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Commit e948e06f authored by Alastair D'Silva's avatar Alastair D'Silva Committed by Michael Ellerman
Browse files

ocxl: Expose the thread_id needed for wait on POWER9 



In order to successfully issue as_notify, an AFU needs to know the TID
to notify, which in turn means that this information should be
available in userspace so it can be communicated to the AFU.

Signed-off-by: default avatarAlastair D'Silva <alastair@d-silva.org>
Acked-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 19df3958

drivers/misc/ocxl/context.c

+4 −1
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu, 
	mutex_init(&ctx->xsl_error_lock);

	mutex_init(&ctx->irq_lock);

	idr_init(&ctx->irq_idr);

	ctx->tidr = 0;



	/*

	 * Keep a reference on the AFU to make sure it's valid for the

	 * duration of the life of the context
@@ -65,6 +67,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr) 
{

	int rc;



	// Locks both status & tidr

	mutex_lock(&ctx->status_mutex);

	if (ctx->status != OPENED) {

		rc = -EIO;
@@ -72,7 +75,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr) 
	}



	rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid,

			current->mm->context.id, 0, amr, current->mm,

			current->mm->context.id, ctx->tidr, amr, current->mm,

			xsl_fault_error, ctx);

	if (rc)

		goto out;

drivers/misc/ocxl/file.c

+53 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
#include <linux/sched/signal.h>

#include <linux/uaccess.h>

#include <uapi/misc/ocxl.h>

#include <asm/reg.h>

#include <asm/switch_to.h>

#include "ocxl_internal.h"
@@ -123,11 +125,55 @@ static long afu_ioctl_get_metadata(struct ocxl_context *ctx, 
	return 0;

}



#ifdef CONFIG_PPC64

static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,

		struct ocxl_ioctl_p9_wait __user *uarg)

{

	struct ocxl_ioctl_p9_wait arg;



	memset(&arg, 0, sizeof(arg));



	if (cpu_has_feature(CPU_FTR_P9_TIDR)) {

		enum ocxl_context_status status;



		// Locks both status & tidr

		mutex_lock(&ctx->status_mutex);

		if (!ctx->tidr) {

			if (set_thread_tidr(current))

				return -ENOENT;



			ctx->tidr = current->thread.tidr;

		}



		status = ctx->status;

		mutex_unlock(&ctx->status_mutex);



		if (status == ATTACHED) {

			int rc;

			struct link *link = ctx->afu->fn->link;



			rc = ocxl_link_update_pe(link, ctx->pasid, ctx->tidr);

			if (rc)

				return rc;

		}



		arg.thread_id = ctx->tidr;

	} else

		return -ENOENT;



	if (copy_to_user(uarg, &arg, sizeof(arg)))

		return -EFAULT;



	return 0;

}

#endif



#define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" :			\

			x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" :	\

			x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" :		\

			x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" :	\

			x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" :	\

			x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" :	\

			"UNKNOWN")



static long afu_ioctl(struct file *file, unsigned int cmd,
@@ -186,6 +232,13 @@ static long afu_ioctl(struct file *file, unsigned int cmd, 
				(struct ocxl_ioctl_metadata __user *) args);

		break;



#ifdef CONFIG_PPC64

	case OCXL_IOCTL_ENABLE_P9_WAIT:

		rc = afu_ioctl_enable_p9_wait(ctx,

				(struct ocxl_ioctl_p9_wait __user *) args);

		break;

#endif



	default:

		rc = -EINVAL;

	}

drivers/misc/ocxl/link.c

+36 −0
Original line number Diff line number Diff line
@@ -544,6 +544,42 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, 
}

EXPORT_SYMBOL_GPL(ocxl_link_add_pe);



int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid)

{

	struct link *link = (struct link *) link_handle;

	struct spa *spa = link->spa;

	struct ocxl_process_element *pe;

	int pe_handle, rc;



	if (pasid > SPA_PASID_MAX)

		return -EINVAL;



	pe_handle = pasid & SPA_PE_MASK;

	pe = spa->spa_mem + pe_handle;



	mutex_lock(&spa->spa_lock);



	pe->tid = tid;



	/*

	 * The barrier makes sure the PE is updated

	 * before we clear the NPU context cache below, so that the

	 * old PE cannot be reloaded erroneously.

	 */

	mb();



	/*

	 * hook to platform code

	 * On powerpc, the entry needs to be cleared from the context

	 * cache of the NPU.

	 */

	rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle);

	WARN_ON(rc);



	mutex_unlock(&spa->spa_lock);

	return rc;

}



int ocxl_link_remove_pe(void *link_handle, int pasid)

{

	struct link *link = (struct link *) link_handle;

drivers/misc/ocxl/ocxl_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ struct ocxl_context { 
	struct ocxl_xsl_error xsl_error;

	struct mutex irq_lock;

	struct idr irq_idr;

	u16 tidr; // Thread ID used for P9 wait implementation

};



struct ocxl_process_element {

include/misc/ocxl.h

+9 −0
Original line number Diff line number Diff line
@@ -188,6 +188,15 @@ extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, 
		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),

		void *xsl_err_data);



/**

 * Update values within a Process Element

 *

 * link_handle: the link handle associated with the process element

 * pasid: the PASID for the AFU context

 * tid: the new thread id for the process element

 */

extern int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid);



/*

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

 */