The kernel's genpool subsystem

Embedded SoCs sometimes have on-chip SRAM that can be used to run suspend code while the external DRAM is disabled, or as a small but fast temporary working memory for GPUs or VPUs. The SRAM driver for example attaches a genalloc pool to an SRAM device, providing it to drivers in other subsystems as a shared resource. The other drivers can then obtain the pool via a reference in the device tree.
The VIDEO_CODA driver for example uses memory from such a pool to let the hardware video encoder do motion estimation in SRAM.