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powerpc/xive: Fix offset for store EOI MMIOs

PATCH Applied Benjamin Herrenschmidt 3 participants 4 messages Jun 14, 2017 – Jun 15, 2017

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#0 lore raw

PATCH 1/1 powerpc/xive: Fix offset for store EOI MMIOs

Architecturally we should apply a 0x400 offset for these. Not doing it will break future HW implementations.

---
 arch/powerpc/include/asm/xive.h         | 12 +++++++-----
 arch/powerpc/kvm/book3s_xive_template.c |  4 ++--
 arch/powerpc/sysdev/xive/common.c       |  2 +-
 3 files changed, 10 insertions(+), 8 deletions(-)
arch/powerpc/include/asm/xive.h +7 -5
index c8a822a..c23ff43 100644
@@ -94,11 +94,13 @@ struct xive_q {
  * store at 0 and some ESBs support doing a trigger via a
  * separate trigger page.
  */
-#define XIVE_ESB_GET		0x800
-#define XIVE_ESB_SET_PQ_00	0xc00
-#define XIVE_ESB_SET_PQ_01	0xd00
-#define XIVE_ESB_SET_PQ_10	0xe00
-#define XIVE_ESB_SET_PQ_11	0xf00
+#define XIVE_ESB_STORE_EOI	0x400 /* Store */
+#define XIVE_ESB_LOAD_EOI	0x000 /* Load */
+#define XIVE_ESB_GET		0x800 /* Load */
+#define XIVE_ESB_SET_PQ_00	0xc00 /* Load */
+#define XIVE_ESB_SET_PQ_01	0xd00 /* Load */
+#define XIVE_ESB_SET_PQ_10	0xe00 /* Load */
+#define XIVE_ESB_SET_PQ_11	0xf00 /* Load */
 
 #define XIVE_ESB_VAL_P		0x2
 #define XIVE_ESB_VAL_Q		0x1
arch/powerpc/kvm/book3s_xive_template.c +2 -2
index 023a311..4636ca6 100644
@@ -69,7 +69,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		__x_writeq(0, __x_eoi_page(xd));
+		__x_writeq(0, __x_eoi_page(xd) + XIVE_ESB_STORE_EOI);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		opal_int_eoi(hw_irq);
 	} else {
@@ -89,7 +89,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 		 * properly.
 		 */
 		if (xd->flags & XIVE_IRQ_FLAG_LSI)
-			__x_readq(__x_eoi_page(xd));
+			__x_readq(__x_eoi_page(xd) + XIVE_ESB_LOAD_EOI);
 		else {
 			eoi_val = GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_00);
 
arch/powerpc/sysdev/xive/common.c +1 -1
index 9138250..8f5e303 100644
@@ -297,7 +297,7 @@ void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		out_be64(xd->eoi_mmio, 0);
+		out_be64(xd->eoi_mmio + XIVE_ESB_STORE_EOI, 0);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		/*
 		 * The FW told us to call it. This happens for some
#1 lore raw
Quoted 2 lines · Benjamin Herrenschmidt

Architecturally we should apply a 0x400 offset for these. Not doing it will break future HW implementations.

Can you elaborate a bit?

You're changing a write to 0x0 to be a write to 0x400, which at face value appears like it breaks something, or is already broken?

cheers

Quoted 58 lines
arch/powerpc/include/asm/xive.h +7 -5
index c8a822a..c23ff43 100644
@@ -94,11 +94,13 @@ struct xive_q {
  * store at 0 and some ESBs support doing a trigger via a
  * separate trigger page.
  */
-#define XIVE_ESB_GET		0x800
-#define XIVE_ESB_SET_PQ_00	0xc00
-#define XIVE_ESB_SET_PQ_01	0xd00
-#define XIVE_ESB_SET_PQ_10	0xe00
-#define XIVE_ESB_SET_PQ_11	0xf00
+#define XIVE_ESB_STORE_EOI	0x400 /* Store */
+#define XIVE_ESB_LOAD_EOI	0x000 /* Load */
+#define XIVE_ESB_GET		0x800 /* Load */
+#define XIVE_ESB_SET_PQ_00	0xc00 /* Load */
+#define XIVE_ESB_SET_PQ_01	0xd00 /* Load */
+#define XIVE_ESB_SET_PQ_10	0xe00 /* Load */
+#define XIVE_ESB_SET_PQ_11	0xf00 /* Load */
 
