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Message-ID: <vxcfrxtbfu4pya56m22icnizsyjzqqha5blzb7zpexqcur56uh@uv6vsjf77npa>
Date: Thu, 21 Dec 2023 01:36:20 +0300
From: Serge Semin <fancer.lancer@...il.com>
To: Yanteng Si <siyanteng@...ngson.cn>
Cc: andrew@...n.ch, hkallweit1@...il.com, peppe.cavallaro@...com,
alexandre.torgue@...s.st.com, joabreu@...opsys.com, Jose.Abreu@...opsys.com,
chenhuacai@...ngson.cn, linux@...linux.org.uk, guyinggang@...ngson.cn,
netdev@...r.kernel.org, chris.chenfeiyang@...il.com
Subject: Re: [PATCH net-next v7 4/9] net: stmmac: Add multi-channel supports
On Tue, Dec 19, 2023 at 10:17:07PM +0800, Yanteng Si wrote:
> Loongson platforms use a DWGMAC which supports multi-channel.
>
> Added dwmac1000_dma_init_channel() and init_chan(), factor out
> all the channel-specific setups from dwmac1000_dma_init() to the
> new function dma_config(), then distinguish dma initialization
> and multi-channel initialization through different parameters.
>
> Signed-off-by: Yanteng Si <siyanteng@...ngson.cn>
> Signed-off-by: Feiyang Chen <chenfeiyang@...ngson.cn>
> Signed-off-by: Yinggang Gu <guyinggang@...ngson.cn>
> ---
> .../ethernet/stmicro/stmmac/dwmac1000_dma.c | 55 ++++++++++++++-----
> .../net/ethernet/stmicro/stmmac/dwmac_dma.h | 17 ++++++
> .../net/ethernet/stmicro/stmmac/dwmac_lib.c | 30 +++++-----
> 3 files changed, 74 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
> index 5e80d3eec9db..0fb48e683970 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
> @@ -12,7 +12,8 @@
> Author: Giuseppe Cavallaro <peppe.cavallaro@...com>
> *******************************************************************************/
>
> -#include <asm/io.h>
> +#include <linux/io.h>
> +#include "stmmac.h"
> #include "dwmac1000.h"
> #include "dwmac_dma.h"
>
> @@ -70,13 +71,16 @@ static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
> writel(value, ioaddr + DMA_AXI_BUS_MODE);
> }
>
> -static void dwmac1000_dma_init(struct stmmac_priv *priv, void __iomem *ioaddr,
> - struct stmmac_dma_cfg *dma_cfg, int atds)
> +static void dma_config(void __iomem *modeaddr, void __iomem *enaddr,
> + struct stmmac_dma_cfg *dma_cfg, u32 dma_intr_mask,
> + int atds)
Please make sure the arguments are aligned with the function open
parenthesis taking into account that tabs are of _8_ chars:
Documentation/process/coding-style.rst.
> {
> - u32 value = readl(ioaddr + DMA_BUS_MODE);
> + u32 value;
> int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
> int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
>
> + value = readl(modeaddr);
> +
> /*
> * Set the DMA PBL (Programmable Burst Length) mode.
