[PATCH v4] PCI: Unify ECAM constants in native PCI Express drivers
Bjorn Helgaas
helgaas at kernel.org
Fri Nov 20 15:34:28 EST 2020
On Mon, Oct 05, 2020 at 12:38:05AM +0000, Krzysztof Wilczyński wrote:
> Unify ECAM-related constants into a single set of standard constants
> defining memory address shift values for the byte-level address that can
> be used when accessing the PCI Express Configuration Space, and then
> move native PCI Express controller drivers to use newly introduced
> definitions retiring any driver-specific ones.
>
> The ECAM ("Enhanced Configuration Access Mechanism") is defined by the
> PCI Express specification (see PCI Express Base Specification, Revision
> 5.0, Version 1.0, Section 7.2.2, p. 676), thus most hardware should
> implement it the same way. Most of the native PCI Express controller
> drivers define their ECAM-related constants, many of these could be
> shared, or use open-coded values when setting the .bus_shift field of
> the struct pci_ecam_ops.
>
> All of the newly added constants should remove ambiguity and reduce the
> number of open-coded values, and also correlate more strongly with the
> descriptions in the aforementioned specification (see Table 7-1
> "Enhanced Configuration Address Mapping", p. 677).
>
> There is no change to functionality.
>
> Suggested-by: Bjorn Helgaas <bhelgaas at google.com>
> Signed-off-by: Krzysztof Wilczyński <kw at linux.com>
I think this is a nice cleanup. PCIE_ECAM_DEV_SHIFT is unused, so I'd
probably remove it and maybe rename PCIE_ECAM_FUN_SHIFT to
PCIE_ECAM_DEVFN_SHIFT or similar.
I assume this would best go through Lorenzo's tree.
> ---
> Changed in v4:
> Removed constants related to "CAM".
> Added more platforms and devices that can use new ECAM macros and
> constants.
> Removed unused ".bus_shift" initialisers from pci-xgene.c as
> xgene_pcie_map_bus() did not use these.
>
> Changes in v3:
> Updated commit message wording.
> Updated regarding custom ECAM bus shift values and concerning PCI base
> configuration space access for Type 1 access.
> Refactored rockchip_pcie_rd_other_conf() and rockchip_pcie_wr_other_conf()
> and removed the "busdev" variable.
> Removed surplus "relbus" variable from nwl_pcie_map_bus() and
> xilinx_pcie_map_bus().
> Renamed the PCIE_ECAM_ADDR() macro to PCIE_ECAM_OFFSET().
>
> Changes in v2:
> Use PCIE_ECAM_ADDR macro when computing ECAM address offset, but drop
> PCI_SLOT and PCI_FUNC macros from the PCIE_ECAM_ADDR macro in favour
> of using a single value for the device/function.
>
> arch/powerpc/platforms/4xx/pci.c | 7 +++--
> drivers/pci/controller/dwc/pcie-al.c | 8 +++---
> drivers/pci/controller/dwc/pcie-hisi.c | 4 +--
> drivers/pci/controller/pci-aardvark.c | 13 +++------
> drivers/pci/controller/pci-host-generic.c | 2 +-
> drivers/pci/controller/pci-thunder-ecam.c | 2 +-
> drivers/pci/controller/pci-thunder-pem.c | 13 +++++++--
