[Skiboot] [PATCH 1/2] hw/phb3: Change reserved PE to 255

[Gavin Shan]

Currently, we have reserved PE#0 to which all RIDs are mapped prior
to PE assignment request from kernel. The last M64 BAR is configured
to have shared mode. So we have to cut off the first M64 segment,
which corresponds to reserved PE#0 in kernel. If the first BAR
(for example PF's IOV BAR) requires huge alignment in kernel, we
have to waste huge M64 space to accomodate the alignment. If we
have reserved PE#256, the waste of M64 space will be avoided.

Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 hw/phb3.c      | 21 ++++++++++++++++-----
 include/phb3.h |  1 +
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/hw/phb3.c b/hw/phb3.c
index cdc20e8..6bf73bf 100644
--- a/hw/phb3.c
+++ b/hw/phb3.c
@@ -559,7 +559,8 @@ static void phb3_init_ioda_cache(struct phb3 *p)
 	 * ever let a live FF RTT even temporarily when resetting
 	 * for EEH etc... (HW278969).
 	 */
-	memset(p->rte_cache, 0x00, RTT_TABLE_SIZE);
+	for (i = 0; i < ARRAY_SIZE(p->rte_cache); i++)
+		p->rte_cache[i] = PHB3_RESERVED_PE_NUM;
 	memset(p->peltv_cache, 0x0,  sizeof(p->peltv_cache));
 
 	/* Disable all LSI */
@@ -1792,7 +1793,8 @@ static int64_t phb3_set_pe(struct phb *phb,
 			for (idx = 0; idx < RTT_TABLE_ENTRIES; idx++)
 				p->rte_cache[idx] = pe_num;
 		} else {
-			memset(p->rte_cache, 0, RTT_TABLE_SIZE);
+			for ( idx = 0; idx < ARRAY_SIZE(p->rte_cache); idx++)
+				p->rte_cache[idx] = PHB3_RESERVED_PE_NUM;
 		}
 		memcpy((void *)p->tbl_rtt, p->rte_cache, RTT_TABLE_SIZE);
 	} else {
@@ -1800,7 +1802,10 @@ static int64_t phb3_set_pe(struct phb *phb,
 		for (idx = 0; idx < RTT_TABLE_ENTRIES; idx++, rte++) {
 			if ((idx & mask) != val)
 				continue;
-			p->rte_cache[idx] = (action ? pe_num : 0);
+			if (action == OPAL_MAP_PE)
+				p->rte_cache[idx] = pe_num;
+			else
+				p->rte_cache[idx] = PHB3_RESERVED_PE_NUM;
 			*rte = p->rte_cache[idx];
 		}
 	}
@@ -4026,6 +4031,9 @@ static void phb3_init_hw(struct phb3 *p, bool first_init)
 
 static void phb3_allocate_tables(struct phb3 *p)
 {
+	uint16_t *rte;
+	uint32_t i;
+
 	/* XXX Our current memalign implementation sucks,
 	 *
 	 * It will do the job, however it doesn't support freeing
@@ -4034,7 +4042,9 @@ static void phb3_allocate_tables(struct phb3 *p)
 	 */
 	p->tbl_rtt = (uint64_t)local_alloc(p->chip_id, RTT_TABLE_SIZE, RTT_TABLE_SIZE);
 	assert(p->tbl_rtt);
-	memset((void *)p->tbl_rtt, 0, RTT_TABLE_SIZE);
+	rte = (uint16_t *)(p->tbl_rtt);
+	for (i = 0; i < RTT_TABLE_ENTRIES; i++, rte++)
+		*rte = PHB3_RESERVED_PE_NUM;
 
 	p->tbl_peltv = (uint64_t)local_alloc(p->chip_id, PELTV_TABLE_SIZE, PELTV_TABLE_SIZE);
 	assert(p->tbl_peltv);
@@ -4100,7 +4110,8 @@ static void phb3_add_properties(struct phb3 *p)
 	dt_add_property(np, "ibm,opal-single-pe", NULL, 0);
 	//dt_add_property_cells(np, "ibm,opal-msi-ports", 2048);
 	dt_add_property_cells(np, "ibm,opal-num-pes", 256);
-	dt_add_property_cells(np, "ibm,opal-reserved-pe", 0);
+	dt_add_property_cells(np, "ibm,opal-reserved-pe",
+			      PHB3_RESERVED_PE_NUM);
 	dt_add_property_cells(np, "ibm,opal-msi-ranges",
 			      p->base_msi, PHB3_MSI_IRQ_COUNT);
 	tkill = reg + PHB_TCE_KILL;
diff --git a/include/phb3.h b/include/phb3.h
index ea3ad87..c15f5d2 100644
--- a/include/phb3.h
+++ b/include/phb3.h
@@ -148,6 +148,7 @@ struct rtt_entry {
  * capability register later.
  */
 #define PHB3_MAX_PE_NUM		256
+#define PHB3_RESERVED_PE_NUM	255
 
 /*
  * State structure for a PHB
-- 
2.1.0