linux/drivers/pci/controller/pcie-cadence-ep.c
Tom Joseph bd22885aa1 PCI: cadence: Refactor driver to use as a core library
Cadence PCIe host and endpoint IP may be embedded into a variety of
SoCs/platforms. Let's extract the platform related APIs/Structures in the
current driver to a separate file (pcie-cadence-plat.c), such that the
common functionality can be used by future platforms.

Signed-off-by: Tom Joseph <tjoseph@cadence.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
2019-11-11 14:56:54 +00:00

480 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Cadence
// Cadence PCIe endpoint controller driver.
// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/pci-epc.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sizes.h>
#include "pcie-cadence.h"
#define CDNS_PCIE_EP_MIN_APERTURE 128 /* 128 bytes */
#define CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE 0x1
#define CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY 0x3
static int cdns_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
struct pci_epf_header *hdr)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
cdns_pcie_ep_fn_writew(pcie, fn, PCI_DEVICE_ID, hdr->deviceid);
cdns_pcie_ep_fn_writeb(pcie, fn, PCI_REVISION_ID, hdr->revid);
cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CLASS_PROG, hdr->progif_code);
cdns_pcie_ep_fn_writew(pcie, fn, PCI_CLASS_DEVICE,
hdr->subclass_code | hdr->baseclass_code << 8);
cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CACHE_LINE_SIZE,
hdr->cache_line_size);
cdns_pcie_ep_fn_writew(pcie, fn, PCI_SUBSYSTEM_ID, hdr->subsys_id);
cdns_pcie_ep_fn_writeb(pcie, fn, PCI_INTERRUPT_PIN, hdr->interrupt_pin);
/*
* Vendor ID can only be modified from function 0, all other functions
* use the same vendor ID as function 0.
*/
if (fn == 0) {
/* Update the vendor IDs. */
u32 id = CDNS_PCIE_LM_ID_VENDOR(hdr->vendorid) |
CDNS_PCIE_LM_ID_SUBSYS(hdr->subsys_vendor_id);
cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
}
return 0;
}
static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
struct pci_epf_bar *epf_bar)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
dma_addr_t bar_phys = epf_bar->phys_addr;
enum pci_barno bar = epf_bar->barno;
int flags = epf_bar->flags;
u32 addr0, addr1, reg, cfg, b, aperture, ctrl;
u64 sz;
/* BAR size is 2^(aperture + 7) */
sz = max_t(size_t, epf_bar->size, CDNS_PCIE_EP_MIN_APERTURE);
/*
* roundup_pow_of_two() returns an unsigned long, which is not suited
* for 64bit values.
*/
sz = 1ULL << fls64(sz - 1);
aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */
if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS;
} else {
bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH);
bool is_64bits = sz > SZ_2G;
if (is_64bits && (bar & 1))
return -EINVAL;
if (is_64bits && !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
if (is_64bits && is_prefetch)
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
else if (is_prefetch)
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
else if (is_64bits)
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS;
else
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS;
}
addr0 = lower_32_bits(bar_phys);
addr1 = upper_32_bits(bar_phys);
cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar),
addr0);
cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar),
addr1);
if (bar < BAR_4) {
reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
b = bar;
} else {
reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
b = bar - BAR_4;
}
cfg = cdns_pcie_readl(pcie, reg);
cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
cdns_pcie_writel(pcie, reg, cfg);
return 0;
}
static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
struct pci_epf_bar *epf_bar)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
enum pci_barno bar = epf_bar->barno;
u32 reg, cfg, b, ctrl;
if (bar < BAR_4) {
reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
b = bar;
} else {
reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
b = bar - BAR_4;
}
ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
cfg = cdns_pcie_readl(pcie, reg);
cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl);
cdns_pcie_writel(pcie, reg, cfg);
cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0);
cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0);
}
static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr,
u64 pci_addr, size_t size)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
u32 r;
r = find_first_zero_bit(&ep->ob_region_map,
sizeof(ep->ob_region_map) * BITS_PER_LONG);
if (r >= ep->max_regions - 1) {
dev_err(&epc->dev, "no free outbound region\n");
return -EINVAL;
}
cdns_pcie_set_outbound_region(pcie, fn, r, false, addr, pci_addr, size);
set_bit(r, &ep->ob_region_map);
ep->ob_addr[r] = addr;
return 0;
}
static void cdns_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn,
phys_addr_t addr)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
u32 r;
for (r = 0; r < ep->max_regions - 1; r++)
if (ep->ob_addr[r] == addr)
break;
if (r == ep->max_regions - 1)
return;
cdns_pcie_reset_outbound_region(pcie, r);
ep->ob_addr[r] = 0;
clear_bit(r, &ep->ob_region_map);
}
static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 mmc)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
u16 flags;
/*
* Set the Multiple Message Capable bitfield into the Message Control
* register.
