[U-Boot] [PATCH v4 1/8] x86: qemu: add fw_cfg support
Miao Yan
yanmiaobest at gmail.com
Thu Dec 31 09:42:09 CET 2015
Hi Simon,
2015-12-31 13:07 GMT+08:00 Simon Glass <sjg at chromium.org>:
> Hi Miao,
>
> On 30 December 2015 at 19:55, Miao Yan <yanmiaobest at gmail.com> wrote:
>> The QEMU fw_cfg interface allows the guest to retrieve various
>> data information from QEMU. For example, APCI/SMBios tables, number
>> of online cpus, kernel data and command line, etc.
>>
>> This patch adds support for QEMU fw_cfg interface.
>>
>> Signed-off-by: Miao Yan <yanmiaobest at gmail.com>
>> ---
>> Changes in v4:
>> - cleanups
>> - change 'fw load' to take second parameter for initrd load address
>>
>> arch/x86/cpu/qemu/Makefile | 2 +-
>> arch/x86/cpu/qemu/fw_cfg.c | 268 +++++++++++++++++++++++++++++++++++++++++++++
>> arch/x86/cpu/qemu/fw_cfg.h | 97 ++++++++++++++++
>> arch/x86/cpu/qemu/qemu.c | 3 +
>> 4 files changed, 369 insertions(+), 1 deletion(-)
>> create mode 100644 arch/x86/cpu/qemu/fw_cfg.c
>> create mode 100644 arch/x86/cpu/qemu/fw_cfg.h
>
> Reviewed-by: Simon Glass <sjg at chromium.org>
>
> But a few nits...
>
>>
>> diff --git a/arch/x86/cpu/qemu/Makefile b/arch/x86/cpu/qemu/Makefile
>> index 3f3958a..ad424ec 100644
>> --- a/arch/x86/cpu/qemu/Makefile
>> +++ b/arch/x86/cpu/qemu/Makefile
>> @@ -7,5 +7,5 @@
>> ifndef CONFIG_EFI_STUB
>> obj-y += car.o dram.o
>> endif
>> -obj-y += qemu.o
>> +obj-y += qemu.o fw_cfg.o
>
> Can you put the new file first, so that the list is in alphabetical order?
>
>> obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi.o dsdt.o
>> diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c
>> new file mode 100644
>> index 0000000..9de8680
>> --- /dev/null
>> +++ b/arch/x86/cpu/qemu/fw_cfg.c
>> @@ -0,0 +1,268 @@
>> +/*
>> + * (C) Copyright 2015 Miao Yan <yanmiaoebst at gmail.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <command.h>
>> +#include <errno.h>
>> +#include <malloc.h>
>> +#include <asm/io.h>
>> +#include "fw_cfg.h"
>> +
>> +static bool fwcfg_present;
>> +static bool fwcfg_dma_present;
>> +
>> +static void qemu_fwcfg_read_entry_pio(uint16_t entry,
>> + uint32_t size, void *address)
>
> Function comment - what does this do?
>
>> +{
>> + uint32_t i = 0;
>> + uint8_t *data = address;
>> +
>> + /*
>> + * writting FW_CFG_INVALID will cause
>> + * read operation to resume at
>> + * last offset, otherwise read will
>> + * start at offset 0
>
> Please can you format comments to 75 columns or thereabout?
>
>> + */
>> +
>> + if (entry != FW_CFG_INVALID)
>> + outw(entry, FW_CONTROL_PORT);
>> + while (size--)
>> + data[i++] = inb(FW_DATA_PORT);
>> +}
>> +
>> +static void qemu_fwcfg_read_entry_dma(uint16_t entry,
>> + uint32_t size, void *address)
>> +{
>> + struct fw_cfg_dma_access dma;
>> +
>> + dma.length = cpu_to_be32(size);
>> + dma.address = cpu_to_be64((uintptr_t)address);
>> + dma.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
>> + */
>> +
>> + if (entry != FW_CFG_INVALID)
>> + dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
>> +
>> + barrier();
>> +
>> + debug("qemu_fwcfg_dma_read_entry: addr %p, length %u control 0x%x\n",
>> + address, size, be32_to_cpu(dma.control));
>> +
>> + outl(cpu_to_be32((uint32_t)&dma), FW_DMA_PORT_HIGH);
>> +
>> + while (be32_to_cpu(dma.control) & ~FW_CFG_DMA_ERROR)
>> + __asm__ __volatile__ ("pause");
>> +}
>> +
>> +static bool qemu_fwcfg_present(void)
>> +{
>> + uint32_t qemu;
>> +
>> + qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
>> + return be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE;
>> +}
>> +
>> +static bool qemu_fwcfg_dma_present(void)
>> +{
>> + uint8_t dma_enabled;
>> +
>> + qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
>> + if (dma_enabled & FW_CFG_DMA_ENABLED)
>> + return true;
>> +
>> + return false;
>> +}
>> +
>> +static 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);
>> + else
>> + qemu_fwcfg_read_entry_pio(entry, length, address);
>> +}
>> +
>> +int qemu_fwcfg_online_cpus(void)
>> +{
>> + uint16_t nb_cpus;
>> +
>> + if (!fwcfg_present)
>> + return 1;
>
> -ENODEV
Can we return 1 cpu if fw_cfg interface is not avaliable (which is
quite unlikey),
and print a warning maybe ? Because there has to be one cpu at least
and returning
-ENODEV wouldn't make much difference.
