[PATCH] drm/panfrost: Add AArch64 page table format support

[Rob Herring]

Bifrost GPUs use the standard format stage 1 LPAE page tables matching
the io-pgtable ARM_64_LPAE_S1 format. The one difference is the TCR or
TRANSCFG register as the Mali driver calls it has its own custom layout.

Signed-off-by: Rob Herring <robh at kernel.org>
---
This and compatible strings should be enough for enabling bifrost. 
There's some other feature and issue differences, but I think they all 
either don't matter (because of differences in panfrost) or I've already 
handled them.

This is only compile tested as I don't have h/w. Running the existing 
IGT tests may be sufficient to test this. We should get an error with 
the command stream rather than a MMU fault if this is working correctly.

Rob

 drivers/gpu/drm/panfrost/panfrost_mmu.c  | 28 +++++++++++++++++++++++-
 drivers/gpu/drm/panfrost/panfrost_regs.h |  3 +++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 762b1bd2a8c2..41d184fab07f 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier:	GPL-2.0
 /* Copyright 2019 Linaro, Ltd, Rob Herring <robh at kernel.org> */
+/* Copyright (C) 2019 Arm Ltd. */
 #include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
@@ -111,6 +112,14 @@ void panfrost_mmu_enable(struct panfrost_device *pfdev, u32 as_nr)
 	u64 transtab = cfg->arm_mali_lpae_cfg.transtab;
 	u64 memattr = cfg->arm_mali_lpae_cfg.memattr;
 
+	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU)) {
+		transtab = cfg->arm_lpae_s1_cfg.ttbr[0];
+		memattr = cfg->arm_lpae_s1_cfg.mair[0];
+	} else {
+		transtab = cfg->arm_mali_lpae_cfg.transtab;
+		memattr = cfg->arm_mali_lpae_cfg.memattr;
+	}
+
 	mmu_write(pfdev, MMU_INT_CLEAR, ~0);
 	mmu_write(pfdev, MMU_INT_MASK, ~0);
 
@@ -123,6 +132,14 @@ void panfrost_mmu_enable(struct panfrost_device *pfdev, u32 as_nr)
 	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), memattr & 0xffffffffUL);
 	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), memattr >> 32);
 
+	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU)) {
+		/* TODO: handle system coherency */
+		mmu_write(pfdev, AS_TRANSCFG_LO(as_nr),
+			AS_TRANSCFG_PTW_MEMATTR_WRITE_BACK |
+			AS_TRANSCFG_ADRMODE_AARCH64_4K);
+		mmu_write(pfdev, AS_TRANSCFG_HI(as_nr), 0);
+	}
+
 	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
 }
 
@@ -134,6 +151,11 @@ static void mmu_disable(struct panfrost_device *pfdev, u32 as_nr)
 	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), 0);
 	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), 0);
 
+	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU)) {
+		mmu_write(pfdev, AS_TRANSCFG_LO(as_nr), 0);
+		mmu_write(pfdev, AS_TRANSCFG_HI(as_nr), 0);
+	}
+
 	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
 }
 
@@ -335,6 +357,7 @@ static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data)
 int panfrost_mmu_init(struct panfrost_device *pfdev)
 {
 	struct io_pgtable_ops *pgtbl_ops;
+	enum io_pgtable_fmt pgt_fmt = ARM_MALI_LPAE;
 	int err, irq;
 
 	pfdev->mmu = devm_kzalloc(pfdev->dev, sizeof(*pfdev->mmu), GFP_KERNEL);
@@ -365,7 +388,10 @@ int panfrost_mmu_init(struct panfrost_device *pfdev)
 		.iommu_dev	= pfdev->dev,
 	};
 
-	pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &pfdev->mmu->pgtbl_cfg,
+	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU))
+		pgt_fmt = ARM_64_LPAE_S1;
+
+	pgtbl_ops = alloc_io_pgtable_ops(pgt_fmt, &pfdev->mmu->pgtbl_cfg,
 					 pfdev);
 	if (!pgtbl_ops)
 		return -ENOMEM;
diff --git a/drivers/gpu/drm/panfrost/panfrost_regs.h b/drivers/gpu/drm/panfrost/panfrost_regs.h
index 578c5fc2188b..31211df83c30 100644
--- a/drivers/gpu/drm/panfrost/panfrost_regs.h
+++ b/drivers/gpu/drm/panfrost/panfrost_regs.h
@@ -287,6 +287,9 @@
 #define AS_TRANSTAB_LPAE_READ_INNER		BIT(2)
 #define AS_TRANSTAB_LPAE_SHARE_OUTER		BIT(4)
 
+#define AS_TRANSCFG_ADRMODE_AARCH64_4K		6
+#define AS_TRANSCFG_PTW_MEMATTR_WRITE_BACK	(2 << 24)
+
 #define AS_STATUS_AS_ACTIVE			0x01
 
 #define AS_FAULTSTATUS_ACCESS_TYPE_MASK		(0x3 << 8)
-- 
2.20.1