[PATCH v3 19/29] iommu/arm-smmu-v3-kvm: Initialize registers

[Mostafa Saleh]

From: Jean-Philippe Brucker <jean-philippe at linaro.org>

Ensure all writable registers are properly initialized. We do not touch
registers that will not be read by the SMMU due to disabled features.

Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
Signed-off-by: Mostafa Saleh <smostafa at google.com>
---
 .../iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c  | 149 +++++++++++++++++-
 .../iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h  |  12 ++
 2 files changed, 160 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
index 2f43804e08e0..e9bc35e019b6 100644
--- a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
@@ -7,15 +7,162 @@
 #include <asm/kvm_hyp.h>
 
 #include <nvhe/iommu.h>
+#include <nvhe/mem_protect.h>
 
 #include "arm_smmu_v3.h"
 
+#define ARM_SMMU_POLL_TIMEOUT_US	100000 /* 100ms arbitrary timeout */
+
 size_t __ro_after_init kvm_hyp_arm_smmu_v3_count;
 struct hyp_arm_smmu_v3_device *kvm_hyp_arm_smmu_v3_smmus;
 
+#define for_each_smmu(smmu) \
+	for ((smmu) = kvm_hyp_arm_smmu_v3_smmus; \
+	     (smmu) != &kvm_hyp_arm_smmu_v3_smmus[kvm_hyp_arm_smmu_v3_count]; \
+	     (smmu)++)
+
+/*
+ * Wait until @cond is true.
+ * Return 0 on success, or -ETIMEDOUT
+ */
+#define smmu_wait(_cond)					\
+({								\
+	int __ret = 0;						\
+	u64 delay = pkvm_time_get() + ARM_SMMU_POLL_TIMEOUT_US;	\
+								\
+	while (!(_cond)) {					\
+		if (pkvm_time_get() >= delay) {			\
+			__ret = -ETIMEDOUT;			\
+			break;					\
+		}						\
+	}							\
+	__ret;							\
+})
+
+static int smmu_write_cr0(struct hyp_arm_smmu_v3_device *smmu, u32 val)
+{
+	writel_relaxed(val, smmu->base + ARM_SMMU_CR0);
+	return smmu_wait(readl_relaxed(smmu->base + ARM_SMMU_CR0ACK) == val);
+}
+
+/* Transfer ownership of structures from host to hyp */
+static int smmu_take_pages(u64 phys, size_t size)
+{
+	WARN_ON(!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size));
+	return __pkvm_host_donate_hyp(phys >> PAGE_SHIFT, size >> PAGE_SHIFT);
+}
+
+static void smmu_reclaim_pages(u64 phys, size_t size)
+{
+	WARN_ON(!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size));
+	WARN_ON(__pkvm_hyp_donate_host(phys >> PAGE_SHIFT, size >> PAGE_SHIFT));
+}
+
+static int smmu_init_registers(struct hyp_arm_smmu_v3_device *smmu)
+{
+	u64 val, old;
+	int ret;
+
+	if (!(readl_relaxed(smmu->base + ARM_SMMU_GBPA) & GBPA_ABORT))
+		return -EINVAL;
+
+	/* Initialize all RW registers that will be read by the SMMU */
+	ret = smmu_write_cr0(smmu, 0);
+	if (ret)
+		return ret;
+
+	val = FIELD_PREP(CR1_TABLE_SH, ARM_SMMU_SH_ISH) |
+	      FIELD_PREP(CR1_TABLE_OC, CR1_CACHE_WB) |
+	      FIELD_PREP(CR1_TABLE_IC, CR1_CACHE_WB) |
+	      FIELD_PREP(CR1_QUEUE_SH, ARM_SMMU_SH_ISH) |
+	      FIELD_PREP(CR1_QUEUE_OC, CR1_CACHE_WB) |
+	      FIELD_PREP(CR1_QUEUE_IC, CR1_CACHE_WB);
+	writel_relaxed(val, smmu->base + ARM_SMMU_CR1);
