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Message-Id: <20230118205006.3182907-4-kan.liang@linux.intel.com>
Date: Wed, 18 Jan 2023 12:50:02 -0800
From: kan.liang@...ux.intel.com
To: joro@...tes.org, will@...nel.org, baolu.lu@...ux.intel.com,
dwmw2@...radead.org, robin.murphy@....com, robert.moore@...el.com,
rafael.j.wysocki@...el.com, lenb@...nel.org, iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org
Cc: Kan Liang <kan.liang@...ux.intel.com>
Subject: [PATCH V2 3/7] iommu/vt-d: Support Enhanced Command Interface
From: Kan Liang <kan.liang@...ux.intel.com>
The Enhanced Command Register is to submit command and operand of
enhanced commands to DMA Remapping hardware. It can supports upto 256
enhanced commands.
There is a HW register to indicate the availability of all 256 enhanced
commands. Each bit stands for each command. But there isn't an existing
interface to read/write all 256 bits. Introduce the u64 ecmdcap[4] to
store the existence of each enhanced command. Read 4 times to get
all of them in map_iommu().
Add a helper to facilitate an enhanced command launch. Make sure hardware
complete the command.
Add a helper to facilitate the check of PMU essentials.
The helpers will be used later.
Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
---
drivers/iommu/intel/dmar.c | 68 +++++++++++++++++++++++++++++++++++++
drivers/iommu/intel/iommu.h | 34 +++++++++++++++++++
2 files changed, 102 insertions(+)
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index 7a03cadb13ff..0f3401428d0e 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1017,6 +1017,16 @@ static int map_iommu(struct intel_iommu *iommu, struct dmar_drhd_unit *drhd)
goto release;
}
}
+
+ if (cap_ecmds(iommu->cap)) {
+ int i;
+
+ for (i = 0; i < DMA_MAX_NUM_ECMDCAP; i++) {
+ iommu->ecmdcap[i] = dmar_readq(iommu->reg + DMAR_ECCAP_REG +
+ i * DMA_ECMD_REG_STEP);
+ }
+ }
+
err = 0;
goto out;
@@ -2426,3 +2436,61 @@ bool dmar_platform_optin(void)
return ret;
}
EXPORT_SYMBOL_GPL(dmar_platform_optin);
+
+#ifdef CONFIG_INTEL_IOMMU
+#define ecmd_get_status_code(res) ((res & 0xff) >> 1)
+
+/*
+ * Function to submit a command to the enhanced command interface. The
+ * valid enhanced command descriptions are defined in Table 47 of the
+ * VT-d spec. The VT-d hardware implementation may support some but not
+ * all commands, which can be determined by checking the Enhanced
+ * Command Capability Register.
+ *
+ * Return values:
+ * - 0: Command successful without any error;
+ * - Negative: software error value;
+ * - Nonzero positive: failure status code defined in Table 48.
+ */
+int ecmd_submit_sync(struct intel_iommu *iommu, u8 ecmd, u64 oa, u64 ob)
+{
+ unsigned long flags;
+ u64 res;
+ int ret;
+
+ if (!cap_ecmds(iommu->cap))
+ return -ENODEV;
+
+ raw_spin_lock_irqsave(&iommu->register_lock, flags);
+
+ res = dmar_readq(iommu->reg + DMAR_ECRSP_REG);
+ if (res & DMA_ECMD_ECRSP_IP) {
+ ret = -EBUSY;
+ goto err;
+ }
+
+ /*
+ * Unconditionally write the operand B, because
+ * - There is no side effect if an ecmd doesn't require an
+ * operand B, but we set the register to some value.
+ * - It's not invoked in any critical path. The extra MMIO
+ * write doesn't bring any performance concerns.
+ */
+ dmar_writeq(iommu->reg + DMAR_ECEO_REG, ob);
+ dmar_writeq(iommu->reg + DMAR_ECMD_REG, ecmd | (oa << DMA_ECMD_OA_SHIFT));
+
+ IOMMU_WAIT_OP(iommu, DMAR_ECRSP_REG, dmar_readq,
+ !(res & DMA_ECMD_ECRSP_IP), res);
+
+ if (res & DMA_ECMD_ECRSP_IP) {
+ ret = -ETIMEDOUT;
+ goto err;
+ }
+
+ ret = ecmd_get_status_code(res);
+err:
+ raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
+
+ return ret;
+}
+#endif /* CONFIG_INTEL_IOMMU */
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 5bcefbea55c9..c25a574680ce 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -130,6 +130,10 @@
#define DMAR_PERFOVFOFF_REG 0x318
#define DMAR_PERFCNTROFF_REG 0x31c
#define DMAR_PERFEVNTCAP_REG 0x380
+#define DMAR_ECMD_REG 0x400
+#define DMAR_ECEO_REG 0x408
+#define DMAR_ECRSP_REG 0x410
+#define DMAR_ECCAP_REG 0x430
#define DMAR_VCCAP_REG 0xe30 /* Virtual command capability register */
#define DMAR_VCMD_REG 0xe00 /* Virtual command register */
#define DMAR_VCRSP_REG 0xe10 /* Virtual command response register */
@@ -304,6 +308,26 @@
#define DMA_CCMD_SID(s) (((u64)((s) & 0xffff)) << 16)
#define DMA_CCMD_DID(d) ((u64)((d) & 0xffff))
+/* ECMD_REG */
+#define DMA_MAX_NUM_ECMD 256
+#define DMA_MAX_NUM_ECMDCAP (DMA_MAX_NUM_ECMD / 64)
+#define DMA_ECMD_REG_STEP 8
+#define DMA_ECMD_ENABLE 0xf0
+#define DMA_ECMD_DISABLE 0xf1
+#define DMA_ECMD_FREEZE 0xf4
+#define DMA_ECMD_UNFREEZE 0xf5
+#define DMA_ECMD_OA_SHIFT 16
+#define DMA_ECMD_ECRSP_IP 0x1
+#define DMA_ECMD_ECCAP3 3
+#define DMA_ECMD_ECCAP3_ECNTS (1ULL << 48)
+#define DMA_ECMD_ECCAP3_DCNTS (1ULL << 49)
+#define DMA_ECMD_ECCAP3_FCNTS (1ULL << 52)
+#define DMA_ECMD_ECCAP3_UFCNTS (1ULL << 53)
+#define DMA_ECMD_ECCAP3_ESSENTIAL (DMA_ECMD_ECCAP3_ECNTS | \
+ DMA_ECMD_ECCAP3_DCNTS | \
+ DMA_ECMD_ECCAP3_FCNTS | \
+ DMA_ECMD_ECCAP3_UFCNTS)
+
/* FECTL_REG */
#define DMA_FECTL_IM (((u32)1) << 31)
@@ -600,6 +624,7 @@ struct intel_iommu {
u64 cap;
u64 ecap;
u64 vccap;
+ u64 ecmdcap[DMA_MAX_NUM_ECMDCAP];
u32 gcmd; /* Holds TE, EAFL. Don't need SRTP, SFL, WBF */
raw_spinlock_t register_lock; /* protect register handling */
int seq_id; /* sequence id of the iommu */
@@ -841,6 +866,15 @@ extern const struct iommu_ops intel_iommu_ops;
extern int intel_iommu_sm;
extern int iommu_calculate_agaw(struct intel_iommu *iommu);
extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu);
+extern int ecmd_submit_sync(struct intel_iommu *iommu, u8 ecmd,
+ u64 oa, u64 ob);
+
+static inline bool ecmd_has_pmu_essential(struct intel_iommu *iommu)
+{
+ return (iommu->ecmdcap[DMA_ECMD_ECCAP3] & DMA_ECMD_ECCAP3_ESSENTIAL) ==
+ DMA_ECMD_ECCAP3_ESSENTIAL;
+}
+
extern int dmar_disabled;
extern int intel_iommu_enabled;
#else
--
2.35.1
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