| Message ID | 20200516153644.13748-7-digetx@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce NVIDIA Tegra Partition Table | expand |
On Sat, May 16, 2020 at 06:36:44PM +0300, Dmitry Osipenko wrote: > It's quite useful to have unencrypted BCT exposed to userspace for > debugging purposes, so let's expose it via sysfs. The BCT data will be > present in '/sys/tegra/boot_config_table' binary file if BCT is available. [...] > +/* > + * spare_bct[] will be released once kernel is booted, hence not wasting > + * kernel space if BCT is missing. The tegra_bct can't be allocated during > + * of BCT setting up because it's too early for the slab allocator. > + */ > +static u8 spare_bct[SZ_8K] __initdata; > +static u8 *tegra_bct; > + > +static ssize_t boot_config_table_read(struct file *filp, > + struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t off, size_t count) > +{ > + memcpy(buf, tegra_bct + off, count); > + return count; > +} > +static BIN_ATTR_RO(boot_config_table, 0); > + > +static int __init tegra_bootdata_bct_sysfs_init(void) > +{ > + if (!bin_attr_boot_config_table.size) > + return 0; > + > + tegra_bct = kmalloc(GFP_KERNEL, bin_attr_boot_config_table.size); > + if (!tegra_bct) > + return -ENOMEM; > + > + memcpy(tegra_bct, spare_bct, bin_attr_boot_config_table.size); > + > + return sysfs_create_bin_file(tegra_soc_kobj, > + &bin_attr_boot_config_table); Should we consider freeing the table if sysfs registration fails? > +} > +late_initcall(tegra_bootdata_bct_sysfs_init) > + > +void __init tegra_bootdata_bct_setup(void __iomem *bct_ptr, size_t bct_size) > +{ > + memcpy_fromio(spare_bct, bct_ptr, bct_size); > + bin_attr_boot_config_table.size = bct_size; [...] The size isn't checked anywhere. How the maximum is obtained? At least a comment would be good if the 8k limit is guaranteed by other means. Best Regards, Michał Mirosław
18.05.2020 10:45, Michał Mirosław пишет: > On Sat, May 16, 2020 at 06:36:44PM +0300, Dmitry Osipenko wrote: >> It's quite useful to have unencrypted BCT exposed to userspace for >> debugging purposes, so let's expose it via sysfs. The BCT data will be >> present in '/sys/tegra/boot_config_table' binary file if BCT is available. > [...] >> +/* >> + * spare_bct[] will be released once kernel is booted, hence not wasting >> + * kernel space if BCT is missing. The tegra_bct can't be allocated during >> + * of BCT setting up because it's too early for the slab allocator. >> + */ >> +static u8 spare_bct[SZ_8K] __initdata; >> +static u8 *tegra_bct; >> + >> +static ssize_t boot_config_table_read(struct file *filp, >> + struct kobject *kobj, >> + struct bin_attribute *bin_attr, >> + char *buf, loff_t off, size_t count) >> +{ >> + memcpy(buf, tegra_bct + off, count); >> + return count; >> +} >> +static BIN_ATTR_RO(boot_config_table, 0); >> + >> +static int __init tegra_bootdata_bct_sysfs_init(void) >> +{ >> + if (!bin_attr_boot_config_table.size) >> + return 0; >> + >> + tegra_bct = kmalloc(GFP_KERNEL, bin_attr_boot_config_table.size); >> + if (!tegra_bct) >> + return -ENOMEM; >> + >> + memcpy(tegra_bct, spare_bct, bin_attr_boot_config_table.size); >> + >> + return sysfs_create_bin_file(tegra_soc_kobj, >> + &bin_attr_boot_config_table); > > Should we consider freeing the table if sysfs registration fails? This is a good suggestion, thank you :) >> +} >> +late_initcall(tegra_bootdata_bct_sysfs_init) >> + >> +void __init tegra_bootdata_bct_setup(void __iomem *bct_ptr, size_t bct_size) >> +{ >> + memcpy_fromio(spare_bct, bct_ptr, bct_size); >> + bin_attr_boot_config_table.size = bct_size; > [...] > > The size isn't checked anywhere. How the maximum is obtained? At least > a comment would be good if the 8k limit is guaranteed by other means. Yes, I can add a clarifying comment about the 8K. It also should be possible to create a union of T20/T30 BCT structs and then use use sizeof(bct_union). I'll consider this change for the next version, thank you for the suggestion.
