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Commit e70d5970 authored by John Allen's avatar John Allen Committed by Michael Ellerman
Browse files

powerpc/pseries: Introduce memory hotplug READD operation 



Currently, memory must be hot removed and subsequently re-added in order
to dynamically update the affinity of LMBs specified by a PRRN event.
Earlier implementations of the PRRN event handler ran into issues in which
the hot remove would occur successfully, but a hotplug event would be
initiated from another source and grab the hotplug lock preventing the hot
add from occurring. To prevent this situation, this patch introduces the
notion of a hot "readd" action for memory which atomizes a hot remove and
a hot add into a single, serialized operation on the hotplug queue.

Signed-off-by: default avatarJohn Allen <jallen@linux.vnet.ibm.com>
Reviewed-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent c21f515c

arch/powerpc/include/asm/rtas.h

+1 −0
Original line number Diff line number Diff line
@@ -318,6 +318,7 @@ struct pseries_hp_errorlog { 


#define PSERIES_HP_ELOG_ACTION_ADD	1

#define PSERIES_HP_ELOG_ACTION_REMOVE	2

#define PSERIES_HP_ELOG_ACTION_READD	3



#define PSERIES_HP_ELOG_ID_DRC_NAME	1

#define PSERIES_HP_ELOG_ID_DRC_INDEX	2

arch/powerpc/platforms/pseries/hotplug-memory.c

+41 −0
Original line number Diff line number Diff line
@@ -563,6 +563,44 @@ static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop) 
	return rc;

}



static int dlpar_memory_readd_by_index(u32 drc_index, struct property *prop)

{

	struct of_drconf_cell *lmbs;

	u32 num_lmbs, *p;

	int lmb_found;

	int i, rc;



	pr_info("Attempting to update LMB, drc index %x\n", drc_index);



	p = prop->value;

	num_lmbs = *p++;

	lmbs = (struct of_drconf_cell *)p;



	lmb_found = 0;

	for (i = 0; i < num_lmbs; i++) {

		if (lmbs[i].drc_index == drc_index) {

			lmb_found = 1;

			rc = dlpar_remove_lmb(&lmbs[i]);

			if (!rc) {

				rc = dlpar_add_lmb(&lmbs[i]);

				if (rc)

					dlpar_release_drc(lmbs[i].drc_index);

			}

			break;

		}

	}



	if (!lmb_found)

		rc = -EINVAL;



	if (rc)

		pr_info("Failed to update memory at %llx\n",

			lmbs[i].base_addr);

	else

		pr_info("Memory at %llx was updated\n", lmbs[i].base_addr);



	return rc;

}

#else

static inline int pseries_remove_memblock(unsigned long base,

					  unsigned int memblock_size)
@@ -779,6 +817,9 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog) 
		else

			rc = -EINVAL;

		break;

	case PSERIES_HP_ELOG_ACTION_READD:

		rc = dlpar_memory_readd_by_index(drc_index, prop);

		break;

	default:

		pr_err("Invalid action (%d) specified\n", hp_elog->action);

		rc = -EINVAL;