[PATCH 2/2] iommu/amd: Refactor set_dte_entry to simplify GCR3 Table Root Pointer programming

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

Separate logic for setting DTE[GCR3 Table Root Pointer] into a helper
function set_dte_gcr3_table().

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/iommu.c | 121 +++++++++++++++++++++-----------------
 1 file changed, 68 insertions(+), 53 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4667b6c4906f..8fc496db5560 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1851,90 +1851,105 @@ int amd_iommu_clear_gcr3(struct iommu_dev_data *dev_data, ioasid_t pasid)
 	return ret;
 }
 
+static void set_dte_gcr3_table(struct amd_iommu *iommu,
+			       struct iommu_dev_data *dev_data,
+			       struct dev_table_entry *target)
+{
+	struct gcr3_tbl_info *gcr3_info = &dev_data->gcr3_info;
+	u64 tmp, gcr3;
+
+	if (!gcr3_info->gcr3_tbl)
+		return;
+
+	pr_debug("%s: devid=%#x, glx=%#x, giov=%#x, gcr3_tbl=%#llx\n",
+		 __func__, dev_data->devid, gcr3_info->glx, gcr3_info->giov,
+		 (unsigned long long)gcr3_info->gcr3_tbl);
+
+	tmp = gcr3_info->glx;
+	target->data[0] |= (tmp & DTE_GLX_MASK) << DTE_GLX_SHIFT;
+	if (gcr3_info->giov)
+		target->data[0] |= DTE_FLAG_GIOV;
+	target->data[0] |= DTE_FLAG_GV;
+
+	/* First mask out possible old values for GCR3 table */
+	tmp = DTE_GCR3_VAL_A(~0ULL) << DTE_GCR3_SHIFT_A;
+	target->data[0] &= ~tmp;
+	tmp = DTE_GCR3_VAL_B(~0ULL) << DTE_GCR3_SHIFT_B;
+	tmp |= DTE_GCR3_VAL_C(~0ULL) << DTE_GCR3_SHIFT_C;
+	target->data[1] &= ~tmp;
+
+	gcr3 = iommu_virt_to_phys(gcr3_info->gcr3_tbl);
+
+	/* Encode GCR3 table into DTE */
+	tmp = DTE_GCR3_VAL_A(gcr3) << DTE_GCR3_SHIFT_A;
+	target->data[0] |= tmp;
+	tmp = DTE_GCR3_VAL_B(gcr3) << DTE_GCR3_SHIFT_B;
+	tmp |= DTE_GCR3_VAL_C(gcr3) << DTE_GCR3_SHIFT_C;
+	target->data[1] |= tmp;
+
+	/* Use system default */
+	tmp = amd_iommu_gpt_level;
+
+	/* Mask out old values for GuestPagingMode */
+	target->data[2] &= ~(0x3ULL << DTE_GPT_LEVEL_SHIFT);
+	target->data[2] |= (tmp << DTE_GPT_LEVEL_SHIFT);
+}
+
 static void set_dte_entry(struct amd_iommu *iommu,
 			  struct iommu_dev_data *dev_data)
 {
-	u64 pte_root = 0;
-	u64 flags = 0;
-	u32 old_domid;
-	u16 devid = dev_data->devid;
 	u16 domid;
+	u16 devid = dev_data->devid;
 	struct protection_domain *domain = dev_data->domain;
+	struct dev_table_entry target = {.data = {0, 0, 0, 0}};
 	struct dev_table_entry *dev_table = get_dev_table(iommu);
 	struct gcr3_tbl_info *gcr3_info = &dev_data->gcr3_info;
+	u32 old_domid = dev_table[devid].data[1] & DEV_DOMID_MASK;
 
-	if (gcr3_info && gcr3_info->gcr3_tbl)
+	if (gcr3_info->gcr3_tbl)
 		domid = dev_data->gcr3_info.domid;
 	else
 		domid = domain->id;
 