> *
> @@ -104,10 +108,34 @@ static void dwmac1000_dma_init(struct stmmac_priv *priv, void __iomem *ioaddr,
> if (dma_cfg->aal)
> value |= DMA_BUS_MODE_AAL;
>
> - writel(value, ioaddr + DMA_BUS_MODE);
> + writel(value, modeaddr);
> + writel(dma_intr_mask, enaddr);
> +}
> +
> +static void dwmac1000_dma_init(struct stmmac_priv *priv, void __iomem *ioaddr,
> + struct stmmac_dma_cfg *dma_cfg, int atds)
> +{
> + u32 dma_intr_mask;
>
> /* Mask interrupts by writing to CSR7 */
> - writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
> + dma_intr_mask = DMA_INTR_DEFAULT_MASK;
> +
> + dma_config(ioaddr + DMA_BUS_MODE, ioaddr + DMA_INTR_ENA,
> + dma_cfg, dma_intr_mask, atds);
> +}
> +
> +static void dwmac1000_dma_init_channel(struct stmmac_priv *priv, void __iomem *ioaddr,
> + struct stmmac_dma_cfg *dma_cfg, u32 chan)
> +{
> + u32 dma_intr_mask;
> +
> + /* Mask interrupts by writing to CSR7 */
> + dma_intr_mask = DMA_INTR_DEFAULT_MASK;
> +
> + if (dma_cfg->multi_msi_en)
> + dma_config(ioaddr + DMA_CHAN_BUS_MODE(chan),
> + ioaddr + DMA_CHAN_INTR_ENA(chan), dma_cfg,
Why so complicated? stmmac_init_chan() is always supposed to be called
in the same context as stmmac_dma_init() (stmmac_xdp_open() is wrong
in not doing that). Seeing DW GMAC v3.x multi-channels feature is
implemented as multiple sets of the same CSRs (except AV traffic
control CSRs specific to channels 1 and higher which are left unused
here anyway) you can just drop the stmmac_dma_ops.init() callback and
convert dwmac1000_dma_init() to being dwmac1000_dma_init_channel()
with no significant modifications:
< you wouldn't need to have a separate dma_config() method.
< you wouldn't need to check for the dma_cfg->multi_msi_en flag state
since the stmmac_init_chan() method is called for as many times as
there are channels available (at least 1 channel always exists).
< just add atds argument.
< just convert the method to using the chan-dependent CSR macros.
> + dma_intr_mask, dma_cfg->multi_msi_en);
^
+-------------------------------------------------+
This is wrong + ATDS flag means Alternative Descriptor Size. This flag
enables the 8 dword DMA-descriptors size with some DMA-desc fields
semantics changed (see enh_desc.c and norm_desc.c). It's useful for
PTP Timestamping, VLANs, AV feature, L3/L4 filtering, CSum offload
Type 2 (if any of that available). It has nothing to do with the
separate DMA IRQs. Just convert the stmmac_dma_ops.dma_init() callback
to accepting the atds flag as an additional argument, use it here to
activate the extended descriptor size and make sure the atds flag is
passed to the stmmac_init_chan() method in the respective source code.
> }
>
> static void dwmac1000_dma_init_rx(struct stmmac_priv *priv,
> @@ -116,7 +144,7 @@ static void dwmac1000_dma_init_rx(struct stmmac_priv *priv,
> dma_addr_t dma_rx_phy, u32 chan)
> {
> /* RX descriptor base address list must be written into DMA CSR3 */
> - writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
> + writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_CHAN_RCV_BASE_ADDR(chan));
> }
>
> static void dwmac1000_dma_init_tx(struct stmmac_priv *priv,
> @@ -125,7 +153,7 @@ static void dwmac1000_dma_init_tx(struct stmmac_priv *priv,
> dma_addr_t dma_tx_phy, u32 chan)
> {
> /* TX descriptor base address list must be written into DMA CSR4 */
> - writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_BASE_ADDR);
> + writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
> }
>
> static u32 dwmac1000_configure_fc(u32 csr6, int rxfifosz)
