x86: qemu: move QFW to its own uclass

We move qfw into its own uclass and split the PIO functions into a
specific driver for that uclass.  The PIO driver is selected in the
qemu-x86 board config (this covers x86 and x86_64).

include/qfw.h is cleaned up and documentation added.

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

4 files changed, 166 insertions, 162 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 7d2a299779..3a254eba4b 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -368,8 +368,15 @@ config WINBOND_W83627
 config QFW
 	bool
 	help
-	  Hidden option to enable QEMU fw_cfg interface. This will be selected by
-	  either CONFIG_CMD_QFW or CONFIG_GENERATE_ACPI_TABLE.
+	  Hidden option to enable QEMU fw_cfg interface and uclass. This will
+	  be selected by either CONFIG_CMD_QFW or CONFIG_GENERATE_ACPI_TABLE.
+
+config QFW_PIO
+	bool
+	depends on QFW
+	help
+	  Hidden option to enable PIO QEMU fw_cfg interface. This will be
+	  selected by the appropriate QEMU board.
 
 config I2C_EEPROM
 	bool "Enable driver for generic I2C-attached EEPROMs"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 1a49396007..53bff72428 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -55,7 +55,10 @@ obj-$(CONFIG_NUVOTON_NCT6102D) += nuvoton_nct6102d.o
 obj-$(CONFIG_P2SB) += p2sb-uclass.o
 obj-$(CONFIG_PCA9551_LED) += pca9551_led.o
 obj-$(CONFIG_$(SPL_)PWRSEQ) += pwrseq-uclass.o
-obj-$(CONFIG_QFW) += qfw.o
+ifdef CONFIG_QFW
+obj-y += qfw.o
+obj-$(CONFIG_QFW_PIO) += qfw_pio.o
+endif
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_ROCKCHIP_OTP) += rockchip-otp.o
 obj-$(CONFIG_SANDBOX) += syscon_sandbox.o misc_sandbox.o
diff --git a/drivers/misc/qfw.c b/drivers/misc/qfw.c
index f6eb6583ed..ea00be88a8 100644
--- a/drivers/misc/qfw.c
+++ b/drivers/misc/qfw.c
@@ -1,25 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
  */
 
+#define LOG_CATEGORY UCLASS_QFW
+
 #include <common.h>
 #include <command.h>
 #include <errno.h>
 #include <log.h>
 #include <malloc.h>
 #include <qfw.h>
-#include <asm/io.h>
+#include <dm.h>
+#include <misc.h>
 #ifdef CONFIG_GENERATE_ACPI_TABLE
 #include <asm/tables.h>
 #endif
-#include <linux/list.h>
-
-static bool fwcfg_present;
-static bool fwcfg_dma_present;
-static struct fw_cfg_arch_ops *fwcfg_arch_ops;
-
-static LIST_HEAD(fw_list);
 
 #ifdef CONFIG_GENERATE_ACPI_TABLE
 /*
@@ -32,7 +29,8 @@ static LIST_HEAD(fw_list);
  *          be ignored.
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
+static int bios_linker_allocate(struct udevice *dev,
+				struct bios_linker_entry *entry, ulong *addr)
 {
 	uint32_t size, align;
 	struct fw_file *file;
@@ -45,7 +43,7 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
 		return -EINVAL;
 	}
 
-	file = qemu_fwcfg_find_file(entry->alloc.file);
+	file = qfw_find_file(dev, entry->alloc.file);
 	if (!file) {
 		printf("error: can't find file %s\n", entry->alloc.file);
 		return -ENOENT;
@@ -75,8 +73,8 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
 	debug("bios_linker_allocate: allocate file %s, size %u, zone %d, align %u, addr 0x%lx\n",
 	      file->cfg.name, size, entry->alloc.zone, align, aligned_addr);
 
-	qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
-			      size, (void *)aligned_addr);
+	qfw_read_entry(dev, be16_to_cpu(file->cfg.select), size,
+		       (void *)aligned_addr);
 	file->addr = aligned_addr;
 
 	/* adjust address for low memory allocation */
@@ -94,16 +92,17 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
  *          ACPI tables
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_add_pointer(struct bios_linker_entry *entry)
+static int bios_linker_add_pointer(struct udevice *dev,
+				   struct bios_linker_entry *entry)
 {
 	struct fw_file *dest, *src;
 	uint32_t offset = le32_to_cpu(entry->pointer.offset);
 	uint64_t pointer = 0;
 
