stmmac/common.h >> @@ -418,6 +418,7 @@ struct dma_features { >> unsigned int frpbs; >> unsigned int frpes; >> unsigned int addr64; >> + unsigned int host_addr; > > Obvious question: is host_addr an address? From the above description it > sounds like this is more of a host address width indicator. > > Maybe call these "dev_addr_width" and "host_addr_width" so it's clear > what each of these are? You are right. I chose the name because the original field was called addr64 which follows the naming from the chip specification. I will switch to host_dma_width which makes it more clear that it's a DMA address width. For both the platform field as well as the driver's private data.
diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h index 6b5d96bced47..55a728b1b708 100644 --- a/drivers/net/ethernet/stmicro/stmmac/common.h +++ b/drivers/net/ethernet/stmicro/stmmac/common.h @@ -418,6 +418,7 @@ struct dma_features { unsigned int frpbs; unsigned int frpes; unsigned int addr64; + unsigned int host_addr; unsigned int rssen; unsigned int vlhash; unsigned int sphen; diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c index ac8580f501e2..bc06c517df9c 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c @@ -289,7 +289,7 @@ static int imx_dwmac_probe(struct platform_device *pdev) goto err_parse_dt; } - plat_dat->addr64 = dwmac->ops->addr_width; + plat_dat->host_addr = dwmac->ops->addr_width; plat_dat->init = imx_dwmac_init; plat_dat->exit = imx_dwmac_exit; plat_dat->clks_config = imx_dwmac_clks_config; diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c index 7deb1f817dac..193c3a842500 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c @@ -684,7 +684,7 @@ static int ehl_pse0_common_data(struct pci_dev *pdev, intel_priv->is_pse = true; plat->bus_id = 2; - plat->addr64 = 32; + plat->host_dma_addr = 32; plat->clk_ptp_rate = 200000000; @@ -725,7 +725,7 @@ static int ehl_pse1_common_data(struct pci_dev *pdev, intel_priv->is_pse = true; plat->bus_id = 3; - plat->addr64 = 32; + plat->host_dma_addr = 32; plat->clk_ptp_rate = 200000000; diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c index 2f7d8e4561d9..968c8172c5bd 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c @@ -591,7 +591,7 @@ static int mediatek_dwmac_common_data(struct platform_device *pdev, plat->use_phy_wol = priv_plat->mac_wol ? 0 : 1; plat->riwt_off = 1; plat->maxmtu = ETH_DATA_LEN; - plat->addr64 = priv_plat->variant->dma_bit_mask; + plat->host_dma_addr = priv_plat->variant->dma_bit_mask; plat->bsp_priv = priv_plat; plat->init = mediatek_dwmac_init; plat->clks_config = mediatek_dwmac_clks_config; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 4886668a54c5..9f9cad178360 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1430,7 +1430,7 @@ static int stmmac_init_rx_buffers(struct stmmac_priv *priv, struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i]; gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); - if (priv->dma_cap.addr64 <= 32) + if (priv->dma_cap.host_addr <= 32) gfp |= GFP_DMA32; if (!buf->page) { @@ -4586,7 +4586,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue) unsigned int entry = rx_q->dirty_rx; gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); - if (priv->dma_cap.addr64 <= 32) + if (priv->dma_cap.host_addr <= 32) gfp |= GFP_DMA32; while (dirty-- > 0) { @@ -6204,7 +6204,7 @@ static int stmmac_dma_cap_show(struct seq_file *seq, void *v) seq_printf(seq, "\tFlexible RX Parser: %s\n", priv->dma_cap.frpsel ? "Y" : "N"); seq_printf(seq, "\tEnhanced Addressing: %d\n", - priv->dma_cap.addr64); + priv->dma_cap.host_addr); seq_printf(seq, "\tReceive Side Scaling: %s\n", priv->dma_cap.rssen ? "Y" : "N"); seq_printf(seq, "\tVLAN Hash Filtering: %s\n", @@ -7177,20 +7177,22 @@ int stmmac_dvr_probe(struct device *device, dev_info(priv->device, "SPH feature enabled\n"); } - /* The current IP register MAC_HW_Feature1[ADDR64] only define - * 32/40/64 bit width, but some SOC support others like i.MX8MP - * support 34 bits but it map to 40 bits width in MAC_HW_Feature1[ADDR64]. - * So overwrite dma_cap.addr64 according to HW real design. + /* Ideally our host DMA address width is the same as for the + * device. However, it may differ and then we have to use our + * host DMA width for allocation and the device DMA width for + * register handling. */ - if (priv->plat->addr64) - priv->dma_cap.addr64 = priv->plat->addr64; + if (priv->plat->host_dma_addr) + priv->dma_cap.host_addr = priv->plat->host_dma_addr; + else + priv->dma_cap.host_addr = priv->dma_cap.addr64; - if (priv->dma_cap.addr64) { + if (priv->dma_cap.host_addr) { ret = dma_set_mask_and_coherent(device, - DMA_BIT_MASK(priv->dma_cap.addr64)); + DMA_BIT_MASK(priv->dma_cap.host_addr)); if (!ret) { - dev_info(priv->device, "Using %d bits DMA width\n", - priv->dma_cap.addr64); + dev_info(priv->device, "Using %d/%d bits DMA host/device width\n", + priv->dma_cap.host_addr, priv->dma_cap.addr64); /* * If more than 32 bits can be addressed, make sure to @@ -7205,7 +7207,7 @@ int stmmac_dvr_probe(struct device *device, goto error_hw_init; } - priv->dma_cap.addr64 = 32; + priv->dma_cap.host_addr = 32; } } diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h index a152678b82b7..1cc4d61d6155 100644 --- a/include/linux/stmmac.h +++ b/include/linux/stmmac.h @@ -215,7 +215,7 @@ struct plat_stmmacenet_data { int unicast_filter_entries; int tx_fifo_size; int rx_fifo_size; - u32 addr64; + u32 host_dma_addr; u32 rx_queues_to_use; u32 tx_queues_to_use; u8 rx_sched_algorithm;
Currently DMA address width is either read from a RO device register or force set from the platform data. This breaks DMA when the host DMA address width is <=32it but the device is >32bit. Right now the driver may decide to use a 2nd DMA descriptor for another buffer (happens in case of TSO xmit) assuming that 32bit addressing is used due to platform configuration but the device will still use both descriptor addresses as one address. This can be observed with the Intel EHL platform driver that sets 32bit for addr64 but the MAC reports 40bit. The TX queue gets stuck in case of TCP with iptables NAT configuration on TSO packets. The logic should be like this: Whatever we do on the host side (memory allocation GFP flags) should happen with the host DMA width, whenever we decide how to set addresses on the device registers we must use the device DMA address width. This patch renames the platform address width field from addr64 (term used in device datasheet) to host_addr and uses this value exclusively for host side operations while all chip operations consider the device DMA width as read from the device register. Fixes: 7cfc4486e7ea ("stmmac: intel: Configure EHL PSE0 GbE and PSE1 GbE to 32 bits DMA addressing") Signed-off-by: Jochen Henneberg <jh@henneberg-systemdesign.com> --- V2: Fixes from checkpatch.pl for commit message drivers/net/ethernet/stmicro/stmmac/common.h | 1 + .../net/ethernet/stmicro/stmmac/dwmac-imx.c | 2 +- .../net/ethernet/stmicro/stmmac/dwmac-intel.c | 4 +-- .../ethernet/stmicro/stmmac/dwmac-mediatek.c | 2 +- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 30 ++++++++++--------- include/linux/stmmac.h | 2 +- 6 files changed, 22 insertions(+), 19 deletions(-)