I'll fix rest of your comments and thanks for the review.
Miao
>
>> +
>> + qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
>> +
>> + return le16_to_cpu(nb_cpus);
>> +}
>> +
>> +static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr)
>
> Function comment
>
>> +{
>> + char *data_addr;
>> + uint32_t setup_size, kernel_size, cmdline_size, initrd_size;
>> +
>> + qemu_fwcfg_read_entry(FW_CFG_SETUP_SIZE, 4, &setup_size);
>> + qemu_fwcfg_read_entry(FW_CFG_KERNEL_SIZE, 4, &kernel_size);
>> +
>> + if (setup_size == 0 || kernel_size == 0) {
>> + printf("warning: no kernel available\n");
>> + return -1;
>> + }
>> +
>> + data_addr = load_addr;
>> + qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA,
>> + le32_to_cpu(setup_size), data_addr);
>> + data_addr += le32_to_cpu(setup_size);
>> +
>> + qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA,
>> + le32_to_cpu(kernel_size), data_addr);
>> + data_addr += le32_to_cpu(kernel_size);
>> +
>> + data_addr = initrd_addr;
>> + qemu_fwcfg_read_entry(FW_CFG_INITRD_SIZE, 4, &initrd_size);
>> + if (initrd_size == 0) {
>> + printf("warning: no initrd available\n");
>> + } else {
>> + qemu_fwcfg_read_entry(FW_CFG_INITRD_DATA,
>> + le32_to_cpu(initrd_size), data_addr);
>> + data_addr += le32_to_cpu(initrd_size);
>> + }
>> +
>> + qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
>> + if (cmdline_size) {
>> + qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA,
>> + le32_to_cpu(cmdline_size), data_addr);
>> + if (setenv("bootargs", data_addr) < 0)
>> + printf("warning: unable to change bootargs\n");
>> + }
>> +
>> + printf("loading kernel to address %p", load_addr);
>> + if (initrd_size)
>> + printf(" initrd %p, size 0x%x\n",
>> + initrd_addr,
>> + le32_to_cpu(initrd_size));
>> + else
>> + printf("\n");
>> +
>> + return 0;
>> +}
>> +
>> +static int qemu_fwcfg_list_firmware(void)
>> +{
>> + int i;
>> + uint32_t count;
>> + struct fw_cfg_files *files;
>> +
>> + qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
>> + if (!count)
>> + return 0;
>> +
>> + count = be32_to_cpu(count);
>> + files = malloc(count * sizeof(struct fw_cfg_file));
>> + if (!files)
>> + return -ENOMEM;
>> +
>> + files->count = count;
>> + qemu_fwcfg_read_entry(FW_CFG_INVALID,
>> + count * sizeof(struct fw_cfg_file),
>> + files->files);
>> +
>> + for (i = 0; i < files->count; i++)
>> + printf("%-56s\n", files->files[i].name);
>> + free(files);
>> + return 0;
>> +}
>> +
>> +void qemu_fwcfg_init(void)
>> +{
>> + fwcfg_present = qemu_fwcfg_present();
>> + if (fwcfg_present)
>> + fwcfg_dma_present = qemu_fwcfg_dma_present();
>> +}
>> +
>> +static int qemu_fwcfg_do_list(cmd_tbl_t *cmdtp, int flag,
>> + int argc, char * const argv[])
>> +{
>> + qemu_fwcfg_list_firmware();
>
> Check return value and return CMD_RET_FAILURE if non-zero.