 #define XIVE_ESB_VAL_P		0x2
 #define XIVE_ESB_VAL_Q		0x1
arch/powerpc/kvm/book3s_xive_template.c +2 -2
index 023a311..4636ca6 100644
@@ -69,7 +69,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		__x_writeq(0, __x_eoi_page(xd));
+		__x_writeq(0, __x_eoi_page(xd) + XIVE_ESB_STORE_EOI);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		opal_int_eoi(hw_irq);
 	} else {
@@ -89,7 +89,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 		 * properly.
 		 */
 		if (xd->flags & XIVE_IRQ_FLAG_LSI)
-			__x_readq(__x_eoi_page(xd));
+			__x_readq(__x_eoi_page(xd) + XIVE_ESB_LOAD_EOI);
 		else {
 			eoi_val = GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_00);
 
arch/powerpc/sysdev/xive/common.c +1 -1
index 9138250..8f5e303 100644
@@ -297,7 +297,7 @@ void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		out_be64(xd->eoi_mmio, 0);
+		out_be64(xd->eoi_mmio + XIVE_ESB_STORE_EOI, 0);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		/*
 		 * The FW told us to call it. This happens for some
#2 lore raw
Quoted 9 lines · Michael Ellerman
Quoted 2 lines · Benjamin Herrenschmidt

Architecturally we should apply a 0x400 offset for these. Not doing it will break future HW implementations.

Can you elaborate a bit?

You're changing a write to 0x0 to be a write to 0x400, which at face value appears like it breaks something, or is already broken?

The code is broken today, I didn't read the spec properly. We never had a proper DD2 model to test until recently. The offset of 0 is supposed to remain for "triggers" though not all sources support both trigger and store EOI, and in P9 specifically, some sources will treat 0 as a store EOI :-) But future chips will not. So this makes us use the properly architected offset which should work always.

Cheers,
Ben.

Quoted 61 lines

cheers

Quoted 58 lines
arch/powerpc/include/asm/xive.h +7 -5
index c8a822a..c23ff43 100644
@@ -94,11 +94,13 @@ struct xive_q {
  * store at 0 and some ESBs support doing a trigger via a
  * separate trigger page.
  */
-#define XIVE_ESB_GET		0x800
-#define XIVE_ESB_SET_PQ_00	0xc00
-#define XIVE_ESB_SET_PQ_01	0xd00
-#define XIVE_ESB_SET_PQ_10	0xe00
-#define XIVE_ESB_SET_PQ_11	0xf00
+#define XIVE_ESB_STORE_EOI	0x400 /* Store */
+#define XIVE_ESB_LOAD_EOI	0x000 /* Load */
+#define XIVE_ESB_GET		0x800 /* Load */
+#define XIVE_ESB_SET_PQ_00	0xc00 /* Load */
+#define XIVE_ESB_SET_PQ_01	0xd00 /* Load */
+#define XIVE_ESB_SET_PQ_10	0xe00 /* Load */
+#define XIVE_ESB_SET_PQ_11	0xf00 /* Load */
 
 #define XIVE_ESB_VAL_P		0x2
 #define XIVE_ESB_VAL_Q		0x1
arch/powerpc/kvm/book3s_xive_template.c +2 -2
index 023a311..4636ca6 100644
@@ -69,7 +69,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		__x_writeq(0, __x_eoi_page(xd));
+		__x_writeq(0, __x_eoi_page(xd) + XIVE_ESB_STORE_EOI);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		opal_int_eoi(hw_irq);
 	} else {
@@ -89,7 +89,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
 		 * properly.
 		 */
 		if (xd->flags & XIVE_IRQ_FLAG_LSI)
-			__x_readq(__x_eoi_page(xd));
+			__x_readq(__x_eoi_page(xd) + XIVE_ESB_LOAD_EOI);
 		else {
 			eoi_val = GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_00);
 
arch/powerpc/sysdev/xive/common.c +1 -1
index 9138250..8f5e303 100644
@@ -297,7 +297,7 @@ void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
 {
 	/* If the XIVE supports the new "store EOI facility, use it */
 	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
-		out_be64(xd->eoi_mmio, 0);
+		out_be64(xd->eoi_mmio + XIVE_ESB_STORE_EOI, 0);
 	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
 		/*
 		 * The FW told us to call it. This happens for some