Re: [PATCH v8 01/27] cxl: add type2 device basic support

[Alejandro Lucero Palau <alucerop@amd.com>]

On 12/24/24 16:35, Jonathan Cameron wrote:
> On Mon, 16 Dec 2024 16:10:16 +0000
> <alejandro.lucero-palau@amd.com> wrote:
>
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> Differentiate CXL memory expanders (type 3) from CXL device accelerators
>> (type 2) with a new function for initializing cxl_dev_state.
>>
>> Create accessors to cxl_dev_state to be used by accel drivers.
>>
>> Based on previous work by Dan Williams [1]
>>
>> Link: [1] https://lore.kernel.org/linux-cxl/168592160379.1948938.12863272903570476312.stgit@dwillia2-xfh.jf.intel.com/
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> Co-developed-by: Dan Williams <dan.j.williams@intel.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> Reviewed-by: Fan Ni <fan.ni@samsung.com>
> Hi, I've missed a few versions due to busy end of year.
> Anyhow, catch up day!


Thanks!


> A few comments inline - with those tweaked (or ignored for the "meh"
> one :)
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
>> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
>> new file mode 100644
>> index 000000000000..19e5d883557a
>> --- /dev/null
>> +++ b/include/cxl/cxl.h
>> @@ -0,0 +1,21 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright(c) 2024 Advanced Micro Devices, Inc. */
>> +
>> +#ifndef __CXL_H
>> +#define __CXL_H
>> +
>> +#include <linux/ioport.h>
>> +
>> +enum cxl_resource {
>> +	CXL_RES_DPA,
>> +	CXL_RES_RAM,
>> +	CXL_RES_PMEM,
>> +};
> Need a few forwards defs to avoid chance of future header reorg
> biting you.
>
> struct cxl_dev_state;
> struct device;
> Should do I think.


I'll do.

Thanks


>> +
>> +struct cxl_dev_state *cxl_accel_state_create(struct device *dev);
>> +
>> +void cxl_set_dvsec(struct cxl_dev_state *cxlds, u16 dvsec);
>> +void cxl_set_serial(struct cxl_dev_state *cxlds, u64 serial);
>> +int cxl_set_resource(struct cxl_dev_state *cxlds, struct resource res,
>> +		     enum cxl_resource);
>> +#endif
>> diff --git a/include/cxl/pci.h b/include/cxl/pci.h
>> new file mode 100644
>> index 000000000000..ad63560caa2c
>> --- /dev/null
>> +++ b/include/cxl/pci.h
>> @@ -0,0 +1,23 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */
>> +
>> +#ifndef __CXL_ACCEL_PCI_H
>> +#define __CXL_ACCEL_PCI_H
>> +
>> +/* CXL 2.0 8.1.3: PCIe DVSEC for CXL Device */
>> +#define CXL_DVSEC_PCIE_DEVICE					0
>> +#define   CXL_DVSEC_CAP_OFFSET		0xA
>> +#define     CXL_DVSEC_MEM_CAPABLE	BIT(2)
>> +#define     CXL_DVSEC_HDM_COUNT_MASK	GENMASK(5, 4)
>> +#define   CXL_DVSEC_CTRL_OFFSET		0xC
>> +#define     CXL_DVSEC_MEM_ENABLE	BIT(2)
>> +#define   CXL_DVSEC_RANGE_SIZE_HIGH(i)	(0x18 + ((i) * 0x10))
>> +#define   CXL_DVSEC_RANGE_SIZE_LOW(i)	(0x1C + ((i) * 0x10))
>> +#define     CXL_DVSEC_MEM_INFO_VALID	BIT(0)
>> +#define     CXL_DVSEC_MEM_ACTIVE	BIT(1)
>> +#define     CXL_DVSEC_MEM_SIZE_LOW_MASK	GENMASK(31, 28)
>> +#define   CXL_DVSEC_RANGE_BASE_HIGH(i)	(0x20 + ((i) * 0x10))
>> +#define   CXL_DVSEC_RANGE_BASE_LOW(i)	(0x24 + ((i) * 0x10))
> The brackets around the multiplication seem like overkill but meh,
> they are harmless :)
>
>> +#define     CXL_DVSEC_MEM_BASE_LOW_MASK	GENMASK(31, 28)
>> +
>> +#endif