Commit 280b983c authored by Frederic Barrat's avatar Frederic Barrat Committed by Michael Ellerman
Browse files

ocxl: Add a kernel API for other opencapi drivers 



Some of the functions done by the generic driver should also be needed
by other opencapi drivers: attaching a context to an adapter,
translation fault handling, AFU interrupt allocation...

So to avoid code duplication, the driver provides a kernel API that
other drivers can use, similar to calling a in-kernel library.

It is still a bit theoretical, for lack of real hardware, and will
likely need adjustements down the road. But we used the cxlflash
driver as a guinea pig.

Signed-off-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent aeddad17

drivers/misc/ocxl/config.c

+12 −1
Original line number Diff line number Diff line
@@ -2,8 +2,8 @@ 
// Copyright 2017 IBM Corp.

#include <linux/pci.h>

#include <asm/pnv-ocxl.h>

#include <misc/ocxl.h>

#include <misc/ocxl-config.h>

#include "ocxl_internal.h"



#define EXTRACT_BIT(val, bit) (!!(val & BIT(bit)))

#define EXTRACT_BITS(val, s, e) ((val & GENMASK(e, s)) >> s)
@@ -243,6 +243,7 @@ int ocxl_config_read_function(struct pci_dev *dev, struct ocxl_fn_config *fn) 
	rc = validate_function(dev, fn);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_config_read_function);



static int read_afu_info(struct pci_dev *dev, struct ocxl_fn_config *fn,

			int offset, u32 *data)
@@ -301,6 +302,7 @@ int ocxl_config_check_afu_index(struct pci_dev *dev, 
	}

	return 1;

}

EXPORT_SYMBOL_GPL(ocxl_config_check_afu_index);



static int read_afu_name(struct pci_dev *dev, struct ocxl_fn_config *fn,

			struct ocxl_afu_config *afu)
@@ -498,6 +500,7 @@ int ocxl_config_read_afu(struct pci_dev *dev, struct ocxl_fn_config *fn, 
	rc = validate_afu(dev, afu);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_config_read_afu);



int ocxl_config_get_actag_info(struct pci_dev *dev, u16 *base, u16 *enabled,

			u16 *supported)
@@ -516,6 +519,7 @@ int ocxl_config_get_actag_info(struct pci_dev *dev, u16 *base, u16 *enabled, 
	}

	return 0;

}

EXPORT_SYMBOL_GPL(ocxl_config_get_actag_info);



void ocxl_config_set_afu_actag(struct pci_dev *dev, int pos, int actag_base,

			int actag_count)
@@ -528,11 +532,13 @@ void ocxl_config_set_afu_actag(struct pci_dev *dev, int pos, int actag_base, 
	val = actag_base & OCXL_DVSEC_ACTAG_MASK;

	pci_write_config_dword(dev, pos + OCXL_DVSEC_AFU_CTRL_ACTAG_BASE, val);

}

EXPORT_SYMBOL_GPL(ocxl_config_set_afu_actag);



int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count)

{

	return pnv_ocxl_get_pasid_count(dev, count);

}

EXPORT_SYMBOL_GPL(ocxl_config_get_pasid_info);



void ocxl_config_set_afu_pasid(struct pci_dev *dev, int pos, int pasid_base,

			u32 pasid_count_log)
@@ -550,6 +556,7 @@ void ocxl_config_set_afu_pasid(struct pci_dev *dev, int pos, int pasid_base, 
	pci_write_config_dword(dev, pos + OCXL_DVSEC_AFU_CTRL_PASID_BASE,

			val32);

}

EXPORT_SYMBOL_GPL(ocxl_config_set_afu_pasid);



void ocxl_config_set_afu_state(struct pci_dev *dev, int pos, int enable)

{
@@ -562,6 +569,7 @@ void ocxl_config_set_afu_state(struct pci_dev *dev, int pos, int enable) 
		val &= 0xFE;

	pci_write_config_byte(dev, pos + OCXL_DVSEC_AFU_CTRL_ENABLE, val);

}

EXPORT_SYMBOL_GPL(ocxl_config_set_afu_state);



int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec)

{
@@ -660,6 +668,7 @@ out: 
	kfree(recv_rate);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_config_set_TL);



int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control, int pasid)

