[PATCH v2 7/8] drm/tegra: Add code for booting RISC-V based engines

Mikko Perttunen
2022-09-13T13:15:17Z

Add helper code for booting RISC-V based engines where firmware is
located in a carveout.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
drivers/gpu/drm/tegra/Makefile | 3 +-
drivers/gpu/drm/tegra/riscv.c | 106 +++++++++++++++++++++++++++++++++
drivers/gpu/drm/tegra/riscv.h | 30 ++++++++++
3 files changed, 138 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/tegra/riscv.c
create mode 100644 drivers/gpu/drm/tegra/riscv.h

diff --git a/drivers/gpu/drm/tegra/Makefile b/drivers/gpu/drm/tegra/Makefile
index df6cc986aeba..bb0d2c144b55 100644
--- a/drivers/gpu/drm/tegra/Makefile
+++ b/drivers/gpu/drm/tegra/Makefile
@@ -24,7 +24,8 @@ tegra-drm-y := \
gr3d.o \
falcon.o \
vic.o \
- nvdec.o
+ nvdec.o \
+ riscv.o

tegra-drm-y += trace.o

diff --git a/drivers/gpu/drm/tegra/riscv.c b/drivers/gpu/drm/tegra/riscv.c
new file mode 100644
index 000000000000..6580416408f8
--- /dev/null
+++ b/drivers/gpu/drm/tegra/riscv.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022, NVIDIA Corporation.
+ */
+
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+
+#include "riscv.h"
+
+#define RISCV_CPUCTL 0x4388
+#define RISCV_CPUCTL_STARTCPU_TRUE (1 << 0)
+#define RISCV_BR_RETCODE 0x465c
+#define RISCV_BR_RETCODE_RESULT_V(x) ((x) & 0x3)
+#define RISCV_BR_RETCODE_RESULT_PASS_V 3
+#define RISCV_BCR_CTRL 0x4668
+#define RISCV_BCR_CTRL_CORE_SELECT_RISCV (1 << 4)
+#define RISCV_BCR_DMACFG 0x466c
+#define RISCV_BCR_DMACFG_TARGET_LOCAL_FB (0 << 0)
+#define RISCV_BCR_DMACFG_LOCK_LOCKED (1 << 31)
+#define RISCV_BCR_DMAADDR_PKCPARAM_LO 0x4670
+#define RISCV_BCR_DMAADDR_PKCPARAM_HI 0x4674
+#define RISCV_BCR_DMAADDR_FMCCODE_LO 0x4678
+#define RISCV_BCR_DMAADDR_FMCCODE_HI 0x467c
+#define RISCV_BCR_DMAADDR_FMCDATA_LO 0x4680
+#define RISCV_BCR_DMAADDR_FMCDATA_HI 0x4684
+#define RISCV_BCR_DMACFG_SEC 0x4694
+#define RISCV_BCR_DMACFG_SEC_GSCID(v) ((v) << 16)
+
+static void riscv_writel(struct tegra_drm_riscv *riscv, u32 value, u32 offset)
+{
+ writel(value, riscv->regs + offset);
+}
+
+int tegra_drm_riscv_read_descriptors(struct tegra_drm_riscv *riscv)
+{
+ struct tegra_drm_riscv_descriptor *bl = &riscv->bl_desc;
+ struct tegra_drm_riscv_descriptor *os = &riscv->os_desc;
+ const struct device_node *np = riscv->dev->of_node;
+ int err;
+
+#define READ_PROP(name, location) \
+ err = of_property_read_u32(np, name, location); \
+ if (err) { \
+ dev_err(riscv->dev, "failed to read " name ": %d\n", err); \
+ return err; \
+ }
+
+ READ_PROP("nvidia,bl-manifest-offset", &bl->manifest_offset);
+ READ_PROP("nvidia,bl-code-offset", &bl->code_offset);
+ READ_PROP("nvidia,bl-data-offset", &bl->data_offset);
