[Intel-gfx] [PATCH 1/5] drm/i915: Create stolen memory region from local memory

Matthew Auld matthew.auld at intel.com
Wed Apr 21 09:46:00 UTC 2021


On 20/04/2021 17:06, Tvrtko Ursulin wrote:
> 
> On 20/04/2021 14:18, Matthew Auld wrote:
>> From: CQ Tang <cq.tang at intel.com>
>>
>> Add "REGION_STOLEN" device info to dg1, create stolen memory
>> region from upper portion of local device memory, starting
>> from DSMBASE.
>>
>> v2:
>>      - s/drm_info/drm_dbg; userspace likely doesn't care about stolen.
>>      - mem->type is only setup after the region probe, so setting the 
>> name
>>        as stolen-local or stolen-system based on this value won't 
>> work. Split
>>        system vs local stolen setup to fix this.
>>      - kill all the region->devmem/is_devmem stuff. We already 
>> differentiate
>>        the different types of stolen so such things shouldn't be needed
>>        anymore.
>> v3:
>>      - split stolen lmem vs smem ops(Tvrtko)
>>      - add shortcut for stolen region in i915(Tvrtko)
>>      - sanity check dsm base vs bar size(Xinyun)
>>
>> Signed-off-by: CQ Tang <cq.tang at intel.com>
>> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
>> Cc: Xinyun Liu <xinyun.liu at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 137 ++++++++++++++++++---
>>   drivers/gpu/drm/i915/i915_drv.h            |   7 ++
>>   drivers/gpu/drm/i915/i915_pci.c            |   2 +-
>>   drivers/gpu/drm/i915/i915_reg.h            |   1 +
>>   drivers/gpu/drm/i915/intel_memory_region.c |   8 ++
>>   drivers/gpu/drm/i915/intel_memory_region.h |   5 +-
>>   6 files changed, 140 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c 
>> b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> index b0597de206de..2ed1ca9aec75 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
>> @@ -10,6 +10,7 @@
>>   #include <drm/drm_mm.h>
>>   #include <drm/i915_drm.h>
>> +#include "gem/i915_gem_lmem.h"
>>   #include "gem/i915_gem_region.h"
>>   #include "i915_drv.h"
>>   #include "i915_gem_stolen.h"
>> @@ -121,6 +122,14 @@ static int i915_adjust_stolen(struct 
>> drm_i915_private *i915,
>>           }
>>       }
>> +    /*
>> +     * With device local memory, we don't need to check the address 
>> range,
>> +     * this is device memory physical address, could overlap with system
>> +     * memory.
>> +     */
>> +    if (HAS_LMEM(i915))
>> +        return 0;
> 
> The grammar in the comment is a bit hard to parse for me, but more 
> importantly, this is now not on the device stolen path, right?
> 
> [Comes back later, hm no, still called okay at least there is a comment 
> now explaining which are the relevant bits.]
> 
>> +
>>       /*
>>        * Verify that nothing else uses this physical address. Stolen
>>        * memory should be reserved by the BIOS and hidden from the
>> @@ -374,8 +383,9 @@ static void icl_get_stolen_reserved(struct 
>> drm_i915_private *i915,
>>       }
>>   }
>> -static int i915_gem_init_stolen(struct drm_i915_private *i915)
>> +static int i915_gem_init_stolen(struct intel_memory_region *mem)
>>   {
>> +    struct drm_i915_private *i915 = mem->i915;
>>       struct intel_uncore *uncore = &i915->uncore;
>>       resource_size_t reserved_base, stolen_top;
>>       resource_size_t reserved_total, reserved_size;
>> @@ -396,10 +406,10 @@ static int i915_gem_init_stolen(struct 
>> drm_i915_private *i915)
>>           return 0;
>>       }
>> -    if (resource_size(&intel_graphics_stolen_res) == 0)
>> +    if (resource_size(&mem->region) == 0)
>>           return 0;
>> -    i915->dsm = intel_graphics_stolen_res;
>> +    i915->dsm = mem->region;
>>       if (i915_adjust_stolen(i915, &i915->dsm))
>>           return 0;
>> @@ -688,39 +698,130 @@ struct drm_i915_gem_object *
>>   i915_gem_object_create_stolen(struct drm_i915_private *i915,
>>                     resource_size_t size)
>>   {
>> -    return 
>> i915_gem_object_create_region(i915->mm.regions[INTEL_REGION_STOLEN_SMEM],
>> +    return i915_gem_object_create_region(i915->mm.stolen_region,
>>                            size, I915_BO_ALLOC_CONTIGUOUS);
>>   }
>> -static int init_stolen(struct intel_memory_region *mem)
>> +static int init_stolen_smem(struct intel_memory_region *mem)
>>   {
>> -    intel_memory_region_set_name(mem, "stolen");
>> -
>>       /*
>>        * Initialise stolen early so that we may reserve preallocated
>>        * objects for the BIOS to KMS transition.
>>        */
>> -    return i915_gem_init_stolen(mem->i915);
>> +    return i915_gem_init_stolen(mem);
>> +}
>> +
>> +static void release_stolen_smem(struct intel_memory_region *mem)
>> +{
>> +    i915_gem_cleanup_stolen(mem->i915);
>> +}
>> +
>> +static const struct intel_memory_region_ops 
>> i915_region_stolen_smem_ops = {
>> +    .init = init_stolen_smem,
>> +    .release = release_stolen_smem,
>> +    .init_object = _i915_gem_object_stolen_init,
>> +};
>> +
>> +static int init_stolen_lmem(struct intel_memory_region *mem)
>> +{
>> +    int err;
>> +
>> +    if (GEM_WARN_ON(resource_size(&mem->region) == 0))
>> +        return -ENODEV;
>> +
>> +    if (!io_mapping_init_wc(&mem->iomap,
>> +                mem->io_start,
>> +                resource_size(&mem->region)))
>> +        return -EIO;
>> +
>> +    /*
>> +     * For stolen lmem we mostly just care about populating the dsm 
>> related
>> +     * bits and setting up the drm_mm allocator for the range.
>> +     */
>> +    err = i915_gem_init_stolen(mem);
> 
> Ideally we would be able to split this into two so there would be no 
> further smem/lmem stolen forking inside it. That way we would also avoid 
> the "mostly" and reach total clarity but okay, can leave for later.