> drivers/pci/controller/pci-xgene.c | 2 --
> drivers/pci/controller/pcie-brcmstb.c | 16 ++----------
> drivers/pci/controller/pcie-iproc.c | 29 ++++++---------------
> drivers/pci/controller/pcie-rockchip-host.c | 27 +++++++++----------
> drivers/pci/controller/pcie-rockchip.h | 8 +-----
> drivers/pci/controller/pcie-tango.c | 2 +-
> drivers/pci/controller/pcie-xilinx-nwl.c | 9 ++-----
> drivers/pci/controller/pcie-xilinx.c | 11 ++------
> drivers/pci/controller/vmd.c | 5 ++--
> drivers/pci/ecam.c | 4 +--
> include/linux/pci-ecam.h | 24 +++++++++++++++++
> 18 files changed, 82 insertions(+), 104 deletions(-)
>
> diff --git a/arch/powerpc/platforms/4xx/pci.c b/arch/powerpc/platforms/4xx/pci.c
> index c13d64c3b019..cee40e0b061c 100644
> --- a/arch/powerpc/platforms/4xx/pci.c
> +++ b/arch/powerpc/platforms/4xx/pci.c
> @@ -20,6 +20,7 @@
>
> #include <linux/kernel.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/init.h>
> #include <linux/of.h>
> #include <linux/delay.h>
> @@ -1585,17 +1586,15 @@ static void __iomem *ppc4xx_pciex_get_config_base(struct ppc4xx_pciex_port *port
> struct pci_bus *bus,
> unsigned int devfn)
> {
> - int relbus;
> -
> /* Remove the casts when we finally remove the stupid volatile
> * in struct pci_controller
> */
> if (bus->number == port->hose->first_busno)
> return (void __iomem *)port->hose->cfg_addr;
>
> - relbus = bus->number - (port->hose->first_busno + 1);
> return (void __iomem *)port->hose->cfg_data +
> - ((relbus << 20) | (devfn << 12));
> + PCIE_ECAM_BUS(bus->number - (port->hose->first_busno + 1)) |
> + PCIE_ECAM_DEVFN(devfn);
Can we tweak the ppc4xx_pciex_get_config_base() interface to add
"where" and then do this?
return port->hose->cfg_data + PCIE_ECAM_OFFSET(relbus, devfn, where);
(See comment below at PCIE_ECAM_OFFSET definition)
> }
>
> static int ppc4xx_pciex_read_config(struct pci_bus *bus, unsigned int devfn,
> diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c
> index d57d4ee15848..7c2aa049113c 100644
> --- a/drivers/pci/controller/dwc/pcie-al.c
> +++ b/drivers/pci/controller/dwc/pcie-al.c
> @@ -76,7 +76,7 @@ static int al_pcie_init(struct pci_config_window *cfg)
> }
>
> const struct pci_ecam_ops al_pcie_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .init = al_pcie_init,
> .pci_ops = {
> .map_bus = al_pcie_map_bus,
> @@ -138,8 +138,6 @@ struct al_pcie {
> struct al_pcie_target_bus_cfg target_bus_cfg;
> };
>
> -#define PCIE_ECAM_DEVFN(x) (((x) & 0xff) << 12)
> -
> #define to_al_pcie(x) dev_get_drvdata((x)->dev)
>
> static inline u32 al_pcie_controller_readl(struct al_pcie *pcie, u32 offset)
> @@ -228,7 +226,7 @@ static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
> void __iomem *pci_base_addr;
>
> pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
> - (busnr_ecam << 20) +
> + PCIE_ECAM_BUS(busnr_ecam) +
> PCIE_ECAM_DEVFN(devfn));
Can't we do this as the last line and drop pci_base_addr?
