soc/mediatek: PCI: Fix translation window

Dojo fails to boot from NVMe with CONFIG_RESOURCE_ALLOCATION_TOP_DOWN
enabled. The root cause is using __fls() will get a smaller value when
the size is not a power of 2, for example, __fls(0x3000000) = 25. Hence
the PCIe translation window size is set to 0x2000000. Accessing
addresses higher than 0x2300000 will fail.

Fix translation window by splitting the MMIO space to multiple tables if
its size is not a power of 2.

Resolves: https://ticket.coreboot.org/issues/508.

TEST=Build pass and boot up to kernel successfully via SSD on Dojo
board, it can boot with and without the
CONFIG_RESOURCE_ALLOCATION_TOP_DOWN option.

BUS=b:298255933
BRANCH=cherry

Change-Id: I42b0f0bf9222d284dee0c29f1a6ed6366d6e6689
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78044
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 58 insertions, 18 deletions

diff --git a/src/soc/mediatek/common/pcie.c b/src/soc/mediatek/common/pcie.c
index 8b5b36b0eb..b3903a528a 100644
--- a/src/soc/mediatek/common/pcie.c
+++ b/src/soc/mediatek/common/pcie.c
@@ -127,11 +127,23 @@ volatile union pci_bank *pci_map_bus(pci_devfn_t dev)
 	return (void *)(base + PCIE_CFG_OFFSET_ADDR);
 }
 
-static int mtk_pcie_set_trans_window(struct device *dev, uintptr_t table,
+static void mtk_pcie_set_table(uintptr_t table, uint32_t cpu_addr,
+			       uint32_t pci_addr, uint32_t size, uint32_t attr)
+{
+	write32p(table, cpu_addr | PCIE_ATR_SIZE(__fls(size)));
+	write32p(table + PCIE_ATR_SRC_ADDR_MSB_OFFSET, 0);
+	write32p(table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET, pci_addr);
+	write32p(table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET, 0);
+	write32p(table + PCIE_ATR_TRSL_PARAM_OFFSET, attr);
+}
+
+static int mtk_pcie_set_trans_window(size_t *count, uintptr_t table_base,
 				     const struct mtk_pcie_mmio_res *mmio_res)
 {
 	const char *range_type;
+	uintptr_t table;
 	uint32_t table_attr;
+	uint32_t cpu_addr, pci_addr, remaining, size;
 
 	if (!mmio_res)
 		return -1;
@@ -148,17 +160,44 @@ static int mtk_pcie_set_trans_window(struct device *dev, uintptr_t table,
 		return -1;
 	}
 
-	write32p(table, mmio_res->cpu_addr |
-		 PCIE_ATR_SIZE(__fls(mmio_res->size)));
-	write32p(table + PCIE_ATR_SRC_ADDR_MSB_OFFSET, 0);
-	write32p(table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET, mmio_res->pci_addr);
-	write32p(table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET, 0);
-	write32p(table + PCIE_ATR_TRSL_PARAM_OFFSET, table_attr);
+	cpu_addr = mmio_res->cpu_addr;
+	pci_addr = mmio_res->pci_addr;
+	remaining = mmio_res->size;
+
+	while (remaining && *count < PCIE_MAX_TRANS_TABLES) {
+		/*
+		 * The table size needs to be a power of 2.
+		 * In addition, cpu_addr needs to be aligned to the size.
+		 */
+		size = BIT(__fls(remaining));
+
+		if (cpu_addr > 0)
+			size = MIN(size, BIT(__ffs(cpu_addr)));
+
+		/* Minimum size of translate table is 4KiB */
+		if (size < 4 * KiB) {
+			printk(BIOS_ERR, "%s: table size %#x is less than 4KiB\n",
+			       __func__, size);
+			return -1;
+		}
+
+		table = table_base + *count * PCIE_ATR_TLB_SET_OFFSET;
+		mtk_pcie_set_table(table, cpu_addr, pci_addr, size, table_attr);
+
+		printk(BIOS_INFO,
+		       "%s: set %s trans window: cpu_addr = %#x, pci_addr = %#x, size = %#x\n",
+		       __func__, range_type, cpu_addr, pci_addr, size);
+		cpu_addr += size;
+		pci_addr += size;
+		remaining -= size;
+		(*count)++;
+	}
 
-	printk(BIOS_INFO,
-	       "%s: set %s trans window: cpu_addr = %#x, pci_addr = %#x, size = %#x\n",
-	       __func__, range_type, mmio_res->cpu_addr, mmio_res->pci_addr,
-	       mmio_res->size);
+	if (remaining) {
+		printk(BIOS_ERR, "%s: Not enough translation windows, remaining size: %#x\n",
+		       __func__, remaining);
+		return -1;
+	}
 
 	return 0;
 }
@@ -194,17 +233,18 @@ void mtk_pcie_domain_set_resources(struct device *dev)
 {
 	const mtk_soc_config_t *config = config_of(dev);
 	const struct mtk_pcie_config *conf = &config->pcie_config;
-	uintptr_t table;
+	uintptr_t table_base = conf->base + PCIE_TRANS_TABLE_BASE_REG;
+	size_t count = 0;
 
 	/* Initialize I/O space constraints. */
-	table = conf->base + PCIE_TRANS_TABLE_BASE_REG;
-	if (mtk_pcie_set_trans_window(dev, table, &conf->mmio_res_io) < 0)
-		printk(BIOS_ERR, "%s: Failed to set IO window\n", __func__);
+	if (mtk_pcie_set_trans_window(&count, table_base, &conf->mmio_res_io) < 0) {
+		printk(BIOS_ERR, "%s: Failed to set IO window, ignore it\n",
+		       __func__);
+		count = 0;
+	}
 
 	/* Initialize memory resources constraints. */
-	table = conf->base + PCIE_TRANS_TABLE_BASE_REG +
-		PCIE_ATR_TLB_SET_OFFSET;
-	if (mtk_pcie_set_trans_window(dev, table, &conf->mmio_res_mem) < 0)
+	if (mtk_pcie_set_trans_window(&count, table_base, &conf->mmio_res_mem) < 0)
 		printk(BIOS_ERR, "%s: Failed to set MEM window\n", __func__);
 
 	pci_domain_set_resources(dev);