drm/msm: add support to take dpu snapshot

Add the msm_disp_snapshot module which adds supports to dump dpu
registers and capture the drm atomic state which can be used in
case of error conditions.

changes in v5:
 - start storing disp_state in msm_kms instead of dpu_kms
 - get rid of MSM_DISP_SNAPSHOT_IN_* enum by simplifying the functions
 - move snprintf inside the snapshot core by using varargs
 - get rid of some stale code comments
 - allow snapshot module for non-DPU targets

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/1618606645-19695-3-git-send-email-abhinavk@codeaurora.org
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 179 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
new file mode 100644
index 000000000000..024ca49cb2e8
--- /dev/null
+++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt)	"[drm:%s:%d] " fmt, __func__, __LINE__
+
+#include "msm_disp_snapshot.h"
+
+static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *base_addr)
+{
+	u32 len_padded;
+	u32 num_rows;
+	u32 x0, x4, x8, xc;
+	void __iomem *addr;
+	u32 *dump_addr = NULL;
+	void __iomem *end_addr;
+	int i;
+
+	len_padded = aligned_len * REG_DUMP_ALIGN;
+	num_rows = aligned_len / REG_DUMP_ALIGN;
+
+	addr = base_addr;
+	end_addr = base_addr + aligned_len;
+
+	if (!(*reg))
+		*reg = kzalloc(len_padded, GFP_KERNEL);
+
+	if (*reg)
+		dump_addr = *reg;
+
+	for (i = 0; i < num_rows; i++) {
+		x0 = (addr < end_addr) ? readl_relaxed(addr + 0x0) : 0;
+		x4 = (addr + 0x4 < end_addr) ? readl_relaxed(addr + 0x4) : 0;
+		x8 = (addr + 0x8 < end_addr) ? readl_relaxed(addr + 0x8) : 0;
+		xc = (addr + 0xc < end_addr) ? readl_relaxed(addr + 0xc) : 0;
+
+		if (dump_addr) {
+			dump_addr[i * 4] = x0;
+			dump_addr[i * 4 + 1] = x4;
+			dump_addr[i * 4 + 2] = x8;
+			dump_addr[i * 4 + 3] = xc;
+		}
+
+		addr += REG_DUMP_ALIGN;
+	}
+}
+
+static void msm_disp_state_print_regs(u32 **reg, u32 len, void __iomem *base_addr,
+		struct drm_printer *p)
+{
+	int i;
+	u32 *dump_addr = NULL;
+	void __iomem *addr;
+	u32 num_rows;
+
+	addr = base_addr;
+	num_rows = len / REG_DUMP_ALIGN;
+
+	if (*reg)
+		dump_addr = *reg;
+
+	for (i = 0; i < num_rows; i++) {
+		drm_printf(p, "0x%lx : %08x %08x %08x %08x\n",
+				(unsigned long)(addr - base_addr),
+				dump_addr[i * 4], dump_addr[i * 4 + 1],
+				dump_addr[i * 4 + 2], dump_addr[i * 4 + 3]);
+		addr += REG_DUMP_ALIGN;
+	}
+}
+
+struct msm_disp_state *msm_disp_state_get(struct drm_device *drm)
+{
+	struct msm_drm_private *priv;
+	struct msm_kms *kms;
+
+	priv = drm->dev_private;
+	kms = priv->kms;
+
+	return kms->disp_state;
+}
+
+void msm_disp_state_print(struct msm_disp_state *state, struct drm_printer *p)
+{
+	struct msm_disp_state_block *block, *tmp;
+
+	if (!p) {
+		DRM_ERROR("invalid drm printer\n");
+		return;
+	}
+
+	drm_printf(p, "---\n");
+
+	drm_printf(p, "module: " KBUILD_MODNAME "\n");
+	drm_printf(p, "dpu devcoredump\n");
+	drm_printf(p, "timestamp %lld\n", ktime_to_ns(state->timestamp));
+
+	list_for_each_entry_safe(block, tmp, &state->blocks, node) {
+		drm_printf(p, "====================%s================\n", block->name);
+		msm_disp_state_print_regs(&block->state, block->size, block->base_addr, p);
+	}
+
+	drm_printf(p, "===================dpu drm state================\n");
+
+	if (state->atomic_state)
+		drm_atomic_print_new_state(state->atomic_state, p);
+}
+
+static void msm_disp_capture_atomic_state(struct msm_disp_state *disp_state)
+{
+	struct drm_device *ddev;
+	struct drm_modeset_acquire_ctx ctx;
+
+	disp_state->timestamp = ktime_get();
+
+	ddev = disp_state->drm_dev;
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	while (drm_modeset_lock_all_ctx(ddev, &ctx) != 0)
+		drm_modeset_backoff(&ctx);
+
+	disp_state->atomic_state = drm_atomic_helper_duplicate_state(ddev,
+			&ctx);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+void msm_disp_snapshot_capture_state(struct msm_disp_state *disp_state)
+{
+	struct msm_drm_private *priv;
+	struct drm_device *drm_dev;
+
+	drm_dev = disp_state->drm_dev;
+	priv = drm_dev->dev_private;
+
+	msm_disp_capture_atomic_state(disp_state);
+}
+
+void msm_disp_state_free(struct msm_disp_state *disp_state)
+{
+	struct msm_disp_state_block *block, *tmp;
+
+	if (disp_state->atomic_state) {
+		drm_atomic_state_put(disp_state->atomic_state);
+		disp_state->atomic_state = NULL;
+	}
+
+	list_for_each_entry_safe(block, tmp, &disp_state->blocks, node) {
+		list_del(&block->node);
+		kfree(block->state);
+		kfree(block);
+	}
+}
+
+void msm_disp_snapshot_add_block(struct msm_disp_state *disp_state, u32 len,
+		void __iomem *base_addr, const char *fmt, ...)
+{
+	struct msm_disp_state_block *new_blk;
+	struct va_format vaf;
+	va_list va;
+
+	new_blk = kzalloc(sizeof(struct msm_disp_state_block), GFP_KERNEL);
+
+	va_start(va, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &va;
+	snprintf(new_blk->name, sizeof(new_blk->name), "%pV", &vaf);
+
+	va_end(va);
+
+	INIT_LIST_HEAD(&new_blk->node);
+	new_blk->size = ALIGN(len, REG_DUMP_ALIGN);
+	new_blk->base_addr = base_addr;
+
+	msm_disp_state_dump_regs(&new_blk->state, new_blk->size, base_addr);
+	list_add(&new_blk->node, &disp_state->blocks);
+}