[03/11] efi: Refactor efi_memmap_init_early() into arch-neutral code

Hi Matt,

On 23 June 2016 at 13:34, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> Every EFI architecture apart from ia64 needs to setup the EFI memory

> map at efi.memmap, and the code for doing that is essentially the same

> across all implementations. Therefore, it makes sense to factor this

> out into the common code under drivers/firmware/efi/.

>

> The only slight variation is the data structure out of which we pull

> the initial memory map information, such as physical address, memory

> descriptor size and version, etc. We can address this by passing a

> generic data structure (struct efi_memory_map_data) as the argument to

> efi_memmap_init_early() which contains the minimum info required for

> initialising the memory map.

>

> In the process, this patch also fixes a few undesirable implementation

> differences:

>

>  - ARM and arm64 were failing to clear the EFI_MEMMAP bit when

>    unmapping the early EFI memory map. EFI_MEMMAP indicates whether

>    the EFI memory map is mapped (not the regions contained within) and

>    can be traversed.  It's more correct to set the bit as soon as we

>    memremap() the passed in EFI memmap.

>


This patch (and the series) looks mostly fine to me, but this patch
does break ARM currently, please see below.

>  - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the

>    regular naming scheme.

>

> This patch also uses a read-write mapping for the memory map instead

> of the read-only mapping currently used on ARM and arm64. x86 needs

> the ability to update the memory map in-place when assigning virtual

> addresses to regions (efi_map_region()) and tagging regions when

> reserving boot services (efi_reserve_boot_services()).

>

> There's no way for the generic fake_mem code to know which mapping to

> use without introducing some arch-specific constant/hook, so just use

> read-write since read-only is of dubious value for the EFI memory map.

>

> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> Cc: Leif Lindholm <leif.lindholm@linaro.org>

> Cc: Peter Jones <pjones@redhat.com>

> Cc: Borislav Petkov <bp@alien8.de>

> Cc: Mark Rutland <mark.rutland@arm.com>

> Cc: Dave Young <dyoung@redhat.com>

> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

> ---

>  arch/x86/include/asm/efi.h      |  1 -

>  arch/x86/platform/efi/efi.c     | 66 +++++++++++------------------------------

>  arch/x86/platform/efi/quirks.c  |  4 +--

>  drivers/firmware/efi/arm-init.c | 17 +++++------

>  drivers/firmware/efi/efi.c      | 46 ++++++++++++++++++++++++++++

>  drivers/firmware/efi/fake_mem.c | 15 ++++++----

>  include/linux/efi.h             | 16 ++++++++++

>  7 files changed, 98 insertions(+), 67 deletions(-)

>

> diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h

> index 78d1e7467eae..67983035bd7b 100644

> --- a/arch/x86/include/asm/efi.h

> +++ b/arch/x86/include/asm/efi.h

> @@ -118,7 +118,6 @@ extern int __init efi_memblock_x86_reserve_range(void);

>  extern pgd_t * __init efi_call_phys_prolog(void);

>  extern void __init efi_call_phys_epilog(pgd_t *save_pgd);

>  extern void __init efi_print_memmap(void);

> -extern void __init efi_unmap_memmap(void);

>  extern void __init efi_memory_uc(u64 addr, unsigned long size);

>  extern void __init efi_map_region(efi_memory_desc_t *md);

>  extern void __init efi_map_region_fixed(efi_memory_desc_t *md);

> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c

> index 7c3d9092c668..b434c887229c 100644

> --- a/arch/x86/platform/efi/efi.c

> +++ b/arch/x86/platform/efi/efi.c

> @@ -188,7 +188,9 @@ static void __init do_add_efi_memmap(void)

>  int __init efi_memblock_x86_reserve_range(void)

>  {

>         struct efi_info *e = &boot_params.efi_info;

> +       struct efi_memory_map_data data;

>         phys_addr_t pmap;

> +       int rv;

>

>         if (efi_enabled(EFI_PARAVIRT))

>                 return 0;

> @@ -203,11 +205,17 @@ int __init efi_memblock_x86_reserve_range(void)

>  #else

>         pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));

>  #endif

> -       efi.memmap.phys_map     = pmap;

> -       efi.memmap.nr_map       = e->efi_memmap_size /

> -                                 e->efi_memdesc_size;

> -       efi.memmap.desc_size    = e->efi_memdesc_size;

> -       efi.memmap.desc_version = e->efi_memdesc_version;

> +       data.phys_map           = pmap;

> +       data.size               = e->efi_memmap_size;

> +       data.desc_size          = e->efi_memdesc_size;