return pp->va_cfg0_base + PCIE_ECAM_OFFSET(relbus, devfn, where);
> if (busnr_reg != target_bus_cfg->reg_val) {
> @@ -300,7 +298,7 @@ static void al_pcie_config_prepare(struct al_pcie *pcie)
>
> target_bus_cfg = &pcie->target_bus_cfg;
>
> - ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
> + ecam_bus_mask = (pcie->ecam_size >> PCIE_ECAM_BUS_SHIFT) - 1;
> if (ecam_bus_mask > 255) {
> dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
> ecam_bus_mask = 255;
> diff --git a/drivers/pci/controller/dwc/pcie-hisi.c b/drivers/pci/controller/dwc/pcie-hisi.c
> index 5ca86796d43a..b7afbf1d4bd9 100644
> --- a/drivers/pci/controller/dwc/pcie-hisi.c
> +++ b/drivers/pci/controller/dwc/pcie-hisi.c
> @@ -100,7 +100,7 @@ static int hisi_pcie_init(struct pci_config_window *cfg)
> }
>
> const struct pci_ecam_ops hisi_pcie_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .init = hisi_pcie_init,
> .pci_ops = {
> .map_bus = hisi_pcie_map_bus,
> @@ -135,7 +135,7 @@ static int hisi_pcie_platform_init(struct pci_config_window *cfg)
> }
>
> static const struct pci_ecam_ops hisi_pcie_platform_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .init = hisi_pcie_platform_init,
> .pci_ops = {
> .map_bus = hisi_pcie_map_bus,
> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 1559f79e63b6..200ad07e4747 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -15,6 +15,7 @@
> #include <linux/irqdomain.h>
> #include <linux/kernel.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/init.h>
> #include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> @@ -163,14 +164,6 @@
> #define PCIE_CONFIG_WR_TYPE0 0xa
> #define PCIE_CONFIG_WR_TYPE1 0xb
>
> -#define PCIE_CONF_BUS(bus) (((bus) & 0xff) << 20)
> -#define PCIE_CONF_DEV(dev) (((dev) & 0x1f) << 15)
> -#define PCIE_CONF_FUNC(fun) (((fun) & 0x7) << 12)
> -#define PCIE_CONF_REG(reg) ((reg) & 0xffc)
> -#define PCIE_CONF_ADDR(bus, devfn, where) \
> - (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \
> - PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where))
> -
> #define PIO_RETRY_CNT 500
> #define PIO_RETRY_DELAY 2 /* 2 us*/
>
> @@ -683,7 +676,7 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
> advk_writel(pcie, reg, PIO_CTRL);
>
> /* Program the address registers */
> - reg = PCIE_CONF_ADDR(bus->number, devfn, where);
> + reg = PCIE_ECAM_OFFSET(bus, devfn, (where & 0xffc));
Maybe this:
reg = ALIGN_DOWN(PCIE_ECAM_OFFSET(bus->number, devfn, where), 4);
IIUC, the point is that aardvark can only do 32-bit, aligned,
accesses. "& 0xffc" does do that, but it' also a range restriction,
so it's not as obvious as it could be which is important here.
> advk_writel(pcie, reg, PIO_ADDR_LS);
> advk_writel(pcie, 0, PIO_ADDR_MS);
>
> @@ -744,7 +737,7 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
> advk_writel(pcie, reg, PIO_CTRL);
>
> /* Program the address registers */
> - reg = PCIE_CONF_ADDR(bus->number, devfn, where);
> + reg = PCIE_ECAM_OFFSET(bus, devfn, (where & 0xffc));
Ditto.
> advk_writel(pcie, reg, PIO_ADDR_LS);
> advk_writel(pcie, 0, PIO_ADDR_MS);
>
> diff --git a/drivers/pci/controller/pci-host-generic.c b/drivers/pci/controller/pci-host-generic.c
> index b51977abfdf1..c1c69b11615f 100644
> --- a/drivers/pci/controller/pci-host-generic.c
> +++ b/drivers/pci/controller/pci-host-generic.c
> @@ -49,7 +49,7 @@ static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
> }
>
> static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .pci_ops = {
> .map_bus = pci_dw_ecam_map_bus,
> .read = pci_generic_config_read,
> diff --git a/drivers/pci/controller/pci-thunder-ecam.c b/drivers/pci/controller/pci-thunder-ecam.c
> index 7e8835fee5f7..22ed7e995b39 100644
> --- a/drivers/pci/controller/pci-thunder-ecam.c
> +++ b/drivers/pci/controller/pci-thunder-ecam.c
> @@ -346,7 +346,7 @@ static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
> }
>
> const struct pci_ecam_ops pci_thunder_ecam_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> .read = thunder_ecam_config_read,
> diff --git a/drivers/pci/controller/pci-thunder-pem.c b/drivers/pci/controller/pci-thunder-pem.c
> index 3f847969143e..1a3f70ac61fc 100644
> --- a/drivers/pci/controller/pci-thunder-pem.c
> +++ b/drivers/pci/controller/pci-thunder-pem.c
> @@ -19,6 +19,15 @@
> #define PEM_CFG_WR 0x28
> #define PEM_CFG_RD 0x30
>
> +/*
> + * Enhanced Configuration Access Mechanism (ECAM)
> + *
> + * N.B. This is a non-standard platform-specific ECAM bus shift value. For
> + * standard values defined in the PCI Express Base Specification see
> + * include/linux/pci-ecam.h.