{
@@ -699,6 +708,7 @@ int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control, int pasid) 
	}

	return 0;

}

EXPORT_SYMBOL_GPL(ocxl_config_terminate_pasid);



void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec, u32 tag_first,

			u32 tag_count)
@@ -710,3 +720,4 @@ void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec, u32 tag_first, 
	pci_write_config_dword(dev, func_dvsec + OCXL_DVSEC_FUNC_OFF_ACTAG,

			val);

}

EXPORT_SYMBOL_GPL(ocxl_config_set_actag);

drivers/misc/ocxl/link.c

+7 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/mmu_context.h>

#include <asm/copro.h>

#include <asm/pnv-ocxl.h>

#include <misc/ocxl.h>

#include "ocxl_internal.h"
@@ -420,6 +421,7 @@ unlock: 
	mutex_unlock(&links_list_lock);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_link_setup);



static void release_xsl(struct kref *ref)

{
@@ -439,6 +441,7 @@ void ocxl_link_release(struct pci_dev *dev, void *link_handle) 
	kref_put(&link->ref, release_xsl);

	mutex_unlock(&links_list_lock);

}

EXPORT_SYMBOL_GPL(ocxl_link_release);



static u64 calculate_cfg_state(bool kernel)

{
@@ -533,6 +536,7 @@ unlock: 
	mutex_unlock(&spa->spa_lock);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_link_add_pe);



int ocxl_link_remove_pe(void *link_handle, int pasid)

{
@@ -601,6 +605,7 @@ unlock: 
	mutex_unlock(&spa->spa_lock);

	return rc;

}

EXPORT_SYMBOL_GPL(ocxl_link_remove_pe);



int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, u64 *trigger_addr)

{
@@ -621,6 +626,7 @@ int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, u64 *trigger_addr) 
	*trigger_addr = addr;

	return 0;

}

EXPORT_SYMBOL_GPL(ocxl_link_irq_alloc);



void ocxl_link_free_irq(void *link_handle, int hw_irq)

{
@@ -629,3 +635,4 @@ void ocxl_link_free_irq(void *link_handle, int hw_irq) 
	pnv_ocxl_free_xive_irq(hw_irq);

	atomic_inc(&link->irq_available);

}

EXPORT_SYMBOL_GPL(ocxl_link_free_irq);

drivers/misc/ocxl/ocxl_internal.h

+1 −70
Original line number Diff line number Diff line
@@ -6,8 +6,8 @@ 
#include <linux/pci.h>

#include <linux/cdev.h>

#include <linux/list.h>

#include <misc/ocxl.h>



#define OCXL_AFU_NAME_SZ      (24+1)  /* add 1 for NULL termination */

#define MAX_IRQ_PER_LINK	2000

#define MAX_IRQ_PER_CONTEXT	MAX_IRQ_PER_LINK
@@ -16,38 +16,6 @@ 


extern struct pci_driver ocxl_pci_driver;



/*

 * The following 2 structures are a fairly generic way of representing

 * the configuration data for a function and AFU, as read from the

 * configuration space.

 */

struct ocxl_afu_config {

	u8 idx;

	int dvsec_afu_control_pos;

	char name[OCXL_AFU_NAME_SZ];

	u8 version_major;

	u8 version_minor;

	u8 afuc_type;

	u8 afum_type;

	u8 profile;

	u8 global_mmio_bar;

	u64 global_mmio_offset;

	u32 global_mmio_size;

	u8 pp_mmio_bar;

	u64 pp_mmio_offset;

	u32 pp_mmio_stride;

	u8 log_mem_size;

	u8 pasid_supported_log;

	u16 actag_supported;

};



struct ocxl_fn_config {

	int dvsec_tl_pos;

	int dvsec_function_pos;

	int dvsec_afu_info_pos;

	s8 max_pasid_log;

	s8 max_afu_index;

