[Pdbg] [PATCH 8/9] main: Convert gdbserver command to path based targeting

[Rashmica Gupta]

On Tue, 2018-11-20 at 15:19 +1100, Amitay Isaacs wrote:
> Signed-off-by: Amitay Isaacs <amitay at ozlabs.org>
> ---
>  src/pdbgproxy.c | 72 +++++++++++++++++++++++----------------------
> ----
>  1 file changed, 33 insertions(+), 39 deletions(-)
> 
> diff --git a/src/pdbgproxy.c b/src/pdbgproxy.c
> 

...

> 
>  static int gdbserver(uint16_t port)
>  {
> -	struct pdbg_target *target = NULL;
> +	struct pdbg_target *target, *adu, *thread = NULL;
>  	uint64_t msr;
>  	int rc;
>  
> -	for_each_class_target("thread", target) {
> -		if (!target_selected(target))
> +	for_each_path_target_class("thread", target) {
> +		if (pdbg_target_probe(target) != PDBG_TARGET_ENABLED)
>  			continue;
> -		if (pdbg_target_probe(target) == PDBG_TARGET_ENABLED)
> -			break;
> +
> +		if (!thread) {
> +			thread = target;
> +		} else {
> +			fprintf(stderr, "GDB server cannot be run on
> multiple threads at once.\n");

Nice


> +			return 0;
> +		}
>  	}
> -	if (!target->class)
> -		return -1;

This check was to return if the user specified a target that didn't
exist (rather than segfault). Can you add a check for that here? Maybe:

if (!thread)
	return -1;

Would also be good to add in a useful message like "didn't find a valid
thread".

Otherwise, this looks good to me :)


> -	assert(!strcmp(target->class, "thread"));
> +
> +	//
>  	// Temporary until I can get this working a bit smoother on p9
> -	if (strcmp(target->compatible, "ibm,power8-thread")) {
> +	if (strcmp(thread->compatible, "ibm,power8-thread")) {
>  		PR_ERROR("GDBSERVER is only tested on POWER8\n");
>  		return -1;
>  	}
>  
>  	/* Check endianess in MSR */
> -	rc = ram_getmsr(target, &msr);
> +	rc = ram_getmsr(thread, &msr);
>  	if (rc) {
>  		PR_ERROR("Couldn't read the MSR. Are all threads on
> this chiplet quiesced?\n");
>  		return 1;
>  	}
>  	littleendian = 0x01 & msr;
>  
> -	gdbserver_start(target, port);
> +	/* Select ADU target */
> +	pdbg_for_each_class_target("adu", adu) {
> +		if (pdbg_target_probe(adu) == PDBG_TARGET_ENABLED)
> +			break;
> +	}
> +
> +	if (!adu) {
> +		PR_ERROR("No ADU found\n");
> +		return 0;
> +	}
> +
> +	gdbserver_start(thread, adu, port);
>  	return 0;
>  }
>  #else
> -- 
> 2.19.1
>