>
>> +
>> + return 0;
>> +}
>> +
>> +static int qemu_fwcfg_do_cpus(cmd_tbl_t *cmdtp, int flag,
>> + int argc, char * const argv[])
>> +{
>> + printf("%d cpu(s) online\n", qemu_fwcfg_online_cpus());
>
> But qemu_fwcfg_online_cpus() can fail.
>
>> +
>> + return 0;
>> +}
>> +
>> +static int qemu_fwcfg_do_load(cmd_tbl_t *cmdtp, int flag,
>> + int argc, char * const argv[])
>> +{
>> + char *env;
>> + void *load_addr;
>> + void *initrd_addr;
>> +
>> + env = getenv("loadaddr");
>> + load_addr = env ?
>> + (void *)simple_strtoul(env, NULL, 16) :
>> + (void *)CONFIG_LOADADDR;
>> +
>> + env = getenv("ramdiskaddr");
>> + initrd_addr = env ?
>> + (void *)simple_strtoul(env, NULL, 16) :
>> + (void *)CONFIG_RAMDISK_ADDR;
>> +
>> + if (argc == 2) {
>> + load_addr = (void *)simple_strtoul(argv[0], NULL, 16);
>> + initrd_addr = (void *)simple_strtoul(argv[1], NULL, 16);
>> + } else if (argc == 1) {
>> + load_addr = (void *)simple_strtoul(argv[0], NULL, 16);
>> + }
>> +
>> + return qemu_fwcfg_setup_kernel(load_addr, initrd_addr);
>> +}
>> +
>> +static cmd_tbl_t fwcfg_commands[] = {
>> + U_BOOT_CMD_MKENT(list, 0, 1, qemu_fwcfg_do_list, "", ""),
>> + U_BOOT_CMD_MKENT(cpus, 0, 1, qemu_fwcfg_do_cpus, "", ""),
>> + U_BOOT_CMD_MKENT(load, 2, 1, qemu_fwcfg_do_load, "", ""),
>> +};
>> +
>> +static int do_qemu_fw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>> +{
>> + int ret;
>> + cmd_tbl_t *fwcfg_cmd;
>> +
>> + if (!fwcfg_present) {
>> + printf("QEMU fw_cfg interface not found\n");
>> + return CMD_RET_USAGE;
>> + }
>> +
>> + fwcfg_cmd = find_cmd_tbl(argv[1], fwcfg_commands,
>> + ARRAY_SIZE(fwcfg_commands));
>> + argc -= 2;
>> + argv += 2;
>> + if (!fwcfg_cmd || argc > fwcfg_cmd->maxargs)
>> + return CMD_RET_USAGE;
>> +
>> + ret = fwcfg_cmd->cmd(fwcfg_cmd, flag, argc, argv);
>> +
>> + return cmd_process_error(fwcfg_cmd, ret);
>> +}
>> +
>> +U_BOOT_CMD(
>> + fw, 4, 1, do_qemu_fw,
>
> I worry that 'fw' is too generic. Perhaps qfw would be better?
