drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

1 files changed, 217 insertions, 0 deletions

diff --git a/drivers/cache/ax45mp_cache.c b/drivers/cache/ax45mp_cache.c
new file mode 100644
index 000000000..934c5087e
--- /dev/null
+++ b/drivers/cache/ax45mp_cache.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * non-coherent cache functions for Andes AX45MP
+ *
+ * Copyright (C) 2023 Renesas Electronics Corp.
+ */
+
+#include <linux/cacheflush.h>
+#include <linux/cacheinfo.h>
+#include <linux/dma-direction.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+#include <asm/dma-noncoherent.h>
+
+/* L2 cache registers */
+#define AX45MP_L2C_REG_CTL_OFFSET		0x8
+
+#define AX45MP_L2C_REG_C0_CMD_OFFSET		0x40
+#define AX45MP_L2C_REG_C0_ACC_OFFSET		0x48
+#define AX45MP_L2C_REG_STATUS_OFFSET		0x80
+
+/* D-cache operation */
+#define AX45MP_CCTL_L1D_VA_INVAL		0 /* Invalidate an L1 cache entry */
+#define AX45MP_CCTL_L1D_VA_WB			1 /* Write-back an L1 cache entry */
+
+/* L2 CCTL status */
+#define AX45MP_CCTL_L2_STATUS_IDLE		0
+
+/* L2 CCTL status cores mask */
+#define AX45MP_CCTL_L2_STATUS_C0_MASK		0xf
+
+/* L2 cache operation */
+#define AX45MP_CCTL_L2_PA_INVAL			0x8 /* Invalidate an L2 cache entry */
+#define AX45MP_CCTL_L2_PA_WB			0x9 /* Write-back an L2 cache entry */
+
+#define AX45MP_L2C_REG_PER_CORE_OFFSET		0x10
+#define AX45MP_CCTL_L2_STATUS_PER_CORE_OFFSET	4
+
+#define AX45MP_L2C_REG_CN_CMD_OFFSET(n)	\
+	(AX45MP_L2C_REG_C0_CMD_OFFSET + ((n) * AX45MP_L2C_REG_PER_CORE_OFFSET))
+#define AX45MP_L2C_REG_CN_ACC_OFFSET(n)	\
+	(AX45MP_L2C_REG_C0_ACC_OFFSET + ((n) * AX45MP_L2C_REG_PER_CORE_OFFSET))
+#define AX45MP_CCTL_L2_STATUS_CN_MASK(n)	\
+	(AX45MP_CCTL_L2_STATUS_C0_MASK << ((n) * AX45MP_CCTL_L2_STATUS_PER_CORE_OFFSET))
+
+#define AX45MP_CCTL_REG_UCCTLBEGINADDR_NUM	0x80b
+#define AX45MP_CCTL_REG_UCCTLCOMMAND_NUM	0x80c
+
+#define AX45MP_CACHE_LINE_SIZE			64
+
+struct ax45mp_priv {
+	void __iomem *l2c_base;
+	u32 ax45mp_cache_line_size;
+};
+
+static struct ax45mp_priv ax45mp_priv;
+
+/* L2 Cache operations */
+static inline uint32_t ax45mp_cpu_l2c_get_cctl_status(void)
+{
+	return readl(ax45mp_priv.l2c_base + AX45MP_L2C_REG_STATUS_OFFSET);
+}
+
+static void ax45mp_cpu_cache_operation(unsigned long start, unsigned long end,
+				       unsigned int l1_op, unsigned int l2_op)
+{
+	unsigned long line_size = ax45mp_priv.ax45mp_cache_line_size;
+	void __iomem *base = ax45mp_priv.l2c_base;
+	int mhartid = smp_processor_id();
+	unsigned long pa;
+
+	while (end > start) {
+		csr_write(AX45MP_CCTL_REG_UCCTLBEGINADDR_NUM, start);
+		csr_write(AX45MP_CCTL_REG_UCCTLCOMMAND_NUM, l1_op);
+
+		pa = virt_to_phys((void *)start);
+		writel(pa, base + AX45MP_L2C_REG_CN_ACC_OFFSET(mhartid));
+		writel(l2_op, base + AX45MP_L2C_REG_CN_CMD_OFFSET(mhartid));
+		while ((ax45mp_cpu_l2c_get_cctl_status() &
+			AX45MP_CCTL_L2_STATUS_CN_MASK(mhartid)) !=
+			AX45MP_CCTL_L2_STATUS_IDLE)
+			;
+
+		start += line_size;
+	}
+}
+
+/* Write-back L1 and L2 cache entry */
+static inline void ax45mp_cpu_dcache_wb_range(unsigned long start, unsigned long end)
+{
+	ax45mp_cpu_cache_operation(start, end, AX45MP_CCTL_L1D_VA_WB,
+				   AX45MP_CCTL_L2_PA_WB);
+}
+
