[Pdbg] [PATCH 12/19] libpdbg: Add in enable_attn function for p8

[Rashmica]

On 29/08/18 17:57, Nicholas Piggin wrote:
> On Wed, 29 Aug 2018 11:50:40 +1000
> Rashmica Gupta <rashmica.g at gmail.com> wrote:
>
>> Signed-off-by: Rashmica Gupta <rashmica.g at gmail.com>
>> ---
>>  libpdbg/p8chip.c | 41 +++++++++++++++++++++++++++++++++++++++++
>>  libpdbg/target.h |  1 +
>>  2 files changed, 42 insertions(+)
>>
>> diff --git a/libpdbg/p8chip.c b/libpdbg/p8chip.c
>> index 89ecfd6..2f1d599 100644
>> --- a/libpdbg/p8chip.c
>> +++ b/libpdbg/p8chip.c
>> @@ -82,6 +82,8 @@
>>  #define  FSP_SPECIAL_WAKEUP		PPC_BIT(0)
>>  #define EX_PM_GP0_REG			0xf0100
>>  #define  SPECIAL_WKUP_DONE		PPC_BIT(31)
>> +#define HID0_REG                 	0x1329c
>> +#define EN_ATTN                 	PPC_BIT(31)
>>  
>>  /* p8 specific opcodes for instruction ramming*/
>>  #define MTXERF0_OPCODE 0x00000008UL
>> @@ -483,6 +485,44 @@ static int p8_thread_probe(struct pdbg_target *target)
>>  	return 0;
>>  }
>>  
>> +static int p8_get_hid0(struct pdbg_target *chip, uint64_t *value)
>> +{
>> +	CHECK_ERR(pib_read(chip, HID0_REG, value));
>> +	return 0;
>> +}
>> +
>> +static int p8_put_hid0(struct pdbg_target *chip, uint64_t value)
>> +{
>> +	CHECK_ERR(pib_write(chip, HID0_REG, value));
>> +	return 0;
>> +}
>> +
>> +static int p8_enable_attn(struct pdbg_target *target)
>> +{
>> +	struct pdbg_target *core;
>> +	uint64_t hid0;
>> +
>> +	core = pdbg_target_parent("core", target);
>> +	if (core == NULL)
>> +	{
>> +		PR_ERROR("CORE NOT FOUND\n");
>> +		return 1;
>> +	}
>> +
>> +	/* Need to enable the attn instruction in HID0 */
>> +	if (p8_get_hid0(core, &hid0)) {
>> +		PR_ERROR("Unable to get HID0\n");
>> +		return 1;
>> +	}
>> +	hid0 |= EN_ATTN;
>> +
>> +	if (p8_put_hid0(core, hid0)) {
>> +		PR_ERROR("Unable to set HID0\n");
>> +		return 1;
>> +	}
>> +	return 0;
>> +}
>> +
>>  static struct thread p8_thread = {
>>  	.target = {
>>  		.name = "POWER8 Thread",
>> @@ -499,6 +539,7 @@ static struct thread p8_thread = {
>>  	.ram_destroy = p8_ram_destroy,
>>  	.ram_getxer = p8_ram_getxer,
>>  	.ram_putxer = p8_ram_putxer,
>> +	.enable_attn = p8_enable_attn,
>>  };
>>  DECLARE_HW_UNIT(p8_thread);
>>  
>> diff --git a/libpdbg/target.h b/libpdbg/target.h
>> index 8bad405..c8da048 100644
>> --- a/libpdbg/target.h
>> +++ b/libpdbg/target.h
>> @@ -155,6 +155,7 @@ struct thread {
>>  	int (*ram_destroy)(struct thread *);
>>  	int (*ram_getxer)(struct pdbg_target *, uint64_t *value);
>>  	int (*ram_putxer)(struct pdbg_target *, uint64_t value);
>> +	int (*enable_attn)(struct pdbg_target *);
>>  };
>>  #define target_to_thread(x) container_of(x, struct thread, target)
>>  
>> -- 
>> 2.14.4
>>
>
> I didn't know we can use attn to get break points, that's pretty cool.
> How does that work, attn makes the thread go inactive and the gdb server
> notices it by polling?

Yup!

> Thanks,
> Nick