-	dest = qemu_fwcfg_find_file(entry->pointer.dest_file);
+	dest = qfw_find_file(dev, entry->pointer.dest_file);
 	if (!dest || !dest->addr)
 		return -ENOENT;
-	src = qemu_fwcfg_find_file(entry->pointer.src_file);
+	src = qfw_find_file(dev, entry->pointer.src_file);
 	if (!src || !src->addr)
 		return -ENOENT;
 
@@ -127,13 +126,14 @@ static int bios_linker_add_pointer(struct bios_linker_entry *entry)
  *          checksums
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_add_checksum(struct bios_linker_entry *entry)
+static int bios_linker_add_checksum(struct udevice *dev,
+				    struct bios_linker_entry *entry)
 {
 	struct fw_file *file;
 	uint8_t *data, cksum = 0;
 	uint8_t *cksum_start;
 
-	file = qemu_fwcfg_find_file(entry->cksum.file);
+	file = qfw_find_file(dev, entry->cksum.file);
 	if (!file || !file->addr)
 		return -ENOENT;
 
@@ -149,20 +149,27 @@ static int bios_linker_add_checksum(struct bios_linker_entry *entry)
 /* This function loads and patches ACPI tables provided by QEMU */
 ulong write_acpi_tables(ulong addr)
 {
-	int i, ret = 0;
+	int i, ret;
 	struct fw_file *file;
 	struct bios_linker_entry *table_loader;
 	struct bios_linker_entry *entry;
 	uint32_t size;
+	struct udevice *dev;
+
+	ret = qfw_get_dev(&dev);
+	if (ret) {
+		printf("error: no qfw\n");
+		return addr;
+	}
 
 	/* make sure fw_list is loaded */
-	ret = qemu_fwcfg_read_firmware_list();
+	ret = qfw_read_firmware_list(dev);
 	if (ret) {
 		printf("error: can't read firmware file list\n");
 		return addr;
 	}
 
-	file = qemu_fwcfg_find_file("etc/table-loader");
+	file = qfw_find_file(dev, "etc/table-loader");
 	if (!file) {
 		printf("error: can't find etc/table-loader\n");
 		return addr;
@@ -180,24 +187,23 @@ ulong write_acpi_tables(ulong addr)
 		return addr;
 	}
 
-	qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
-			      size, table_loader);
+	qfw_read_entry(dev, be16_to_cpu(file->cfg.select), size, table_loader);
 
 	for (i = 0; i < (size / sizeof(*entry)); i++) {
 		entry = table_loader + i;
 		switch (le32_to_cpu(entry->command)) {
 		case BIOS_LINKER_LOADER_COMMAND_ALLOCATE:
-			ret = bios_linker_allocate(entry, &addr);
+			ret = bios_linker_allocate(dev, entry, &addr);
 			if (ret)
 				goto out;
 			break;
 		case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER:
-			ret = bios_linker_add_pointer(entry);
+			ret = bios_linker_add_pointer(dev, entry);
 			if (ret)
 				goto out;
 			break;
 		case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM:
-			ret = bios_linker_add_checksum(entry);
+			ret = bios_linker_add_checksum(dev, entry);
 			if (ret)
 				goto out;
 			break;
@@ -209,9 +215,9 @@ ulong write_acpi_tables(ulong addr)
 out:
 	if (ret) {
 		struct fw_cfg_file_iter iter;
-		for (file = qemu_fwcfg_file_iter_init(&iter);
-		     !qemu_fwcfg_file_iter_end(&iter);
-		     file = qemu_fwcfg_file_iter_next(&iter)) {
+		for (file = qfw_file_iter_init(dev, &iter);
+		     !qfw_file_iter_end(&iter);
+		     file = qfw_file_iter_next(&iter)) {
 			if (file->addr) {
 				free((void *)file->addr);
 				file->addr = 0;
@@ -225,170 +231,89 @@ out:
 
 ulong acpi_get_rsdp_addr(void)
 {
+	int ret;
 	struct fw_file *file;
+	struct udevice *dev;
 
-	file = qemu_fwcfg_find_file("etc/acpi/rsdp");
+	ret = qfw_get_dev(&dev);
+	if (ret) {
+		printf("error: no qfw\n");
+		return 0;
+	}
+
+	file = qfw_find_file(dev, "etc/acpi/rsdp");
 	return file->addr;
 }
 #endif
 