I'll add a TODO comment :)

> 
>> +    if (err)
>> +        goto err_fini;
>> +
>> +    return 0;
>> +
>> +err_fini:
>> +    io_mapping_fini(&mem->iomap);
>> +    return err;
>>   }
>> -static void release_stolen(struct intel_memory_region *mem)
>> +static void release_stolen_lmem(struct intel_memory_region *mem)
>>   {
>> +    io_mapping_fini(&mem->iomap);
>>       i915_gem_cleanup_stolen(mem->i915);
>>   }
>> -static const struct intel_memory_region_ops i915_region_stolen_ops = {
>> -    .init = init_stolen,
>> -    .release = release_stolen,
>> +static const struct intel_memory_region_ops 
>> i915_region_stolen_lmem_ops = {
>> +    .init = init_stolen_lmem,
>> +    .release = release_stolen_lmem,
>>       .init_object = _i915_gem_object_stolen_init,
>>   };
>> +static struct intel_memory_region *
>> +setup_lmem_stolen(struct drm_i915_private *i915)
>> +{
>> +    struct intel_uncore *uncore = &i915->uncore;
>> +    struct pci_dev *pdev = i915->drm.pdev;
>> +    struct intel_memory_region *mem;
>> +    resource_size_t io_start;
>> +    resource_size_t lmem_size;
>> +    u64 lmem_base;
>> +
>> +    if (!IS_DGFX(i915))
>> +        return ERR_PTR(-ENODEV);
> 
> Is this check needed? Looks like the caller will only call this based on 
> HAS_REGION. GEM_DEBUG_WARN_ON(!IS_DGFX())?
> 
>> +
>> +    lmem_base = intel_uncore_read64(uncore, GEN12_DSMBASE);
>> +    if (GEM_WARN_ON(lmem_base >= pci_resource_len(pdev, 2)))
>> +        return ERR_PTR(-ENODEV);
>> +
>> +    lmem_size = pci_resource_len(pdev, 2) - lmem_base;
>> +    io_start = pci_resource_start(pdev, 2) + lmem_base;
>> +
>> +    mem = intel_memory_region_create(i915, lmem_base, lmem_size,
>> +                     I915_GTT_PAGE_SIZE_4K, io_start,
>> +                     &i915_region_stolen_lmem_ops);
>> +    if (IS_ERR(mem))
>> +        return mem;
>> +
>> +    drm_dbg(&i915->drm, "Stolen Local memory IO start: %pa\n",
>> +        &mem->io_start);
> 
> Printouts I'd prefer if they were done by the common code which calls 
> region->init(). Afterwards it could generically print all the region 
> data with common formatting and using the set region name. Optional, 
> later, is fine.