+	writel_relaxed(CR2_PTM, smmu->base + ARM_SMMU_CR2);
+	writel_relaxed(0, smmu->base + ARM_SMMU_IRQ_CTRL);
+
+	val = readl_relaxed(smmu->base + ARM_SMMU_GERROR);
+	old = readl_relaxed(smmu->base + ARM_SMMU_GERRORN);
+	/* Service Failure Mode is fatal */
+	if ((val ^ old) & GERROR_SFM_ERR)
+		return -EIO;
+	/* Clear pending errors */
+	writel_relaxed(val, smmu->base + ARM_SMMU_GERRORN);
+
+	return 0;
+}
+
+/* Put the device in a state that can be probed by the host driver. */
+static void smmu_deinit_device(struct hyp_arm_smmu_v3_device *smmu)
+{
+	int i;
+	size_t nr_pages = smmu->mmio_size >> PAGE_SHIFT;
+
+	for (i = 0 ; i < nr_pages ; ++i) {
+		u64 pfn = (smmu->mmio_addr >> PAGE_SHIFT) + i;
+
+		WARN_ON(__pkvm_hyp_donate_host_mmio(pfn));
+	}
+}
+
+static int smmu_init_device(struct hyp_arm_smmu_v3_device *smmu)
+{
+	int i;
+	size_t nr_pages;
+	int ret;
+
+	if (!PAGE_ALIGNED(smmu->mmio_addr | smmu->mmio_size))
+		return -EINVAL;
+
+	nr_pages = smmu->mmio_size >> PAGE_SHIFT;
+	for (i = 0 ; i < nr_pages ; ++i) {
+		u64 pfn = (smmu->mmio_addr >> PAGE_SHIFT) + i;
+
+		/*
+		 * This should never happen, so it's fine to be strict to avoid
+		 * complicated error handling.
+		 */
+		WARN_ON(__pkvm_host_donate_hyp_mmio(pfn));
+	}
+	smmu->base = hyp_phys_to_virt(smmu->mmio_addr);
+
+	ret = smmu_init_registers(smmu);
+	if (ret)
+		goto out_err;
+	return ret;
+
+out_err:
+	smmu_deinit_device(smmu);
+	return ret;
+}
+
 static int smmu_init(void)
 {
-	return -ENOSYS;
+	int ret;
+	struct hyp_arm_smmu_v3_device *smmu;
+	size_t smmu_arr_size = PAGE_ALIGN(sizeof(*kvm_hyp_arm_smmu_v3_smmus) *
+					  kvm_hyp_arm_smmu_v3_count);
+	phys_addr_t smmu_arr_phys;
+
+	kvm_hyp_arm_smmu_v3_smmus = kern_hyp_va(kvm_hyp_arm_smmu_v3_smmus);
+	smmu_arr_phys = hyp_virt_to_phys(kvm_hyp_arm_smmu_v3_smmus);
+
+	ret = smmu_take_pages(smmu_arr_phys, smmu_arr_size);
+	if (ret)
+		return ret;
+
+	for_each_smmu(smmu) {
+		ret = smmu_init_device(smmu);
+		if (ret)
+			goto out_reclaim_smmu;
+	}
+
+	return 0;
+out_reclaim_smmu:
+	while (smmu != kvm_hyp_arm_smmu_v3_smmus)
+		smmu_deinit_device(--smmu);
+	smmu_reclaim_pages(smmu_arr_phys, smmu_arr_size);
+	return ret;
 }
 
 /* Shared with the kernel driver in EL1 */
diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
index f6ad91d3fb85..9b1d021ada63 100644
--- a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
@@ -4,7 +4,19 @@
 
 #include <asm/kvm_asm.h>
 
+#include "../arm-smmu-v3-common.h"
+
+/*
+ * Parameters from the trusted host:
+ * @mmio_addr		base address of the SMMU registers
+ * @mmio_size		size of the registers resource
+ * @base		Virtual address of SMMU registers
+ * Other members are filled and used at runtime by the SMMU driver.
+ */
 struct hyp_arm_smmu_v3_device {
+	phys_addr_t		mmio_addr;
+	size_t			mmio_size;
+	void __iomem		*base;
 };
 
 extern size_t kvm_nvhe_sym(kvm_hyp_arm_smmu_v3_count);
-- 
2.50.1.552.g942d659e1b-goog