[U-Boot] [PATCH 4/4] efi_loader: indent entry/exit prints to show nesting level

Rob Clark
2017-07-28T09:34:17Z

On Fri, Jul 28, 2017 at 5:25 AM, Alexander Graf <agraf@suse.de> wrote:
>
>
> On 28.07.17 11:19, Rob Clark wrote:
>>
>> On Fri, Jul 28, 2017 at 3:24 AM, Alexander Graf <agraf@suse.de> wrote:
>>>
>>>
>>>
>>> On 27.07.17 14:04, Rob Clark wrote:
>>>>
>>>>
>>>> This should make it easier to see when a callback back to UEFI world
>>>> calls back in to the u-boot world, and generally match up EFI_ENTRY()
>>>> and EFI_EXIT() calls.
>>>>
>>>> Signed-off-by: Rob Clark <robdclark@gmail.com>
>>>
>>>
>>>
>>> Doesn't the previous patch ensure that we're always only going 1 level
>>> deep?
>>
>>
>> two separate counters for nesting and entry level. We can be more
>> deeply nested when EFI_CALL() is used :-)
>
>
> Ah, so this basically gives you the EFI_CALL nesting level? Wouldn't it make
> sense to also increase the nesting level on every application invocation?

I specifically avoided that since (at least at what I was looking at)
each successive application invocation never returns.

Maybe instead we should just do something like:
debug("========================================\n") to show the
application invocation boundaries more easily?

>
>>
>>>
>>>> ---
>>>> include/efi_loader.h | 12 ++++++++----
>>>> lib/efi_loader/efi_boottime.c | 25 +++++++++++++++++++++++++
>>>> 2 files changed, 33 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/include/efi_loader.h b/include/efi_loader.h
>>>> index 4262d0ac6b..037cc7c543 100644
>>>> --- a/include/efi_loader.h
>>>> +++ b/include/efi_loader.h
>>>> @@ -17,13 +17,16 @@
>>>> int __efi_entry_check(void);
>>>> int __efi_exit_check(void);
>>>> +const char *__efi_nesting_inc(void);
>>>> +const char *__efi_nesting_dec(void);
>>>> /*
>>>> * Enter the u-boot world from UEFI:
>>>> */
>>>> #define EFI_ENTRY(format, ...) do { \
>>>> assert(__efi_entry_check()); \
>>>> - debug("EFI: Entry %s(" format ")\n", __func__, ##__VA_ARGS__); \
>>>> + debug("%sEFI: Entry %s(" format ")\n", __efi_nesting_inc(), \
>>>> + __func__, ##__VA_ARGS__); \
>>>> } while(0)
>>>> /*
>>>> @@ -31,7 +34,8 @@ int __efi_exit_check(void);
>>>> */
>>>> #define EFI_EXIT(ret) ({ \
>>>> efi_status_t _r = ret; \
>>>> - debug("EFI: Exit: %s: %u\n", __func__, (u32)(_r &
>>>> ~EFI_ERROR_MASK)); \
>>>> + debug("%sEFI: Exit: %s: %u\n", __efi_nesting_dec(), \
>>>> + __func__, (u32)(_r & ~EFI_ERROR_MASK)); \
>>>> assert(__efi_exit_check()); \
>>>> _r; \
>>>> })
>>>> @@ -40,11 +44,11 @@ int __efi_exit_check(void);
>>>> * Callback into UEFI world from u-boot:
>>>> */
>>>> #define EFI_CALL(exp) do { \
>>>> - debug("EFI: Call: %s\n", #exp); \
>>>> + debug("%sEFI: Call: %s\n", __efi_nesting_inc(), #exp); \
>>>> assert(__efi_exit_check()); \
>>>> exp; \
>>>> assert(__efi_entry_check()); \
>>>> - debug("EFI: Return From: %s\n", #exp); \
>>>> + debug("%sEFI: Return From: %s\n", __efi_nesting_dec(), #exp); \
>>>> } while(0)
>>>> extern struct efi_runtime_services efi_runtime_services;
>>>> diff --git a/lib/efi_loader/efi_boottime.c
>>>> b/lib/efi_loader/efi_boottime.c
>>>> index 66137d4ff9..de338f009c 100644
>>>> --- a/lib/efi_loader/efi_boottime.c
>>>> +++ b/lib/efi_loader/efi_boottime.c
>>>> @@ -50,6 +50,7 @@ static volatile void *efi_gd, *app_gd;
>>>> #endif
>>>> static int entry_count;
>>>> +static int nesting_level;
>>>> /* Called on every callback entry */
>>>> int __efi_entry_check(void)
>>>> @@ -96,6 +97,28 @@ void efi_restore_gd(void)
>>>> #endif
>>>> }
>>>> +/*
>>>> + * Two spaces per indent level, maxing out at 10.. which ought to be
>>>> + * enough for anyone ;-)
>>>> + */
>>>> +static const char *indent_string(int level)
>>>> +{
>>>> + static const char *indent = " ";
>>>
>>>
>>>
>>> There's no need for this to be static, no?
>>
>>
>> I suppose it doesn't *need* to be.. but it also doesn't need to have
>> scope outside the file, and usually static is a good hint to the
>> compiler to inline it. (If non-static the compiler needs to emit a
>> non-inlined version of it since it doesn't know it won't be called
>> outside of this object file.
>
>
> I don't mean the function, I mean the indent. If you do
>
> static const char *indent = <const value>;
>
> it should be practically the same as
>
> const char *indent = <const value>;
>
> no?

hmm, I didn't want the compiler to instantiate the array on the stack.
But I suppose I need to check the generated asm to see how clever it
is.

BR,
-R