[GIT PULL 2/3] intel_th: Fix resource handling for ACPI glue layer

[Alexander Shishkin]

The core of the driver expects the resource array from the glue layer
to be indexed by even numbers, as is the case for 64-bit PCI resources.
This doesn't hold true for others, ACPI in this instance, which leads
to an out-of-bounds access and an ioremap() on whatever address that
access fetches.

This patch fixes the problem by reading resource array differently based
on whether the 64-bit flag is set, which would indicate PCI glue layer.

Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Fixes: ebc57e399b8e ("intel_th: Add ACPI glue layer")
CC: stable@xxxxxxxxxxxxxxx # v4.17+
---
 drivers/hwtracing/intel_th/core.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 4e70ecee2103..fc6b7f8b62fb 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -488,7 +488,7 @@ static const struct intel_th_subdevice {
 				.flags	= IORESOURCE_MEM,
 			},
 			{
-				.start	= TH_MMIO_SW,
+				.start	= 1, /* use resource[1] */
 				.end	= 0,
 				.flags	= IORESOURCE_MEM,
 			},
@@ -581,6 +581,7 @@ intel_th_subdevice_alloc(struct intel_th *th,
 	struct intel_th_device *thdev;
 	struct resource res[3];
 	unsigned int req = 0;
+	bool is64bit = false;
 	int r, err;
 
 	thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
@@ -590,12 +591,18 @@ intel_th_subdevice_alloc(struct intel_th *th,
 
 	thdev->drvdata = th->drvdata;
 
+	for (r = 0; r < th->num_resources; r++)
+		if (th->resource[r].flags & IORESOURCE_MEM_64) {
+			is64bit = true;
+			break;
+		}
+
 	memcpy(res, subdev->res,
 	       sizeof(struct resource) * subdev->nres);
 
 	for (r = 0; r < subdev->nres; r++) {
 		struct resource *devres = th->resource;
-		int bar = TH_MMIO_CONFIG;
+		int bar = 0; /* cut subdevices' MMIO from resource[0] */
 
 		/*
 		 * Take .end == 0 to mean 'take the whole bar',
@@ -604,6 +611,8 @@ intel_th_subdevice_alloc(struct intel_th *th,
 		 */
 		if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
 			bar = res[r].start;
+			if (is64bit)
+				bar *= 2;
 			res[r].start = 0;
 			res[r].end = resource_size(&devres[bar]) - 1;
 		}
-- 
2.18.0