Commit b7d5333c authored by Nathan Lynch's avatar Nathan Lynch Committed by Michael Ellerman
Browse files

powerpc/pseries/setup: add missing RTAS retry status handling 



The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

pSeries_cmo_feature_init() ignores this, making it possible to fail to
detect cooperative memory overcommit capabilities during boot.

Move the RTAS call into a conventional rtas_busy_delay()-based
loop, dropping unnecessary clearing of rtas_data_buf.

Signed-off-by: default avatarNathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-5-26929c8cce78@linux.ibm.com
parent 5d08633e

arch/powerpc/platforms/pseries/setup.c

+12 −8
Original line number Diff line number Diff line
@@ -941,21 +941,25 @@ void pSeries_coalesce_init(void) 
 */

static void __init pSeries_cmo_feature_init(void)

{

	const s32 token = rtas_token("ibm,get-system-parameter");

	char *ptr, *key, *value, *end;

	int call_status;

	int page_order = IOMMU_PAGE_SHIFT_4K;



	pr_debug(" -> fw_cmo_feature_init()\n");



	do {

		spin_lock(&rtas_data_buf_lock);

	memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);

	call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,

				NULL,

		call_status = rtas_call(token, 3, 1, NULL,

					CMO_CHARACTERISTICS_TOKEN,

					__pa(rtas_data_buf),

					RTAS_DATA_BUF_SIZE);

		if (call_status == 0)

			break;

		spin_unlock(&rtas_data_buf_lock);

	} while (rtas_busy_delay(call_status));



	if (call_status != 0) {

		spin_unlock(&rtas_data_buf_lock);

		pr_debug("CMO not available\n");

		pr_debug(" <- fw_cmo_feature_init()\n");

		return;