@@ -1673,6 +1673,12 @@
In such case C2/C3 won't be used again.
idle=nomwait: Disable mwait for CPU C-states
+ idxd.sva= [HW]
+ Format: <bool>
+ Allow force disabling of Shared Virtual Memory (SVA)
+ support for the idxd driver. By default it is set to
+ true (1).
+
ieee754= [MIPS] Select IEEE Std 754 conformance mode
Format: { strict | legacy | 2008 | relaxed }
Default: strict
@@ -26,6 +26,10 @@ MODULE_VERSION(IDXD_DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Intel Corporation");
+static bool sva = true;
+module_param(sva, bool, 0644);
+MODULE_PARM_DESC(sva, "Toggle SVA support on/off");
+
#define DRV_NAME "idxd"
bool support_enqcmd;
@@ -338,12 +342,14 @@ static int idxd_probe(struct idxd_device *idxd)
idxd_device_init_reset(idxd);
dev_dbg(dev, "IDXD reset complete\n");
- if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM)) {
+ if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
rc = idxd_enable_system_pasid(idxd);
if (rc < 0)
dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
else
set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
+ } else if (!sva) {
+ dev_warn(dev, "User forced SVA off via module param.\n");
}
idxd_read_caps(idxd);
Add a module parameter that overrides the SVA feature enabling. This keeps the driver in legacy mode even when intel_iommu=sm_on is set. In this mode, the descriptor fields must be programmed with dma_addr_t from the Linux DMA API for source, destination, and completion descriptors. Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- v2: - Add documentation (Vinod) Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ drivers/dma/idxd/init.c | 8 +++++++- 2 files changed, 13 insertions(+), 1 deletion(-)