> @@ -153,7 +181,7 @@ static void dwmac1000_dma_operation_mode_rx(struct stmmac_priv *priv,
> void __iomem *ioaddr, int mode,
> u32 channel, int fifosz, u8 qmode)
> {
> - u32 csr6 = readl(ioaddr + DMA_CONTROL);
> + u32 csr6 = readl(ioaddr + DMA_CHAN_CONTROL(channel));
>
> if (mode == SF_DMA_MODE) {
> pr_debug("GMAC: enable RX store and forward mode\n");
> @@ -175,14 +203,14 @@ static void dwmac1000_dma_operation_mode_rx(struct stmmac_priv *priv,
> /* Configure flow control based on rx fifo size */
> csr6 = dwmac1000_configure_fc(csr6, fifosz);
>
> - writel(csr6, ioaddr + DMA_CONTROL);
> + writel(csr6, ioaddr + DMA_CHAN_CONTROL(channel));
> }
>
> static void dwmac1000_dma_operation_mode_tx(struct stmmac_priv *priv,
> void __iomem *ioaddr, int mode,
> u32 channel, int fifosz, u8 qmode)
> {
> - u32 csr6 = readl(ioaddr + DMA_CONTROL);
> + u32 csr6 = readl(ioaddr + DMA_CHAN_CONTROL(channel));
>
> if (mode == SF_DMA_MODE) {
> pr_debug("GMAC: enable TX store and forward mode\n");
> @@ -209,7 +237,7 @@ static void dwmac1000_dma_operation_mode_tx(struct stmmac_priv *priv,
> csr6 |= DMA_CONTROL_TTC_256;
> }
>
> - writel(csr6, ioaddr + DMA_CONTROL);
> + writel(csr6, ioaddr + DMA_CHAN_CONTROL(channel));
> }
>
> static void dwmac1000_dump_dma_regs(struct stmmac_priv *priv,
> @@ -271,12 +299,13 @@ static int dwmac1000_get_hw_feature(void __iomem *ioaddr,
> static void dwmac1000_rx_watchdog(struct stmmac_priv *priv,
> void __iomem *ioaddr, u32 riwt, u32 queue)
> {
> - writel(riwt, ioaddr + DMA_RX_WATCHDOG);
> + writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(queue));
> }
>
> const struct stmmac_dma_ops dwmac1000_dma_ops = {
> .reset = dwmac_dma_reset,
> .init = dwmac1000_dma_init,
This could be dropped. See my comment above.
> + .init_chan = dwmac1000_dma_init_channel,
> .init_rx_chan = dwmac1000_dma_init_rx,
> .init_tx_chan = dwmac1000_dma_init_tx,
> .axi = dwmac1000_dma_axi,
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
> index e7aef136824b..395d5e4c3922 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
> @@ -148,6 +148,9 @@
> DMA_STATUS_TI | \
> DMA_STATUS_MSK_COMMON)
>
> +/* Following DMA defines are chanels oriented */
s/chanels/channels
> +#define DMA_CHAN_OFFSET 0x100
DMA_CHAN_BASE_OFFSET? to be looking the same as in DW QoS Eth GMAC
v4.x/v5.x (dwmac4_dma.h).
> +
> #define NUM_DWMAC100_DMA_REGS 9
> #define NUM_DWMAC1000_DMA_REGS 23
> #define NUM_DWMAC4_DMA_REGS 27
> @@ -170,4 +173,18 @@ int dwmac_dma_interrupt(struct stmmac_priv *priv, void __iomem *ioaddr,
> struct stmmac_extra_stats *x, u32 chan, u32 dir);
> int dwmac_dma_reset(void __iomem *ioaddr);
>
> +static inline u32 dma_chan_base_addr(u32 base, u32 chan)
> +{
> + return base + chan * DMA_CHAN_OFFSET;
> +}
> +
> +#define DMA_CHAN_XMT_POLL_DEMAND(chan) dma_chan_base_addr(DMA_XMT_POLL_DEMAND, chan)
> +#define DMA_CHAN_INTR_ENA(chan) dma_chan_base_addr(DMA_INTR_ENA, chan)
> +#define DMA_CHAN_CONTROL(chan) dma_chan_base_addr(DMA_CONTROL, chan)
> +#define DMA_CHAN_STATUS(chan) dma_chan_base_addr(DMA_STATUS, chan)
> +#define DMA_CHAN_BUS_MODE(chan) dma_chan_base_addr(DMA_BUS_MODE, chan)
> +#define DMA_CHAN_RCV_BASE_ADDR(chan) dma_chan_base_addr(DMA_RCV_BASE_ADDR, chan)
> +#define DMA_CHAN_TX_BASE_ADDR(chan) dma_chan_base_addr(DMA_TX_BASE_ADDR, chan)
> +#define DMA_CHAN_RX_WATCHDOG(chan) dma_chan_base_addr(DMA_RX_WATCHDOG, chan)
> +
> #endif /* __DWMAC_DMA_H__ */
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
> index 2f0df16fb7e4..968801c694e9 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
> @@ -31,63 +31,63 @@ int dwmac_dma_reset(void __iomem *ioaddr)
