/*
* \brief Gpu session interface.
* \author Josef Soentgen
* \author Sebastian Sumpf
* \date 2017-04-28
*
* Notes:
*
* Because of different GPU driver architectures, functions here may have
* different semantics. In short, libdrm or any other client must be aware of
* the semantics of the respective GPU driver.
*
* Here a short explanation of the difference of Intel and Lima.
*
* Intel:
*
* 'alloc_vram' is used by Iris to create an internal buffer object cache on the
* internal Mesa side. Because the allocated memory is RAM, Iris 'mmap's it
* directly into the clients address space (Genode::attach) Iris assigns Gpu
* virtual addresses to buffers, these addresses may change when buffers are
* reused later. On DRM side, Iris calls DRM_MAP_PPGTT, which we implement
* through 'map_gpu' (establish a GPU mapping) on the client and multiplexer
* side. Graphics memory can be also mapped through the aperture (for example,
* when tiling/untiling buffers, which we currently do not see, but have seen in
* the past). This is what 'map_cpu' is used for on Intel. It adds a GTT mapping
* into the aperture (IOMEM) and returns a dataspace with the physical address
* within the aperture. This dataspace has a different physical address than the
* one returned by 'alloc_vram' but in the end points to the same RAM through
* the GTT. This is now a nop because it is not used, which may change in newer
* Mesa versions again.
*
* Lima:
*
* The ported Lima driver assigns a GPU virtual address during buffer
* allocation. We found a way to at least tell the driver what virtual address
* to use, because on default it will use an arbitrary fitting GPU virtual
* address, which means unlike Iris, the GPU driver manages the virtual address
* space on Lima. So on Lima the semantic is as follows now:
*
* 'alloc_vram' is a nop because we cannot hand a GPU virtual address over,
* instead 'map_gpu' will actually allocate a buffer of given size at a given
* Gpu::Virtual_address in the GPU page tables. On the Mesa side, we implemented
* a virtual address-allocator, and therefore, handle the GPU address space
* ourselves as Iris does in contrib Mesa code. 'map_cpu' will return the
* Dataspace_capability of the allocated buffer that then can be directly
* attached by Mesa because the GPU memory is again ordinary RAM.
*/
/*
* Copyright (C) 2017-2023 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _INCLUDE__GPU_SESSION__GPU_SESSION_H_
#define _INCLUDE__GPU_SESSION__GPU_SESSION_H_
#include
#include
namespace Gpu {
using addr_t = Genode::uint64_t;
struct Vram;
using Vram_id_space = Genode::Id_space;
using Vram_id = Vram_id_space::Id;
using Vram_capability = Genode::Capability;
/*
* Attributes for mapping a buffer
*/
struct Mapping_attributes
{
bool readable;
bool writeable;
static Mapping_attributes ro()
{
return { .readable = true, .writeable = false };
}
static Mapping_attributes rw()
{
return { .readable = true, .writeable = true };
}
static Mapping_attributes wo()
{
return { .readable = false, .writeable = true };
}
};
struct Sequence_number;
struct Session;
struct Virtual_address;
}
/*
* Execution buffer sequence number
*/
struct Gpu::Sequence_number
{
Genode::uint64_t value;
};
struct Gpu::Virtual_address
{
Genode::uint64_t value;
};
/*
* Gpu session interface
*/
struct Gpu::Session : public Genode::Session
{
struct Out_of_ram : Genode::Exception { };
struct Out_of_caps : Genode::Exception { };
struct Invalid_state : Genode::Exception { };
struct Conflicting_id : Genode::Exception { };
struct Mapping_vram_failed : Genode::Exception { };
static constexpr Genode::size_t REQUIRED_QUOTA = 1024*1024;
static constexpr unsigned CAP_QUOTA = 32;
static const char *service_name() { return "Gpu"; }
virtual ~Session() { }
/***********************
** Session interface **
***********************/
/**
* Get GPU information dataspace
*/
virtual Genode::Dataspace_capability info_dataspace() const = 0;
/**
* Execute commands in vram
*
* \param id vram id
* \param offset offset in vram to start execution
*
* \return execution sequence number for complete checks
*
* \throw Invalid_state is thrown if the provided vram is not valid, e.g not mapped
*/