+/* Invalidate the L1 and L2 cache entry */
+static inline void ax45mp_cpu_dcache_inval_range(unsigned long start, unsigned long end)
+{
+	ax45mp_cpu_cache_operation(start, end, AX45MP_CCTL_L1D_VA_INVAL,
+				   AX45MP_CCTL_L2_PA_INVAL);
+}
+
+static void ax45mp_dma_cache_inv(phys_addr_t paddr, size_t size)
+{
+	unsigned long start = (unsigned long)phys_to_virt(paddr);
+	unsigned long end = start + size;
+	unsigned long line_size;
+	unsigned long flags;
+
+	if (unlikely(start == end))
+		return;
+
+	line_size = ax45mp_priv.ax45mp_cache_line_size;
+
+	start = start & (~(line_size - 1));
+	end = ((end + line_size - 1) & (~(line_size - 1)));
+
+	local_irq_save(flags);
+
+	ax45mp_cpu_dcache_inval_range(start, end);
+
+	local_irq_restore(flags);
+}
+
+static void ax45mp_dma_cache_wback(phys_addr_t paddr, size_t size)
+{
+	unsigned long start = (unsigned long)phys_to_virt(paddr);
+	unsigned long end = start + size;
+	unsigned long line_size;
+	unsigned long flags;
+
+	if (unlikely(start == end))
+		return;
+
+	line_size = ax45mp_priv.ax45mp_cache_line_size;
+	start = start & (~(line_size - 1));
+	end = ((end + line_size - 1) & (~(line_size - 1)));
+	local_irq_save(flags);
+	ax45mp_cpu_dcache_wb_range(start, end);
+	local_irq_restore(flags);
+}
+
+static void ax45mp_dma_cache_wback_inv(phys_addr_t paddr, size_t size)
+{
+	ax45mp_dma_cache_wback(paddr, size);
+	ax45mp_dma_cache_inv(paddr, size);
+}
+
+static int ax45mp_get_l2_line_size(struct device_node *np)
+{
+	int ret;
+
+	ret = of_property_read_u32(np, "cache-line-size", &ax45mp_priv.ax45mp_cache_line_size);
+	if (ret) {
+		pr_err("Failed to get cache-line-size, defaulting to 64 bytes\n");
+		return ret;
+	}
+
+	if (ax45mp_priv.ax45mp_cache_line_size != AX45MP_CACHE_LINE_SIZE) {
+		pr_err("Expected cache-line-size to be 64 bytes (found:%u)\n",
+		       ax45mp_priv.ax45mp_cache_line_size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct riscv_nonstd_cache_ops ax45mp_cmo_ops __initdata = {
+	.wback = &ax45mp_dma_cache_wback,
+	.inv = &ax45mp_dma_cache_inv,
+	.wback_inv = &ax45mp_dma_cache_wback_inv,
+};
+
+static const struct of_device_id ax45mp_cache_ids[] = {
+	{ .compatible = "andestech,ax45mp-cache" },
+	{ /* sentinel */ }
+};
+
+static int __init ax45mp_cache_init(void)
+{
+	struct resource res;
+	int ret;
+
+	struct device_node *np __free(device_node) =
+		of_find_matching_node(NULL, ax45mp_cache_ids);
+	if (!of_device_is_available(np))
+		return -ENODEV;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		return ret;
+
+	/*
+	 * If IOCP is present on the Andes AX45MP core riscv_cbom_block_size
+	 * will be 0 for sure, so we can definitely rely on it. If
+	 * riscv_cbom_block_size = 0 we don't need to handle CMO using SW any
+	 * more so we just return success here and only if its being set we
+	 * continue further in the probe path.
+	 */
+	if (!riscv_cbom_block_size)
+		return 0;
+
+	ax45mp_priv.l2c_base = ioremap(res.start, resource_size(&res));
+	if (!ax45mp_priv.l2c_base)
+		return -ENOMEM;
+
+	ret = ax45mp_get_l2_line_size(np);
+	if (ret) {
+		iounmap(ax45mp_priv.l2c_base);
+		return ret;
+	}
+
+	riscv_noncoherent_register_cache_ops(&ax45mp_cmo_ops);
+
+	return 0;
+}
+early_initcall(ax45mp_cache_init);