iommu/mediatek: Fix share pgtable for iova over 4GB

In mt8192/mt8186, there is only one MM IOMMU that supports 16GB iova
space, which is shared by display, vcodec and camera. These two SoC use
one pgtable and have not the flag SHARE_PGTABLE, we should also keep
share pgtable for this case.

In mtk_iommu_domain_finalise, MM IOMMU always share pgtable, thus remove
the flag SHARE_PGTABLE checking. Infra IOMMU always uses independent
pgtable.

Fixes: cf69ef46 ("iommu/mediatek: Fix two IOMMU share pagetable issue")
Reported-by: Laura Nao <laura.nao@collabora.com>
Closes: https://lore.kernel.org/linux-iommu/20230818154156.314742-1-laura.nao@collabora.com/Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20230819081443.8333-1-yong.wu@mediatek.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.c

@@ -262,7 +262,7 @@ struct mtk_iommu_data {
 	struct device			*smicomm_dev;
 
 	struct mtk_iommu_bank_data	*bank;
-	struct mtk_iommu_domain		*share_dom; /* For 2 HWs share pgtable */
+	struct mtk_iommu_domain		*share_dom;
 
 	struct regmap			*pericfg;
 	struct mutex			mutex; /* Protect m4u_group/m4u_dom above */
@@ -643,8 +643,8 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
 	struct mtk_iommu_domain	*share_dom = data->share_dom;
 	const struct mtk_iommu_iova_region *region;
 
-	/* Always use share domain in sharing pgtable case */
-	if (MTK_IOMMU_HAS_FLAG(data->plat_data, SHARE_PGTABLE) && share_dom) {
+	/* Share pgtable when 2 MM IOMMU share the pgtable or one IOMMU use multiple iova ranges */
+	if (share_dom) {
 		dom->iop = share_dom->iop;
 		dom->cfg = share_dom->cfg;
 		dom->domain.pgsize_bitmap = share_dom->cfg.pgsize_bitmap;
@@ -677,8 +677,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
 	/* Update our support page sizes bitmap */
 	dom->domain.pgsize_bitmap = dom->cfg.pgsize_bitmap;
 
-	if (MTK_IOMMU_HAS_FLAG(data->plat_data, SHARE_PGTABLE))
-		data->share_dom = dom;
+	data->share_dom = dom;
 
 update_iova_region:
 	/* Update the iova region for this domain */