> + */
> +#define THUNDER_PCIE_ECAM_BUS_SHIFT 24
> +
> struct thunder_pem_pci {
> u32 ea_entry[3];
> void __iomem *pem_reg_base;
> @@ -404,7 +413,7 @@ static int thunder_pem_acpi_init(struct pci_config_window *cfg)
> }
>
> const struct pci_ecam_ops thunder_pem_ecam_ops = {
> - .bus_shift = 24,
> + .bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
> .init = thunder_pem_acpi_init,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> @@ -441,7 +450,7 @@ static int thunder_pem_platform_init(struct pci_config_window *cfg)
> }
>
> static const struct pci_ecam_ops pci_thunder_pem_ops = {
> - .bus_shift = 24,
> + .bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
> .init = thunder_pem_platform_init,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
> index 8e0db84f089d..85e7c98265e8 100644
> --- a/drivers/pci/controller/pci-xgene.c
> +++ b/drivers/pci/controller/pci-xgene.c
> @@ -257,7 +257,6 @@ static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
> }
>
> const struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
> - .bus_shift = 16,
> .init = xgene_v1_pcie_ecam_init,
> .pci_ops = {
> .map_bus = xgene_pcie_map_bus,
> @@ -272,7 +271,6 @@ static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg)
> }
>
> const struct pci_ecam_ops xgene_v2_pcie_ecam_ops = {
> - .bus_shift = 16,
> .init = xgene_v2_pcie_ecam_init,
> .pci_ops = {
> .map_bus = xgene_pcie_map_bus,
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 85fa7d54f11f..5d1e64550bba 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -22,6 +22,7 @@
> #include <linux/of_pci.h>
> #include <linux/of_platform.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/printk.h>
> #include <linux/sizes.h>
> #include <linux/slab.h>
> @@ -116,11 +117,7 @@
> #define PCIE_MSI_INTR2_MASK_CLR 0x4514
>
> #define PCIE_EXT_CFG_DATA 0x8000
> -
> #define PCIE_EXT_CFG_INDEX 0x9000
> -#define PCIE_EXT_BUSNUM_SHIFT 20
> -#define PCIE_EXT_SLOT_SHIFT 15
> -#define PCIE_EXT_FUNC_SHIFT 12
>
> #define PCIE_RGR1_SW_INIT_1 0x9210
> #define PCIE_RGR1_SW_INIT_1_PERST_MASK 0x1
> @@ -569,15 +566,6 @@ static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
> return dla && plu;
> }
>
> -/* Configuration space read/write support */
> -static inline int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
> -{
> - return ((PCI_SLOT(devfn) & 0x1f) << PCIE_EXT_SLOT_SHIFT)
> - | ((PCI_FUNC(devfn) & 0x07) << PCIE_EXT_FUNC_SHIFT)
> - | (busnr << PCIE_EXT_BUSNUM_SHIFT)
> - | (reg & ~3);
> -}
> -
> static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> int where)
> {
> @@ -590,7 +578,7 @@ static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> return PCI_SLOT(devfn) ? NULL : base + where;
>
> /* For devices, write to the config space index register */
> - idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
> + idx = PCIE_ECAM_BUS(bus->number) | PCIE_ECAM_DEVFN(devfn);
idx = PCIE_ECAM_OFFSET(bus->number, devfn, 0);
brcm_pcie_cfg_index() enforced 32-bit alignment, but was only ever
used with "reg == 0", so that never did anything. Not sure if that is
a hint that *something* here requires alignment?
