xive: Enable memory backing of queues

This dedicates 6x64k pages of memory permanently for the XIVE to
use for internal queue overflow. This allows the XIVE to deal with
some corner cases where the internal queues might prove insufficient.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 35 insertions, 6 deletions

diff --git a/hw/xive.c b/hw/xive.c
index 36e05b8..03b9478 100644
--- a/hw/xive.c
+++ b/hw/xive.c
@@ -470,6 +470,9 @@ struct xive {
 
 	/* Embedded escalation interrupts */
 	struct xive_src	esc_irqs;
+
+	/* In memory queue overflow */
+	void		*q_ovf;
 };
 
 /* Global DT node */
@@ -742,6 +745,7 @@ static uint64_t __xive_regr(struct xive *x, uint32_t m_reg, uint32_t x_reg,
 	x->last_reg_error = false;
 
 	if (use_xscom) {
+		assert(x_reg != 0);
 		rc = xscom_read(x->chip_id, x->xscom_base + x_reg, &val);
 		if (rc) {
 			if (!rname)
@@ -1431,7 +1435,7 @@ static bool xive_set_vsd(struct xive *x, uint32_t tbl, uint32_t idx, uint64_t v)
 
 static bool xive_set_local_tables(struct xive *x)
 {
-	uint64_t base;
+	uint64_t base, i;
 
 	/* These have to be power of 2 sized */
 	assert(is_pow2(SBE_SIZE));
@@ -1478,9 +1482,22 @@ static bool xive_set_local_tables(struct xive *x)
 		return false;
 #endif
 
-	/* XXX For the queue overflow, configure VSD VST_TSEL_IRQ
-	 * with block id 0 to 5 (6 queues) with some 64k page
-	 */
+	/* Setup quue overflows */
+	for (i = 0; i < VC_QUEUE_OVF_COUNT; i++) {
+		u64 addr = ((uint64_t)x->q_ovf) + i * 0x10000;
+		u64 cfg, sreg, sregx;
+
+		if (!xive_set_vsd(x, VST_TSEL_IRQ, i, base |
+				  (addr & VSD_ADDRESS_MASK) |
+			  SETFIELD(VSD_TSIZE, 0ull, 4)))
+			return false;
+		sreg = VC_IRQ_CONFIG_IPI +  i * 8;
+		sregx = X_VC_IRQ_CONFIG_IPI + i;
+		cfg = __xive_regr(x, sreg, sregx, NULL);
+		cfg |= VC_IRQ_CONFIG_MEMB_EN;
+		cfg = SETFIELD(VC_IRQ_CONFIG_MEMB_SZ, cfg, 4);
+		__xive_regw(x, sreg, sregx, cfg, NULL);
+	}
 
 	return true;
 }
@@ -1783,6 +1800,12 @@ static bool xive_prealloc_tables(struct xive *x)
 	memset(x->vp_base, 0, VPT_SIZE);
 #endif /* USE_INDIRECT */
 
+	/* Allocate the queue overflow pages */
+	x->q_ovf = local_alloc(x->chip_id, VC_QUEUE_OVF_COUNT * 0x10000, 0x10000);
+	if (!x->q_ovf) {
+		xive_err(x, "Failed to allocate queue overflow\n");
+		return false;
+	}
 	return true;
 }
 
@@ -3942,7 +3965,10 @@ static void xive_cleanup_vp_ind(struct xive *x)
 			xive_dbg(x, " %04x ... skip (firmware)\n", i);
 			continue;
 		}
-		x->vp_ind_base[i] = 0;
+		if (x->vp_ind_base[i] != 0) {
+			x->vp_ind_base[i] = 0;
+			xive_dbg(x, " %04x ... cleaned\n", i);
+		}
 	}
 	xive_pc_ind_cache_kill(x);
 }
@@ -3957,7 +3983,10 @@ static void xive_cleanup_eq_ind(struct xive *x)
 			xive_dbg(x, " %04x ... skip (firmware)\n", i);
 			continue;
 		}
-		x->eq_ind_base[i] = 0;
+		if (x->eq_ind_base[i] != 0) {
+			x->eq_ind_base[i] = 0;
+			xive_dbg(x, " %04x ... cleaned\n", i);
+		}
 	}
 	xive_vc_ind_cache_kill(x, VC_KILL_EQD);
 }