};



struct ocxl_fn {

	struct device dev;
@@ -135,43 +103,6 @@ extern void ocxl_unregister_afu(struct ocxl_afu *afu); 
extern int ocxl_file_init(void);

extern void ocxl_file_exit(void);



extern int ocxl_config_read_function(struct pci_dev *dev,

				struct ocxl_fn_config *fn);



extern int ocxl_config_check_afu_index(struct pci_dev *dev,

				struct ocxl_fn_config *fn, int afu_idx);

extern int ocxl_config_read_afu(struct pci_dev *dev,

				struct ocxl_fn_config *fn,

				struct ocxl_afu_config *afu,

				u8 afu_idx);

extern int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count);

extern void ocxl_config_set_afu_pasid(struct pci_dev *dev,

				int afu_control,

				int pasid_base, u32 pasid_count_log);

extern int ocxl_config_get_actag_info(struct pci_dev *dev,

				u16 *base, u16 *enabled, u16 *supported);

extern void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec,

				u32 tag_first, u32 tag_count);

extern void ocxl_config_set_afu_actag(struct pci_dev *dev, int afu_control,

				int actag_base, int actag_count);

extern void ocxl_config_set_afu_state(struct pci_dev *dev, int afu_control,

				int enable);

extern int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);

extern int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control,

				int pasid);



extern int ocxl_link_setup(struct pci_dev *dev, int PE_mask,

			void **link_handle);

extern void ocxl_link_release(struct pci_dev *dev, void *link_handle);

extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,

		u64 amr, struct mm_struct *mm,

		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),

		void *xsl_err_data);

extern int ocxl_link_remove_pe(void *link_handle, int pasid);

extern int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,

			u64 *addr);

extern void ocxl_link_free_irq(void *link_handle, int hw_irq);



extern int ocxl_pasid_afu_alloc(struct ocxl_fn *fn, u32 size);

extern void ocxl_pasid_afu_free(struct ocxl_fn *fn, u32 start, u32 size);

extern int ocxl_actag_afu_alloc(struct ocxl_fn *fn, u32 size);

include/misc/ocxl.h

0 → 100644
+214 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

// Copyright 2017 IBM Corp.

#ifndef _MISC_OCXL_H_

#define _MISC_OCXL_H_



#include <linux/pci.h>



/*

 * Opencapi drivers all need some common facilities, like parsing the

 * device configuration space, adding a Process Element to the Shared

 * Process Area, etc...

 *

 * The ocxl module provides a kernel API, to allow other drivers to

 * reuse common code. A bit like a in-kernel library.

 */



#define OCXL_AFU_NAME_SZ      (24+1)  /* add 1 for NULL termination */



/*

 * The following 2 structures are a fairly generic way of representing

 * the configuration data for a function and AFU, as read from the

 * configuration space.

 */

struct ocxl_afu_config {

	u8 idx;

	int dvsec_afu_control_pos; /* offset of AFU control DVSEC */

	char name[OCXL_AFU_NAME_SZ];

	u8 version_major;

	u8 version_minor;

	u8 afuc_type;

	u8 afum_type;

	u8 profile;

	u8 global_mmio_bar;     /* global MMIO area */

	u64 global_mmio_offset;

	u32 global_mmio_size;

	u8 pp_mmio_bar;         /* per-process MMIO area */

	u64 pp_mmio_offset;

	u32 pp_mmio_stride;

	u8 log_mem_size;

	u8 pasid_supported_log;

	u16 actag_supported;

};



struct ocxl_fn_config {

	int dvsec_tl_pos;       /* offset of the Transaction Layer DVSEC */

	int dvsec_function_pos; /* offset of the Function DVSEC */

	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */

	s8 max_pasid_log;

	s8 max_afu_index;

};



/*

 * Read the configuration space of a function and fill in a

 * ocxl_fn_config structure with all the function details

 */

extern int ocxl_config_read_function(struct pci_dev *dev,

				struct ocxl_fn_config *fn);



/*

 * Check if an AFU index is valid for the given function.

 *

 * AFU indexes can be sparse, so a driver should check all indexes up

 * to the maximum found in the function description

 */

extern int ocxl_config_check_afu_index(struct pci_dev *dev,

				struct ocxl_fn_config *fn, int afu_idx);



/*

 * Read the configuration space of a function for the AFU specified by

 * the index 'afu_idx'. Fills in a ocxl_afu_config structure

 */

extern int ocxl_config_read_afu(struct pci_dev *dev,

				struct ocxl_fn_config *fn,

				struct ocxl_afu_config *afu,

				u8 afu_idx);



/*

 * Get the max PASID value that can be used by the function

 */

extern int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count);



/*

 * Tell an AFU, by writing in the configuration space, the PASIDs that

 * it can use. Range starts at 'pasid_base' and its size is a multiple

 * of 2

 *

 * 'afu_control_offset' is the offset of the AFU control DVSEC which

 * can be found in the function configuration

 */

extern void ocxl_config_set_afu_pasid(struct pci_dev *dev,

				int afu_control_offset,

				int pasid_base, u32 pasid_count_log);



/*

 * Get the actag configuration for the function:

 * 'base' is the first actag value that can be used.

