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author | Kishon Vijay Abraham I <kishon@ti.com> | 2020-07-22 16:33:06 +0530 |
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committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2020-07-27 15:46:16 +0100 |
commit | a8b661eb50abaac97401625d3ff28761bcf1822d (patch) | |
tree | 2923b3bb5b6dbc97fc6b78b48bca83e4f4fd7174 /drivers/pci/controller/cadence/pcie-cadence.h | |
parent | 229f5879facf96e5640c0385f62b8cb5f27b8a43 (diff) | |
download | linux-stable-a8b661eb50abaac97401625d3ff28761bcf1822d.tar.gz linux-stable-a8b661eb50abaac97401625d3ff28761bcf1822d.tar.bz2 linux-stable-a8b661eb50abaac97401625d3ff28761bcf1822d.zip |
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>
Diffstat (limited to 'drivers/pci/controller/cadence/pcie-cadence.h')
-rw-r--r-- | drivers/pci/controller/cadence/pcie-cadence.h | 76 |
1 files changed, 58 insertions, 18 deletions
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h index bc49c22e48a9..736b07274981 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)) { + 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 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)) { + 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) |