> writel(idx, pcie->base + PCIE_EXT_CFG_INDEX);
> return base + PCIE_EXT_CFG_DATA + where;
> }
> diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
> index 905e93808243..30abe4b7be70 100644
> --- a/drivers/pci/controller/pcie-iproc.c
> +++ b/drivers/pci/controller/pcie-iproc.c
> @@ -6,6 +6,7 @@
>
> #include <linux/kernel.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/msi.h>
> #include <linux/clk.h>
> #include <linux/module.h>
> @@ -39,15 +40,7 @@
>
> #define CFG_IND_ADDR_MASK 0x00001ffc
>
> -#define CFG_ADDR_BUS_NUM_SHIFT 20
> -#define CFG_ADDR_BUS_NUM_MASK 0x0ff00000
> -#define CFG_ADDR_DEV_NUM_SHIFT 15
> -#define CFG_ADDR_DEV_NUM_MASK 0x000f8000
> -#define CFG_ADDR_FUNC_NUM_SHIFT 12
> -#define CFG_ADDR_FUNC_NUM_MASK 0x00007000
> -#define CFG_ADDR_REG_NUM_SHIFT 2
> #define CFG_ADDR_REG_NUM_MASK 0x00000ffc
> -#define CFG_ADDR_CFG_TYPE_SHIFT 0
> #define CFG_ADDR_CFG_TYPE_MASK 0x00000003
>
> #define SYS_RC_INTX_MASK 0xf
> @@ -459,18 +452,16 @@ static inline void iproc_pcie_apb_err_disable(struct pci_bus *bus,
>
> static void __iomem *iproc_pcie_map_ep_cfg_reg(struct iproc_pcie *pcie,
> unsigned int busno,
> - unsigned int slot,
> - unsigned int fn,
> + unsigned int devfn,
> int where)
> {
> u16 offset;
> u32 val;
>
> /* EP device access */
> - val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
> - (slot << CFG_ADDR_DEV_NUM_SHIFT) |
> - (fn << CFG_ADDR_FUNC_NUM_SHIFT) |
> - (where & CFG_ADDR_REG_NUM_MASK) |
> + val = PCIE_ECAM_BUS(busno) |
> + PCIE_ECAM_DEVFN(devfn) |
> + PCIE_ECAM_REG(where & CFG_ADDR_REG_NUM_MASK) |
> (1 & CFG_ADDR_CFG_TYPE_MASK);
val = ALIGN_DOWN(PCIE_ECAM_OFFSET(busno, devfn, where), 4) | 1;
Looks like there really should be a #define for that "1" at the end.
"1 & CFG_ADDR_CFG_TYPE_MASK" is just "1 & 0x3", which would be
unnecessarily verbose if there were a CFG_ADDR_CFG_TYPE_1 or whatever
that is.
> iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_ADDR, val);
> @@ -574,8 +565,6 @@ static int iproc_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> int where, int size, u32 *val)
> {
> struct iproc_pcie *pcie = iproc_data(bus);
> - unsigned int slot = PCI_SLOT(devfn);
> - unsigned int fn = PCI_FUNC(devfn);
> unsigned int busno = bus->number;
> void __iomem *cfg_data_p;
> unsigned int data;
> @@ -590,7 +579,7 @@ static int iproc_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> return ret;
> }
>
> - cfg_data_p = iproc_pcie_map_ep_cfg_reg(pcie, busno, slot, fn, where);
> + cfg_data_p = iproc_pcie_map_ep_cfg_reg(pcie, busno, devfn, where);
>
> if (!cfg_data_p)
> return PCIBIOS_DEVICE_NOT_FOUND;
> @@ -631,13 +620,11 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct iproc_pcie *pcie,
> int busno, unsigned int devfn,
> int where)
> {
> - unsigned slot = PCI_SLOT(devfn);
> - unsigned fn = PCI_FUNC(devfn);
> u16 offset;
>
> /* root complex access */
> if (busno == 0) {
> - if (slot > 0 || fn > 0)
> + if (PCIE_ECAM_DEVFN(devfn) > 0)
> return NULL;
>
> iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR,
> @@ -649,7 +636,7 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct iproc_pcie *pcie,
> return (pcie->base + offset);
> }
>
