Messages in this thread | | | Date | Tue, 1 Feb 2022 09:41:26 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 2/2] ARM: aspeed: Add secure boot controller support |
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On Tue, Feb 01, 2022 at 03:35:01PM +1030, Joel Stanley wrote: > This reads out the status of the secure boot controller and exposes it > in sysfs using the bootinfo sysfs api. > > An example on a AST2600A3 QEMU model: > > # grep -r . /sys/firmware/bootinfo/* > /sys/firmware/bootinfo/abr_image:0 > /sys/firmware/bootinfo/low_security_key:0 > /sys/firmware/bootinfo/otp_protected:0 > /sys/firmware/bootinfo/secure_boot:1 > /sys/firmware/bootinfo/uart_boot:0 > > On boot the state of the system according to the secure boot controller > will be printed: > > [ 0.037634] AST2600 secure boot enabled > > or > > [ 0.037935] AST2600 secure boot disabled > > The initialisation is changed from early_initcall to subsys_initcall > because we need the firmware_kobj to be initialised, and because there's > no requirement to print this information early. > > Signed-off-by: Joel Stanley <joel@jms.id.au> > Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com> > --- > drivers/soc/aspeed/aspeed-socinfo.c | 84 ++++++++++++++++++++++++++++- > 1 file changed, 83 insertions(+), 1 deletion(-) > > diff --git a/drivers/soc/aspeed/aspeed-socinfo.c b/drivers/soc/aspeed/aspeed-socinfo.c > index 1ca140356a08..fe77b31e4d1d 100644 > --- a/drivers/soc/aspeed/aspeed-socinfo.c > +++ b/drivers/soc/aspeed/aspeed-socinfo.c > @@ -8,6 +8,9 @@ > #include <linux/platform_device.h> > #include <linux/slab.h> > #include <linux/sys_soc.h> > +#include <linux/firmware_bootinfo.h> > + > +static u32 security_status; > > static struct { > const char *name; > @@ -74,6 +77,83 @@ static const char *siliconid_to_rev(u32 siliconid) > return "??"; > } > > +#define SEC_STATUS 0x14 > +#define ABR_IMAGE_SOURCE BIT(13) > +#define OTP_PROTECTED BIT(8) > +#define LOW_SEC_KEY BIT(7) > +#define SECURE_BOOT BIT(6) > +#define UART_BOOT BIT(5)
Where do these bits come from?
> + > +static ssize_t abr_image_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + return sprintf(buf, "%d\n", !!(security_status & ABR_IMAGE_SOURCE));
sysfs_emit() here and everywhere else you use sprintf() please.
> +} > +static DEVICE_ATTR_RO(abr_image); > + > +static ssize_t low_security_key_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + return sprintf(buf, "%d\n", !!(security_status & LOW_SEC_KEY)); > +} > +static DEVICE_ATTR_RO(low_security_key); > + > +static ssize_t otp_protected_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + return sprintf(buf, "%d\n", !!(security_status & OTP_PROTECTED)); > +} > +static DEVICE_ATTR_RO(otp_protected); > + > +static ssize_t secure_boot_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + return sprintf(buf, "%d\n", !!(security_status & SECURE_BOOT)); > +} > +static DEVICE_ATTR_RO(secure_boot); > + > +static ssize_t uart_boot_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + /* Invert the bit, as 1 is boot from SPI/eMMC */ > + return sprintf(buf, "%d\n", !(security_status & UART_BOOT)); > +} > +static DEVICE_ATTR_RO(uart_boot); > + > +static struct attribute *aspeed_attrs[] = { > + &dev_attr_abr_image.attr, > + &dev_attr_low_security_key.attr, > + &dev_attr_otp_protected.attr, > + &dev_attr_secure_boot.attr, > + &dev_attr_uart_boot.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(aspeed); > + > +static int __init aspeed_bootinfo_init(void) > +{ > + struct device_node *np; > + void __iomem *base; > + > + /* AST2600 only */ > + np = of_find_compatible_node(NULL, NULL, "aspeed,ast2600-sbc"); > + if (!of_device_is_available(np)) > + return -ENODEV; > + > + base = of_iomap(np, 0); > + if (!base) { > + of_node_put(np); > + return -ENODEV; > + } > + > + security_status = readl(base + SEC_STATUS); > + > + iounmap(base); > + of_node_put(np); > + > + firmware_bootinfo_init(aspeed_groups[0]); > + > + pr_info("AST2600 secure boot %s\n", > + (security_status & SECURE_BOOT) ? "enabled" : "disabled");
When all is good, no need to print anything out.
> + > + return 0; > +} > + > static int __init aspeed_socinfo_init(void) > { > struct soc_device_attribute *attrs; > @@ -148,6 +228,8 @@ static int __init aspeed_socinfo_init(void) > attrs->revision, > attrs->soc_id); > > + aspeed_bootinfo_init();
Why does this function return a value and yet you ignore it?
thanks,
greg k-h
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