*/
flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
flags = (flags & ~PCI_MSI_FLAGS_QMASK) | (mmc << 1);
flags |= PCI_MSI_FLAGS_64BIT;
flags &= ~PCI_MSI_FLAGS_MASKBIT;
cdns_pcie_ep_fn_writew(pcie, fn, cap + PCI_MSI_FLAGS, flags);
return 0;
}
static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
u16 flags, mme;
/* Validate that the MSI feature is actually enabled. */
flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
if (!(flags & PCI_MSI_FLAGS_ENABLE))
return -EINVAL;
/*
* Get the Multiple Message Enable bitfield from the Message Control
* register.
*/
mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
return mme;
}
static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
u8 intx, bool is_asserted)
{
struct cdns_pcie *pcie = &ep->pcie;
u32 offset;
u16 status;
u8 msg_code;
intx &= 3;
/* Set the outbound region if needed. */
if (unlikely(ep->irq_pci_addr != CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY ||
ep->irq_pci_fn != fn)) {
/* First region was reserved for IRQ writes. */
cdns_pcie_set_outbound_region_for_normal_msg(pcie, fn, 0,
ep->irq_phys_addr);
ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY;
ep->irq_pci_fn = fn;
}
if (is_asserted) {
ep->irq_pending |= BIT(intx);
msg_code = MSG_CODE_ASSERT_INTA + intx;
} else {
ep->irq_pending &= ~BIT(intx);
msg_code = MSG_CODE_DEASSERT_INTA + intx;
}
status = cdns_pcie_ep_fn_readw(pcie, fn, PCI_STATUS);
if (((status & PCI_STATUS_INTERRUPT) != 0) ^ (ep->irq_pending != 0)) {
status ^= PCI_STATUS_INTERRUPT;
cdns_pcie_ep_fn_writew(pcie, fn, PCI_STATUS, status);
}
offset = CDNS_PCIE_NORMAL_MSG_ROUTING(MSG_ROUTING_LOCAL) |
CDNS_PCIE_NORMAL_MSG_CODE(msg_code) |
CDNS_PCIE_MSG_NO_DATA;
writel(0, ep->irq_cpu_addr + offset);
}
static int cdns_pcie_ep_send_legacy_irq(struct cdns_pcie_ep *ep, u8 fn, u8 intx)
{
u16 cmd;
cmd = cdns_pcie_ep_fn_readw(&ep->pcie, fn, PCI_COMMAND);
if (cmd & PCI_COMMAND_INTX_DISABLE)
return -EINVAL;
cdns_pcie_ep_assert_intx(ep, fn, intx, true);
/*
* The mdelay() value was taken from dra7xx_pcie_raise_legacy_irq()
* from drivers/pci/dwc/pci-dra7xx.c
*/
mdelay(1);
cdns_pcie_ep_assert_intx(ep, fn, intx, false);
return 0;
}
static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
u8 interrupt_num)
{
struct cdns_pcie *pcie = &ep->pcie;
u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
u16 flags, mme, data, data_mask;
u8 msi_count;
u64 pci_addr, pci_addr_mask = 0xff;
/* Check whether the MSI feature has been enabled by the PCI host. */
flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
if (!(flags & PCI_MSI_FLAGS_ENABLE))
return -EINVAL;
/* Get the number of enabled MSIs */
mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
msi_count = 1 << mme;
if (!interrupt_num || interrupt_num > msi_count)
return -EINVAL;
/* Compute the data value to be written. */
data_mask = msi_count - 1;
data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64);
data = (data & ~data_mask) | ((interrupt_num - 1) & data_mask);
/* Get the PCI address where to write the data into. */
pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI);
pci_addr <<= 32;
pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO);
pci_addr &= GENMASK_ULL(63, 2);
/* Set the outbound region if needed. */
if (unlikely(ep->irq_pci_addr != (pci_addr & ~pci_addr_mask) ||
ep->irq_pci_fn != fn)) {
/* First region was reserved for IRQ writes. */
cdns_pcie_set_outbound_region(pcie, fn, 0,
false,
ep->irq_phys_addr,
pci_addr & ~pci_addr_mask,
pci_addr_mask + 1);
ep->irq_pci_addr = (pci_addr & ~pci_addr_mask);
ep->irq_pci_fn = fn;
}
writel(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask));
return 0;
}
static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
enum pci_epc_irq_type type,
u16 interrupt_num)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
switch (type) {
case PCI_EPC_IRQ_LEGACY:
return cdns_pcie_ep_send_legacy_irq(ep, fn, 0);
case PCI_EPC_IRQ_MSI:
return cdns_pcie_ep_send_msi_irq(ep, fn, interrupt_num);
default:
break;
}
return -EINVAL;
}
static int cdns_pcie_ep_start(struct pci_epc *epc)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
struct pci_epf *epf;
u32 cfg;
/*
* BIT(0) is hardwired to 1, hence function 0 is always enabled
* and can't be disabled anyway.
