[PATCH 4.4 20/74] iommu/amd: Fix boot warning when device 00:00.0 is not iommu covered

Greg Kroah-Hartman
2016-03-08T00:12:04Z

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

commit 38e45d02ea9f194b89d6bf41e52ccafc8e2c2b47 upstream.

The setup code for the performance counters in the AMD IOMMU driver
tests whether the counters can be written. It tests to setup a counter
for device 00:00.0, which fails on systems where this particular device
is not covered by the IOMMU.

Fix this by not relying on device 00:00.0 but only on the IOMMU being
present.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iommu/amd_iommu_init.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)

--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -228,6 +228,10 @@ static int amd_iommu_enable_interrupts(v
static int __init iommu_go_to_state(enum iommu_init_state state);
static void init_device_table_dma(void);

+static int iommu_pc_get_set_reg_val(struct amd_iommu *iommu,
+ u8 bank, u8 cntr, u8 fxn,
+ u64 *value, bool is_write);
+
static inline void update_last_devid(u16 devid)
{
if (devid > amd_iommu_last_bdf)
@@ -1170,8 +1174,8 @@ static void init_iommu_perf_ctr(struct a
amd_iommu_pc_present = true;

/* Check if the performance counters can be written to */
- if ((0 != amd_iommu_pc_get_set_reg_val(0, 0, 0, 0, &val, true)) ||
- (0 != amd_iommu_pc_get_set_reg_val(0, 0, 0, 0, &val2, false)) ||
+ if ((0 != iommu_pc_get_set_reg_val(iommu, 0, 0, 0, &val, true)) ||
+ (0 != iommu_pc_get_set_reg_val(iommu, 0, 0, 0, &val2, false)) ||
(val != val2)) {
pr_err("AMD-Vi: Unable to write to IOMMU perf counter.\n");
amd_iommu_pc_present = false;
@@ -2312,22 +2316,15 @@ u8 amd_iommu_pc_get_max_counters(u16 dev
}
EXPORT_SYMBOL(amd_iommu_pc_get_max_counters);

-int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
+static int iommu_pc_get_set_reg_val(struct amd_iommu *iommu,
+ u8 bank, u8 cntr, u8 fxn,
u64 *value, bool is_write)
{
- struct amd_iommu *iommu;
u32 offset;
u32 max_offset_lim;

- /* Make sure the IOMMU PC resource is available */
- if (!amd_iommu_pc_present)
- return -ENODEV;
-
- /* Locate the iommu associated with the device ID */
- iommu = amd_iommu_rlookup_table[devid];
-
/* Check for valid iommu and pc register indexing */
- if (WARN_ON((iommu == NULL) || (fxn > 0x28) || (fxn & 7)))
+ if (WARN_ON((fxn > 0x28) || (fxn & 7)))
return -ENODEV;

offset = (u32)(((0x40|bank) << 12) | (cntr << 8) | fxn);
@@ -2351,3 +2348,16 @@ int amd_iommu_pc_get_set_reg_val(u16 dev
return 0;
}
EXPORT_SYMBOL(amd_iommu_pc_get_set_reg_val);
+
+int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
+ u64 *value, bool is_write)
+{
+ struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
+
+ /* Make sure the IOMMU PC resource is available */
+ if (!amd_iommu_pc_present || iommu == NULL)
+ return -ENODEV;
+
+ return iommu_pc_get_set_reg_val(iommu, bank, cntr, fxn,
+ value, is_write);
+}