Hi Simon,
Subject: Re: [PATCH V2 1/9] uclass: cpu: Add new API to get udevice for current CPU
Hi Peng,
On Fri, 1 May 2020 at 07:22, Peng Fan peng.fan@nxp.com wrote:
When running on SoC with multiple clusters, the boot CPU may not be fixed, saying booting from cluster A or cluster B. Add a API that can return the udevice for current boot CPU. Cpu driver needs to implement is_current_cpu interface for this feature, otherwise the API only returns the first udevice in cpu uclass.
Signed-off-by: Peng Fan peng.fan@nxp.com Signed-off-by: Ye Li ye.li@nxp.com
V2: Per Simon's comment,
- Add cpu_is_current
- use uclass_foreach_dev_probe
- Update code comment
drivers/cpu/cpu-uclass.c | 34 ++++++++++++++++++++++++++++++++++ include/cpu.h | 23 +++++++++++++++++++++++ 2 files changed, 57 insertions(+)
Reviewed-by: Simon Glass sjg@chromium.org
diff --git a/drivers/cpu/cpu-uclass.c b/drivers/cpu/cpu-uclass.c index 457f77b7c8..33d38a0fde 100644 --- a/drivers/cpu/cpu-uclass.c +++ b/drivers/cpu/cpu-uclass.c @@ -10,6 +10,7 @@ #include <errno.h> #include <dm/lists.h> #include <dm/root.h> +#include <linux/err.h>
int cpu_probe_all(void) { @@ -34,6 +35,39 @@ int cpu_probe_all(void) return 0; }
+int cpu_is_current(struct udevice *cpu) {
struct cpu_ops *ops = cpu_get_ops(cpu);if (ops && ops->is_current) {if (ops->is_current(cpu))return 1;return 0 here I think
I prefer to use 1 here, since is_current return 0 seems werid to show it is the cpu that uboot is running from.
Also you should not check 'ops'.
I'll drop it.
Thanks, Peng.
}return -ENOSYS;+}
+struct udevice *cpu_get_current_dev(void) {
struct udevice *cpu;int ret;uclass_foreach_dev_probe(UCLASS_CPU, cpu) {if (cpu_is_current(cpu) > 0)return cpu;}/* If can't find current cpu device, use the first dev instead */ret = uclass_first_device_err(UCLASS_CPU, &cpu);if (ret) {debug("%s: Could not get CPU device (err = %d)\n",__func__, ret);return NULL;}return cpu;+}
int cpu_get_desc(struct udevice *dev, char *buf, int size) { struct cpu_ops *ops = cpu_get_ops(dev); diff --git a/include/cpu.h b/include/cpu.h index 6b1b6b37b3..2f283fe244 100644 --- a/include/cpu.h +++ b/include/cpu.h @@ -89,6 +89,15 @@ struct cpu_ops { * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on
error
*/ int (*get_vendor)(struct udevice *dev, char *buf, int size);
/*** is_current() - Check if the CPU that U-Boot is currently runningfrom
** @dev: Device to check (UCLASS_CPU)* @return 1 if the CPU that U-Boot is currently running from, 0* if not.*/int (*is_current)(struct udevice *dev);};
#define cpu_get_ops(dev) ((struct cpu_ops *)(dev)->driver->ops) @@ -137,4 +146,18 @@ int cpu_get_vendor(struct udevice *dev, char *buf,
int size);
*/ int cpu_probe_all(void);
+/**
- cpu_is_current() - Check if the CPU that U-Boot is currently
+running from
- Return: 1 if yes, - 0 if not
- */
+int cpu_is_current(struct udevice *cpu);
+/**
- cpu_get_current_dev() - Get CPU udevice for current CPU
- Return: udevice if OK, - NULL on error */ struct udevice
+*cpu_get_current_dev(void);
#endif
2.16.4