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PCI: cadence: Convert all r/w accessors to perform only 32-bit accesses 

Certain platforms like TI's J721E using Cadence PCIe IP can perform only
32-bit accesses for reading or writing to Cadence registers. Convert all
read and write accesses to 32-bit in Cadence PCIe driver in preparation
for adding PCIe support in TI's J721E SoC.

Also add spin lock to disable interrupts while modifying PCI_STATUS
register while raising legacy interrupt since PCI_STATUS is accessible
by both remote RC and EP and time between read and write should be
minimized.

Link: https://lore.kernel.org/r/20200722110317.4744-5-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
This commit is contained in:
Kishon Vijay Abraham I 2020-07-22 16:33:06 +05:30 committed by Lorenzo Pieralisi
parent 229f5879fa
commit a8b661eb50
2 changed files with 64 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/pci/controller/cadence/pcie-cadence-ep.c
View File

@ -228,6 +228,7 @@ 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;
unsigned long flags;
u32 offset;
u16 status;
u8 msg_code;
@ -252,11 +253,13 @@ static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
msg_code = MSG_CODE_DEASSERT_INTA + intx;
}
spin_lock_irqsave(&ep->lock, flags);
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);
}
spin_unlock_irqrestore(&ep->lock, flags);
offset = CDNS_PCIE_NORMAL_MSG_ROUTING(MSG_ROUTING_LOCAL) |
CDNS_PCIE_NORMAL_MSG_CODE(msg_code) |
@ -464,6 +467,7 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE;
/* Reserve region 0 for IRQs */
set_bit(0, &ep->ob_region_map);
spin_lock_init(&ep->lock);
return 0;

80
drivers/pci/controller/cadence/pcie-cadence.h
View File

@ -304,6 +304,9 @@ struct cdns_pcie_rc {
* @irq_pci_fn: the latest PCI function that has updated the mapping of
* the MSI/legacy IRQ dedicated outbound region.
* @irq_pending: bitmask of asserted legacy IRQs.
* @lock: spin lock to disable interrupts while modifying PCIe controller
* registers fields (RMW) accessible by both remote RC and EP to
* minimize time between read and write
*/
struct cdns_pcie_ep {
struct cdns_pcie pcie;
@ -315,20 +318,12 @@ struct cdns_pcie_ep {
u64 irq_pci_addr;
u8 irq_pci_fn;
u8 irq_pending;
/* protect writing to PCI_STATUS while raising legacy interrupts */
spinlock_t lock;
};
/* Register access */
static inline void cdns_pcie_writeb(struct cdns_pcie *pcie, u32 reg, u8 value)
{
writeb(value, pcie->reg_base + reg);
}
static inline void cdns_pcie_writew(struct cdns_pcie *pcie, u32 reg, u16 value)
{
writew(value, pcie->reg_base + reg);
}
static inline void cdns_pcie_writel(struct cdns_pcie *pcie, u32 reg, u32 value)
{
writel(value, pcie->reg_base + reg);
@ -339,30 +334,78 @@ static inline u32 cdns_pcie_readl(struct cdns_pcie *pcie, u32 reg)
return readl(pcie->reg_base + reg);
}
static inline u32 cdns_pcie_read_sz(void __iomem *addr, int size)
{
void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4);
unsigned int offset = (unsigned long)addr & 0x3;
u32 val = readl(aligned_addr);
if (!IS_ALIGNED((uintptr_t)addr, size)) {
pr_warn("Address %p and size %d are not aligned\n", addr, size);
return 0;
}
if (size > 2)
return val;
return (val >> (8 * offset)) & ((1 << (size * 8)) - 1);
}
static inline void cdns_pcie_write_sz(void __iomem *addr, int size, u32 value)
{
void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4);
unsigned int offset = (unsigned long)addr & 0x3;
u32 mask;
u32 val;
if (!IS_ALIGNED((uintptr_t)addr, size)) {
pr_warn("Address %p and size %d are not aligned\n", addr, size);
return;
}
if (size > 2) {
writel(value, addr);
return;
}
mask = ~(((1 << (size * 8)) - 1) << (offset * 8));
val = readl(aligned_addr) & mask;
val |= value << (offset * 8);
writel(val, aligned_addr);
}
/* Root Port register access */
static inline void cdns_pcie_rp_writeb(struct cdns_pcie *pcie,
u32 reg, u8 value)
{
writeb(value, pcie->reg_base + CDNS_PCIE_RP_BASE + reg);
void __iomem *addr = pcie->reg_base + CDNS_PCIE_RP_BASE + reg;
cdns_pcie_write_sz(addr, 0x1, value);
}
static inline void cdns_pcie_rp_writew(struct cdns_pcie *pcie,
u32 reg, u16 value)
{
writew(value, pcie->reg_base + CDNS_PCIE_RP_BASE + reg);
void __iomem *addr = pcie->reg_base + CDNS_PCIE_RP_BASE + reg;
cdns_pcie_write_sz(addr, 0x2, value);
}
/* Endpoint Function register access */
static inline void cdns_pcie_ep_fn_writeb(struct cdns_pcie *pcie, u8 fn,
u32 reg, u8 value)
{
writeb(value, pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
void __iomem *addr = pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg;
cdns_pcie_write_sz(addr, 0x1, value);
}
static inline void cdns_pcie_ep_fn_writew(struct cdns_pcie *pcie, u8 fn,
u32 reg, u16 value)
{
writew(value, pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
void __iomem *addr = pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg;
cdns_pcie_write_sz(addr, 0x2, value);
}
static inline void cdns_pcie_ep_fn_writel(struct cdns_pcie *pcie, u8 fn,
@ -371,14 +414,11 @@ static inline void cdns_pcie_ep_fn_writel(struct cdns_pcie *pcie, u8 fn,
writel(value, pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
}
static inline u8 cdns_pcie_ep_fn_readb(struct cdns_pcie *pcie, u8 fn, u32 reg)
{
return readb(pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
}
static inline u16 cdns_pcie_ep_fn_readw(struct cdns_pcie *pcie, u8 fn, u32 reg)
{
return readw(pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
void __iomem *addr = pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg;
return cdns_pcie_read_sz(addr, 0x2);
}
static inline u32 cdns_pcie_ep_fn_readl(struct cdns_pcie *pcie, u8 fn, u32 reg)