From 1d7ad68559e2238d42730c7de0a3d5e159d72cdd Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Sun, 26 Sep 2021 00:54:44 +0200 Subject: [PATCH] arm: a37xx: pci: Handle propagation of CRSSVE bit from PCIe Root Port MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Now that PCI Bridge (PCIe Root Port) for Aardvark is emulated in U-Boot, add support for handling and propagation of CRSSVE bit. When CRSSVE bit is unset (default), driver has to reissue config read/write request on CRS response. CRSSVE bit is supported only when CRSVIS bit is provided in read-only Root Capabilities register. So manually inject this CRSVIS bit into read response for that register. Signed-off-by: Pali Rohár Reviewed-by: Marek Behún Reviewed-by: Stefan Roese --- drivers/pci/pci-aardvark.c | 26 ++++++++++++++++++++++---- include/pci.h | 4 ++++ 2 files changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index 2481cbea52..591bc8b48c 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -41,6 +41,7 @@ #define PCIE_CORE_CMD_MEM_IO_REQ_EN BIT(2) #define PCIE_CORE_DEV_REV_REG 0x8 #define PCIE_CORE_EXP_ROM_BAR_REG 0x30 +#define PCIE_CORE_PCIEXP_CAP_OFF 0xc0 #define PCIE_CORE_DEV_CTRL_STATS_REG 0xc8 #define PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE (0 << 4) #define PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE (0 << 11) @@ -201,6 +202,7 @@ struct pcie_advk { struct udevice *dev; struct gpio_desc reset_gpio; u32 cfgcache[0x34 - 0x10]; + bool cfgcrssve; }; static inline void advk_writel(struct pcie_advk *pcie, uint val, uint reg) @@ -413,6 +415,18 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, data |= PCI_HEADER_TYPE_BRIDGE << 16; } + if ((offset & ~3) == PCIE_CORE_PCIEXP_CAP_OFF + PCI_EXP_RTCTL) { + /* CRSSVE bit is stored only in cache */ + if (pcie->cfgcrssve) + data |= PCI_EXP_RTCTL_CRSSVE; + } + + if ((offset & ~3) == PCIE_CORE_PCIEXP_CAP_OFF + + (PCI_EXP_RTCAP & ~3)) { + /* CRS is emulated below, so set CRSVIS capability */ + data |= PCI_EXP_RTCAP_CRSVIS << 16; + } + *valuep = pci_conv_32_to_size(data, offset, size); return 0; @@ -423,13 +437,14 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, * OS is allowed only for 4-byte PCI_VENDOR_ID config read request and * only when CRSSVE bit in Root Port PCIe device is enabled. In all * other error PCIe Root Complex must return all-ones. - * Aardvark HW does not have Root Port PCIe device and U-Boot does not - * implement emulation of this device. + * * U-Boot currently does not support handling of CRS return value for * PCI_VENDOR_ID config read request and also does not set CRSSVE bit. - * Therefore disable returning CRS response for now. + * So it means that pcie->cfgcrssve is false. But the code is prepared + * for returning CRS, so that if U-Boot does support CRS in the future, + * it will work for Aardvark. */ - allow_crs = false; + allow_crs = pcie->cfgcrssve; if (advk_readl(pcie, PIO_START)) { dev_err(pcie->dev, @@ -583,6 +598,9 @@ static int pcie_advk_write_config(struct udevice *bus, pci_dev_t bdf, (offset == PCI_PRIMARY_BUS && size != PCI_SIZE_8)) pcie->sec_busno = (data >> 8) & 0xff; + if ((offset & ~3) == PCIE_CORE_PCIEXP_CAP_OFF + PCI_EXP_RTCTL) + pcie->cfgcrssve = data & PCI_EXP_RTCTL_CRSSVE; + return 0; } diff --git a/include/pci.h b/include/pci.h index 11009a2f78..797f224e2f 100644 --- a/include/pci.h +++ b/include/pci.h @@ -495,6 +495,10 @@ #define PCI_EXP_LNKSTA_DLLLA 0x2000 /* Data Link Layer Link Active */ #define PCI_EXP_SLTCAP 20 /* Slot Capabilities */ #define PCI_EXP_SLTCAP_PSN 0xfff80000 /* Physical Slot Number */ +#define PCI_EXP_RTCTL 28 /* Root Control */ +#define PCI_EXP_RTCTL_CRSSVE 0x0010 /* CRS Software Visibility Enable */ +#define PCI_EXP_RTCAP 30 /* Root Capabilities */ +#define PCI_EXP_RTCAP_CRSVIS 0x0001 /* CRS Software Visibility capability */ #define PCI_EXP_DEVCAP2 36 /* Device Capabilities 2 */ #define PCI_EXP_DEVCAP2_ARI 0x00000020 /* ARI Forwarding Supported */ #define PCI_EXP_DEVCTL2 40 /* Device Control 2 */ -- 2.39.5