[Intel-gfx] [RFC] x86/e820: Add E820_RESERVED_GFX for graphics memory

[Joonas Lahtinen]

(Correcting the bad CC's.)

What do others think?

This failed in the CI due to i915 driver not being able to claim
RESERVED_GFX memory as it's handled like RESERVED_KERN in all places.
So that'll need some tweaking, still.

Regards, Joonas

On pe, 2016-04-22 at 16:29 +0300, Joonas Lahtinen wrote:
> Add a type of memory alongside E820_RESERVED_KERN that is specifically
> reserved for graphics usage, E820_RESERVED_GFX. An example is Intel
> Gen graphics stolen memory.
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  arch/x86/include/uapi/asm/e820.h | 5 +++++
>  arch/x86/kernel/e820.c           | 8 +++++++-
>  arch/x86/kernel/early-quirks.c   | 2 +-
>  arch/x86/kernel/tboot.c          | 3 ++-
>  arch/x86/mm/init_64.c            | 9 ++++++---
>  5 files changed, 21 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h
> index 9dafe59..f5324f4 100644
> --- a/arch/x86/include/uapi/asm/e820.h
> +++ b/arch/x86/include/uapi/asm/e820.h
> @@ -53,6 +53,11 @@
>   */
>  #define E820_RESERVED_KERN        128
>  
> +/*
> + * RAM to be reserved for graphics device use.
> + */
> +#define E820_RESERVED_GFX         129
> +
>  #ifndef __ASSEMBLY__
>  #include 
>  struct e820entry {
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 621b501..9bbdbc0 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -136,6 +136,7 @@ static void __init e820_print_type(u32 type)
>  	switch (type) {
>  	case E820_RAM:
>  	case E820_RESERVED_KERN:
> +	case E820_RESERVED_GFX:
>  		printk(KERN_CONT "usable");
>  		break;
>  	case E820_RESERVED:
> @@ -694,7 +695,9 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
>  
>  		pfn = PFN_DOWN(ei->addr + ei->size);
>  
> -		if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
> +		if (ei->type != E820_RAM &&
> +		    ei->type != E820_RESERVED_KERN &&
> +		    ei->type != E820_RESERVED_GFX)
>  			register_nosave_region(PFN_UP(ei->addr), pfn);
>  
>  		if (pfn >= limit_pfn)
> @@ -916,6 +919,7 @@ static const char *e820_type_to_string(int e820_type)
>  {
>  	switch (e820_type) {
>  	case E820_RESERVED_KERN:
> +	case E820_RESERVED_GFX:
>  	case E820_RAM:	return "System RAM";
>  	case E820_ACPI:	return "ACPI Tables";
>  	case E820_NVS:	return "ACPI Non-volatile Storage";
> @@ -930,6 +934,7 @@ static unsigned long e820_type_to_iomem_type(int e820_type)
>  {
>  	switch (e820_type) {
>  	case E820_RESERVED_KERN:
> +	case E820_RESERVED_GFX:
>  	case E820_RAM:
>  		return IORESOURCE_SYSTEM_RAM;
>  	case E820_ACPI:
> @@ -954,6 +959,7 @@ static unsigned long e820_type_to_iores_desc(int e820_type)
>  	case E820_PRAM:
>  		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
>  	case E820_RESERVED_KERN:
> +	case E820_RESERVED_GFX:
>  	case E820_RAM:
>  	case E820_UNUSABLE:
>  	default:
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index d2f75b4..7c87b2f 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -539,7 +539,7 @@ intel_graphics_stolen(int num, int slot, int func,
>  	       "0x%llx-0x%llx\n", base, base + size - 1);
>  
>  	/* Mark this space as reserved */
> -	e820_add_region(base, size, E820_RESERVED);
> +	e820_add_region(base, size, E820_RESERVED_GFX);
>  	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
>  }
>  
> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
> index e72a07f..077d0c7 100644
> --- a/arch/x86/kernel/tboot.c
> +++ b/arch/x86/kernel/tboot.c
> @@ -196,7 +196,8 @@ static int tboot_setup_sleep(void)
>  
>  	for (i = 0; i < e820.nr_map; i++) {
>  		if ((e820.map[i].type != E820_RAM)
> -		 && (e820.map[i].type != E820_RESERVED_KERN))
> +		 && (e820.map[i].type != E820_RESERVED_KERN)
> +		 && (e820.map[i].type != E820_RESERVED_GFX))
>  			continue;
>  
>  		add_mac_region(e820.map[i].addr, e820.map[i].size);
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index 214afda..d426fae 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -415,7 +415,8 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
>  		if (addr >= end) {
>  			if (!after_bootmem &&
>  			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
> -			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
> +			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN) &&
> +			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_GFX))
>  				set_pte(pte, __pte(0));
>  			continue;
>  		}
> @@ -463,7 +464,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
>  		if (address >= end) {
>  			if (!after_bootmem &&
>  			    !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
> -			    !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
> +			    !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN) &&
> +			    !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_GFX))
>  				set_pmd(pmd, __pmd(0));
>  			continue;
>  		}
> @@ -537,7 +539,8 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
>  		if (addr >= end) {
>  			if (!after_bootmem &&
>  			    !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
> -			    !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
> +			    !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN) &&
> +			    !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_GFX))
>  				set_pud(pud, __pud(0));
>  			continue;
>  		}
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation