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Commit 0d7fc080 authored by Vaibhav Jain's avatar Vaibhav Jain Committed by Michael Ellerman
Browse files

powerpc/papr_scm: Update drc_pmem_unbind() to use H_SCM_UNBIND_ALL 



The new hcall named H_SCM_UNBIND_ALL has been introduce that can
unbind all or specific scm memory assigned to an lpar. This is
more efficient than using H_SCM_UNBIND_MEM as currently we don't
support partial unbind of scm memory.

Hence this patch proposes following changes to drc_pmem_unbind():

    * Update drc_pmem_unbind() to replace hcall H_SCM_UNBIND_MEM to
      H_SCM_UNBIND_ALL.

    * Update drc_pmem_unbind() to handles cases when PHYP asks the guest
      kernel to wait for specific amount of time before retrying the
      hcall via the 'LONG_BUSY' return value.

    * Ensure appropriate error code is returned back from the function
      in case of an error.

Reviewed-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarVaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-3-vaibhav@linux.ibm.com
parent 6d140e75

arch/powerpc/platforms/pseries/papr_scm.c

+22 −7
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/sched.h>

#include <linux/libnvdimm.h>

#include <linux/platform_device.h>

#include <linux/delay.h>



#include <asm/plpar_wrappers.h>
@@ -78,22 +79,36 @@ static int drc_pmem_bind(struct papr_scm_priv *p) 
static int drc_pmem_unbind(struct papr_scm_priv *p)

{

	unsigned long ret[PLPAR_HCALL_BUFSIZE];

	uint64_t rc, token;

	uint64_t token = 0;

	int64_t rc;



	token = 0;

	dev_dbg(&p->pdev->dev, "unbind drc %x\n", p->drc_index);



	/* NB: unbind has the same retry requirements mentioned above */

	/* NB: unbind has the same retry requirements as drc_pmem_bind() */

	do {

		rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,

				p->bound_addr, p->blocks, token);



		/* Unbind of all SCM resources associated with drcIndex */

		rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,

				 p->drc_index, token);

		token = ret[0];



		/* Check if we are stalled for some time */

		if (H_IS_LONG_BUSY(rc)) {

			msleep(get_longbusy_msecs(rc));

			rc = H_BUSY;

		} else if (rc == H_BUSY) {

			cond_resched();

		}



	} while (rc == H_BUSY);



	if (rc)

		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);

	else

		dev_dbg(&p->pdev->dev, "unbind drc %x complete\n",

			p->drc_index);



	return !!rc;

	return rc == H_SUCCESS ? 0 : -ENXIO;

}



static int papr_scm_meta_get(struct papr_scm_priv *p,