| Message ID | 1430206196-3483-2-git-send-email-contact@paulk.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 28 Apr 2015 09:29:56 +0200 , Paul Kocialkowski <contact@paulk.fr> wrote: > This grabs the serial number shown in cpuinfo from the serial-number devicetree > property in priority. When booting with ATAGs (and without device-tree), the > provided number is still shown instead. > > Signed-off-by: Paul Kocialkowski <contact@paulk.fr> One comment below, but otherwise: Acked-by: Grant Likely <grant.likely@linaro.org> > --- > arch/arm/include/asm/system_info.h | 1 + > arch/arm/kernel/setup.c | 23 +++++++++++++++++++++-- > 2 files changed, 22 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h > index 720ea03..3860cbd40 100644 > --- a/arch/arm/include/asm/system_info.h > +++ b/arch/arm/include/asm/system_info.h > @@ -17,6 +17,7 @@ > > /* information about the system we're running on */ > extern unsigned int system_rev; > +extern const char *system_serial; > extern unsigned int system_serial_low; > extern unsigned int system_serial_high; > extern unsigned int mem_fclk_21285; > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index 1d60beb..b501754 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -93,6 +93,9 @@ unsigned int __atags_pointer __initdata; > unsigned int system_rev; > EXPORT_SYMBOL(system_rev); > > +const char *system_serial; > +EXPORT_SYMBOL(system_serial); > + Is there any need to export this symbol? It's only used by built-in code. Not by modules. > unsigned int system_serial_low; > EXPORT_SYMBOL(system_serial_low); > > @@ -821,8 +824,25 @@ arch_initcall(customize_machine); > > static int __init init_machine_late(void) > { > + struct device_node *root; > + int ret; > + > if (machine_desc->init_late) > machine_desc->init_late(); > + > + root = of_find_node_by_path("/"); > + if (root) { > + ret = of_property_read_string(root, "serial-number", > + &system_serial); of_property_read_string() will not modify the argument on failure. If system_serial is initialized to NULL, then the failure path is unnecessary. > + if (ret) > + system_serial = NULL; > + } Calls to of_find_node* functions increment the refcount for the node. Need an of_node_put() here, or just use the of_root pointer directly. It is safe to call of_property_read_string() with a NULL node pointer too, it will fail gracefully. So, the whole thing can safely boil down to: of_property_read_string(of_root, "serial-number", &system_serial); if (!system_serial) system_serial = kasprintf(GFP_KERNEL, "%08x%08x", system_serial_high, system_serial_low); g.
Le dimanche 07 juin 2015 à 18:03 +0100, Grant Likely a écrit : > On Tue, 28 Apr 2015 09:29:56 +0200 > , Paul Kocialkowski <contact@paulk.fr> > wrote: > > This grabs the serial number shown in cpuinfo from the serial-number devicetree > > property in priority. When booting with ATAGs (and without device-tree), the > > provided number is still shown instead. > > > > Signed-off-by: Paul Kocialkowski <contact@paulk.fr> > > One comment below, but otherwise: > > Acked-by: Grant Likely <grant.likely@linaro.org> I'm afraid this was merged in Russell's tree already: http://ftp.arm.linux.org.uk/cgit/linux-arm.git/commit/?h=for-next&id=3f599875e5202986b350618a617527ab441bf206 Still, it might be useful to make another patch on top with your comments! > > --- > > arch/arm/include/asm/system_info.h | 1 + > > arch/arm/kernel/setup.c | 23 +++++++++++++++++++++-- > > 2 files changed, 22 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h > > index 720ea03..3860cbd40 100644 > > --- a/arch/arm/include/asm/system_info.h > > +++ b/arch/arm/include/asm/system_info.h > > @@ -17,6 +17,7 @@ > > > > /* information about the system we're running on */ > > extern unsigned int system_rev; > > +extern const char *system_serial; > > extern unsigned int system_serial_low; > > extern unsigned int system_serial_high; > > extern unsigned int mem_fclk_21285; > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > > index 1d60beb..b501754 100644 > > --- a/arch/arm/kernel/setup.c > > +++ b/arch/arm/kernel/setup.c > > @@ -93,6 +93,9 @@ unsigned int __atags_pointer __initdata; > > unsigned int system_rev; > > EXPORT_SYMBOL(system_rev); > > > > +const char *system_serial; > > +EXPORT_SYMBOL(system_serial); > > + > > Is there any need to export this symbol? It's only used by built-in > code. Not by modules. I agree, but I thought it would be consistent with the way system_serial_high/low are exported. I'm not sure this was ever needed either, but generally, I guess it makes sense to export parameters that are passed to the kernel (it was through ATAGs before, now it's through device-tree, but the logic remains the same). > > unsigned int system_serial_low; > > EXPORT_SYMBOL(system_serial_low); > > > > @@ -821,8 +824,25 @@ arch_initcall(customize_machine); > > > > static int __init init_machine_late(void) > > { > > + struct device_node *root; > > + int ret; > > + > > if (machine_desc->init_late) > > machine_desc->init_late(); > > + > > + root = of_find_node_by_path("/"); > > + if (root) { > > + ret = of_property_read_string(root, "serial-number", > > + &system_serial); > > of_property_read_string() will not modify the argument on failure. If > system_serial is initialized to NULL, then the failure path is > unnecessary. Makes sense. > > + if (ret) > > + system_serial = NULL; > > + } > > Calls to of_find_node* functions increment the refcount for the node. > Need an of_node_put() here, or just use the of_root pointer directly. It > is safe to call of_property_read_string() with a NULL node pointer too, > it will fail gracefully. > > So, the whole thing can safely boil down to: > > of_property_read_string(of_root, "serial-number", &system_serial); > if (!system_serial) > system_serial = kasprintf(GFP_KERNEL, "%08x%08x", > system_serial_high, system_serial_low); Looks good to me, feel free to commit this change, on top of: http://ftp.arm.linux.org.uk/cgit/linux-arm.git/commit/?h=for-next&id=3f599875e5202986b350618a617527ab441bf206
diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h index 720ea03..3860cbd40 100644 --- a/arch/arm/include/asm/system_info.h +++ b/arch/arm/include/asm/system_info.h @@ -17,6 +17,7 @@ /* information about the system we're running on */ extern unsigned int system_rev; +extern const char *system_serial; extern unsigned int system_serial_low; extern unsigned int system_serial_high; extern unsigned int mem_fclk_21285; diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 1d60beb..b501754 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -93,6 +93,9 @@ unsigned int __atags_pointer __initdata; unsigned int system_rev; EXPORT_SYMBOL(system_rev); +const char *system_serial; +EXPORT_SYMBOL(system_serial); + unsigned int system_serial_low; EXPORT_SYMBOL(system_serial_low); @@ -821,8 +824,25 @@ arch_initcall(customize_machine); static int __init init_machine_late(void) { + struct device_node *root; + int ret; + if (machine_desc->init_late) machine_desc->init_late(); + + root = of_find_node_by_path("/"); + if (root) { + ret = of_property_read_string(root, "serial-number", + &system_serial); + if (ret) + system_serial = NULL; + } + + if (!system_serial) + system_serial = kasprintf(GFP_KERNEL, "%08x%08x", + system_serial_high, + system_serial_low); + return 0; } late_initcall(init_machine_late); @@ -1091,8 +1111,7 @@ static int c_show(struct seq_file *m, void *v) seq_printf(m, "Hardware\t: %s\n", machine_name); seq_printf(m, "Revision\t: %04x\n", system_rev); - seq_printf(m, "Serial\t\t: %08x%08x\n", - system_serial_high, system_serial_low); + seq_printf(m, "Serial\t\t: %s\n", system_serial); return 0; }
This grabs the serial number shown in cpuinfo from the serial-number devicetree property in priority. When booting with ATAGs (and without device-tree), the provided number is still shown instead. Signed-off-by: Paul Kocialkowski <contact@paulk.fr> --- arch/arm/include/asm/system_info.h | 1 + arch/arm/kernel/setup.c | 23 +++++++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-)