+ READ_PROP("nvidia,os-manifest-offset", &os->manifest_offset);
+ READ_PROP("nvidia,os-code-offset", &os->code_offset);
+ READ_PROP("nvidia,os-data-offset", &os->data_offset);
+#undef READ_PROP
+
+ if (bl->manifest_offset == 0 && bl->code_offset == 0 &&
+ bl->data_offset == 0 && os->manifest_offset == 0 &&
+ os->code_offset == 0 && os->data_offset == 0) {
+ dev_err(riscv->dev, "descriptors not available\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int tegra_drm_riscv_boot_bootrom(struct tegra_drm_riscv *riscv, phys_addr_t image_address,
+ u32 gscid, const struct tegra_drm_riscv_descriptor *desc)
+{
+ phys_addr_t addr;
+ int err;
+ u32 val;
+
+ riscv_writel(riscv, RISCV_BCR_CTRL_CORE_SELECT_RISCV, RISCV_BCR_CTRL);
+
+ addr = image_address + desc->manifest_offset;
+ riscv_writel(riscv, lower_32_bits(addr >> 8), RISCV_BCR_DMAADDR_PKCPARAM_LO);
+ riscv_writel(riscv, upper_32_bits(addr >> 8), RISCV_BCR_DMAADDR_PKCPARAM_HI);
+
+ addr = image_address + desc->code_offset;
+ riscv_writel(riscv, lower_32_bits(addr >> 8), RISCV_BCR_DMAADDR_FMCCODE_LO);
+ riscv_writel(riscv, upper_32_bits(addr >> 8), RISCV_BCR_DMAADDR_FMCCODE_HI);
+
+ addr = image_address + desc->data_offset;
+ riscv_writel(riscv, lower_32_bits(addr >> 8), RISCV_BCR_DMAADDR_FMCDATA_LO);
+ riscv_writel(riscv, upper_32_bits(addr >> 8), RISCV_BCR_DMAADDR_FMCDATA_HI);
+
+ riscv_writel(riscv, RISCV_BCR_DMACFG_SEC_GSCID(gscid), RISCV_BCR_DMACFG_SEC);
+ riscv_writel(riscv,
+ RISCV_BCR_DMACFG_TARGET_LOCAL_FB | RISCV_BCR_DMACFG_LOCK_LOCKED, RISCV_BCR_DMACFG);
+
+ riscv_writel(riscv, RISCV_CPUCTL_STARTCPU_TRUE, RISCV_CPUCTL);
+
+ err = readl_poll_timeout(
+ riscv->regs + RISCV_BR_RETCODE, val,
+ RISCV_BR_RETCODE_RESULT_V(val) == RISCV_BR_RETCODE_RESULT_PASS_V,
+ 10, 100000);
+ if (err) {
+ dev_err(riscv->dev, "error during bootrom execution. BR_RETCODE=%d\n", val);
+ return err;
+ }
+
+ return 0;
+}
diff --git a/drivers/gpu/drm/tegra/riscv.h b/drivers/gpu/drm/tegra/riscv.h
new file mode 100644
index 000000000000..bbeb2db078b6
--- /dev/null
+++ b/drivers/gpu/drm/tegra/riscv.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022, NVIDIA Corporation.
+ */
+
+#ifndef DRM_TEGRA_RISCV_H
+#define DRM_TEGRA_RISCV_H
+
+struct tegra_drm_riscv_descriptor {
+ u32 manifest_offset;
+ u32 code_offset;
+ u32 code_size;
+ u32 data_offset;
+ u32 data_size;
+};
+
+struct tegra_drm_riscv {
+ /* User initializes */
+ struct device *dev;
+ void __iomem *regs;
+
+ struct tegra_drm_riscv_descriptor bl_desc;
+ struct tegra_drm_riscv_descriptor os_desc;
+};
+
+int tegra_drm_riscv_read_descriptors(struct tegra_drm_riscv *riscv);
+int tegra_drm_riscv_boot_bootrom(struct tegra_drm_riscv *riscv, phys_addr_t image_address,
+ u32 gscid, const struct tegra_drm_riscv_descriptor *desc);
+
+#endif
--
2.37.0