diff options
| -rw-r--r-- | drivers/pci/pci.c | 101 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 8 | ||||
| -rw-r--r-- | include/uapi/linux/pci_regs.h | 8 |
3 files changed, 115 insertions, 2 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6078dfc11b11..832b96756e83 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2966,6 +2966,107 @@ bool pci_acs_path_enabled(struct pci_dev *start, } /** + * pci_rebar_find_pos - find position of resize ctrl reg for BAR + * @pdev: PCI device + * @bar: BAR to find + * + * Helper to find the position of the ctrl register for a BAR. + * Returns -ENOTSUPP if resizable BARs are not supported at all. + * Returns -ENOENT if no ctrl register for the BAR could be found. + */ +static int pci_rebar_find_pos(struct pci_dev *pdev, int bar) +{ + unsigned int pos, nbars, i; + u32 ctrl; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); + if (!pos) + return -ENOTSUPP; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> + PCI_REBAR_CTRL_NBAR_SHIFT; + + for (i = 0; i < nbars; i++, pos += 8) { + int bar_idx; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; + if (bar_idx == bar) + return pos; + } + + return -ENOENT; +} + +/** + * pci_rebar_get_possible_sizes - get possible sizes for BAR + * @pdev: PCI device + * @bar: BAR to query + * + * Get the possible sizes of a resizable BAR as bitmask defined in the spec + * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable. + */ +u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar) +{ + int pos; + u32 cap; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return 0; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap); + return (cap & PCI_REBAR_CAP_SIZES) >> 4; +} + +/** + * pci_rebar_get_current_size - get the current size of a BAR + * @pdev: PCI device + * @bar: BAR to set size to + * + * Read the size of a BAR from the resizable BAR config. + * Returns size if found or negative error code. + */ +int pci_rebar_get_current_size(struct pci_dev *pdev, int bar) +{ + int pos; + u32 ctrl; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return pos; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> 8; +} + +/** + * pci_rebar_set_size - set a new size for a BAR + * @pdev: PCI device + * @bar: BAR to set size to + * @size: new size as defined in the spec (0=1MB, 19=512GB) + * + * Set the new size of a BAR as defined in the spec. + * Returns zero if resizing was successful, error code otherwise. + */ +int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size) +{ + int pos; + u32 ctrl; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return pos; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; + ctrl |= size << 8; + pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); + return 0; +} + +/** * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge * @dev: the PCI device * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index a6560c9baa52..33469a33738d 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -366,4 +366,12 @@ int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment, struct resource *res); #endif +u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar); +int pci_rebar_get_current_size(struct pci_dev *pdev, int bar); +int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size); +static inline u64 pci_rebar_size_to_bytes(int size) +{ + return 1ULL << (size + 20); +} + #endif /* DRIVERS_PCI_H */ diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index f8d58045926f..d34000a59f24 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -939,9 +939,13 @@ #define PCI_SATA_SIZEOF_LONG 16 /* Resizable BARs */ +#define PCI_REBAR_CAP 4 /* capability register */ +#define PCI_REBAR_CAP_SIZES 0x00FFFFF0 /* supported BAR sizes */ #define PCI_REBAR_CTRL 8 /* control register */ -#define PCI_REBAR_CTRL_NBAR_MASK (7 << 5) /* mask for # bars */ -#define PCI_REBAR_CTRL_NBAR_SHIFT 5 /* shift for # bars */ +#define PCI_REBAR_CTRL_BAR_IDX 0x00000007 /* BAR index */ +#define PCI_REBAR_CTRL_NBAR_MASK 0x000000E0 /* # of resizable BARs */ +#define PCI_REBAR_CTRL_NBAR_SHIFT 5 /* shift for # of BARs */ +#define PCI_REBAR_CTRL_BAR_SIZE 0x00001F00 /* BAR size */ /* Dynamic Power Allocation */ #define PCI_DPA_CAP 4 /* capability register */ |