From 7dd12fe34686d89c332b1a05104d18d728591f0a Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Mon, 4 Dec 2023 11:08:10 +0100 Subject: [PATCH 1/2] net: mvmdio: Avoid excessive sleeps in polled mode Before this change, when operating in polled mode, i.e. no IRQ is available, every individual C45 access would be hit with a 150us sleep after the bus access. For example, on a board with a CN9130 SoC connected to an MV88X3310 PHY, a single C45 read would take around 165us: root@infix:~$ mdio f212a600.mdio-mii mmd 4:1 bench 0xc003 Performed 1000 reads in 165ms By replacing the long sleep with a tighter poll loop, we observe a 10x increase in bus throughput: root@infix:~$ mdio f212a600.mdio-mii mmd 4:1 bench 0xc003 Performed 1000 reads in 15ms Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Tested-by: Andrew Lunn Link: https://lore.kernel.org/r/20231204100811.2708884-3-tobias@waldekranz.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/marvell/mvmdio.c | 53 ++++++++------------------- 1 file changed, 16 insertions(+), 37 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c index 89f26402f8fb8..5f66f779e56fc 100644 --- a/drivers/net/ethernet/marvell/mvmdio.c +++ b/drivers/net/ethernet/marvell/mvmdio.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -58,11 +59,6 @@ * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled) */ #define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */ -#define MVMDIO_SMI_POLL_INTERVAL_MIN 45 -#define MVMDIO_SMI_POLL_INTERVAL_MAX 55 - -#define MVMDIO_XSMI_POLL_INTERVAL_MIN 150 -#define MVMDIO_XSMI_POLL_INTERVAL_MAX 160 struct orion_mdio_dev { void __iomem *regs; @@ -84,8 +80,6 @@ enum orion_mdio_bus_type { struct orion_mdio_ops { int (*is_done)(struct orion_mdio_dev *); - unsigned int poll_interval_min; - unsigned int poll_interval_max; }; /* Wait for the SMI unit to be ready for another operation @@ -94,34 +88,23 @@ static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops, struct mii_bus *bus) { struct orion_mdio_dev *dev = bus->priv; - unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT); - unsigned long end = jiffies + timeout; - int timedout = 0; + unsigned long timeout; + int done; - while (1) { - if (ops->is_done(dev)) + if (dev->err_interrupt <= 0) { + if (!read_poll_timeout_atomic(ops->is_done, done, done, 2, + MVMDIO_SMI_TIMEOUT, false, dev)) + return 0; + } else { + /* wait_event_timeout does not guarantee a delay of at + * least one whole jiffie, so timeout must be no less + * than two. + */ + timeout = max(usecs_to_jiffies(MVMDIO_SMI_TIMEOUT), 2); + + if (wait_event_timeout(dev->smi_busy_wait, + ops->is_done(dev), timeout)) return 0; - else if (timedout) - break; - - if (dev->err_interrupt <= 0) { - usleep_range(ops->poll_interval_min, - ops->poll_interval_max); - - if (time_is_before_jiffies(end)) - ++timedout; - } else { - /* wait_event_timeout does not guarantee a delay of at - * least one whole jiffie, so timeout must be no less - * than two. - */ - if (timeout < 2) - timeout = 2; - wait_event_timeout(dev->smi_busy_wait, - ops->is_done(dev), timeout); - - ++timedout; - } } dev_err(bus->parent, "Timeout: SMI busy for too long\n"); @@ -135,8 +118,6 @@ static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev) static const struct orion_mdio_ops orion_mdio_smi_ops = { .is_done = orion_mdio_smi_is_done, - .poll_interval_min = MVMDIO_SMI_POLL_INTERVAL_MIN, - .poll_interval_max = MVMDIO_SMI_POLL_INTERVAL_MAX, }; static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id, @@ -194,8 +175,6 @@ static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev) static const struct orion_mdio_ops orion_mdio_xsmi_ops = { .is_done = orion_mdio_xsmi_is_done, - .poll_interval_min = MVMDIO_XSMI_POLL_INTERVAL_MIN, - .poll_interval_max = MVMDIO_XSMI_POLL_INTERVAL_MAX, }; static int orion_mdio_xsmi_read_c45(struct mii_bus *bus, int mii_id, From eb6a6605ff5a2b2ad2ceada49bba2464f6ad26a4 Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Mon, 4 Dec 2023 11:08:11 +0100 Subject: [PATCH 2/2] net: mvmdio: Support setting the MDC frequency on XSMI controllers Support the standard "clock-frequency" attribute to set the generated MDC frequency. If not specified, the driver will leave the divisor untouched. Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Tested-by: Andrew Lunn Link: https://lore.kernel.org/r/20231204100811.2708884-4-tobias@waldekranz.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/marvell/mvmdio.c | 44 +++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c index 5f66f779e56fc..9190eff6c0bba 100644 --- a/drivers/net/ethernet/marvell/mvmdio.c +++ b/drivers/net/ethernet/marvell/mvmdio.c @@ -53,6 +53,13 @@ #define MVMDIO_XSMI_BUSY BIT(30) #define MVMDIO_XSMI_ADDR_REG 0x8 +#define MVMDIO_XSMI_CFG_REG 0xc +#define MVMDIO_XSMI_CLKDIV_MASK 0x3 +#define MVMDIO_XSMI_CLKDIV_256 0x0 +#define MVMDIO_XSMI_CLKDIV_64 0x1 +#define MVMDIO_XSMI_CLKDIV_32 0x2 +#define MVMDIO_XSMI_CLKDIV_8 0x3 + /* * SMI Timeout measurements: * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt) @@ -225,6 +232,40 @@ static int orion_mdio_xsmi_write_c45(struct mii_bus *bus, int mii_id, return 0; } +static void orion_mdio_xsmi_set_mdc_freq(struct mii_bus *bus) +{ + struct orion_mdio_dev *dev = bus->priv; + struct clk *mg_core; + u32 div, freq, cfg; + + if (device_property_read_u32(bus->parent, "clock-frequency", &freq)) + return; + + mg_core = of_clk_get_by_name(bus->parent->of_node, "mg_core_clk"); + if (IS_ERR(mg_core)) { + dev_err(bus->parent, + "MG core clock unknown, not changing MDC frequency"); + return; + } + + div = clk_get_rate(mg_core) / (freq + 1) + 1; + clk_put(mg_core); + + if (div <= 8) + div = MVMDIO_XSMI_CLKDIV_8; + else if (div <= 32) + div = MVMDIO_XSMI_CLKDIV_32; + else if (div <= 64) + div = MVMDIO_XSMI_CLKDIV_64; + else + div = MVMDIO_XSMI_CLKDIV_256; + + cfg = readl(dev->regs + MVMDIO_XSMI_CFG_REG); + cfg &= ~MVMDIO_XSMI_CLKDIV_MASK; + cfg |= div; + writel(cfg, dev->regs + MVMDIO_XSMI_CFG_REG); +} + static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id) { struct orion_mdio_dev *dev = dev_id; @@ -303,6 +344,9 @@ static int orion_mdio_probe(struct platform_device *pdev) dev_warn(&pdev->dev, "unsupported number of clocks, limiting to the first " __stringify(ARRAY_SIZE(dev->clk)) "\n"); + + if (type == BUS_TYPE_XSMI) + orion_mdio_xsmi_set_mdc_freq(bus); } else { dev->clk[0] = clk_get(&pdev->dev, NULL); if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {