[RFC,22/29] xen/arm: Allow Xen to run on multiple platform without recompilation

Xen can include various platform support (ie: exynos5, versatile express...)
and choose during boot time a set of callbacks for the current board.
These callbacks will be called in places where each board can have specific
code. For the moment the callbacks are:
  - platform_init: additional initialization for the platform
  - platform_init_time: some platform (ie: Exynos 5) needs to initialize
  the timer with an uncommon way
  - platform_specific_mapping: add mapping to dom0 which are not specified
  in the device tree
  - platform_reset: reset the platform

Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
 xen/arch/arm/Makefile          |    1 +
 xen/arch/arm/domain_build.c    |    4 ++
 xen/arch/arm/platform.c        |  121 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/setup.c           |    3 +
 xen/arch/arm/shutdown.c        |    2 +
 xen/arch/arm/time.c            |    6 ++
 xen/arch/arm/xen.lds.S         |    6 ++
 xen/include/asm-arm/platform.h |   70 +++++++++++++++++++++++
 8 files changed, 213 insertions(+)
 create mode 100644 xen/arch/arm/platform.c
 create mode 100644 xen/include/asm-arm/platform.h

On Mon, 2013-04-29 at 00:02 +0100, Julien Grall wrote:
> Xen can include various platform support (ie: exynos5, versatile express...)
> and choose during boot time a set of callbacks for the current board.
> These callbacks will be called in places where each board can have specific
> code. For the moment the callbacks are:
>   - platform_init: additional initialization for the platform
>   - platform_init_time: some platform (ie: Exynos 5) needs to initialize
>   the timer with an uncommon way
>   - platform_specific_mapping: add mapping to dom0 which are not specified
>   in the device tree
>   - platform_reset: reset the platform
> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>

alignment in xen.lds.S again, otherwise:

Acked-by: Ian Campbell <ian.campbell@citrix.com>

On 04/29/2013 05:15 PM, Ian Campbell wrote:

> On Mon, 2013-04-29 at 00:02 +0100, Julien Grall wrote:
>> Xen can include various platform support (ie: exynos5, versatile express...)
>> and choose during boot time a set of callbacks for the current board.
>> These callbacks will be called in places where each board can have specific
>> code. For the moment the callbacks are:
>>   - platform_init: additional initialization for the platform
>>   - platform_init_time: some platform (ie: Exynos 5) needs to initialize
>>   the timer with an uncommon way
>>   - platform_specific_mapping: add mapping to dom0 which are not specified
>>   in the device tree
>>   - platform_reset: reset the platform
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
> 
> alignment in xen.lds.S again, otherwise:

I will fix with ALIGN(8).

> Acked-by: Ian Campbell <ian.campbell@citrix.com>
> 
> 
>

On Mon, 29 Apr 2013, Julien Grall wrote:
> Xen can include various platform support (ie: exynos5, versatile express...)
> and choose during boot time a set of callbacks for the current board.
> These callbacks will be called in places where each board can have specific
> code. For the moment the callbacks are:
>   - platform_init: additional initialization for the platform
>   - platform_init_time: some platform (ie: Exynos 5) needs to initialize
>   the timer with an uncommon way
>   - platform_specific_mapping: add mapping to dom0 which are not specified
>   in the device tree
>   - platform_reset: reset the platform

given that you added a platform_reset hook, you might as well add a
platform_poweroff hook too.


> Signed-off-by: Julien Grall <julien.grall@linaro.org>
> ---
>  xen/arch/arm/Makefile          |    1 +
>  xen/arch/arm/domain_build.c    |    4 ++
>  xen/arch/arm/platform.c        |  121 ++++++++++++++++++++++++++++++++++++++++
>  xen/arch/arm/setup.c           |    3 +
>  xen/arch/arm/shutdown.c        |    2 +
>  xen/arch/arm/time.c            |    6 ++
>  xen/arch/arm/xen.lds.S         |    6 ++
>  xen/include/asm-arm/platform.h |   70 +++++++++++++++++++++++
>  8 files changed, 213 insertions(+)
>  create mode 100644 xen/arch/arm/platform.c
>  create mode 100644 xen/include/asm-arm/platform.h
> 
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 7a73b79..981ad78 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -17,6 +17,7 @@ obj-y += p2m.o
>  obj-y += percpu.o
>  obj-y += guestcopy.o
>  obj-y += physdev.o
> +obj-y += platform.o
>  obj-y += setup.o
>  obj-y += time.o
>  obj-y += smpboot.o
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 11298e1..d6b8086 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -12,6 +12,7 @@
>  #include <xen/libfdt/libfdt.h>
>  #include <xen/guest_access.h>
>  #include <asm/setup.h>
> +#include <asm/platform.h>
>  
>  #include <asm/gic.h>
>  #include <xen/irq.h>
> @@ -516,6 +517,9 @@ int construct_dom0(struct domain *d)
>          return rc;
>  
>      parse_device_tree(d);
> +    rc = platform_specific_mapping(d);
> +    if ( rc < 0 )
> +        return rc;
>  
>      /* The following loads use the domain's p2m */
>      p2m_load_VTTBR(d);
> diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
> new file mode 100644
> index 0000000..ba569ea
> --- /dev/null
> +++ b/xen/arch/arm/platform.c
> @@ -0,0 +1,121 @@
> +/*
> + * xen/arch/arm/platform.c
> + *
> + * Helpers to execute platform specific code.
> + *
> + * Julien Grall <julien.grall@linaro.org>
> + * Copyright (C) 2013 Linaro Limited.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <asm/platform.h>
> +#include <xen/device_tree.h>
> +#include <xen/init.h>
> +
> +extern const struct platform_desc _splatform[], _eplatform[];
> +
> +/* Pointer to the current platform description */
> +static const struct platform_desc *platform;
> +
> +
> +static bool_t __init platform_is_compatible(const struct platform_desc *plat)
> +{
> +    const char *const *compat;
> +
> +    if ( !plat->compatible )
> +        return 0;
> +
> +    for ( compat = plat->compatible; *compat; compat++ )
> +    {
> +        if ( dt_machine_is_compatible(*compat) )
> +            return 1;
> +    }
> +
> +    return 0;
> +}
> +
> +/* List of possible platform */
> +static void dump_platform_table(void)
> +{
> +    const struct platform_desc *p;
> +
> +    printk("Available platform support:\n");
> +
> +    for ( p = _splatform; p != _eplatform; p++ )
> +        printk("    - %s\n", p->name);
> +}
> +
> +int __init platform_init(void)
> +{
> +    int res = 0;
> +
> +    ASSERT(platform == NULL);
> +
> +    /* Looking for the platform description */
> +    for ( platform = _splatform; platform != _eplatform; platform++ )
> +    {
> +        if ( platform_is_compatible(platform) )
> +            break;
> +    }
> +
> +    /* We don't have specific operations for this platform */
> +    if ( platform == _eplatform )
> +    {
> +        /* TODO: List compatible */
> +        printk(XENLOG_WARNING "WARNING: Unrecognized/unsupported device tree "
> +              "compatible list\n");
> +        dump_platform_table();
> +        platform = NULL;
> +    }
> +    else
> +        printk(XENLOG_INFO "Platform: %s\n", platform->name);
> +
> +    if ( platform && platform->init )
> +        res = platform->init();
> +
> +    return res;
> +}
> +
> +int __init platform_init_time(void)
> +{
> +    int res = 0;
> +
> +    if ( platform && platform->init_time )
> +        res = platform->init_time();
> +
> +    return res;
> +}
> +
> +int __init platform_specific_mapping(struct domain *d)
> +{
> +    int res = 0;
> +
> +    if ( platform && platform->specific_mapping )
> +        res = platform->specific_mapping(d);
> +
> +    return res;
> +}
> +
> +void platform_reset(void)
> +{
> +    if ( platform && platform->reset )
> +        platform->reset();