-/* Read configuration item using fw_cfg PIO interface */
-static void qemu_fwcfg_read_entry_pio(uint16_t entry,
-		uint32_t size, void *address)
+static void qfw_read_entry_io(struct qfw_dev *qdev, u16 entry, u32 size,
+			      void *address)
 {
-	debug("qemu_fwcfg_read_entry_pio: entry 0x%x, size %u address %p\n",
-	      entry, size, address);
+	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);
+
+	debug("%s: entry 0x%x, size %u address %p\n", __func__, entry, size,
+	      address);
 
-	return fwcfg_arch_ops->arch_read_pio(entry, size, address);
+	ops->read_entry_io(qdev->dev, entry, size, address);
 }
 
-/* Read configuration item using fw_cfg DMA interface */
-static void qemu_fwcfg_read_entry_dma(uint16_t entry,
-		uint32_t size, void *address)
+static void qfw_read_entry_dma(struct qfw_dev *qdev, u16 entry, u32 size,
+			       void *address)
 {
-	struct fw_cfg_dma_access dma;
+	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);
 
-	dma.length = cpu_to_be32(size);
-	dma.address = cpu_to_be64((uintptr_t)address);
-	dma.control = cpu_to_be32(FW_CFG_DMA_READ);
+	struct qfw_dma dma = {
+		.length = cpu_to_be32(size),
+		.address = cpu_to_be64((uintptr_t)address),
+		.control = cpu_to_be32(FW_CFG_DMA_READ),
+	};
 
 	/*
-	 * writting FW_CFG_INVALID will cause read operation to resume at
-	 * last offset, otherwise read will start at offset 0
+	 * writing FW_CFG_INVALID will cause read operation to resume at last
+	 * offset, otherwise read will start at offset 0
 	 */
 	if (entry != FW_CFG_INVALID)
 		dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
 
-	barrier();
-
-	debug("qemu_fwcfg_read_entry_dma: entry 0x%x, size %u address %p, control 0x%x\n",
+	debug("%s: entry 0x%x, size %u address %p, control 0x%x\n", __func__,
 	      entry, size, address, be32_to_cpu(dma.control));
 
-	fwcfg_arch_ops->arch_read_dma(&dma);
-}
+	barrier();
 
-bool qemu_fwcfg_present(void)
-{
-	return fwcfg_present;
+	ops->read_entry_dma(qdev->dev, &dma);
 }
 
-bool qemu_fwcfg_dma_present(void)
+void qfw_read_entry(struct udevice *dev, u16 entry, u32 size, void *address)
 {
-	return fwcfg_dma_present;
-}
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
 
-void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address)
-{
-	if (fwcfg_dma_present)
-		qemu_fwcfg_read_entry_dma(entry, length, address);
+	if (qdev->dma_present)
+		qfw_read_entry_dma(qdev, entry, size, address);
 	else
-		qemu_fwcfg_read_entry_pio(entry, length, address);
+		qfw_read_entry_io(qdev, entry, size, address);
 }
 
-int qemu_fwcfg_online_cpus(void)
+int qfw_register(struct udevice *dev)
 {
-	uint16_t nb_cpus;
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
+	u32 qemu, dma_enabled;
 
-	if (!fwcfg_present)
-		return -ENODEV;
-
-	qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
-
-	return le16_to_cpu(nb_cpus);
-}
+	qdev->dev = dev;
+	INIT_LIST_HEAD(&qdev->fw_list);
 
-int qemu_fwcfg_read_firmware_list(void)
-{
-	int i;
-	uint32_t count;
-	struct fw_file *file;
-	struct list_head *entry;
-
-	/* don't read it twice */
-	if (!list_empty(&fw_list))
-		return 0;
+	qfw_read_entry_io(qdev, FW_CFG_SIGNATURE, 4, &qemu);
+	if (be32_to_cpu(qemu) != QEMU_FW_CFG_SIGNATURE)
+		return -ENODEV;
 
-	qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
-	if (!count)
-		return 0;
-
-	count = be32_to_cpu(count);
-	for (i = 0; i < count; i++) {
-		file = malloc(sizeof(*file));
-		if (!file) {
-			printf("error: allocating resource\n");
-			goto err;
-		}
-		qemu_fwcfg_read_entry(FW_CFG_INVALID,
-				      sizeof(struct fw_cfg_file), &file->cfg);
-		file->addr = 0;
-		list_add_tail(&file->list, &fw_list);
-	}
+	qfw_read_entry_io(qdev, FW_CFG_ID, 1, &dma_enabled);
+	if (dma_enabled & FW_CFG_DMA_ENABLED)
+		qdev->dma_present = true;
 
 	return 0;
-
-err:
-	list_for_each(entry, &fw_list) {
-		file = list_entry(entry, struct fw_file, list);
-		free(file);
-	}
-
-	return -ENOMEM;
 }
 