Yeah, having a common helper to print everything interesting in 
intel_memory_region might be quite nice. I'll add a TODO.

> 
>> +
>> +    intel_memory_region_set_name(mem, "stolen-local");
> 
> Should the name just be passed in to intel_memory_region_create or there 
> is a good reason for it to be a follow up step?

I don't see a good reason, so yeah it looks like we can just pass it 
along. I don't have a strong opinion here.

> 
>> +
>> +    return mem;
>> +}
>> +
>> +static struct intel_memory_region*
>> +setup_smem_stolen(struct drm_i915_private *i915)
>> +{
>> +    struct intel_memory_region *mem;
>> +
>> +    mem = intel_memory_region_create(i915,
>> +                     intel_graphics_stolen_res.start,
>> +                     resource_size(&intel_graphics_stolen_res),
>> +                     PAGE_SIZE, 0,
>> +                     &i915_region_stolen_smem_ops);
>> +    if (IS_ERR(mem))
>> +        return mem;
>> +
>> +    intel_memory_region_set_name(mem, "stolen-system");
>> +
>> +    return mem;
>> +}
>> +
>>   struct intel_memory_region *i915_gem_stolen_setup(struct 
>> drm_i915_private *i915)
>>   {
>> -    return intel_memory_region_create(i915,
>> -                      intel_graphics_stolen_res.start,
>> -                      resource_size(&intel_graphics_stolen_res),
>> -                      PAGE_SIZE, 0,
>> -                      &i915_region_stolen_ops);
>> +    struct intel_memory_region *mem;
>> +
>> +    mem = setup_lmem_stolen(i915);
>> +    if (mem == ERR_PTR(-ENODEV))
>> +        mem = setup_smem_stolen(i915);
> 
> This helper is possibly not needed any more since the caller is a switch 
> statement with a fallthrough. So eliminate the falltrough and call the 
> correct setup directly from there? There is the i915->mm.stolen 
> assignment to be duplicated in that case so up to you.

Yes, let's go with that.