> +       data.desc_version       = e->efi_memdesc_version;

> +

> +       rv = efi_memmap_init_early(&data);

> +       if (rv)

> +               return rv;

> +

> +       if (add_efi_memmap)

> +               do_add_efi_memmap();

>

>         WARN(efi.memmap.desc_version != 1,

>              "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",

> @@ -234,19 +242,6 @@ void __init efi_print_memmap(void)

>         }

>  }

>

> -void __init efi_unmap_memmap(void)

> -{

> -       unsigned long size;

> -

> -       clear_bit(EFI_MEMMAP, &efi.flags);

> -

> -       size = efi.memmap.nr_map * efi.memmap.desc_size;

> -       if (efi.memmap.map) {

> -               early_memunmap(efi.memmap.map, size);

> -               efi.memmap.map = NULL;

> -       }

> -}

> -

>  static int __init efi_systab_init(void *phys)

>  {

>         if (efi_enabled(EFI_64BIT)) {

> @@ -430,33 +425,6 @@ static int __init efi_runtime_init(void)

>         return 0;

>  }

>

> -static int __init efi_memmap_init(void)

> -{

> -       unsigned long addr, size;

> -

> -       if (efi_enabled(EFI_PARAVIRT))

> -               return 0;

> -

> -       /* Map the EFI memory map */

> -       size = efi.memmap.nr_map * efi.memmap.desc_size;

> -       addr = (unsigned long)efi.memmap.phys_map;

> -

> -       efi.memmap.map = early_memremap(addr, size);

> -       if (efi.memmap.map == NULL) {

> -               pr_err("Could not map the memory map!\n");

> -               return -ENOMEM;

> -       }

> -

> -       efi.memmap.map_end = efi.memmap.map + size;

> -

> -       if (add_efi_memmap)

> -               do_add_efi_memmap();

> -

> -       set_bit(EFI_MEMMAP, &efi.flags);

> -

> -       return 0;

> -}

> -

>  void __init efi_init(void)

>  {

>         efi_char16_t *c16;

> @@ -514,11 +482,11 @@ void __init efi_init(void)

>         if (!efi_runtime_supported())

>                 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");

>         else {

> -               if (efi_runtime_disabled() || efi_runtime_init())

> +               if (efi_runtime_disabled() || efi_runtime_init()) {

> +                       efi_memmap_unmap();

>                         return;

> +               }

>         }

> -       if (efi_memmap_init())

> -               return;

>

>         if (efi_enabled(EFI_DBG))

>                 efi_print_memmap();

> @@ -855,7 +823,7 @@ static void __init kexec_enter_virtual_mode(void)

>          * non-native EFI

>          */

>         if (!efi_is_native()) {

> -               efi_unmap_memmap();

> +               efi_memmap_unmap();

>                 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);

>                 return;

>         }

> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c

> index 4480c06cade7..0af180004e74 100644

> --- a/arch/x86/platform/efi/quirks.c

> +++ b/arch/x86/platform/efi/quirks.c

> @@ -266,7 +266,7 @@ void __init efi_free_boot_services(void)

>                 free_bootmem_late(start, size);

>         }

>

> -       efi_unmap_memmap();

> +       efi_memmap_unmap();

>  }

>

>  /*

> @@ -344,7 +344,7 @@ void __init efi_apply_memmap_quirks(void)

>          */

>         if (!efi_runtime_supported()) {

>                 pr_info("Setup done, disabling due to 32/64-bit mismatch\n");

> -               efi_unmap_memmap();

> +               efi_memmap_unmap();

>         }

>

>         /* UV2+ BIOS has a fix for this issue.  UV1 still needs the quirk. */

> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c

> index c49d50e68aee..5a2df3fefccc 100644

> --- a/drivers/firmware/efi/arm-init.c

> +++ b/drivers/firmware/efi/arm-init.c

> @@ -211,12 +211,11 @@ static __init void reserve_regions(void)

>                         memblock_mark_nomap(paddr, size);

>

>         }

> -

> -       set_bit(EFI_MEMMAP, &efi.flags);

>  }

>

>  void __init efi_init(void)

>  {

> +       struct efi_memory_map_data data;

>         struct efi_fdt_params params;

>

>         /* Grab UEFI information placed in FDT by stub */

> @@ -225,9 +224,12 @@ void __init efi_init(void)

>

>         efi_system_table = params.system_table;

>

> -       efi.memmap.phys_map = params.mmap;

> -       efi.memmap.map = early_memremap_ro(params.mmap, params.mmap_size);

> -       if (efi.memmap.map == NULL) {

> +       data.desc_version = params.desc_ver;

