[U-Boot] [PATCH v1 2/2] WIP: x86: acpi: Generate SPCR table

[Bin Meng]

Hi Andy,

On Sat, Sep 22, 2018 at 9:05 PM Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
>
> TBD
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> ---
>  arch/x86/include/asm/acpi_table.h | 25 ++++++++++
>  arch/x86/lib/acpi_table.c         | 82 +++++++++++++++++++++++++++++++
>  2 files changed, 107 insertions(+)
>
> diff --git a/arch/x86/include/asm/acpi_table.h b/arch/x86/include/asm/acpi_table.h
> index 95fae036f6..27435871b9 100644
> --- a/arch/x86/include/asm/acpi_table.h
> +++ b/arch/x86/include/asm/acpi_table.h
> @@ -303,6 +303,31 @@ struct acpi_mcfg_mmconfig {
>  /* ACPI global NVS structure */
>  struct acpi_global_nvs;
>
> +/* SPCR (Serial Port Console Redirection table) */
> +struct __packed acpi_spcr {
> +       struct acpi_table_header header;        /* Common ACPI table header */
> +       u8 interface_type;      /* 0=full 16550, 1=subset of 16550 */
> +       u8 reserved[3];
> +       struct acpi_gen_regaddr serial_port;    /* The base address of the Serial Port register set */
> +       u8 interrupt_type;
> +       u8 pc_interrupt;
> +       u32 interrupt;          /* Global system interrupt */
> +       u8 baud_rate;
> +       u8 parity;
> +       u8 stop_bits;
> +       u8 flow_control;
> +       u8 terminal_type;
> +       u8 reserved1;
> +       u16 pci_device_id;      /* Must be 0xffff if not PCI device */
> +       u16 pci_vendor_id;      /* Must be 0xffff if not PCI device */
> +       u8 pci_bus;
> +       u8 pci_device;
> +       u8 pci_function;
> +       u32 pci_flags;
> +       u8 pci_segment;
> +       u32 reserved2;
> +};
> +
>  /* These can be used by the target port */
>
>  void acpi_fill_header(struct acpi_table_header *header, char *signature);
> diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
> index c6b2026613..551a78b11a 100644
> --- a/arch/x86/lib/acpi_table.c
> +++ b/arch/x86/lib/acpi_table.c
> @@ -12,6 +12,7 @@
>  #include <cpu.h>
>  #include <dm.h>
>  #include <dm/uclass-internal.h>
> +#include <serial.h>
>  #include <version.h>
>  #include <asm/acpi/global_nvs.h>
>  #include <asm/acpi_table.h>
> @@ -338,6 +339,79 @@ static void acpi_create_mcfg(struct acpi_mcfg *mcfg)
>         header->checksum = table_compute_checksum((void *)mcfg, header->length);
>  }
>
> +static void acpi_create_spcr(struct acpi_spcr *spcr)
> +{
> +       struct acpi_table_header *header = &(spcr->header);
> +       struct serial_device_info info = {0};
> +       int access_size;
> +       int ret;
> +
> +       /* Fill out header fields */
> +       acpi_fill_header(header, "SPCR");
> +       header->length = sizeof(struct acpi_spcr);
> +       header->revision = 2;
> +
> +       ret = serial_getinfo(&info);
> +       if (ret)
> +               debug("Can't get information of serial device: %d\n", ret);
> +
> +       /* Encode baud rate */
> +       switch (info.baudrate) {
> +       case 9600:
> +               spcr->baud_rate = 3;
> +               break;
> +       case 19200:
> +               spcr->baud_rate = 4;
> +               break;
> +       case 57600:
> +               spcr->baud_rate = 6;
> +               break;
> +       case 115200:
> +               spcr->baud_rate = 7;
> +               break;
> +       default:
> +               spcr->baud_rate = 0;
> +               break;
> +       }
> +
> +       /* Encode register access size */
> +       switch (info.reg_shift) {
> +       case 0:
> +               access_size = ACPI_ACCESS_SIZE_BYTE_ACCESS;
> +               break;
> +       case 1:
> +               access_size = ACPI_ACCESS_SIZE_WORD_ACCESS;
> +               break;
> +       case 2:
> +               access_size = ACPI_ACCESS_SIZE_DWORD_ACCESS;
> +               break;
> +       case 3:
> +               access_size = ACPI_ACCESS_SIZE_QWORD_ACCESS;
> +               break;
> +       default:
> +               access_size = ACPI_ACCESS_SIZE_UNDEFINED;
> +               break;
> +       }
> +
> +       spcr->serial_port.space_id = ACPI_ADDRESS_SPACE_MEMORY;
> +       spcr->serial_port.bit_width = info.reg_width;
> +       spcr->serial_port.bit_offset = info.reg_offset;
> +       spcr->serial_port.access_size = access_size;
> +       spcr->serial_port.addrl = info.addr >> 0;
> +       spcr->serial_port.addrh = info.addr >> 32;
> +
> +       /* Hard coded values for now */
> +       spcr->parity = 0;
> +       spcr->stop_bits = 1;
> +
> +       /* No PCI devices for now */
> +       spcr->pci_device_id = 0xffff;
> +       spcr->pci_vendor_id = 0xffff;
> +

I see not every member of 'struct __packed acpi_spcr' is populated.
Are they not used by kernel? If kernel does not use it, it is used by
Windows?

> +       /* Fix checksum */
> +       header->checksum = table_compute_checksum((void *)spcr, header->length);
> +}
> +
>  /*
>   * QEMU's version of write_acpi_tables is defined in drivers/misc/qfw.c
>   */
> @@ -352,6 +426,7 @@ ulong write_acpi_tables(ulong start)
>         struct acpi_fadt *fadt;
>         struct acpi_mcfg *mcfg;
>         struct acpi_madt *madt;
> +       struct acpi_spcr *spcr;
>         int i;
>
>         current = start;
> @@ -440,6 +515,13 @@ ulong write_acpi_tables(ulong start)
>         acpi_add_table(rsdp, mcfg);
>         current = ALIGN(current, 16);
>
> +       debug("ACPI:    * SPCR\n");
> +       spcr = (struct acpi_spcr *)current;
> +       acpi_create_spcr(spcr);
> +       current += spcr->header.length;
> +       acpi_add_table(rsdp, spcr);
> +       current = ALIGN(current, 16);
> +
>         debug("current = %x\n", current);
>
>         acpi_rsdp_addr = (unsigned long)rsdp;
> --

Regards,
Bin