From 9ff4750eafb6af9ee7ea73898f39e86a97c0cf2d Mon Sep 17 00:00:00 2001
From: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Date: Tue, 22 Jul 2025 13:26:03 +0200
Subject: [PATCH] ac/cmdbuf: introduce ac_cmdbuf

This will be shared by both drivers.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36292>
---
 src/amd/common/ac_cmdbuf.h | 61 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/src/amd/common/ac_cmdbuf.h b/src/amd/common/ac_cmdbuf.h
index a855d2d3fd7..6a0a3990db8 100644
--- a/src/amd/common/ac_cmdbuf.h
+++ b/src/amd/common/ac_cmdbuf.h
@@ -15,6 +15,67 @@
 extern "C" {
 #endif
 
+struct ac_cmdbuf {
+   uint32_t cdw;         /* Number of used dwords. */
+   uint32_t max_dw;      /* Maximum number of dwords. */
+   uint32_t reserved_dw; /* Number of dwords reserved. */
+   uint32_t *buf;        /* The base pointer of the chunk. */
+};
+
+#define ac_cmdbuf_begin(cs) struct ac_cmdbuf *__cs = (cs);                        \
+                            uint32_t __cs_num = __cs->cdw;                        \
+                            UNUSED uint32_t __cs_num_initial = __cs_num;          \
+                            UNUSED uint32_t __cs_reserved_dw = __cs->reserved_dw; \
+                            uint32_t *__cs_buf = __cs->buf
+
+#define ac_cmdbuf_begin_again(cs) do { \
+   assert(__cs == NULL);               \
+   __cs = (cs);                        \
+   __cs_num = __cs->cdw;               \
+   __cs_num_initial = __cs_num;        \
+   __cs_buf = __cs->buf;               \
+} while (0)
+
+#define ac_cmdbuf_emit(value)                                   \
+   do {                                                         \
+      assert(!__cs_reserved_dw || __cs_num < __cs_reserved_dw); \
+      __cs_buf[__cs_num++] = (value);                           \
+   } while (0)
+
+#define ac_cmdbuf_packets_added()  (__cs_num != __cs_num_initial)
+
+#define ac_cmdbuf_emit_array(values, num) do {                       \
+   unsigned __n = (num);                                             \
+   assert(!__cs_reserved_dw || __cs_num + __n <= __cs_reserved_dw);  \
+   memcpy(__cs_buf + __cs_num, (values), __n * 4);                   \
+   __cs_num += __n;                                                  \
+} while (0)
+
+#define ac_cmdbuf_end() do {           \
+   __cs->cdw = __cs_num;               \
+   assert(__cs->cdw <= __cs->max_dw);  \
+   __cs = NULL;                        \
+} while (0)
+
+/* Packet building helpers. Don't use directly. */
+#define __ac_cmdbuf_set_reg_seq(reg, num, idx, prefix_name, packet, reset_filter_cam)     \
+   do {                                                                                   \
+      assert((reg) >= prefix_name##_REG_OFFSET && (reg) < prefix_name##_REG_END);         \
+      ac_cmdbuf_emit(PKT3(packet, num, 0) | PKT3_RESET_FILTER_CAM_S(reset_filter_cam));   \
+      ac_cmdbuf_emit((((reg) - prefix_name##_REG_OFFSET) >> 2) | ((idx) << 28));          \
+   } while (0)
+
+#define __ac_cmdbuf_set_reg(reg, idx, value, prefix_name, packet)                         \
+   do {                                                                                   \
+      __ac_cmdbuf_set_reg_seq(reg, 1, idx, prefix_name, packet, 0);                       \
+      ac_cmdbuf_emit(value);                                                              \
+   } while (0)
+
+/* Packet building helpers for CONFIG registers. */
+#define ac_cmdbuf_set_config_reg_seq(reg, num) __ac_cmdbuf_set_reg_seq(reg, num, 0, SI_CONFIG, PKT3_SET_CONFIG_REG, 0)
+
+#define ac_cmdbuf_set_config_reg(reg, value) __ac_cmdbuf_set_reg(reg, 0, value, SI_CONFIG, PKT3_SET_CONFIG_REG)
+
 struct ac_preamble_state {
    uint64_t border_color_va;