[PATCH 1/2] IOMMU/AMD: Adding IOMMU PC resource management

From: steven.kinney
Date: Mon May 13 2013 - 17:44:13 EST


From: Steven L Kinney <Steven.Kinney@xxxxxxx>

Add functionality to check the availability of the AMD IOMMU Performance
Counters and export this functionality to other core drivers, such as in this
case, a perf AMD IOMMU PMU. This feature is not bound to any specific AMD
family/model other than the presence of the IOMMU with PC enabled.

The AMD IOMMU PC support static counting only at this time.

Signed-off-by: Steven Kinney <steven.kinney@xxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 116 ++++++++++++++++++++++++++++++++++++++-
drivers/iommu/amd_iommu_proto.h | 7 +++
drivers/iommu/amd_iommu_types.h | 12 +++-
3 files changed, 129 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index bf51abb..ef1c3c8 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -154,6 +154,7 @@ bool amd_iommu_iotlb_sup __read_mostly = true;
u32 amd_iommu_max_pasids __read_mostly = ~0;

bool amd_iommu_v2_present __read_mostly;
+bool amd_iommu_pc_present __read_mostly;

bool amd_iommu_force_isolation __read_mostly;

@@ -371,21 +372,21 @@ static void iommu_disable(struct amd_iommu *iommu)
*/
static u8 __iomem * __init iommu_map_mmio_space(u64 address)
{
- if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu")) {
+ if (!request_mem_region(address, MMIO_REG_END_OFFSET, "amd_iommu")) {
pr_err("AMD-Vi: Can not reserve memory region %llx for mmio\n",
address);
pr_err("AMD-Vi: This is a BIOS bug. Please contact your hardware vendor\n");
return NULL;
}

- return (u8 __iomem *)ioremap_nocache(address, MMIO_REGION_LENGTH);
+ return (u8 __iomem *)ioremap_nocache(address, MMIO_REG_END_OFFSET);
}

static void __init iommu_unmap_mmio_space(struct amd_iommu *iommu)
{
if (iommu->mmio_base)
iounmap(iommu->mmio_base);
- release_mem_region(iommu->mmio_phys, MMIO_REGION_LENGTH);
+ release_mem_region(iommu->mmio_phys, MMIO_REG_END_OFFSET);
}

/****************************************************************************
@@ -1160,6 +1161,32 @@ static int __init init_iommu_all(struct acpi_table_header *table)
return 0;
}

+
+static void init_iommu_perf_ctr(struct amd_iommu *iommu)
+{
+ u32 val = 0xabcd, val2 = 0;
+
+ if (!iommu_feature(iommu, FEATURE_PC))
+ return;
+
+ 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)) ||
+ (val != val2)) {
+ pr_err("AMD-Vi: Unable to write to IOMMU perf counter.\n");
+ return;
+ }
+
+ pr_info("AMD-Vi: IOMMU performance counters " "supported\n");
+
+ val = readl(iommu->mmio_base + MMIO_CNTR_CONF_OFFSET);
+ iommu->max_banks = (u8) ((val >> 12) & 0x3f);
+ iommu->max_counters = (u8) ((val >> 7) & 0xf);
+}
+
+
static int iommu_init_pci(struct amd_iommu *iommu)
{
int cap_ptr = iommu->cap_ptr;
@@ -1226,6 +1253,8 @@ static int iommu_init_pci(struct amd_iommu *iommu)
if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE))
amd_iommu_np_cache = true;

+ init_iommu_perf_ctr(iommu);
+
if (is_rd890_iommu(iommu->dev)) {
int i, j;

