Use the coroutines framework to scan USB buses in parallel for better performance. Tested on arm64 QEMU on a somewhat contrived example (4 USB buses, each with one audio device, one keyboard, one mouse and one tablet).
$ make qemu_arm64_defconfig $ make -j$(nproc) CROSS_COMPILE="ccache aarch64-linux-gnu-" $ qemu-system-aarch64 -M virt -nographic -cpu max -bios u-boot.bin \ $(for i in {1..4}; do echo -device qemu-xhci,id=xhci$i \ -device\ usb-{audio,kbd,mouse,tablet},bus=xhci$i.0; \ done)
The time spent in usb_init() is reported on the console and shows a significant improvement with COROUTINES enabled.
** Without COROUTINES
Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 scanning bus xhci_pci for devices... 6 USB Device(s) found scanning bus xhci_pci for devices... 6 USB Device(s) found scanning bus xhci_pci for devices... 6 USB Device(s) found scanning bus xhci_pci for devices... 6 USB Device(s) found USB: 4 bus(es) scanned in 5873 ms
** With COROUTINES
Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Bus xhci_pci: Register 8001040 NbrPorts 8 Starting the controller USB XHCI 1.00 Scanning 4 USB bus(es)... done Bus xhci_pci: 6 USB device(s) found Bus xhci_pci: 6 USB device(s) found Bus xhci_pci: 6 USB device(s) found Bus xhci_pci: 6 USB device(s) found USB: 4 bus(es) scanned in 2213 ms
Signed-off-by: Jerome Forissier jerome.forissier@linaro.org --- drivers/usb/host/usb-uclass.c | 152 +++++++++++++++++++++++++++++++++- 1 file changed, 149 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c index bfec303e7af..3104efe7f9e 100644 --- a/drivers/usb/host/usb-uclass.c +++ b/drivers/usb/host/usb-uclass.c @@ -9,6 +9,7 @@ #define LOG_CATEGORY UCLASS_USB
#include <bootdev.h> +#include <coroutines.h> #include <dm.h> #include <errno.h> #include <log.h> @@ -18,6 +19,8 @@ #include <dm/lists.h> #include <dm/uclass-internal.h>
+#include <time.h> + static bool asynch_allowed;
struct usb_uclass_priv { @@ -221,6 +224,40 @@ int usb_stop(void) return err; }
+static int nbus; + +#if CONFIG_IS_ENABLED(COROUTINES) +static void usb_scan_bus(struct udevice *bus, bool recurse) +{ + struct usb_bus_priv *priv; + struct udevice *dev; + int ret; + + priv = dev_get_uclass_priv(bus); + + assert(recurse); /* TODO: Support non-recusive */ + + debug("\n"); + ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev); + if (ret) + printf("Scanning bus %s failed, error %d\n", bus->name, ret); +} + +static void usb_report_devices(struct uclass *uc) +{ + struct usb_bus_priv *priv; + struct udevice *bus; + + uclass_foreach_dev(bus, uc) { + priv = dev_get_uclass_priv(bus); + printf("Bus %s: ", bus->name); + if (priv->next_addr == 0) + printf("No USB device found\n"); + else + printf("%d USB device(s) found\n", priv->next_addr); + } +} +#else static void usb_scan_bus(struct udevice *bus, bool recurse) { struct usb_bus_priv *priv; @@ -240,7 +277,81 @@ static void usb_scan_bus(struct udevice *bus, bool recurse) printf("No USB Device found\n"); else printf("%d USB Device(s) found\n", priv->next_addr); + nbus++; } +#endif + +#if CONFIG_IS_ENABLED(COROUTINES) +extern int udelay_yield; + +static void usb_scan_bus_co(void) +{ + usb_scan_bus((struct udevice *)co_get_arg(), true); + co_exit(); +} + +static struct co_stack *stk; +static struct co *main_co; +static struct co **co; +static int co_sz = 8; + +static int add_usb_scan_bus_co(struct udevice *bus) +{ + if (!co) { + co = malloc(co_sz * sizeof(*co)); + if (!co) + return -ENOMEM; + } + if (nbus == co_sz) { + struct co **nco; + + co_sz *= 2; + nco = realloc(co, co_sz * sizeof(*co)); + if (!nco) + return -ENOMEM; + co = nco; + } + if (!main_co) { + main_co = co_create(NULL, NULL, 0, NULL, NULL); + if (!main_co) + return -ENOMEM; + } + if (!stk) { + stk = co_stack_new(32768); + if (!stk) + return -ENOMEM; + } + co[nbus] = co_create(main_co, stk, 0, usb_scan_bus_co, bus); + if (!co[nbus]) + return -ENOMEM; + nbus++; + return 0; +} + +static void usb_scan_cleanup(void) +{ + int i; + + for (i = 0; i < nbus; i++) { + co_destroy(co[i]); + co[i] = NULL; + } + nbus = 0; + co_destroy(main_co); + main_co = NULL; + co_stack_destroy(stk); + stk = NULL; +} +#else +static int add_usb_scan_bus_co(struct udevice *bus) +{ + return 0; +} + +static void usb_scan_cleanup(void) +{ +} +#endif
static void remove_inactive_children(struct uclass *uc, struct udevice *bus) { @@ -289,6 +400,7 @@ static int usb_probe_companion(struct udevice *bus)
int usb_init(void) { + unsigned long t0 = timer_get_us(); int controllers_initialized = 0; struct usb_uclass_priv *uc_priv; struct usb_bus_priv *priv; @@ -355,10 +467,40 @@ int usb_init(void) continue;
priv = dev_get_uclass_priv(bus); - if (!priv->companion) - usb_scan_bus(bus, true); + if (!priv->companion) { + if (CONFIG_IS_ENABLED(COROUTINES)) { + ret = add_usb_scan_bus_co(bus); + if (ret) + goto out; + } else { + usb_scan_bus(bus, true); + } + } }
+#if CONFIG_IS_ENABLED(COROUTINES) + { + bool done; + int i; + + printf("Scanning %d USB bus(es)... ", nbus); + udelay_yield = 0xCAFEDECA; + do { + done = true; + for (i = 0; i < nbus; i++) { + if (!co[i]->done) { + done = false; + co_resume(co[i]); + } + } + } while (!done); + udelay_yield = 0; + printf("done\n"); + + usb_report_devices(uc); + } +#endif + /* * Now that the primary controllers have been scanned and have handed * over any devices they do not understand to their companions, scan @@ -388,7 +530,11 @@ int usb_init(void) /* if we were not able to find at least one working bus, bail out */ if (controllers_initialized == 0) printf("No USB controllers found\n"); - +out: + if (nbus) + printf("USB: %d bus(es) scanned in %ld ms\n", nbus, + (timer_get_us() - t0) / 1000); + usb_scan_cleanup(); return usb_started ? 0 : -ENOENT; }