> void dwmac_enable_dma_transmission(struct stmmac_priv *priv,
> void __iomem *ioaddr, u32 chan)
> {
> - writel(1, ioaddr + DMA_XMT_POLL_DEMAND);
> + writel(1, ioaddr + DMA_CHAN_XMT_POLL_DEMAND(chan));
> }
>
> void dwmac_enable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,
> u32 chan, bool rx, bool tx)
> {
> - u32 value = readl(ioaddr + DMA_INTR_ENA);
> + u32 value = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
>
> if (rx)
> value |= DMA_INTR_DEFAULT_RX;
> if (tx)
> value |= DMA_INTR_DEFAULT_TX;
>
> - writel(value, ioaddr + DMA_INTR_ENA);
> + writel(value, ioaddr + DMA_CHAN_INTR_ENA(chan));
> }
>
> void dwmac_disable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,
> u32 chan, bool rx, bool tx)
> {
> - u32 value = readl(ioaddr + DMA_INTR_ENA);
> + u32 value = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
>
> if (rx)
> value &= ~DMA_INTR_DEFAULT_RX;
> if (tx)
> value &= ~DMA_INTR_DEFAULT_TX;
>
> - writel(value, ioaddr + DMA_INTR_ENA);
> + writel(value, ioaddr + DMA_CHAN_INTR_ENA(chan));
> }
>
> void dwmac_dma_start_tx(struct stmmac_priv *priv, void __iomem *ioaddr,
> u32 chan)
> {
> - u32 value = readl(ioaddr + DMA_CONTROL);
> + u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
> value |= DMA_CONTROL_ST;
> - writel(value, ioaddr + DMA_CONTROL);
> + writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
> }
>
> void dwmac_dma_stop_tx(struct stmmac_priv *priv, void __iomem *ioaddr, u32 chan)
> {
> - u32 value = readl(ioaddr + DMA_CONTROL);
> + u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
> value &= ~DMA_CONTROL_ST;
> - writel(value, ioaddr + DMA_CONTROL);
> + writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
> }
>
> void dwmac_dma_start_rx(struct stmmac_priv *priv, void __iomem *ioaddr,
> u32 chan)
> {
> - u32 value = readl(ioaddr + DMA_CONTROL);
> + u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
> value |= DMA_CONTROL_SR;
> - writel(value, ioaddr + DMA_CONTROL);
> + writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
> }
>
> void dwmac_dma_stop_rx(struct stmmac_priv *priv, void __iomem *ioaddr, u32 chan)
> {
> - u32 value = readl(ioaddr + DMA_CONTROL);
> + u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
> value &= ~DMA_CONTROL_SR;
> - writel(value, ioaddr + DMA_CONTROL);
> + writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
> }
>
> #ifdef DWMAC_DMA_DEBUG
> @@ -167,7 +167,7 @@ int dwmac_dma_interrupt(struct stmmac_priv *priv, void __iomem *ioaddr,
> struct stmmac_txq_stats *txq_stats = &priv->xstats.txq_stats[chan];
> int ret = 0;
> /* read the status register (CSR5) */
> - u32 intr_status = readl(ioaddr + DMA_STATUS);
> + u32 intr_status = readl(ioaddr + DMA_CHAN_STATUS(chan));
>
> #ifdef DWMAC_DMA_DEBUG
> /* Enable it to monitor DMA rx/tx status in case of critical problems */
> @@ -237,7 +237,7 @@ int dwmac_dma_interrupt(struct stmmac_priv *priv, void __iomem *ioaddr,
> pr_warn("%s: unexpected status %08x\n", __func__, intr_status);
>
> /* Clear the interrupt by writing a logic 1 to the CSR5[15-0] */
> - writel((intr_status & 0x1ffff), ioaddr + DMA_STATUS);
> + writel((intr_status & 0x7ffff), ioaddr + DMA_CHAN_STATUS(chan));
Em, please explain the mask change. Bits CSR5[17:28] are defined as RO
on a normal DW GMAC. Anyway it seems like the mask changes belongs to
the patch 5/9.
Except the last comment, AFAICS this patch provides a generic DW GMAC
v3.x multi-channel support. Despite of several issues noted above the
change in general looks very good.
-Serge(y)
>
> return ret;
> }
> --
> 2.31.4
>
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