> 
>> +
>> +    return mem;
>>   }
>>   struct drm_i915_gem_object *
>> @@ -728,7 +829,7 @@ 
>> i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private 
>> *i915,
>>                              resource_size_t stolen_offset,
>>                              resource_size_t size)
>>   {
>> -    struct intel_memory_region *mem = 
>> i915->mm.regions[INTEL_REGION_STOLEN_SMEM];
>> +    struct intel_memory_region *mem = i915->mm.stolen_region;
>>       struct drm_i915_gem_object *obj;
>>       struct drm_mm_node *stolen;
>>       int ret;
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h 
>> b/drivers/gpu/drm/i915/i915_drv.h
>> index e20294e9227a..0b44333eb703 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -514,6 +514,13 @@ struct intel_l3_parity {
>>   };
>>   struct i915_gem_mm {
>> +    /*
>> +     * Shortcut for the stolen region. This points to either
>> +     * INTEL_REGION_STOLEN_SMEM for integrated platforms, or
>> +     * INTEL_REGION_STOLEN_LMEM for discrete, or NULL if the device 
>> doesn't
>> +     * support stolen.
>> +     */
>> +    struct intel_memory_region *stolen_region;
>>       /** Memory allocator for GTT stolen memory */
>>       struct drm_mm stolen;
>>       /** Protects the usage of the GTT stolen memory allocator. This is
>> diff --git a/drivers/gpu/drm/i915/i915_pci.c 
>> b/drivers/gpu/drm/i915/i915_pci.c
>> index 44e7b94db63d..d4673e43a46d 100644
>> --- a/drivers/gpu/drm/i915/i915_pci.c
>> +++ b/drivers/gpu/drm/i915/i915_pci.c
>> @@ -908,7 +908,7 @@ static const struct intel_device_info rkl_info = {
>>   };
>>   #define DGFX_FEATURES \
>> -    .memory_regions = REGION_SMEM | REGION_LMEM, \
>> +    .memory_regions = REGION_SMEM | REGION_LMEM | REGION_STOLEN_LMEM, \
>>       .has_master_unit_irq = 1, \
>>       .has_llc = 0, \
>>       .has_snoop = 1, \
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index f80d656331f4..ea20058bc13f 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -12191,6 +12191,7 @@ enum skl_power_gate {
>>   #define GEN12_GLOBAL_MOCS(i)    _MMIO(0x4000 + (i) * 4) /* Global 
>> MOCS regs */
>>   #define GEN12_GSMBASE            _MMIO(0x108100)
>> +#define GEN12_DSMBASE            _MMIO(0x1080C0)
>>   /* gamt regs */
>>   #define GEN8_L3_LRA_1_GPGPU _MMIO(0x4dd4)
>> diff --git a/drivers/gpu/drm/i915/intel_memory_region.c 
>> b/drivers/gpu/drm/i915/intel_memory_region.c
>> index bf837b6bb185..9941a4a07fde 100644
>> --- a/drivers/gpu/drm/i915/intel_memory_region.c
>> +++ b/drivers/gpu/drm/i915/intel_memory_region.c
>> @@ -22,6 +22,10 @@ static const struct {
>>           .class = INTEL_MEMORY_STOLEN_SYSTEM,
>>           .instance = 0,
>>       },
>> +    [INTEL_REGION_STOLEN_LMEM] = {
>> +        .class = INTEL_MEMORY_STOLEN_LOCAL,
>> +        .instance = 0,
>> +    },
>>   };
>>   struct intel_memory_region *
>> @@ -278,8 +282,12 @@ int intel_memory_regions_hw_probe(struct 
>> drm_i915_private *i915)
>>           case INTEL_MEMORY_SYSTEM:
>>               mem = i915_gem_shmem_setup(i915);
>>               break;
>> +        case INTEL_MEMORY_STOLEN_LOCAL:
>> +            fallthrough;
>>           case INTEL_MEMORY_STOLEN_SYSTEM:
>>               mem = i915_gem_stolen_setup(i915);
>> +            if (!IS_ERR(mem))
>> +                i915->mm.stolen_region = mem;
>>               break;
>>           default:
>>               continue;
>> diff --git a/drivers/gpu/drm/i915/intel_memory_region.h 
>> b/drivers/gpu/drm/i915/intel_memory_region.h
>> index edd49067c8ca..4c8ec15af55f 100644
>> --- a/drivers/gpu/drm/i915/intel_memory_region.h
>> +++ b/drivers/gpu/drm/i915/intel_memory_region.h
>> @@ -26,18 +26,21 @@ enum intel_memory_type {
>>       INTEL_MEMORY_SYSTEM = 0,
>>       INTEL_MEMORY_LOCAL,
>>       INTEL_MEMORY_STOLEN_SYSTEM,
>> +    INTEL_MEMORY_STOLEN_LOCAL,
>>   };
>>   enum intel_region_id {
>>       INTEL_REGION_SMEM = 0,
>>       INTEL_REGION_LMEM,
>>       INTEL_REGION_STOLEN_SMEM,
>> +    INTEL_REGION_STOLEN_LMEM,
>>       INTEL_REGION_UNKNOWN, /* Should be last */
>>   };
>>   #define REGION_SMEM     BIT(INTEL_REGION_SMEM)
>>   #define REGION_LMEM     BIT(INTEL_REGION_LMEM)
>>   #define REGION_STOLEN_SMEM   BIT(INTEL_REGION_STOLEN_SMEM)
>> +#define REGION_STOLEN_LMEM   BIT(INTEL_REGION_STOLEN_LMEM)
>>   #define I915_ALLOC_MIN_PAGE_SIZE  BIT(0)
>>   #define I915_ALLOC_CONTIGUOUS     BIT(1)
>> @@ -82,7 +85,7 @@ struct intel_memory_region {
>>       u16 type;
>>       u16 instance;
>>       enum intel_region_id id;
>> -    char name[8];
>> +    char name[16];
>>       struct list_head reserved;
>>
> Regards,
> 
> Tvrtko


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