*/
cfg = BIT(0);
list_for_each_entry(epf, &epc->pci_epf, list)
cfg |= BIT(epf->func_no);
cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg);
return 0;
}
static const struct pci_epc_features cdns_pcie_epc_features = {
.linkup_notifier = false,
.msi_capable = true,
.msix_capable = false,
};
static const struct pci_epc_features*
cdns_pcie_ep_get_features(struct pci_epc *epc, u8 func_no)
{
return &cdns_pcie_epc_features;
}
static const struct pci_epc_ops cdns_pcie_epc_ops = {
.write_header = cdns_pcie_ep_write_header,
.set_bar = cdns_pcie_ep_set_bar,
.clear_bar = cdns_pcie_ep_clear_bar,
.map_addr = cdns_pcie_ep_map_addr,
.unmap_addr = cdns_pcie_ep_unmap_addr,
.set_msi = cdns_pcie_ep_set_msi,
.get_msi = cdns_pcie_ep_get_msi,
.raise_irq = cdns_pcie_ep_raise_irq,
.start = cdns_pcie_ep_start,
.get_features = cdns_pcie_ep_get_features,
};
int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
{
struct device *dev = ep->pcie.dev;
struct platform_device *pdev = to_platform_device(dev);
struct device_node *np = dev->of_node;
struct cdns_pcie *pcie = &ep->pcie;
struct resource *res;
struct pci_epc *epc;
int ret;
pcie->is_rc = false;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
pcie->reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(pcie->reg_base)) {
dev_err(dev, "missing \"reg\"\n");
return PTR_ERR(pcie->reg_base);
}
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
if (!res) {
dev_err(dev, "missing \"mem\"\n");
return -EINVAL;
}
pcie->mem_res = res;
ret = of_property_read_u32(np, "cdns,max-outbound-regions",
&ep->max_regions);
if (ret < 0) {
dev_err(dev, "missing \"cdns,max-outbound-regions\"\n");
return ret;
}
ep->ob_addr = devm_kcalloc(dev,
ep->max_regions, sizeof(*ep->ob_addr),
GFP_KERNEL);
if (!ep->ob_addr)
return -ENOMEM;
/* Disable all but function 0 (anyway BIT(0) is hardwired to 1). */
cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, BIT(0));
epc = devm_pci_epc_create(dev, &cdns_pcie_epc_ops);
if (IS_ERR(epc)) {
dev_err(dev, "failed to create epc device\n");
ret = PTR_ERR(epc);
goto err_init;
}
epc_set_drvdata(epc, ep);
if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
epc->max_functions = 1;
ret = pci_epc_mem_init(epc, pcie->mem_res->start,
resource_size(pcie->mem_res));
if (ret < 0) {
dev_err(dev, "failed to initialize the memory space\n");
goto err_init;
}
ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
SZ_128K);
if (!ep->irq_cpu_addr) {
dev_err(dev, "failed to reserve memory space for MSI\n");
ret = -ENOMEM;
goto free_epc_mem;
}
ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE;
/* Reserve region 0 for IRQs */
set_bit(0, &ep->ob_region_map);
return 0;
free_epc_mem:
pci_epc_mem_exit(epc);
err_init:
pm_runtime_put_sync(dev);
return ret;
}