linux/drivers/pci/host/pcie-iproc-bcma.c
Ray Jui 3bc2b23488 PCI: iproc: Add iProc PCIe MSI support
Add PCIe MSI support for both PAXB and PAXC interfaces on all iProc-based
platforms.

The iProc PCIe MSI support deploys an event queue-based implementation.
Each event queue is serviced by a GIC interrupt and can support up to 64
MSI vectors.  Host memory is allocated for the event queues, and each event
queue consists of 64 word-sized entries.  MSI data is written to the lower
16-bit of each entry, whereas the upper 16-bit of the entry is reserved for
the controller for internal processing.

Each event queue is tracked by a head pointer and tail pointer.  Head
pointer indicates the next entry in the event queue to be processed by
the driver and is updated by the driver after processing is done.
The controller uses the tail pointer as the next MSI data insertion
point.  The controller ensures MSI data is flushed to host memory before
updating the tail pointer and then triggering the interrupt.

MSI IRQ affinity is supported by evenly distributing the interrupts to each
CPU core.  MSI vector is moved from one GIC interrupt to another in order
to steer to the target CPU.

Therefore, the actual number of supported MSI vectors is:

  M * 64 / N

where M denotes the number of GIC interrupts (event queues), and N denotes
the number of CPU cores.

This iProc event queue-based MSI support should not be used with newer
platforms with integrated MSI support in the GIC (e.g., giv2m or
gicv3-its).

[bhelgaas: fold in Kconfig fixes from Arnd Bergmann <arnd@arndb.de>]
Signed-off-by: Ray Jui <rjui@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Vikram Prakash <vikramp@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-06 18:04:35 -06:00

112 lines
3.0 KiB
C

/*
* Copyright (C) 2015 Broadcom Corporation
* Copyright (C) 2015 Hauke Mehrtens <hauke@hauke-m.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/phy/phy.h>
#include <linux/bcma/bcma.h>
#include <linux/ioport.h>
#include "pcie-iproc.h"
/* NS: CLASS field is R/O, and set to wrong 0x200 value */
static void bcma_pcie2_fixup_class(struct pci_dev *dev)
{
dev->class = PCI_CLASS_BRIDGE_PCI << 8;
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_BROADCOM, 0x8011, bcma_pcie2_fixup_class);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_BROADCOM, 0x8012, bcma_pcie2_fixup_class);
static int iproc_pcie_bcma_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
struct pci_sys_data *sys = dev->sysdata;
struct iproc_pcie *pcie = sys->private_data;
struct bcma_device *bdev = container_of(pcie->dev, struct bcma_device, dev);
return bcma_core_irq(bdev, 5);
}
static int iproc_pcie_bcma_probe(struct bcma_device *bdev)
{
struct iproc_pcie *pcie;
LIST_HEAD(res);
struct resource res_mem;
int ret;
pcie = devm_kzalloc(&bdev->dev, sizeof(*pcie), GFP_KERNEL);
if (!pcie)
return -ENOMEM;
pcie->dev = &bdev->dev;
bcma_set_drvdata(bdev, pcie);
pcie->base = bdev->io_addr;
pcie->base_addr = bdev->addr;
res_mem.start = bdev->addr_s[0];
res_mem.end = bdev->addr_s[0] + SZ_128M - 1;
res_mem.name = "PCIe MEM space";
res_mem.flags = IORESOURCE_MEM;
pci_add_resource(&res, &res_mem);
pcie->map_irq = iproc_pcie_bcma_map_irq;
ret = iproc_pcie_setup(pcie, &res);
if (ret)
dev_err(pcie->dev, "PCIe controller setup failed\n");
pci_free_resource_list(&res);
return ret;
}
static void iproc_pcie_bcma_remove(struct bcma_device *bdev)
{
struct iproc_pcie *pcie = bcma_get_drvdata(bdev);
iproc_pcie_remove(pcie);
}
static const struct bcma_device_id iproc_pcie_bcma_table[] = {
BCMA_CORE(BCMA_MANUF_BCM, BCMA_CORE_NS_PCIEG2, BCMA_ANY_REV, BCMA_ANY_CLASS),
{},
};
MODULE_DEVICE_TABLE(bcma, iproc_pcie_bcma_table);
static struct bcma_driver iproc_pcie_bcma_driver = {
.name = KBUILD_MODNAME,
.id_table = iproc_pcie_bcma_table,
.probe = iproc_pcie_bcma_probe,
.remove = iproc_pcie_bcma_remove,
};
static int __init iproc_pcie_bcma_init(void)
{
return bcma_driver_register(&iproc_pcie_bcma_driver);
}
module_init(iproc_pcie_bcma_init);
static void __exit iproc_pcie_bcma_exit(void)
{
bcma_driver_unregister(&iproc_pcie_bcma_driver);
}
module_exit(iproc_pcie_bcma_exit);
MODULE_AUTHOR("Hauke Mehrtens");
MODULE_DESCRIPTION("Broadcom iProc PCIe BCMA driver");
MODULE_LICENSE("GPL v2");