>
>> + "QEMU firmware interface",
>> + "<command>\n"
>> + " - list : print firmware(s) currently loaded\n"
>> + " - cpus : print online cpu number\n"
>
> print number of online CPUs
>
>> + " - load <kernel addr> <initrd addr> : load kernel and initrd (if any), and setup for zboot\n"
>> +)
>> diff --git a/arch/x86/cpu/qemu/fw_cfg.h b/arch/x86/cpu/qemu/fw_cfg.h
>> new file mode 100644
>> index 0000000..03ac27d
>> --- /dev/null
>> +++ b/arch/x86/cpu/qemu/fw_cfg.h
>> @@ -0,0 +1,97 @@
>> +/*
>> + * (C) Copyright 2015 Miao Yan <yanmiaobest at gmail.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0+
>> + */
>> +
>> +#ifndef __FW_CFG__
>> +#define __FW_CFG__
>> +
>> +#define FW_CONTROL_PORT 0x510
>> +#define FW_DATA_PORT 0x511
>> +#define FW_DMA_PORT_LOW 0x514
>> +#define FW_DMA_PORT_HIGH 0x518
>> +
>> +enum qemu_fwcfg_items {
>> + FW_CFG_SIGNATURE = 0x00,
>> + FW_CFG_ID = 0x01,
>> + FW_CFG_UUID = 0x02,
>> + FW_CFG_RAM_SIZE = 0x03,
>> + FW_CFG_NOGRAPHIC = 0x04,
>> + FW_CFG_NB_CPUS = 0x05,
>> + FW_CFG_MACHINE_ID = 0x06,
>> + FW_CFG_KERNEL_ADDR = 0x07,
>> + FW_CFG_KERNEL_SIZE = 0x08,
>> + FW_CFG_KERNEL_CMDLINE = 0x09,
>> + FW_CFG_INITRD_ADDR = 0x0a,
>> + FW_CFG_INITRD_SIZE = 0x0b,
>> + FW_CFG_BOOT_DEVICE = 0x0c,
>> + FW_CFG_NUMA = 0x0d,
>> + FW_CFG_BOOT_MENU = 0x0e,
>> + FW_CFG_MAX_CPUS = 0x0f,
>> + FW_CFG_KERNEL_ENTRY = 0x10,
>> + FW_CFG_KERNEL_DATA = 0x11,
>> + FW_CFG_INITRD_DATA = 0x12,
>> + FW_CFG_CMDLINE_ADDR = 0x13,
>> + FW_CFG_CMDLINE_SIZE = 0x14,
>> + FW_CFG_CMDLINE_DATA = 0x15,
>> + FW_CFG_SETUP_ADDR = 0x16,
>> + FW_CFG_SETUP_SIZE = 0x17,
>> + FW_CFG_SETUP_DATA = 0x18,
>> + FW_CFG_FILE_DIR = 0x19,
>> + FW_CFG_FILE_FIRST = 0x20,
>> + FW_CFG_WRITE_CHANNEL = 0x4000,
>> + FW_CFG_ARCH_LOCAL = 0x8000,
>> + FW_CFG_INVALID = 0xffff,
>> +};
>> +
>> +#define FW_CFG_FILE_SLOTS 0x10
>> +#define FW_CFG_MAX_ENTRY (FW_CFG_FILE_FIRST+FW_CFG_FILE_SLOTS)
>> +#define FW_CFG_ENTRY_MASK ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
>> +
>> +#define FW_CFG_MAX_FILE_PATH 56
>> +
>> +#define QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
>> +
>> +#define FW_CFG_DMA_ERROR (1 << 0)
>> +#define FW_CFG_DMA_READ (1 << 1)
>> +#define FW_CFG_DMA_SKIP (1 << 2)
>> +#define FW_CFG_DMA_SELECT (1 << 3)
>> +
>> +#define FW_CFG_DMA_ENABLED (1 << 1)
>> +
>> +struct fw_cfg_file {
>> + __be32 size;
>> + __be16 select;
>> + __be16 reserved;
>> + char name[FW_CFG_MAX_FILE_PATH];
>> +};
>> +
>> +struct fw_cfg_files {
>> + __be32 count;
>> + struct fw_cfg_file files[];
>> +};
>> +
>> +struct fw_cfg_dma_access {
>> + __be32 control;
>> + __be32 length;
>> + __be64 address;
>> +};
>> +
>> +/**
>> + * Initialize QEMU fw_cfg interface
>> + *
>> + * @return: None
>
> You can drop this line
>
>> + */
>> +
>> +void qemu_fwcfg_init(void);
>> +
>> +/**
>> + * Get system cpu number
>> + *
>> + * @return: cpu number in system
>> + */
>> +
>> +int qemu_fwcfg_online_cpus(void);
>> +
>> +#endif
>> diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c
>> index 1f93f72..d9ae066 100644
>> --- a/arch/x86/cpu/qemu/qemu.c
>> +++ b/arch/x86/cpu/qemu/qemu.c
>> @@ -11,6 +11,7 @@
>> #include <asm/processor.h>
>> #include <asm/arch/device.h>
>> #include <asm/arch/qemu.h>
>> +#include "fw_cfg.h"
>>
>> static bool i440fx;
>>
>> @@ -57,6 +58,8 @@ static void qemu_chipset_init(void)
>> x86_pci_write_config32(PCI_BDF(0, 0, 0), PCIEX_BAR,
>> CONFIG_PCIE_ECAM_BASE | BAR_EN);
>> }
>> +
>> + qemu_fwcfg_init();
>> }
>>
>> int arch_cpu_init(void)
>> --
>> 1.9.1
>>
>
> Regards,
> Simon
More information about the U-Boot
mailing list