> +       data.desc_size = params.desc_size;

> +       data.size = params.mmap_size;

> +       data.phys_map = params.mmap;

> +

> +       if (efi_memmap_init_early(&data) < 0) {

>                 /*

>                 * If we are booting via UEFI, the UEFI memory map is the only

>                 * description of memory we have, so there is little point in

> @@ -235,9 +237,6 @@ void __init efi_init(void)

>                 */

>                 panic("Unable to map EFI memory map.\n");

>         }

> -       efi.memmap.map_end = efi.memmap.map + params.mmap_size;

> -       efi.memmap.desc_size = params.desc_size;

> -       efi.memmap.desc_version = params.desc_ver;

>

>         WARN(efi.memmap.desc_version != 1,

>              "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",

> @@ -248,7 +247,7 @@ void __init efi_init(void)

>

>         reserve_regions();

>         efi_memattr_init();

> -       early_memunmap(efi.memmap.map, params.mmap_size);

> +       efi_memmap_unmap();

>

>         memblock_reserve(params.mmap & PAGE_MASK,

>                          PAGE_ALIGN(params.mmap_size +

> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c

> index 05509f3aaee8..3e6dce71f54d 100644

> --- a/drivers/firmware/efi/efi.c

> +++ b/drivers/firmware/efi/efi.c

> @@ -448,6 +448,52 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)

>         return ret;

>  }

>

> +/**

> + * efi_memmap_init_early - Map the EFI memory map data structure

> + * @data: EFI memory map data

> + *

> + * Use early_memremap() to map the passed in EFI memory map and assign

> + * it to efi.memmap.

> + */

> +int __init efi_memmap_init_early(struct efi_memory_map_data *data)

> +{

> +       struct efi_memory_map map;

> +

> +       if (efi_enabled(EFI_PARAVIRT))

> +               return 0;

> +

> +       map.phys_map = data->phys_map;

> +

> +       map.map = early_memremap(data->phys_map, data->size);

> +       if (!map.map) {

> +               pr_err("Could not map the memory map!\n");

> +               return -ENOMEM;

> +       }

> +

> +       map.nr_map = data->size / data->desc_size;

> +       map.map_end = map.map + data->size;

> +

> +       map.desc_version = data->desc_version;

> +       map.desc_size = data->desc_size;

> +

> +       set_bit(EFI_MEMMAP, &efi.flags);

> +

> +       efi.memmap = map;

> +

> +       return 0;

> +}

> +

> +void __init efi_memmap_unmap(void)

> +{

> +       unsigned long size;

> +

> +       size = efi.memmap.desc_size * efi.memmap.nr_map;

> +

> +       early_memunmap(efi.memmap.map, size);

> +       efi.memmap.map = NULL;


This assignment breaks the calculation of mapsize in
arm_enable_runtime_services(), so you should probably fold the
following hunk into this patch.



With that change (or an equivalent one):

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> On 4 jul. 2016, at 20:19, Matt Fleming <matt@codeblueprint.co.uk> wrote:

> 

>> On Fri, 24 Jun, at 01:44:48PM, Ard Biesheuvel wrote:

>> 

>> This assignment breaks the calculation of mapsize in

>> arm_enable_runtime_services(), so you should probably fold the

>> following hunk into this patch.

>> 

>> diff --git a/drivers/firmware/efi/arm-runtime.c

>> b/drivers/firmware/efi/arm-runtime.c

>> index ce1424672d89..1884347a3ef6 100644

>> --- a/drivers/firmware/efi/arm-runtime.c

>> +++ b/drivers/firmware/efi/arm-runtime.c

>> @@ -109,7 +109,7 @@ static int __init arm_enable_runtime_services(void)

>> 

>>        pr_info("Remapping and enabling EFI services.\n");

>> 

>> -       mapsize = efi.memmap.map_end - efi.memmap.map;

>> +       mapsize = efi.memmap.desc_size * efi.memmap.nr_map;

>> 

>>        if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {

>>                pr_err("Failed to remap EFI memory map\n");

> 

> Thanks Ard, I folded this in.

> 

>> With that change (or an equivalent one):

>> 

>> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> 

> Are those tags for just this patch or the entire series?

> 


That is for the series (but I only tested arm, so ymmv)

> FYI, my plan right now is to queue this for v4.9 because it's fairly

> invasive and I expect some fallout. If anyone has a problem with that

> and knows of a reason it should be queued sooner, please let me know.


No problem, but once you've queued it i'd like the arm esrt patches to go on top, ideally in the same release. I will dust those off once this series hits your tree