> - return iproc_pcie_map_ep_cfg_reg(pcie, busno, slot, fn, where);
> + return iproc_pcie_map_ep_cfg_reg(pcie, busno, devfn, where);
> }
>
> static void __iomem *iproc_pcie_bus_map_cfg_bus(struct pci_bus *bus,
> diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
> index 0bb2fb3e8a0b..4c069f8fa420 100644
> --- a/drivers/pci/controller/pcie-rockchip-host.c
> +++ b/drivers/pci/controller/pcie-rockchip-host.c
> @@ -160,12 +160,11 @@ static int rockchip_pcie_rd_other_conf(struct rockchip_pcie *rockchip,
> struct pci_bus *bus, u32 devfn,
> int where, int size, u32 *val)
> {
> - u32 busdev;
> + void __iomem *addr;
>
> - busdev = PCIE_ECAM_ADDR(bus->number, PCI_SLOT(devfn),
> - PCI_FUNC(devfn), where);
> + addr = rockchip->reg_base + PCIE_ECAM_OFFSET(bus, devfn, where);
If you adopt the bus->number change,
addr = rockchip->reg_base + PCIE_ECAM_OFFSET(bus->number, devfn, where);
> - if (!IS_ALIGNED(busdev, size)) {
> + if (!IS_ALIGNED((uintptr_t)addr, size)) {
> *val = 0;
> return PCIBIOS_BAD_REGISTER_NUMBER;
> }
> @@ -178,11 +177,11 @@ static int rockchip_pcie_rd_other_conf(struct rockchip_pcie *rockchip,
> AXI_WRAPPER_TYPE1_CFG);
>
> if (size == 4) {
> - *val = readl(rockchip->reg_base + busdev);
> + *val = readl(addr);
> } else if (size == 2) {
> - *val = readw(rockchip->reg_base + busdev);
> + *val = readw(addr);
> } else if (size == 1) {
> - *val = readb(rockchip->reg_base + busdev);
> + *val = readb(addr);
> } else {
> *val = 0;
> return PCIBIOS_BAD_REGISTER_NUMBER;
> @@ -194,11 +193,11 @@ static int rockchip_pcie_wr_other_conf(struct rockchip_pcie *rockchip,
> struct pci_bus *bus, u32 devfn,
> int where, int size, u32 val)
> {
> - u32 busdev;
> + void __iomem *addr;
>
> - busdev = PCIE_ECAM_ADDR(bus->number, PCI_SLOT(devfn),
> - PCI_FUNC(devfn), where);
> - if (!IS_ALIGNED(busdev, size))
> + addr = rockchip->reg_base + PCIE_ECAM_OFFSET(bus, devfn, where);
Ditto.
> + if (!IS_ALIGNED((uintptr_t)addr, size))
> return PCIBIOS_BAD_REGISTER_NUMBER;
>
> if (pci_is_root_bus(bus->parent))
> @@ -209,11 +208,11 @@ static int rockchip_pcie_wr_other_conf(struct rockchip_pcie *rockchip,
> AXI_WRAPPER_TYPE1_CFG);
>
> if (size == 4)
> - writel(val, rockchip->reg_base + busdev);
> + writel(val, addr);
> else if (size == 2)
> - writew(val, rockchip->reg_base + busdev);
> + writew(val, addr);
> else if (size == 1)
> - writeb(val, rockchip->reg_base + busdev);
> + writeb(val, addr);
> else
> return PCIBIOS_BAD_REGISTER_NUMBER;
>
> diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
> index c7d0178fc8c2..1650a5087450 100644
> --- a/drivers/pci/controller/pcie-rockchip.h
> +++ b/drivers/pci/controller/pcie-rockchip.h
> @@ -13,6 +13,7 @@
>
> #include <linux/kernel.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
>
> /*
> * The upper 16 bits of PCIE_CLIENT_CONFIG are a write mask for the lower 16
> @@ -178,13 +179,6 @@
> #define MIN_AXI_ADDR_BITS_PASSED 8
> #define PCIE_RC_SEND_PME_OFF 0x11960
> #define ROCKCHIP_VENDOR_ID 0x1d87
> -#define PCIE_ECAM_BUS(x) (((x) & 0xff) << 20)
> -#define PCIE_ECAM_DEV(x) (((x) & 0x1f) << 15)
> -#define PCIE_ECAM_FUNC(x) (((x) & 0x7) << 12)
