Commit a4bc676e authored by Oliver O'Halloran's avatar Oliver O'Halloran Committed by Michael Ellerman
Browse files

powerpc/powernv/pci: Refactor pnv_ioda_alloc_pe() 



Rework the PE allocation logic to allow allocating blocks of PEs rather
than individually. We'll use this to allocate contigious blocks of PEs for
the SR-IOVs.

This patch also adds code to pnv_ioda_alloc_pe() and pnv_ioda_reserve_pe() to
use the existing, but unused, phb->pe_alloc_mutex. Currently these functions
use atomic bit ops to release a currently allocated PE number. However,
the pnv_ioda_alloc_pe() wants to have exclusive access to the bit map while
scanning for hole large enough to accomodate the allocation size.

Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200722065715.1432738-10-oohall@gmail.com
parent a610d35c

arch/powerpc/platforms/powernv/pci-ioda.c

+33 −8
Original line number Diff line number Diff line
@@ -145,23 +145,45 @@ static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no) 
		return;

	}



	mutex_lock(&phb->ioda.pe_alloc_mutex);

	if (test_and_set_bit(pe_no, phb->ioda.pe_alloc))

		pr_debug("%s: PE %x was reserved on PHB#%x\n",

			 __func__, pe_no, phb->hose->global_number);

	mutex_unlock(&phb->ioda.pe_alloc_mutex);



	pnv_ioda_init_pe(phb, pe_no);

}



struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb)

struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb, int count)

{

	long pe;

	struct pnv_ioda_pe *ret = NULL;

	int run = 0, pe, i;



	mutex_lock(&phb->ioda.pe_alloc_mutex);



	/* scan backwards for a run of @count cleared bits */

	for (pe = phb->ioda.total_pe_num - 1; pe >= 0; pe--) {

		if (!test_and_set_bit(pe, phb->ioda.pe_alloc))

			return pnv_ioda_init_pe(phb, pe);

		if (test_bit(pe, phb->ioda.pe_alloc)) {

			run = 0;

			continue;

		}



	return NULL;

		run++;

		if (run == count)

			break;

	}

	if (run != count)

		goto out;



	for (i = pe; i < pe + count; i++) {

		set_bit(i, phb->ioda.pe_alloc);

		pnv_ioda_init_pe(phb, i);

	}

	ret = &phb->ioda.pe_array[pe];



out:

	mutex_unlock(&phb->ioda.pe_alloc_mutex);

	return ret;

}



void pnv_ioda_free_pe(struct pnv_ioda_pe *pe)
@@ -173,7 +195,10 @@ void pnv_ioda_free_pe(struct pnv_ioda_pe *pe) 
	WARN_ON(pe->npucomp); /* NPUs for nvlink are not supposed to be freed */

	kfree(pe->npucomp);

	memset(pe, 0, sizeof(struct pnv_ioda_pe));



	mutex_lock(&phb->ioda.pe_alloc_mutex);

	clear_bit(pe_num, phb->ioda.pe_alloc);

	mutex_unlock(&phb->ioda.pe_alloc_mutex);

}



/* The default M64 BAR is shared by all PEs */
@@ -976,7 +1001,7 @@ static struct pnv_ioda_pe *pnv_ioda_setup_dev_PE(struct pci_dev *dev) 
	if (pdn->pe_number != IODA_INVALID_PE)

		return NULL;



	pe = pnv_ioda_alloc_pe(phb);

	pe = pnv_ioda_alloc_pe(phb, 1);

	if (!pe) {

		pr_warn("%s: Not enough PE# available, disabling device\n",

			pci_name(dev));
@@ -1047,7 +1072,7 @@ static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all) 


	/* The PE number isn't pinned by M64 */

	if (!pe)

		pe = pnv_ioda_alloc_pe(phb);

		pe = pnv_ioda_alloc_pe(phb, 1);



	if (!pe) {

		pr_warn("%s: Not enough PE# available for PCI bus %04x:%02x\n",
@@ -3065,7 +3090,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np, 
		pnv_ioda_reserve_pe(phb, phb->ioda.root_pe_idx);

	} else {

		/* otherwise just allocate one */

		root_pe = pnv_ioda_alloc_pe(phb);

		root_pe = pnv_ioda_alloc_pe(phb, 1);

		phb->ioda.root_pe_idx = root_pe->pe_number;

	}

arch/powerpc/platforms/powernv/pci.h

+1 −1
Original line number Diff line number Diff line
@@ -224,7 +224,7 @@ int pnv_ioda_deconfigure_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe); 
void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe);

void pnv_pci_ioda2_release_pe_dma(struct pnv_ioda_pe *pe);



struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb);

struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb, int count);

void pnv_ioda_free_pe(struct pnv_ioda_pe *pe);



#ifdef CONFIG_PCI_IOV

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