-struct fw_file *qemu_fwcfg_find_file(const char *name)
-{
-	struct list_head *entry;
-	struct fw_file *file;
-
-	list_for_each(entry, &fw_list) {
-		file = list_entry(entry, struct fw_file, list);
-		if (!strcmp(file->cfg.name, name))
-			return file;
-	}
-
-	return NULL;
-}
-
-struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter)
-{
-	iter->entry = fw_list.next;
-	return list_entry((struct list_head *)iter->entry,
-			  struct fw_file, list);
-}
-
-struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter)
-{
-	iter->entry = ((struct list_head *)iter->entry)->next;
-	return list_entry((struct list_head *)iter->entry,
-			  struct fw_file, list);
-}
-
-bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter)
-{
-	return iter->entry == &fw_list;
-}
-
-void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops)
-{
-	uint32_t qemu;
-	uint32_t dma_enabled;
-
-	fwcfg_present = false;
-	fwcfg_dma_present = false;
-	fwcfg_arch_ops = NULL;
-
-	if (!ops || !ops->arch_read_pio || !ops->arch_read_dma)
-		return;
-	fwcfg_arch_ops = ops;
-
-	qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
-	if (be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE)
-		fwcfg_present = true;
-
-	if (fwcfg_present) {
-		qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
-		if (dma_enabled & FW_CFG_DMA_ENABLED)
-			fwcfg_dma_present = true;
-	}
-}
+UCLASS_DRIVER(qfw) = {
+	.id		= UCLASS_QFW,
+	.name		= "qfw",
+	.per_device_auto	= sizeof(struct qfw_dev),
+};
diff --git a/drivers/misc/qfw_pio.c b/drivers/misc/qfw_pio.c
new file mode 100644
index 0000000000..e2f628d338
--- /dev/null
+++ b/drivers/misc/qfw_pio.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PIO interface for QFW
+ *
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#define LOG_CATEGORY UCLASS_QFW
+
+#include <asm/io.h>
+#include <dm/device.h>
+#include <qfw.h>
+
+/*
+ * PIO ports are correct for x86, which appears to be the only arch that uses
+ * PIO.
+ */
+#define FW_CONTROL_PORT      0x510
+#define FW_DATA_PORT         0x511
+#define FW_DMA_PORT_LOW      0x514
+#define FW_DMA_PORT_HIGH     0x518
+
+static void qfw_pio_read_entry_io(struct udevice *dev, u16 entry, u32 size,
+				  void *address)
+{
+	/*
+	 * writing FW_CFG_INVALID will cause read operation to resume at last
+	 * offset, otherwise read will start at offset 0
+	 *
+	 * Note: on platform where the control register is IO port, the
+	 * endianness is little endian.
+	 */
+	if (entry != FW_CFG_INVALID)
+		outw(cpu_to_le16(entry), FW_CONTROL_PORT);
+
+	/* the endianness of data register is string-preserving */
+	u32 i = 0;
+	u8 *data = address;
+
+	while (size--)
+		data[i++] = inb(FW_DATA_PORT);
+}
+
+/* Read configuration item using fw_cfg DMA interface */
+static void qfw_pio_read_entry_dma(struct udevice *dev, struct qfw_dma *dma)
+{
+	/* the DMA address register is big-endian */
+	outl(cpu_to_be32((uintptr_t)dma), FW_DMA_PORT_HIGH);
+
+	while (be32_to_cpu(dma->control) & ~FW_CFG_DMA_ERROR);
+}
+
+static int qfw_pio_probe(struct udevice *dev)
+{
+	return qfw_register(dev);
+}
+
+static struct dm_qfw_ops qfw_pio_ops = {
+	.read_entry_io = qfw_pio_read_entry_io,
+	.read_entry_dma = qfw_pio_read_entry_dma,
+};
+
+U_BOOT_DRIVER(qfw_pio) = {
+	.name	= "qfw_pio",
+	.id	= UCLASS_QFW,
+	.probe	= qfw_pio_probe,
+	.ops	= &qfw_pio_ops,
+};