@@ -2232,3 +2261,84 @@ bool amd_iommu_v2_supported(void)
return amd_iommu_v2_present;
}
EXPORT_SYMBOL(amd_iommu_v2_supported);
+
+/****************************************************************************
+ *
+ * IOMMU EFR Performance Counter support functionality. This code allows
+ * access to the IOMMU PC functionality.
+ *
+ ****************************************************************************/
+
+u8 amd_iommu_pc_get_max_banks(u16 devid)
+{
+ struct amd_iommu *iommu;
+
+ /* locate the iommu governing the devid */
+ iommu = amd_iommu_rlookup_table[devid];
+
+ if (iommu)
+ return iommu->max_banks;
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL(amd_iommu_pc_get_max_banks);
+
+bool amd_iommu_pc_supported(void)
+{
+ return amd_iommu_pc_present;
+}
+EXPORT_SYMBOL(amd_iommu_pc_supported);
+
+u8 amd_iommu_pc_get_max_counters(u16 devid)
+{
+ struct amd_iommu *iommu;
+
+ /* locate the iommu governing the devid */
+ iommu = amd_iommu_rlookup_table[devid];
+
+ if (iommu)
+ return iommu->max_counters;
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL(amd_iommu_pc_get_max_counters);
+
+int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
+ u32 *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) {
+ pr_info("AMD IOMMU - PC Not supported in amd_iommu_pc_get_set_reg_val\n");
+ return -ENODEV;
+ }
+
+ /* locate the iommu associated with the device ID */
+ iommu = amd_iommu_rlookup_table[devid];
+ if (iommu == NULL)
+ return -ENODEV;
+
+ /* check for valid iommu pc register indexing */
+ if (fxn < 0 || fxn > 0x28 || (fxn & 7))
+ return -ENODEV;
+
+ offset = (u32)(((0x40|bank) << 12) | (cntr << 8) | fxn);
+
+ /* limit the offset to the hw defined mmio region aperture */
+ max_offset_lim = (u32)(((0x40|iommu->max_banks) << 12) |
+ (iommu->max_counters << 8) | 0x28);
+ if ((offset < MMIO_CNTR_REG_OFFSET) ||
+ (offset > max_offset_lim))
+ return -EINVAL;
+
+ if (is_write)
+ writel(*value, iommu->mmio_base + offset);
+ else
+ *value = readl(iommu->mmio_base + offset);
+
+ return 0;
+}
+EXPORT_SYMBOL(amd_iommu_pc_get_set_reg_val);
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index c294961..8523c09 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -56,6 +56,13 @@ extern int amd_iommu_domain_set_gcr3(struct iommu_domain *dom, int pasid,
extern int amd_iommu_domain_clear_gcr3(struct iommu_domain *dom, int pasid);
extern struct iommu_domain *amd_iommu_get_v2_domain(struct pci_dev *pdev);

+/* IOMMU Performance Counter functions */
+extern bool amd_iommu_pc_supported(void);
+extern u8 amd_iommu_pc_get_max_banks(u16 devid);
+extern u8 amd_iommu_pc_get_max_counters(u16 devid);
+extern int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
+ u32 *value, bool is_write);
+
#define PPR_SUCCESS 0x0
#define PPR_INVALID 0x1
#define PPR_FAILURE 0xf
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 0285a21..a95f0ae 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -38,9 +38,6 @@
#define ALIAS_TABLE_ENTRY_SIZE 2
#define RLOOKUP_TABLE_ENTRY_SIZE (sizeof(void *))

-/* Length of the MMIO region for the AMD IOMMU */
-#define MMIO_REGION_LENGTH 0x4000
-
/* Capability offsets used by the driver */
#define MMIO_CAP_HDR_OFFSET 0x00
#define MMIO_RANGE_OFFSET 0x0c
@@ -78,6 +75,10 @@
#define MMIO_STATUS_OFFSET 0x2020
#define MMIO_PPR_HEAD_OFFSET 0x2030
#define MMIO_PPR_TAIL_OFFSET 0x2038
+#define MMIO_CNTR_CONF_OFFSET 0x4000
+#define MMIO_CNTR_REG_OFFSET 0x40000
+#define MMIO_REG_END_OFFSET 0x80000
+


/* Extended Feature Bits */
@@ -507,6 +508,7 @@ struct amd_iommu {

/* physical address of MMIO space */
u64 mmio_phys;
+
/* virtual address of MMIO space */
u8 __iomem *mmio_base;

@@ -584,6 +586,10 @@ struct amd_iommu {

/* The l2 indirect registers */
u32 stored_l2[0x83];
+
+ /* The maximum PC banks and counters/bank (PCSup=1) */
+ u8 max_banks;
+ u8 max_counters;
};

struct devid_map {
--
1.7.10.4


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/