[U-Boot] [PATCH v5 088/101] x86: apl: Add systemagent driver

[Bin Meng]

Hi Simon,

On Mon, Nov 25, 2019 at 12:12 PM Simon Glass <sjg at chromium.org> wrote:
>
> This driver handles communication with the systemagent which needs to be
> told when U-Boot has completed its init.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
>
> ---
>
> Changes in v5: None
> Changes in v4:
> - Add a comment for enable_bios_reset_cpl()
> - Tidy up header guards
> - use GENMASK() for VTBAR_MASK
>
> Changes in v3: None
> Changes in v2: None
>
>  arch/x86/cpu/apollolake/Makefile              |  2 +
>  arch/x86/cpu/apollolake/systemagent.c         | 19 ++++++++++
>  .../include/asm/arch-apollolake/systemagent.h | 37 +++++++++++++++++++
>  3 files changed, 58 insertions(+)
>  create mode 100644 arch/x86/cpu/apollolake/systemagent.c
>  create mode 100644 arch/x86/include/asm/arch-apollolake/systemagent.h
>
> diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile
> index fdda748ea3..3a8c2f66a3 100644
> --- a/arch/x86/cpu/apollolake/Makefile
> +++ b/arch/x86/cpu/apollolake/Makefile
> @@ -2,5 +2,7 @@
>  #
>  # Copyright 2019 Google LLC
>
> +obj-$(CONFIG_SPL_BUILD) += systemagent.o
> +
>  obj-y += pmc.o
>  obj-y += uart.o
> diff --git a/arch/x86/cpu/apollolake/systemagent.c b/arch/x86/cpu/apollolake/systemagent.c
> new file mode 100644
> index 0000000000..3a41b329c3
> --- /dev/null
> +++ b/arch/x86/cpu/apollolake/systemagent.c
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2017 Intel Corporation.
> + * Take from coreboot project file of the same name
> + */
> +
> +#include <common.h>
> +#include <asm/intel_regs.h>
> +#include <asm/io.h>
> +#include <asm/arch/systemagent.h>
> +
> +void enable_bios_reset_cpl(void)
> +{
> +       /*
> +        * Set bits 0+1 of BIOS_RESET_CPL to indicate to the CPU
> +        * that BIOS has initialised memory and power management
> +        */

Is this absolutely necessary? What happens if we don't do this? Or
does FSP-S do such for us?

> +       setbits_8(MCHBAR_REG(BIOS_RESET_CPL), 3);
> +}
> diff --git a/arch/x86/include/asm/arch-apollolake/systemagent.h b/arch/x86/include/asm/arch-apollolake/systemagent.h
> new file mode 100644
> index 0000000000..206d8903fa
> --- /dev/null
> +++ b/arch/x86/include/asm/arch-apollolake/systemagent.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2017 Intel Corporation.
> + * Take from coreboot project file of the same name
> + */
> +
> +#ifndef _ASM_ARCH_SYSTEMAGENT_H
> +#define _ASM_ARCH_SYSTEMAGENT_H
> +
> +/* Device 0:0.0 PCI configuration space */
> +#define MCHBAR         0x48
> +
> +/* RAPL Package Power Limit register under MCHBAR */
> +#define PUNIT_THERMAL_DEVICE_IRQ               0x700C
> +#define PUINT_THERMAL_DEVICE_IRQ_VEC_NUMBER    0x18
> +#define PUINT_THERMAL_DEVICE_IRQ_LOCK          0x80000000
> +#define BIOS_RESET_CPL         0x7078
> +#define   PCODE_INIT_DONE      BIT(8)
> +#define MCHBAR_RAPL_PPL                0x70A8
> +#define CORE_DISABLE_MASK      0x7168
> +#define CAPID0_A               0xE4
> +#define   VTD_DISABLE          BIT(23)
> +#define DEFVTBAR               0x6c80
> +#define GFXVTBAR               0x6c88
> +#define   VTBAR_ENABLED                0x01
> +#define VTBAR_MASK             GENMASK_ULL(39, 12)
> +#define VTBAR_SIZE             0x1000
> +
> +/**
> + * enable_bios_reset_cpl() - Tell the system agent that memory/power are ready
> + *
> + * This should be called when U-Boot has set up the memory and power
> + * management.
> + */
> +void enable_bios_reset_cpl(void);
> +
> +#endif
> --

Regards,
Bin