+	/*
+	 * Need to get the current value in dte[1,2] because they contain
+	 * interrupt-remapping settings, which has been programmed earlier.
+	 */
+	target.data[1] = dev_table[devid].data[1];
+	target.data[2] = dev_table[devid].data[2];
+
 	if (domain->iop.mode != PAGE_MODE_NONE)
-		pte_root = iommu_virt_to_phys(domain->iop.root);
+		target.data[0] = iommu_virt_to_phys(domain->iop.root);
 
-	pte_root |= (domain->iop.mode & DEV_ENTRY_MODE_MASK)
+	target.data[0] |= (domain->iop.mode & DEV_ENTRY_MODE_MASK)
 		    << DEV_ENTRY_MODE_SHIFT;
 
-	pte_root |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V;
+	target.data[0] |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V;
 
 	/*
 	 * When SNP is enabled, Only set TV bit when IOMMU
 	 * page translation is in use.
 	 */
 	if (!amd_iommu_snp_en || (domid != 0))
-		pte_root |= DTE_FLAG_TV;
-
-	flags = dev_table[devid].data[1];
+		target.data[0] |= DTE_FLAG_TV;
 
 	if (dev_data->ats_enabled)
-		flags |= DTE_FLAG_IOTLB;
+		target.data[1] |= DTE_FLAG_IOTLB;
 
 	if (dev_data->ppr)
-		pte_root |= 1ULL << DEV_ENTRY_PPR;
+		target.data[0] |= 1ULL << DEV_ENTRY_PPR;
 
 	if (domain->dirty_tracking)
-		pte_root |= DTE_FLAG_HAD;
-
-	if (gcr3_info && gcr3_info->gcr3_tbl) {
-		u64 gcr3 = iommu_virt_to_phys(gcr3_info->gcr3_tbl);
-		u64 glx  = gcr3_info->glx;
-		u64 tmp;
-
-		pte_root |= DTE_FLAG_GV;
-		pte_root |= (glx & DTE_GLX_MASK) << DTE_GLX_SHIFT;
-
-		/* First mask out possible old values for GCR3 table */
-		tmp = DTE_GCR3_VAL_B(~0ULL) << DTE_GCR3_SHIFT_B;
-		flags    &= ~tmp;
+		target.data[0] |= DTE_FLAG_HAD;
 
-		tmp = DTE_GCR3_VAL_C(~0ULL) << DTE_GCR3_SHIFT_C;
-		flags    &= ~tmp;
-
-		/* Encode GCR3 table into DTE */
-		tmp = DTE_GCR3_VAL_A(gcr3) << DTE_GCR3_SHIFT_A;
-		pte_root |= tmp;
-
-		tmp = DTE_GCR3_VAL_B(gcr3) << DTE_GCR3_SHIFT_B;
-		flags    |= tmp;
-
-		tmp = DTE_GCR3_VAL_C(gcr3) << DTE_GCR3_SHIFT_C;
-		flags    |= tmp;
-
-		if (amd_iommu_gpt_level == PAGE_MODE_5_LEVEL) {
-			dev_table[devid].data[2] |=
-				((u64)GUEST_PGTABLE_5_LEVEL << DTE_GPT_LEVEL_SHIFT);
-		}
-
-		/* GIOV is supported with V2 page table mode only */
-		if (pdom_is_v2_pgtbl_mode(domain))
-			pte_root |= DTE_FLAG_GIOV;
-	}
+	target.data[1] &= ~DEV_DOMID_MASK;
+	target.data[1] |= domid;
 
-	flags &= ~DEV_DOMID_MASK;
-	flags |= domid;
+	set_dte_gcr3_table(iommu, dev_data, &target);
 
-	old_domid = dev_table[devid].data[1] & DEV_DOMID_MASK;
-	dev_table[devid].data[1]  = flags;
-	dev_table[devid].data[0]  = pte_root;
+	dev_table[devid].data[0] = target.data[0];
+	dev_table[devid].data[1] = target.data[1];
+	dev_table[devid].data[2] = target.data[2];
 
 	/*
 	 * A kdump kernel might be replacing a domain ID that was copied from
-- 
2.34.1