> -#define PCIE_ECAM_REG(x) (((x) & 0xfff) << 0)
> -#define PCIE_ECAM_ADDR(bus, dev, func, reg) \
> - (PCIE_ECAM_BUS(bus) | PCIE_ECAM_DEV(dev) | \
> - PCIE_ECAM_FUNC(func) | PCIE_ECAM_REG(reg))
> #define PCIE_LINK_IS_L2(x) \
> (((x) & PCIE_CLIENT_DEBUG_LTSSM_MASK) == PCIE_CLIENT_DEBUG_LTSSM_L2)
> #define PCIE_LINK_UP(x) \
> diff --git a/drivers/pci/controller/pcie-tango.c b/drivers/pci/controller/pcie-tango.c
> index d093a8ce4bb1..8f0d695afbde 100644
> --- a/drivers/pci/controller/pcie-tango.c
> +++ b/drivers/pci/controller/pcie-tango.c
> @@ -208,7 +208,7 @@ static int smp8759_config_write(struct pci_bus *bus, unsigned int devfn,
> }
>
> static const struct pci_ecam_ops smp8759_ecam_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> .read = smp8759_config_read,
> diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c
> index f3cf7d61924f..cfd12b75bacb 100644
> --- a/drivers/pci/controller/pcie-xilinx-nwl.c
> +++ b/drivers/pci/controller/pcie-xilinx-nwl.c
> @@ -18,6 +18,7 @@
> #include <linux/of_platform.h>
> #include <linux/of_irq.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/platform_device.h>
> #include <linux/irqchip/chained_irq.h>
>
> @@ -124,8 +125,6 @@
> #define E_ECAM_CR_ENABLE BIT(0)
> #define E_ECAM_SIZE_LOC GENMASK(20, 16)
> #define E_ECAM_SIZE_SHIFT 16
> -#define ECAM_BUS_LOC_SHIFT 20
> -#define ECAM_DEV_LOC_SHIFT 12
> #define NWL_ECAM_VALUE_DEFAULT 12
>
> #define CFG_DMA_REG_BAR GENMASK(2, 0)
> @@ -240,15 +239,11 @@ static void __iomem *nwl_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> int where)
> {
> struct nwl_pcie *pcie = bus->sysdata;
> - int relbus;
>
> if (!nwl_pcie_valid_device(bus, devfn))
> return NULL;
>
> - relbus = (bus->number << ECAM_BUS_LOC_SHIFT) |
> - (devfn << ECAM_DEV_LOC_SHIFT);
> -
> - return pcie->ecam_base + relbus + where;
> + return pcie->ecam_base + PCIE_ECAM_OFFSET(bus, devfn, where);
Ditto.
> }
>
> /* PCIe operations */
> diff --git a/drivers/pci/controller/pcie-xilinx.c b/drivers/pci/controller/pcie-xilinx.c
> index 8523be61bba5..49bde5266aa2 100644
> --- a/drivers/pci/controller/pcie-xilinx.c
> +++ b/drivers/pci/controller/pcie-xilinx.c
> @@ -21,6 +21,7 @@
> #include <linux/of_platform.h>
> #include <linux/of_irq.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/platform_device.h>
>
> #include "../pci.h"
> @@ -86,10 +87,6 @@
> /* Phy Status/Control Register definitions */
> #define XILINX_PCIE_REG_PSCR_LNKUP BIT(11)
>
> -/* ECAM definitions */
> -#define ECAM_BUS_NUM_SHIFT 20
> -#define ECAM_DEV_NUM_SHIFT 12
> -
> /* Number of MSI IRQs */
> #define XILINX_NUM_MSI_IRQS 128
>
> @@ -183,15 +180,11 @@ static void __iomem *xilinx_pcie_map_bus(struct pci_bus *bus,
> unsigned int devfn, int where)
> {
> struct xilinx_pcie_port *port = bus->sysdata;
> - int relbus;
>
> if (!xilinx_pcie_valid_device(bus, devfn))
> return NULL;
>
> - relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
> - (devfn << ECAM_DEV_NUM_SHIFT);
> -
> - return port->reg_base + relbus + where;
> + return port->reg_base + PCIE_ECAM_OFFSET(bus, devfn, where);
And here. Boy, we really cargo-culted that "relbus" name, even when
there's no "base" to be relative to, didn't we?
