From 13aadde56e22c1e136e20cf00ff3b6eaf18b3b78 Mon Sep 17 00:00:00 2001
From: Amber Lin <Amber.Lin@amd.com>
Date: Thu, 22 Jun 2017 12:12:17 -0400
Subject: [PATCH] Use environment variable to force gfx version

For experimental purpose, we need an option to change compute capability
by forcing the GfxIp version. This patch allows to use environment
variable HSA_OVERRIDE_GFX_VERSION=major.minor.stepping to replace the
default version. For example:
export HSA_OVERRIDE_GFX_VERSION=9.0.1

Change-Id: I90cfbd43619d9d3aebf53321d4e058f01bcd7088
Signed-off-by: Amber Lin <Amber.Lin@amd.com>
---
 src/topology.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/topology.c b/src/topology.c
index 1f36a1cac5..2456a9c197 100644
--- a/src/topology.c
+++ b/src/topology.c
@@ -73,7 +73,6 @@ static const char *supported_processor_vendor_name[] = {
 
 static HSAKMT_STATUS topology_take_snapshot(void);
 static HSAKMT_STATUS topology_drop_snapshot(void);
-//static int get_cpu_stepping(uint16_t* stepping);
 
 static struct hsa_gfxip_table {
 	uint16_t device_id;		// Device ID
@@ -706,11 +705,11 @@ HSAKMT_STATUS topology_sysfs_get_node_props(uint32_t node_id,
 					    struct pci_access *pacc)
 {
 	FILE *fd;
-	char *read_buf, *p;
+	char *read_buf, *p, *envvar, dummy;
 	char prop_name[256];
 	char path[256];
 	unsigned long long prop_val;
-	uint32_t i, prog;
+	uint32_t i, prog, major, minor, step;
 	uint16_t fw_version = 0;
 	int read_size;
 	const struct hsa_gfxip_table *hsa_gfxip;
@@ -802,7 +801,6 @@ HSAKMT_STATUS topology_sysfs_get_node_props(uint32_t node_id,
 
 	}
 
-//	get_cpu_stepping(&stepping);
 	props->EngineId.ui32.uCode = fw_version & 0x3ff;
 	props->EngineId.ui32.Major = 0;
 	props->EngineId.ui32.Minor = 0;
@@ -810,9 +808,26 @@ HSAKMT_STATUS topology_sysfs_get_node_props(uint32_t node_id,
 
 	hsa_gfxip = find_hsa_gfxip_device(props->DeviceId);
 	if (hsa_gfxip) {
-		props->EngineId.ui32.Major = hsa_gfxip->major & 0x3f;
-		props->EngineId.ui32.Minor = hsa_gfxip->minor;
-		props->EngineId.ui32.Stepping = hsa_gfxip->stepping;
+		envvar = getenv("HSA_OVERRIDE_GFX_VERSION");
+		if (envvar) {
+			/* HSA_OVERRIDE_GFX_VERSION=major.minor.stepping */
+			if ((sscanf(envvar, "%u.%u.%u%c",
+					&major, &minor, &step, &dummy) != 3) ||
+				(major > 63 || minor > 255 || step > 255)) {
+				fprintf(stderr,
+					"HSA_OVERRIDE_GFX_VERSION %s is invalid\n",
+					envvar);
+				ret = HSAKMT_STATUS_ERROR;
+				goto err;
+			}
+			props->EngineId.ui32.Major = major & 0x3f;
+			props->EngineId.ui32.Minor = minor & 0xff;
+			props->EngineId.ui32.Stepping = step & 0xff;
+		} else {
+			props->EngineId.ui32.Major = hsa_gfxip->major & 0x3f;
+			props->EngineId.ui32.Minor = hsa_gfxip->minor;
+			props->EngineId.ui32.Stepping = hsa_gfxip->stepping;
+		}
 
 		if (!hsa_gfxip->amd_name) {
 			ret = HSAKMT_STATUS_ERROR;