 * 'enabled' it the number of actags available, starting from base.

 * 'supported' is the total number of actags desired by all the AFUs

 *             of the function.

 */

extern int ocxl_config_get_actag_info(struct pci_dev *dev,

				u16 *base, u16 *enabled, u16 *supported);



/*

 * Tell a function, by writing in the configuration space, the actags

 * it can use.

 *

 * 'func_offset' is the offset of the Function DVSEC that can found in

 * the function configuration

 */

extern void ocxl_config_set_actag(struct pci_dev *dev, int func_offset,

				u32 actag_base, u32 actag_count);



/*

 * Tell an AFU, by writing in the configuration space, the actags it

 * can use.

 *

 * 'afu_control_offset' is the offset of the AFU control DVSEC for the

 * desired AFU. It can be found in the AFU configuration

 */

extern void ocxl_config_set_afu_actag(struct pci_dev *dev,

				int afu_control_offset,

				int actag_base, int actag_count);



/*

 * Enable/disable an AFU, by writing in the configuration space.

 *

 * 'afu_control_offset' is the offset of the AFU control DVSEC for the

 * desired AFU. It can be found in the AFU configuration

 */

extern void ocxl_config_set_afu_state(struct pci_dev *dev,

				int afu_control_offset, int enable);



/*

 * Set the Transaction Layer configuration in the configuration space.

 * Only needed for function 0.

 *

 * It queries the host TL capabilities, find some common ground

 * between the host and device, and set the Transaction Layer on both

 * accordingly.

 */

extern int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);



/*

 * Request an AFU to terminate a PASID.

 * Will return once the AFU has acked the request, or an error in case

 * of timeout.

 *

 * The hardware can only terminate one PASID at a time, so caller must

 * guarantee some kind of serialization.

 *

 * 'afu_control_offset' is the offset of the AFU control DVSEC for the

 * desired AFU. It can be found in the AFU configuration

 */

extern int ocxl_config_terminate_pasid(struct pci_dev *dev,

				int afu_control_offset, int pasid);



/*

 * Set up the opencapi link for the function.

 *

 * When called for the first time for a link, it sets up the Shared

 * Process Area for the link and the interrupt handler to process

 * translation faults.

 *

 * Returns a 'link handle' that should be used for further calls for

 * the link

 */

extern int ocxl_link_setup(struct pci_dev *dev, int PE_mask,

			void **link_handle);



/*

 * Remove the association between the function and its link.

 */

extern void ocxl_link_release(struct pci_dev *dev, void *link_handle);



/*

 * Add a Process Element to the Shared Process Area for a link.

 * The process is defined by its PASID, pid, tid and its mm_struct.

 *

 * 'xsl_err_cb' is an optional callback if the driver wants to be

 * notified when the translation fault interrupt handler detects an

 * address error.

 * 'xsl_err_data' is an argument passed to the above callback, if

 * defined

 */

extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,

		u64 amr, struct mm_struct *mm,

		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),

		void *xsl_err_data);



/*

 * Remove a Process Element from the Shared Process Area for a link

 */

extern int ocxl_link_remove_pe(void *link_handle, int pasid);



/*

 * Allocate an AFU interrupt associated to the link.

 *

 * 'hw_irq' is the hardware interrupt number

 * 'obj_handle' is the 64-bit object handle to be passed to the AFU to

 * trigger the interrupt.

 * On P9, 'obj_handle' is an address, which, if written, triggers the

 * interrupt. It is an MMIO address which needs to be remapped (one

 * page).

 */

extern int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,

			u64 *obj_handle);



/*

 * Free a previously allocated AFU interrupt

 */

extern void ocxl_link_free_irq(void *link_handle, int hw_irq);



#endif /* _MISC_OCXL_H_ */

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