[igt-dev] [PATCH i-g-t 3/4] tools/intel_reg: Add support for register access via the MCHBAR mirror

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Remembering the MCHBAR mirror offset is too much work. Make the tool
remember it for me.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 tools/intel_reg.c      | 17 +++++++++++++++++
 tools/intel_reg_spec.c | 15 +++++++++++++++
 tools/intel_reg_spec.h |  4 ++++
 3 files changed, 36 insertions(+)

diff --git a/tools/intel_reg.c b/tools/intel_reg.c
index 7f8ddbd8e927..69af0f5a19ff 100644
--- a/tools/intel_reg.c
+++ b/tools/intel_reg.c
@@ -185,6 +185,9 @@ static bool port_is_mmio(enum port_addr port)
 	case PORT_MMIO_32:
 	case PORT_MMIO_16:
 	case PORT_MMIO_8:
+	case PORT_MCHBAR_32:
+	case PORT_MCHBAR_16:
+	case PORT_MCHBAR_8:
 		return true;
 	default:
 		return false;
@@ -366,20 +369,34 @@ static int register_srm(struct config *config, struct reg *reg,
 	return val;
 }
 
+static uint32_t mcbar_offset(uint32_t devid)
+{
+	return intel_gen(devid) >= 6 ? 0x140000 : 0x10000;
+}
+
 static int read_register(struct config *config, struct reg *reg, uint32_t *valp)
 {
 	uint32_t val = 0;
 
 	switch (reg->port_desc.port) {
+	case PORT_MCHBAR_32:
+		reg->mmio_offset = mcbar_offset(config->devid);
+		/* fall through */
 	case PORT_MMIO_32:
 		if (reg->engine)
 			val = register_srm(config, reg, NULL);
 		else
 			val = INREG(reg->mmio_offset + reg->addr);
 		break;
+	case PORT_MCHBAR_16:
+		reg->mmio_offset = mcbar_offset(config->devid);
+		/* fall through */
 	case PORT_MMIO_16:
 		val = INREG16(reg->mmio_offset + reg->addr);
 		break;
+	case PORT_MCHBAR_8:
+		reg->mmio_offset = mcbar_offset(config->devid);
+		/* fall through */
 	case PORT_MMIO_8:
 		val = INREG8(reg->mmio_offset + reg->addr);
 		break;
diff --git a/tools/intel_reg_spec.c b/tools/intel_reg_spec.c
index 7c1c6ed34a9e..dadd844730f0 100644
--- a/tools/intel_reg_spec.c
+++ b/tools/intel_reg_spec.c
@@ -48,6 +48,21 @@ static const struct port_desc port_descs[] = {
 		.port = PORT_MMIO_8,
 		.stride = 1,
 	},
+	{
+		.name = "mchbar",
+		.port = PORT_MCHBAR_32,
+		.stride = 4,
+	},
+	{
+		.name = "mchbar16",
+		.port = PORT_MCHBAR_16,
+		.stride = 2,
+	},
+	{
+		.name = "mchbar8",
+		.port = PORT_MCHBAR_8,
+		.stride = 1,
+	},
 	{
 		.name = "portio",
 		.port = PORT_PORTIO,
diff --git a/tools/intel_reg_spec.h b/tools/intel_reg_spec.h
index 29f4d9ae2a47..fc27a9a62f6f 100644
--- a/tools/intel_reg_spec.h
+++ b/tools/intel_reg_spec.h
@@ -29,6 +29,10 @@ enum port_addr {
 	PORT_MMIO_16,
 	PORT_MMIO_8,
 
+	PORT_MCHBAR_32,
+	PORT_MCHBAR_16,
+	PORT_MCHBAR_8,
+
 	PORT_PORTIO,
 
 	PORT_NONE = 0,
-- 
2.24.1