On 13/06/17 15:01, Marc Gonzalez wrote:
> The MSI controller in Tango supports 256 message-signaled interrupts,
> and a single doorbell address.
>
> Signed-off-by: Marc Gonzalez <marc_gonzalez@xxxxxxxxxxxxxxxx>
> ---
> Changes from v5 to v6
> o Rename 'used' bitmap to 'used_msi'
> o Rename 'lock' spinlock to 'used_msi_lock'
> o Take lock in interrupt handler
> o Remove irq_dom in error path
> ---
> drivers/pci/host/pcie-tango.c | 225 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 225 insertions(+)
>
> diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c
> index 67aaadcc1c5e..b06446b23bc8 100644
> --- a/drivers/pci/host/pcie-tango.c
> +++ b/drivers/pci/host/pcie-tango.c
> @@ -1,16 +1,228 @@
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> #include <linux/pci-ecam.h>
> #include <linux/delay.h>
> +#include <linux/msi.h>
> #include <linux/of.h>
>
> #define MSI_MAX 256
>
> #define SMP8759_MUX 0x48
> #define SMP8759_TEST_OUT 0x74
> +#define SMP8759_STATUS 0x80
> +#define SMP8759_ENABLE 0xa0
> +#define SMP8759_DOORBELL 0xa002e07c
>
> struct tango_pcie {
> + DECLARE_BITMAP(used_msi, MSI_MAX);
> + spinlock_t used_msi_lock;
> void __iomem *mux;
> + void __iomem *msi_status;
> + void __iomem *msi_enable;
> + phys_addr_t msi_doorbell;
> + struct irq_domain *irq_dom;
> + struct irq_domain *msi_dom;
> + int irq;
> };
>
> +/*** MSI CONTROLLER SUPPORT ***/
> +
> +static void tango_msi_isr(struct irq_desc *desc)
> +{
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + struct tango_pcie *pcie = irq_desc_get_handler_data(desc);
> + unsigned long flags, status, base, virq, idx, pos = 0;
> +
> + chained_irq_enter(chip, desc);
> + spin_lock_irqsave(&pcie->used_msi_lock, flags);
You're already in interrupt context, so there is no need to disable
interrupts any further. spin_lock() should do the trick
Thanks,
M.
--
Jazz is not dead. It just smells funny...
