[PATCH 3.12 14/58] iommu/amd: Fix boot warning when device 00:00.0 is not iommu covered

From: Jiri Slaby
Date: Wed Mar 16 2016 - 07:13:32 EST


From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

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@xxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 8f798be6e398..9afa397df661 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -227,6 +227,10 @@ static enum iommu_init_state init_state = IOMMU_START_STATE;
static int amd_iommu_enable_interrupts(void);
static int __init iommu_go_to_state(enum iommu_init_state state);

+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)
@@ -1183,8 +1187,8 @@ static void init_iommu_perf_ctr(struct amd_iommu *iommu)
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;
@@ -2315,22 +2319,15 @@ u8 amd_iommu_pc_get_max_counters(u16 devid)
}
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);
@@ -2354,3 +2351,16 @@ int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
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);
+}
--
2.7.3