virtual Gpu::Sequence_number execute(Vram_id id, Genode::off_t offset) = 0;
/**
* Check if execution has been completed
*
* \param seqno sequence number of the execution
*
* \return true if execution has been finished, otherwise
* false is returned
*/
virtual bool complete(Sequence_number seqno) = 0;
/**
* Register completion signal handler
*
* \param sigh signal handler that is called when the execution
* has completed
*/
virtual void completion_sigh(Genode::Signal_context_capability sigh) = 0;
/**
* Allocate video ram
*
* \param id id to be associated with the vram
* \param size size of memory in bytes
*
* \throw Out_of_ram
* \throw Out_of_caps
* \throw Conflicting_id
*/
virtual Genode::Dataspace_capability alloc_vram(Vram_id id, Genode::size_t size) = 0;
/**
* Free vram
*
* \param id id of vram
*/
virtual void free_vram(Vram_id id) = 0;
/**
* Export vram dataspace from GPU session
*
* \param id id of associated vram
*
* \return cability of exported vram
*/
virtual Vram_capability export_vram(Vram_id id) = 0;
/**
* Import vram to GPU session
*
* \param cap capability of vram as retrieved by 'exportvram'
* \param id vram id to be associated to this vram in the session
*
* \throw Conflicting_id
* \throw Out_of_caps
* \throw Out_of_ram
* \throw Invalid_state (cap is no longer valid)
*/
virtual void import_vram(Vram_capability cap, Vram_id id) = 0;
/**
* Map vram at CPU
*
* \param id id of vram
* \param attrs specify how the buffer is mapped
*
* \throw Mapping_vram_failed
* \throw Out_of_caps
* \throw Out_of_ram
*/
virtual Genode::Dataspace_capability map_cpu(Vram_id id, Mapping_attributes attrs) = 0;
/**
* Unmap vram
*
* \param id id of vram
*/
virtual void unmap_cpu(Vram_id id) = 0;
/**
* Map vram at GPU
*
* \param id vram id
* \param size size of vram to be mapped
* \pram offset offset in vram
* \param va GPU virtual address
*
* \return true on success, false otherwise
* \throw Mapping_vram_failed
* \throw Out_of_caps
* \throw Out_of_ram
*/
virtual bool map_gpu(Vram_id id, Genode::size_t size,
Genode::off_t offset,
Virtual_address va) = 0;
/**
* Unmap vram on GPU
*
* \param id vram id
* \param offset offset in vram
* \param va GPU virtual address
*/
virtual void unmap_gpu(Vram_id id, Genode::off_t offset,
Virtual_address va) = 0;
/**
* Set tiling for vram on GPU
*
* \param id vram id
* \param offset offset in vram
* \param mode tiling mode
*/
virtual bool set_tiling_gpu(Vram_id id, Genode::off_t offset, unsigned mode) = 0;
/*******************
** RPC interface **
*******************/
GENODE_RPC(Rpc_info_dataspace, Genode::Dataspace_capability, info_dataspace);
GENODE_RPC(Rpc_complete, bool, complete,
Gpu::Sequence_number);
GENODE_RPC(Rpc_completion_sigh, void, completion_sigh,
Genode::Signal_context_capability);
GENODE_RPC_THROW(Rpc_execute, Gpu::Sequence_number, execute,
GENODE_TYPE_LIST(Invalid_state),
Gpu::Vram_id, Genode::off_t);
GENODE_RPC_THROW(Rpc_alloc_vram, Genode::Dataspace_capability, alloc_vram,
GENODE_TYPE_LIST(Out_of_caps, Out_of_ram),
Gpu::Vram_id, Genode::size_t);
GENODE_RPC(Rpc_free_vram, void, free_vram, Gpu::Vram_id);
GENODE_RPC(Rpc_export_vram, Gpu::Vram_capability, export_vram, Gpu::Vram_id);
GENODE_RPC_THROW(Rpc_import_vram, void, import_vram,
GENODE_TYPE_LIST(Out_of_caps, Out_of_ram, Conflicting_id, Invalid_state),
Gpu::Vram_capability, Gpu::Vram_id);
GENODE_RPC_THROW(Rpc_map_cpu, Genode::Dataspace_capability, map_cpu,
GENODE_TYPE_LIST(Mapping_vram_failed, Out_of_caps, Out_of_ram),
Gpu::Vram_id, Gpu::Mapping_attributes);
GENODE_RPC(Rpc_unmap_cpu, void, unmap_cpu,
Gpu::Vram_id);
GENODE_RPC_THROW(Rpc_map_gpu, bool, map_gpu,
GENODE_TYPE_LIST(Mapping_vram_failed, Out_of_caps, Out_of_ram),
Gpu::Vram_id, Genode::size_t, Genode::off_t, Gpu::Virtual_address);
GENODE_RPC(Rpc_unmap_gpu, void, unmap_gpu,
Gpu::Vram_id, Genode::off_t, Gpu::Virtual_address);
GENODE_RPC(Rpc_set_tiling_gpu, bool, set_tiling_gpu, Gpu::Vram_id, Genode::off_t, unsigned);
GENODE_RPC_INTERFACE(Rpc_info_dataspace, Rpc_complete, Rpc_completion_sigh, Rpc_execute,
Rpc_alloc_vram, Rpc_free_vram, Rpc_export_vram, Rpc_import_vram,
Rpc_map_cpu, Rpc_unmap_cpu, Rpc_map_gpu, Rpc_unmap_gpu, Rpc_set_tiling_gpu);
};
#endif /* _INCLUDE__GPU_SESSION__GPU_SESSION_H_ */