29317f8dc6
Unlike the cxl_pci class driver that opportunistically enables memory expansion with no other dependent functionality, CXL accelerator drivers have distinct PCIe-only and CXL-enhanced operation states. If CXL is available some additional coherent memory/cache operations can be enabled, otherwise traditional DMA+MMIO over PCIe/CXL.io is a fallback. This constitutes a new mode of operation where the caller of devm_cxl_add_memdev() wants to make a "go/no-go" decision about running in CXL accelerated mode or falling back to PCIe-only operation. Part of that decision making process likely also includes additional CXL-acceleration-specific resource setup. Encapsulate both of those requirements into 'struct cxl_memdev_attach' that provides a ->probe() callback. The probe callback runs in cxl_mem_probe() context, after the port topology is successfully attached for the given memdev. It supports a contract where, upon successful return from devm_cxl_add_memdev(), everything needed for CXL accelerated operation has been enabled. Additionally the presence of @cxlmd->attach indicates that the accelerator driver be detached when CXL operation ends. This conceptually makes a CXL link loss event mirror a PCIe link loss event which results in triggering the ->remove() callback of affected devices+drivers. A driver can re-attach to recover back to PCIe-only operation. Live recovery, i.e. without a ->remove()/->probe() cycle, is left as a future consideration. [ dj: Repalce with updated commit log from Dan ] Cc: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20251216005616.3090129-7-dan.j.williams@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> |
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| .. | ||
| accounting | ||
| arch | ||
| bootconfig | ||
| bpf | ||
| build | ||
| certs | ||
| cgroup | ||
| counter | ||
| crypto | ||
| debugging | ||
| dma | ||
| docs | ||
| firewire | ||
| firmware | ||
| gpio | ||
| hv | ||
| iio | ||
| include | ||
| kvm/kvm_stat | ||
| laptop | ||
| leds | ||
| lib | ||
| memory-model | ||
| mm | ||
| net | ||
| objtool | ||
| pcmcia | ||
| perf | ||
| power | ||
| rcu | ||
| sched | ||
| sched_ext | ||
| scripts | ||
| sound | ||
| spi | ||
| testing | ||
| thermal | ||
| time | ||
| tracing | ||
| usb | ||
| verification | ||
| virtio | ||
| wmi | ||
| workqueue | ||
| writeback | ||
| Makefile | ||