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c index da6bcd85398b..5f40463f1b97 100644 --- a/arch/arm/mach-tegra/tegra.c +++ b/arch/arm/mach-tegra/tegra.c @@ -72,6 +72,7 @@ static void __init tegra_boot_config_table_init(void) u32 iram_end = TEGRA_IRAM_BASE + TEGRA_IRAM_SIZE; u32 iram_start = TEGRA_IRAM_BASE; u32 pt_addr, pt_size, bct_size; + void __iomem *bct_ptr; t20_bit = IO_ADDRESS(TEGRA_IRAM_BASE); @@ -90,6 +91,7 @@ static void __init tegra_boot_config_table_init(void) pt_addr = t20_bct->partition_table_logical_sector_address; pt_size = t20_bct->partition_table_num_logical_sectors; + bct_ptr = t20_bct; } else if (of_machine_is_compatible("nvidia,tegra30")) { bct_size = sizeof(*t30_bct); @@ -106,12 +108,14 @@ static void __init tegra_boot_config_table_init(void) pt_addr = t30_bct->partition_table_logical_sector_address; pt_size = t30_bct->partition_table_num_logical_sectors; + bct_ptr = t30_bct; } else { return; } pr_info("%s: BCT found in IRAM\n", __func__); + tegra_bootdata_bct_setup(bct_ptr, bct_size); tegra_partition_table_setup(pt_addr, pt_size); } diff --git a/drivers/soc/tegra/Makefile b/drivers/soc/tegra/Makefile index 9c809c1814bd..8be2bfb4d95d 100644 --- a/drivers/soc/tegra/Makefile +++ b/drivers/soc/tegra/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += fuse/ +obj-y += bootdata.o obj-y += common.o obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o diff --git a/drivers/soc/tegra/bootdata.c b/drivers/soc/tegra/bootdata.c new file mode 100644 index 000000000000..e18a27b74023 --- /dev/null +++ b/drivers/soc/tegra/bootdata.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/sizes.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/types.h> + +#include <soc/tegra/bootdata.h> +#include <soc/tegra/common.h> + +/* + * spare_bct[] will be released once kernel is booted, hence not wasting + * kernel space if BCT is missing. The tegra_bct can't be allocated during + * of BCT setting up because it's too early for the slab allocator. + */ +static u8 spare_bct[SZ_8K] __initdata; +static u8 *tegra_bct; + +static ssize_t boot_config_table_read(struct file *filp, + struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + memcpy(buf, tegra_bct + off, count); + return count; +} +static BIN_ATTR_RO(boot_config_table, 0); + +static int __init tegra_bootdata_bct_sysfs_init(void) +{ + if (!bin_attr_boot_config_table.size) + return 0; + + tegra_bct = kmalloc(GFP_KERNEL, bin_attr_boot_config_table.size); + if (!tegra_bct) + return -ENOMEM; + + memcpy(tegra_bct, spare_bct, bin_attr_boot_config_table.size); + + return sysfs_create_bin_file(tegra_soc_kobj, + &bin_attr_boot_config_table); +} +late_initcall(tegra_bootdata_bct_sysfs_init) + +void __init tegra_bootdata_bct_setup(void __iomem *bct_ptr, size_t bct_size) +{ + memcpy_fromio(spare_bct, bct_ptr, bct_size); + bin_attr_boot_config_table.size = bct_size; +} diff --git a/drivers/soc/tegra/common.c b/drivers/soc/tegra/common.c index 3dc54f59cafe..2b4b49eacb2e 100644 --- a/drivers/soc/tegra/common.c +++ b/drivers/soc/tegra/common.c @@ -3,10 +3,15 @@ * Copyright (C) 2014 NVIDIA CORPORATION. All rights reserved. */ +#include <linux/init.h> +#include <linux/kernel.h> #include <linux/of.h> +#include <linux/sysfs.h> #include <soc/tegra/common.h> +struct kobject *tegra_soc_kobj; + static const struct of_device_id tegra_machine_match[] = { { .compatible = "nvidia,tegra20", }, { .compatible = "nvidia,tegra30", }, @@ -31,3 +36,15 @@ bool soc_is_tegra(void) return match != NULL; } + +static int __init tegra_soc_sysfs_init(void) +{ + if (!soc_is_tegra()) + return 0; + + tegra_soc_kobj = kobject_create_and_add("tegra", NULL); + WARN_ON(!tegra_soc_kobj); + + return 0; +} +arch_initcall(tegra_soc_sysfs_init) diff --git a/include/soc/tegra/bootdata.h b/include/soc/tegra/bootdata.h index 7be207cb2519..d5c7a251517d 100644 --- a/include/soc/tegra/bootdata.h +++ b/include/soc/tegra/bootdata.h @@ -43,4 +43,6 @@ struct tegra30_boot_config_table { u32 unused_data[3]; } __packed; +void tegra_bootdata_bct_setup(void __iomem *bct_ptr, size_t bct_size); + #endif /* __SOC_TEGRA_BOOTDATA_H__ */ diff --git a/include/soc/tegra/common.h b/include/soc/tegra/common.h index 744280ecab5f..0bc11b45c98e 100644 --- a/include/soc/tegra/common.h +++ b/include/soc/tegra/common.h @@ -7,8 +7,11 @@ #define __SOC_TEGRA_COMMON_H__ #include <linux/types.h> +#include <linux/sysfs.h> #ifdef CONFIG_ARCH_TEGRA +extern struct kobject *tegra_soc_kobj; + bool soc_is_tegra(void); #else static inline bool soc_is_tegra(void)
It's quite useful to have unencrypted BCT exposed to userspace for debugging purposes, so let's expose it via sysfs. The BCT data will be present in '/sys/tegra/boot_config_table' binary file if BCT is available. Suggested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- arch/arm/mach-tegra/tegra.c | 4 +++ drivers/soc/tegra/Makefile | 1 + drivers/soc/tegra/bootdata.c | 51 ++++++++++++++++++++++++++++++++++++ drivers/soc/tegra/common.c | 17 ++++++++++++ include/soc/tegra/bootdata.h | 2 ++ include/soc/tegra/common.h | 3 +++ 6 files changed, 78 insertions(+) create mode 100644 drivers/soc/tegra/bootdata.c