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. Signed-off-by: Kishon Vijay Abraham I <[email protected]> --- .../pci/controller/cadence/pcie-cadence-ep.c | 4 + drivers/pci/controller/cadence/pcie-cadence.h | 76 ++++++++++++++----- 2 files changed, 62 insertions(+), 18 deletions(-) diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c index 4a829ccff7d0..c6eb2db94680 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c @@ -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; diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h index bc49c22e48a9..a45c11158f49 100644 --- a/drivers/pci/controller/cadence/pcie-cadence.h +++ b/drivers/pci/controller/cadence/pcie-cadence.h @@ -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; @@ -315,54 +318,94 @@ 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) +static inline void cdns_pcie_writel(struct cdns_pcie *pcie, u32 reg, u32 value) { - writeb(value, pcie->reg_base + reg); + writel(value, pcie->reg_base + reg); } -static inline void cdns_pcie_writew(struct cdns_pcie *pcie, u32 reg, u16 value) +static inline u32 cdns_pcie_readl(struct cdns_pcie *pcie, u32 reg) { - writew(value, pcie->reg_base + reg); + return readl(pcie->reg_base + reg); } -static inline void cdns_pcie_writel(struct cdns_pcie *pcie, u32 reg, u32 value) +static inline u32 cdns_pcie_read_sz(void __iomem *addr, int size) { - writel(value, pcie->reg_base + reg); + 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)) { + WARN(1, "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 u32 cdns_pcie_readl(struct cdns_pcie *pcie, u32 reg) +static inline void cdns_pcie_write_sz(void __iomem *addr, int size, u32 value) { - return readl(pcie->reg_base + reg); + 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)) { + WARN(1, "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) -- 2.17.1
