RE: [PATCH v3 2/5] PCI: designware: refactor MSI code to work with v3.65 dw hardware

From: Mohit KUMAR DCG
Date: Mon Jul 07 2014 - 00:19:02 EST


Hello Murali,

> -----Original Message-----
> From: Murali Karicheri [mailto:m-karicheri2@xxxxxx]
> Sent: Tuesday, July 01, 2014 3:15 AM
> To: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx
> Cc: Murali Karicheri; Santosh Shilimkar; Russell King; Grant Likely; Rob Herring;
> Mohit KUMAR DCG; Jingoo Han; Bjorn Helgaas; Pratyush ANAND; Richard
> Zhu; Kishon Vijay Abraham I; Marek Vasut; Arnd Bergmann; Pawel Moll;
> Mark Rutland; Ian Campbell; Kumar Gala; Randy Dunlap
> Subject: [PATCH v3 2/5] PCI: designware: refactor MSI code to work with
> v3.65 dw hardware
>
> Keystone PCI controller is based on v3.65 version of the DW PCI h/w that
> implements MSI controller registers in application space compared to the
> newer version. This requires updates to the DW core API to support the PCI
> controller driver based on this old DW hardware. Add msi_irq_set()/clear()
> API functions to allow Set/Clear MSI IRQ enable bit in the application register.
> Also the old h/w uses MSI_IRQ register in application register space to raise
> MSI IRQ to the RC from EP. Current code uses the standard mechanism as
> per PCI spec. So add another API get_msi_data() to get the address of this
> register so that common code can be re-used on old h/w.
>
> Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
>
> CC: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> CC: Russell King <linux@xxxxxxxxxxxxxxxx>
> CC: Grant Likely <grant.likely@xxxxxxxxxx>
> CC: Rob Herring <robh+dt@xxxxxxxxxx>
> CC: Mohit Kumar <mohit.kumar@xxxxxx>
> CC: Jingoo Han <jg1.han@xxxxxxxxxxx>
> CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> CC: Pratyush Anand <pratyush.anand@xxxxxx>
> CC: Richard Zhu <r65037@xxxxxxxxxxxxx>
> CC: Kishon Vijay Abraham I <kishon@xxxxxx>
> CC: Marek Vasut <marex@xxxxxxx>
> CC: Arnd Bergmann <arnd@xxxxxxxx>
> CC: Pawel Moll <pawel.moll@xxxxxxx>
> CC: Mark Rutland <mark.rutland@xxxxxxx>
> CC: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>
> CC: Kumar Gala <galak@xxxxxxxxxxxxxx>
> CC: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> CC: Grant Likely <grant.likely@xxxxxxxxxx>
> ---
> drivers/pci/host/pcie-designware.c | 50 ++++++++++++++++++++++++++-
> ---------
> drivers/pci/host/pcie-designware.h | 3 +++
> 2 files changed, 39 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-
> designware.c
> index d8f3af7..905941c 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -217,27 +217,47 @@ static int find_valid_pos0(struct pcie_port *pp, int
> msgvec, int pos, int *pos0)
> return 0;
> }
>
> +static void dw_pcie_msi_clear_irq(struct pcie_port *pp, int irq) {
> + unsigned int res, bit, val;
> +
> + res = (irq / 32) * 12;
> + bit = irq % 32;
> + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
> + val &= ~(1 << bit);
> + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); }
> +
> static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
> unsigned int nvec, unsigned int pos) {
> - unsigned int i, res, bit, val;
> + unsigned int i;
>
> for (i = 0; i < nvec; i++) {
> irq_set_msi_desc_off(irq_base, i, NULL);
> clear_bit(pos + i, pp->msi_irq_in_use);
> /* Disable corresponding interrupt on MSI controller */
> - res = ((pos + i) / 32) * 12;
> - bit = (pos + i) % 32;
> - dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res,
> 4, &val);
> - val &= ~(1 << bit);
> - dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res,
> 4, val);
> + if (pp->ops->msi_clear_irq)
> + pp->ops->msi_clear_irq(pp, pos + i);
> + else
> + dw_pcie_msi_clear_irq(pp, pos + i);
> }
> }
>
> +static void dw_pcie_msi_set_irq(struct pcie_port *pp, int irq) {
> + unsigned int res, bit, val;
> +
> + res = (irq / 32) * 12;
> + bit = irq % 32;
> + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
> + val |= 1 << bit;
> + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); }
> +
> static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos) {
> - int res, bit, irq, pos0, pos1, i;
> - u32 val;
> + int irq, pos0, pos1, i;
> struct pcie_port *pp = sys_to_pcie(desc->dev->bus->sysdata);
>
> if (!pp) {
> @@ -281,11 +301,10 @@ static int assign_irq(int no_irqs, struct msi_desc
> *desc, int *pos)
> }
> set_bit(pos0 + i, pp->msi_irq_in_use);
> /*Enable corresponding interrupt in MSI interrupt controller
> */
> - res = ((pos0 + i) / 32) * 12;
> - bit = (pos0 + i) % 32;
> - dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res,
> 4, &val);
> - val |= 1 << bit;
> - dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res,
> 4, val);
> + if (pp->ops->msi_set_irq)
> + pp->ops->msi_set_irq(pp, pos0 + i);
> + else
> + dw_pcie_msi_set_irq(pp, pos0 + i);
> }
>
> *pos = pos0;
> @@ -353,7 +372,10 @@ static int dw_msi_setup_irq(struct msi_chip *chip,
> struct pci_dev *pdev,
> */
> desc->msi_attrib.multiple = msgvec;
>
> - msg.address_lo = virt_to_phys((void *)pp->msi_data);
> + if (pp->ops->get_msi_data)
> + msg.address_lo = pp->ops->get_msi_data(pp);
> + else
> + msg.address_lo = virt_to_phys((void *)pp->msi_data);
> msg.address_hi = 0x0;
> msg.data = pos;
> write_msi_msg(irq, &msg);
> diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-
> designware.h
> index 8121901..387f69e 100644
> --- a/drivers/pci/host/pcie-designware.h
> +++ b/drivers/pci/host/pcie-designware.h
> @@ -67,6 +67,9 @@ struct pcie_host_ops {
> unsigned int devfn, int where, int size, u32 val);
> int (*link_up)(struct pcie_port *pp);
> void (*host_init)(struct pcie_port *pp);
> + void (*msi_set_irq)(struct pcie_port *pp, int irq);
> + void (*msi_clear_irq)(struct pcie_port *pp, int irq);
> + u32 (*get_msi_data)(struct pcie_port *pp);
> };
>
> int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val);

- Now MSI specific dw code can be shared b/w old Synopsys controller (ver < 3.70)
and newer controller that standardize the MSI settings inside design ware core itself.

Jingoo,

Pls let us know if you have any concern or comment over this.

Acked-by: Mohit Kumar <mohit.kumar@xxxxxx>

Regards
Mohit

> --
> 1.7.9.5

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