Commit f62da6e7 authored by Niklas Cassel's avatar Niklas Cassel Committed by Bjorn Helgaas
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PCI: endpoint: Align pci_epc_set_msi(), pci_epc_ops::set_msi() nr_irqs encoding 



The kdoc for pci_epc_set_msi() says:
"Invoke to set the required number of MSI interrupts."

The kdoc for the callback pci_epc_ops::set_msi() says:
"ops to set the requested number of MSI interrupts in the MSI capability
register"

pci_epc_ops::set_msi() does however expect the parameter 'interrupts' to be
in the encoding as defined by the Multiple Message Capable (MMC) field of
the MSI capability structure. Nowhere in the kdoc does it say that the
number of interrupts should be in MMC encoding.

It is very confusing that the API pci_epc_set_msi() and the callback
function pci_epc_ops::set_msi() both take a parameter named 'interrupts',
but they expect completely different encodings.

Clean up the API and the callback function to have the same semantics,
i.e. the parameter represents the number of interrupts, regardless of the
internal encoding of that value.

Also rename the parameter 'interrupts' to 'nr_irqs', in both the wrapper
function and the callback function, such that the name is unambiguous.

[bhelgaas: more specific subject]

Signed-off-by: default avatarNiklas Cassel <cassel@kernel.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Cc: stable+noautosel@kernel.org # this is simply a cleanup
Link: https://patch.msgid.link/20250514074313.283156-13-cassel@kernel.org
parent 0917ed8f

drivers/pci/controller/cadence/pcie-cadence-ep.c

+2 −1
Original line number Diff line number Diff line
@@ -220,10 +220,11 @@ static void cdns_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn, 
	clear_bit(r, &ep->ob_region_map);

}



static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, u8 mmc)

static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, u8 nr_irqs)

{

	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);

	struct cdns_pcie *pcie = &ep->pcie;

	u8 mmc = order_base_2(nr_irqs);

	u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;

	u16 flags;

drivers/pci/controller/dwc/pcie-designware-ep.c

+3 −2
Original line number Diff line number Diff line
@@ -536,11 +536,12 @@ static int dw_pcie_ep_get_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no) 
}



static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no,

			      u8 interrupts)

			      u8 nr_irqs)

{

	struct dw_pcie_ep *ep = epc_get_drvdata(epc);

	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

	struct dw_pcie_ep_func *ep_func;

	u8 mmc = order_base_2(nr_irqs);

	u32 val, reg;



	ep_func = dw_pcie_ep_get_func_from_ep(ep, func_no);
@@ -550,7 +551,7 @@ static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, 
	reg = ep_func->msi_cap + PCI_MSI_FLAGS;

	val = dw_pcie_ep_readw_dbi(ep, func_no, reg);

	val &= ~PCI_MSI_FLAGS_QMASK;

	val |= FIELD_PREP(PCI_MSI_FLAGS_QMASK, interrupts);

	val |= FIELD_PREP(PCI_MSI_FLAGS_QMASK, mmc);

	dw_pcie_dbi_ro_wr_en(pci);

	dw_pcie_ep_writew_dbi(ep, func_no, reg, val);

	dw_pcie_dbi_ro_wr_dis(pci);

drivers/pci/controller/pcie-rcar-ep.c

+3 −3
Original line number Diff line number Diff line
@@ -256,15 +256,15 @@ static void rcar_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn, u8 vfn, 
	clear_bit(atu_index + 1, ep->ib_window_map);

}



static int rcar_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn,

				u8 interrupts)

static int rcar_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, u8 nr_irqs)

{

	struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);

	struct rcar_pcie *pcie = &ep->pcie;

	u8 mmc = order_base_2(nr_irqs);

	u32 flags;



	flags = rcar_pci_read_reg(pcie, MSICAP(fn));

	flags |= interrupts << MSICAP0_MMESCAP_OFFSET;

	flags |= mmc << MSICAP0_MMESCAP_OFFSET;

	rcar_pci_write_reg(pcie, flags, MSICAP(fn));



	return 0;

drivers/pci/controller/pcie-rockchip-ep.c

+3 −2
Original line number Diff line number Diff line
@@ -308,10 +308,11 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn, 
}



static int rockchip_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn,

				    u8 multi_msg_cap)

				    u8 nr_irqs)

{

	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);

	struct rockchip_pcie *rockchip = &ep->rockchip;

	u8 mmc = order_base_2(nr_irqs);

	u32 flags;



	flags = rockchip_pcie_read(rockchip,
@@ -319,7 +320,7 @@ static int rockchip_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, 
				   ROCKCHIP_PCIE_EP_MSI_CTRL_REG);

	flags &= ~ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_MASK;

	flags |=

	   (multi_msg_cap << ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_OFFSET) |

	   (mmc << ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_OFFSET) |

	   (PCI_MSI_FLAGS_64BIT << ROCKCHIP_PCIE_EP_MSI_FLAGS_OFFSET);

	flags &= ~ROCKCHIP_PCIE_EP_MSI_CTRL_MASK_MSI_CAP;

	rockchip_pcie_write(rockchip, flags,

drivers/pci/endpoint/pci-epc-core.c

+4 −7
Original line number Diff line number Diff line
@@ -302,28 +302,25 @@ EXPORT_SYMBOL_GPL(pci_epc_get_msi); 
 * @epc: the EPC device on which MSI has to be configured

 * @func_no: the physical endpoint function number in the EPC device

 * @vfunc_no: the virtual endpoint function number in the physical function

 * @interrupts: number of MSI interrupts required by the EPF

 * @nr_irqs: number of MSI interrupts required by the EPF

 *

 * Invoke to set the required number of MSI interrupts.

 */

int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, u8 interrupts)

int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, u8 nr_irqs)

{

	int ret;

	u8 encode_int;



	if (!pci_epc_function_is_valid(epc, func_no, vfunc_no))

		return -EINVAL;



	if (interrupts < 1 || interrupts > 32)

	if (nr_irqs < 1 || nr_irqs > 32)

		return -EINVAL;



	if (!epc->ops->set_msi)

		return 0;



	encode_int = order_base_2(interrupts);



	mutex_lock(&epc->lock);

	ret = epc->ops->set_msi(epc, func_no, vfunc_no, encode_int);

	ret = epc->ops->set_msi(epc, func_no, vfunc_no, nr_irqs);

	mutex_unlock(&epc->lock);



	return ret;