> }
>
> /* PCIe operations */
> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index f69ef8c89f72..b14751845263 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -11,6 +11,7 @@
> #include <linux/module.h>
> #include <linux/msi.h>
> #include <linux/pci.h>
> +#include <linux/pci-ecam.h>
> #include <linux/srcu.h>
> #include <linux/rculist.h>
> #include <linux/rcupdate.h>
> @@ -302,8 +303,8 @@ static char __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
> unsigned int devfn, int reg, int len)
> {
> char __iomem *addr = vmd->cfgbar +
> - ((bus->number - vmd->busn_start) << 20) +
> - (devfn << 12) + reg;
> + PCIE_ECAM_BUS(bus->number - vmd->busn_start) +
> + PCIE_ECAM_DEVFN(devfn) + PCIE_ECAM_REG(reg);
PCIE_ECAM_OFFSET(bus->number - vmd->busn_start, ...);
> if ((addr - vmd->cfgbar) + len >=
> resource_size(&vmd->dev->resource[VMD_CFGBAR]))
Looks like sort of a weird way to bounds check this. Maybe this
instead?
u32 offset = PCIE_ECAM_OFFSET(bus->number - vmd->busn_start, ...);
if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
return NULL;
return vmd->cfgbar + offset;
> diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> index 8f065a42fc1a..ffd010290084 100644
> --- a/drivers/pci/ecam.c
> +++ b/drivers/pci/ecam.c
> @@ -149,7 +149,7 @@ EXPORT_SYMBOL_GPL(pci_ecam_map_bus);
>
> /* ECAM ops */
> const struct pci_ecam_ops pci_generic_ecam_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> .read = pci_generic_config_read,
> @@ -161,7 +161,7 @@ EXPORT_SYMBOL_GPL(pci_generic_ecam_ops);
> #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
> /* ECAM ops for 32-bit access only (non-compliant) */
> const struct pci_ecam_ops pci_32b_ops = {
> - .bus_shift = 20,
> + .bus_shift = PCIE_ECAM_BUS_SHIFT,
> .pci_ops = {
> .map_bus = pci_ecam_map_bus,
> .read = pci_generic_config_read32,
> diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
> index 1af5cb02ef7f..3ca5674fdf5e 100644
> --- a/include/linux/pci-ecam.h
> +++ b/include/linux/pci-ecam.h
> @@ -9,6 +9,30 @@
> #include <linux/kernel.h>
> #include <linux/platform_device.h>
>
> +/*
> + * Memory address shift values for the byte-level address that
> + * can be used when accessing the PCI Express Configuration Space.
> + */
> +
> +/*
> + * Enhanced Configuration Access Mechanism (ECAM)
> + *
> + * See PCI Express Base Specification, Revision 5.0, Version 1.0,
> + * Section 7.2.2, Table 7-1, p. 677.
> + */
> +#define PCIE_ECAM_BUS_SHIFT 20 /* Bus Number */
> +#define PCIE_ECAM_DEV_SHIFT 15 /* Device Number */
> +#define PCIE_ECAM_FUN_SHIFT 12 /* Function Number */
> +
> +#define PCIE_ECAM_BUS(x) (((x) & 0xff) << PCIE_ECAM_BUS_SHIFT)
> +#define PCIE_ECAM_DEVFN(x) (((x) & 0xff) << PCIE_ECAM_FUN_SHIFT)
> +#define PCIE_ECAM_REG(x) ((x) & 0xfff)
> +
> +#define PCIE_ECAM_OFFSET(bus, devfn, where) \
> + (PCIE_ECAM_BUS(bus->number) | \
If you use "PCIE_ECAM_BUS(bus)" here so the caller does the
"bus->number" part, this will be usable in a few more places.
> + PCIE_ECAM_DEVFN(devfn) | \
> + PCIE_ECAM_REG(where))
> +
> /*
> * struct to hold pci ops and bus shift of the config window
> * for a PCI controller.
> --
> 2.28.0
>
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