Commit b1db5513 authored by Christophe Lombard's avatar Christophe Lombard Committed by Michael Ellerman
Browse files

cxl: Add support for ASB_Notify on POWER9 



The POWER9 core supports a new feature: ASB_Notify which requires the
support of the Special Purpose Register: TIDR.

The ASB_Notify command, generated by the AFU, will attempt to
wake-up the host thread identified by the particular LPID:PID:TID.

This patch assign a unique TIDR (thread id) for the current thread which
will be used in the process element entry.

Signed-off-by: default avatarChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: default avatarPhilippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: default avatarVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 074db39e

arch/powerpc/kernel/process.c

+1 −0
Original line number Diff line number Diff line
@@ -1590,6 +1590,7 @@ int set_thread_tidr(struct task_struct *t) 


	return 0;

}

EXPORT_SYMBOL_GPL(set_thread_tidr);



#endif /* CONFIG_PPC64 */

drivers/misc/cxl/context.c

+2 −0
Original line number Diff line number Diff line
@@ -45,6 +45,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) 
	ctx->pid = NULL; /* Set in start work ioctl */

	mutex_init(&ctx->mapping_lock);

	ctx->mapping = NULL;

	ctx->tidr = 0;

	ctx->assign_tidr = false;



	if (cxl_is_power8()) {

		spin_lock_init(&ctx->sste_lock);

drivers/misc/cxl/cxl.h

+3 −0
Original line number Diff line number Diff line
@@ -630,6 +630,9 @@ struct cxl_context { 
	struct list_head extra_irq_contexts;



	struct mm_struct *mm;



	u16 tidr;

	bool assign_tidr;

};



struct cxl_irq_info;

drivers/misc/cxl/cxllib.c

+2 −1
Original line number Diff line number Diff line
@@ -199,10 +199,11 @@ int cxllib_get_PE_attributes(struct task_struct *task, 
		 */

		attr->pid = mm->context.id;

		mmput(mm);

		attr->tid = task->thread.tidr;

	} else {

		attr->pid = 0;

	}

		attr->tid = 0;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(cxllib_get_PE_attributes);

drivers/misc/cxl/file.c

+13 −2
Original line number Diff line number Diff line
@@ -173,7 +173,7 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, 
	 * flags are set it's invalid

	 */

	if (work.reserved1 || work.reserved2 || work.reserved3 ||

	    work.reserved4 || work.reserved5 || work.reserved6 ||

	    work.reserved4 || work.reserved5 ||

	    (work.flags & ~CXL_START_WORK_ALL)) {

		rc = -EINVAL;

		goto out;
@@ -186,12 +186,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, 
		rc =  -EINVAL;

		goto out;

	}



	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))

		goto out;



	if (work.flags & CXL_START_WORK_AMR)

		amr = work.amr & mfspr(SPRN_UAMOR);



	if (work.flags & CXL_START_WORK_TID)

		ctx->assign_tidr = true;



	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);



	/*
@@ -263,8 +267,15 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, 
		goto out;

	}



	ctx->status = STARTED;

	rc = 0;

	if (work.flags & CXL_START_WORK_TID) {

		work.tid = ctx->tidr;

		if (copy_to_user(uwork, &work, sizeof(work)))

			rc = -EFAULT;

	}



	ctx->status = STARTED;



out:

	mutex_unlock(&ctx->status_mutex);

	return rc;

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