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index aee491d..9721150 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -41,6 +41,7 @@
>  #include <asm/early_printk.h>
>  #include <asm/gic.h>
>  #include <asm/cpufeature.h>
> +#include <asm/platform.h>
>  
>  struct cpuinfo_arm __read_mostly boot_cpu_data;
>  
> @@ -439,6 +440,8 @@ void __init start_xen(unsigned long boot_phys_offset,
>  
>      processor_id();
>  
> +    platform_init();
> +
>      init_xen_time();
>  
>      gic_init();
> diff --git a/xen/arch/arm/shutdown.c b/xen/arch/arm/shutdown.c
> index c1b60af..a5c2085 100644
> --- a/xen/arch/arm/shutdown.c
> +++ b/xen/arch/arm/shutdown.c
> @@ -5,6 +5,7 @@
>  #include <xen/lib.h>
>  #include <xen/mm.h>
>  #include <xen/smp.h>
> +#include <asm/platform.h>
>  
>  static void raw_machine_reset(void)
>  {
> @@ -21,6 +22,7 @@ static void raw_machine_reset(void)
>      dsb(); isb();
>      clear_fixmap(FIXMAP_MISC);
>  #endif
> +    platform_reset();
>  }
>  
>  static void halt_this_cpu(void *arg)
> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> index 63dace2..f01be3f 100644
> --- a/xen/arch/arm/time.c
> +++ b/xen/arch/arm/time.c
> @@ -33,6 +33,7 @@
>  #include <asm/time.h>
>  #include <asm/gic.h>
>  #include <asm/cpufeature.h>
> +#include <asm/platform.h>
>  
>  /*
>   * Unfortunately the hypervisor timer interrupt appears to be buggy in
> @@ -130,6 +131,11 @@ int __init init_xen_time(void)
>          panic("CPU does not support the Generic Timer v1 interface.\n");
>  
>      cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
> +
> +    res = platform_init_time();
> +    if ( res )
> +        return res;
> +
>      boot_count = READ_SYSREG64(CNTPCT_EL0);
>      printk("Using generic timer at %lu KHz\n", cpu_khz);
>  
> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> index 7434e83..b5c99b7 100644
> --- a/xen/arch/arm/xen.lds.S
> +++ b/xen/arch/arm/xen.lds.S
> @@ -76,6 +76,12 @@ SECTIONS
>    __lock_profile_end = .;
>  #endif
>  
> +  .arch.info : {
> +      _splatform = .;
> +      *(.arch.info)
> +      _eplatform = .;
> +  } :text
> +
>    .dev.info : {
>        _sdevice = .;
>        *(.dev.info)
> diff --git a/xen/include/asm-arm/platform.h b/xen/include/asm-arm/platform.h
> new file mode 100644
> index 0000000..c89a4ca
> --- /dev/null
> +++ b/xen/include/asm-arm/platform.h
> @@ -0,0 +1,70 @@
> +#ifndef __ASM_ARM_PLATFORM_H
> +#define __ASM_ARM_PLATFORM_H
> +
> +#include <xen/init.h>
> +#include <xen/sched.h>
> +#include <xen/mm.h>
> +
> +/* Describe specific operation for a board */
> +struct platform_desc {
> +    /* Platform name */
> +    const char *name;
> +    /* Array of device tree 'compatible' strings */
> +    const char *const *compatible;
> +    /* Platform initialization */
> +    int (*init)(void);
> +    int (*init_time)(void);
> +    /* Specific mapping for dom0 */
> +    int (*specific_mapping)(struct domain *d);
> +    /* Platform reset */
> +    void (*reset)(void);
> +};
> +
> +int __init platform_init(void);
> +int __init platform_init_time(void);
> +int __init platform_specific_mapping(struct domain *d);
> +void platform_reset(void);
> +
> +/* Helper to read/write a register */
> +static inline uint32_t platform_read_register(uint32_t addr)
> +{
> +    volatile const uint32_t *reg;
> +    uint32_t value;
> +
> +    set_fixmap(FIXMAP_MISC, addr >> PAGE_SHIFT, DEV_SHARED);
> +    reg = (uint32_t *)(FIXMAP_ADDR(FIXMAP_MISC) + (addr & ~PAGE_MASK));
> +    value = *reg;
> +    dsb(); isb();
> +    clear_fixmap(FIXMAP_MISC);
> +
> +    return value;
> +}
> +
> +static inline void platform_write_register(uint32_t addr, uint32_t value)
> +{
> +    volatile uint32_t *reg;
> +
> +    set_fixmap(FIXMAP_MISC, addr >> PAGE_SHIFT, DEV_SHARED);
> +    reg = (uint32_t *)(FIXMAP_ADDR(FIXMAP_MISC) + (addr & ~PAGE_MASK));
> +    *reg = value;
> +    clear_fixmap(FIXMAP_MISC);
> +}
> +
> +#define PLATFORM_START(_name, _namestr)                         \
> +static const struct platform_desc  __plat_desc_##_name __used   \
> +__attribute__((__section__(".arch.info"))) = {                  \
> +    .name = _namestr,
> +
> +#define PLATFORM_END                                            \
> +};
> +
> +#endif /* __ASM_ARM_PLATFORM_H */
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> -- 
> Julien Grall
>