[Skiboot] [PATCH v2] phb4: set TVT1 for tunneled operations in capi mode

[Philippe Bergheaud]

The ASN indication is used for tunneled operations (as_notify and
atomics). Tunneled operation messages can be sent in PCI mode as
well as CAPI mode.

The address field of as_notify messages is hijacked to encode the
LPID/PID/TID of the target thread, so those messages should not go
through address translation. Therefore bit 59 is part of the ASN
indication.

This patch sets TVT#1 in bypass mode when capi mode is enabled,
to prevent as_notify messages from being dropped.

Signed-off-by: Philippe Bergheaud <felix at linux.ibm.com>
---
Changelog:

v2: Describe problem and solution in the commit message
---
 hw/phb4.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/hw/phb4.c b/hw/phb4.c
index 7ef6f3d4..df76d96a 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -150,11 +150,6 @@ static bool pci_tracing;
 static bool pci_eeh_mmio;
 static bool pci_retry_all;
 
-enum capi_dma_tvt {
-	CAPI_DMA_TVT0,
-	CAPI_DMA_TVT1,
-};
-
 /* Note: The "ASB" name is historical, practically this means access via
  * the XSCOM backdoor
  */
@@ -3825,7 +3820,6 @@ static void phb4_init_capp_errors(struct phb4 *p)
  *             = 000000C0 for Stack2
  */
 static int64_t enable_capi_mode(struct phb4 *p, uint64_t pe_number,
-				enum capi_dma_tvt dma_tvt,
 				uint32_t capp_eng)
 {
 	uint64_t reg, start_addr, end_addr, stq_eng, dma_eng;
@@ -3944,13 +3938,11 @@ static int64_t enable_capi_mode(struct phb4 *p, uint64_t pe_number,
 	p->tve_cache[pe_number * 2] =
 		tve_encode_50b_noxlate(start_addr, end_addr);
 
-	/* TVT#1: DMA, all memory, in bypass mode */
-	if (dma_tvt == CAPI_DMA_TVT1) {
-		start_addr = (1ull << 59);
-		end_addr   = start_addr + 0x0003ffffffffffffull;
-		p->tve_cache[pe_number * 2 + 1] =
-			tve_encode_50b_noxlate(start_addr, end_addr);
-	}
+	/* TVT#1: CAPI window + DMA, all memory, in bypass mode */
+	start_addr = (1ull << 59);
+	end_addr   = start_addr + 0x0003ffffffffffffull;
+	p->tve_cache[pe_number * 2 + 1] =
+		tve_encode_50b_noxlate(start_addr, end_addr);
 
 	phb4_ioda_sel(p, IODA3_TBL_TVT, 0, true);
 	for (i = 0; i < p->tvt_size; i++)
@@ -4038,13 +4030,13 @@ static int64_t phb4_set_capi_mode(struct phb *phb, uint64_t mode,
 
 	switch (mode) {
 	case OPAL_PHB_CAPI_MODE_CAPI:
-		ret = enable_capi_mode(p, pe_number, CAPI_DMA_TVT0,
+		ret = enable_capi_mode(p, pe_number,
 					CAPP_MAX_STQ_ENGINES |
 					CAPP_MIN_DMA_READ_ENGINES);
 		disable_fast_reboot("CAPP being enabled");
 		break;
 	case OPAL_PHB_CAPI_MODE_DMA_TVT1:
-		ret = enable_capi_mode(p, pe_number, CAPI_DMA_TVT1,
+		ret = enable_capi_mode(p, pe_number,
 					CAPP_MIN_STQ_ENGINES |
 					CAPP_MAX_DMA_READ_ENGINES);
 		disable_fast_reboot("CAPP being enabled");
-- 
2.16.2