From 145e2198d749ec09a405f1607a9932499b76f1eb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Wed, 4 Jan 2023 10:03:14 +0100 Subject: [PATCH] hw/mips/gt64xxx_pci: Endian-swap using PCI_HOST_BRIDGE MemoryRegionOps MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GT64120's PCI endianness swapping works on little-endian hosts, but doesn't on big-endian ones. Instead of complicating how CFGADDR/CFGDATA registers deal with endianness, use the existing MemoryRegionOps from hw/pci/pci_host.c. Doing so also reduce the access to internal PCI_HOST_BRIDGE fields. Map the PCI_HOST_BRIDGE MemoryRegionOps into the corresponding CFGADDR/CFGDATA regions in the ISD MMIO and remove the unused code in the current ISD read/write handlers. Update the mapping when PCI0_CMD register is accessed (in case the endianness is changed). This allows using the GT64120 on a big-endian host (and boot the MIPS Malta machine in little-endian). Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20230104133935.4639-6-philmd@linaro.org> --- hw/mips/gt64xxx_pci.c | 70 ++++++++++++++++++++++++++++++------------- 1 file changed, 50 insertions(+), 20 deletions(-) diff --git a/hw/mips/gt64xxx_pci.c b/hw/mips/gt64xxx_pci.c index 65416c7b27..81232514c5 100644 --- a/hw/mips/gt64xxx_pci.c +++ b/hw/mips/gt64xxx_pci.c @@ -298,6 +298,50 @@ static void gt64120_isd_mapping(GT64120State *s) memory_region_transaction_commit(); } +static void gt64120_update_pci_cfgdata_mapping(GT64120State *s) +{ + /* Indexed on MByteSwap bit, see Table 158: PCI_0 Command, Offset: 0xc00 */ + static const MemoryRegionOps *pci_host_conf_ops[] = { + &pci_host_conf_be_ops, &pci_host_conf_le_ops + }; + static const MemoryRegionOps *pci_host_data_ops[] = { + &pci_host_data_be_ops, &pci_host_data_le_ops + }; + PCIHostState *phb = PCI_HOST_BRIDGE(s); + + memory_region_transaction_begin(); + + /* + * The setting of the MByteSwap bit and MWordSwap bit in the PCI Internal + * Command Register determines how data transactions from the CPU to/from + * PCI are handled along with the setting of the Endianess bit in the CPU + * Configuration Register. See: + * - Table 16: 32-bit PCI Transaction Endianess + * - Table 158: PCI_0 Command, Offset: 0xc00 + */ + if (memory_region_is_mapped(&phb->conf_mem)) { + memory_region_del_subregion(&s->ISD_mem, &phb->conf_mem); + object_unparent(OBJECT(&phb->conf_mem)); + } + memory_region_init_io(&phb->conf_mem, OBJECT(phb), + pci_host_conf_ops[s->regs[GT_PCI0_CMD] & 1], + s, "pci-conf-idx", 4); + memory_region_add_subregion_overlap(&s->ISD_mem, GT_PCI0_CFGADDR << 2, + &phb->conf_mem, 1); + + if (memory_region_is_mapped(&phb->data_mem)) { + memory_region_del_subregion(&s->ISD_mem, &phb->data_mem); + object_unparent(OBJECT(&phb->data_mem)); + } + memory_region_init_io(&phb->data_mem, OBJECT(phb), + pci_host_data_ops[s->regs[GT_PCI0_CMD] & 1], + s, "pci-conf-data", 4); + memory_region_add_subregion_overlap(&s->ISD_mem, GT_PCI0_CFGDATA << 2, + &phb->data_mem, 1); + + memory_region_transaction_commit(); +} + static void gt64120_pci_mapping(GT64120State *s) { memory_region_transaction_begin(); @@ -389,7 +433,6 @@ static void gt64120_writel(void *opaque, hwaddr addr, uint64_t val, unsigned size) { GT64120State *s = opaque; - PCIHostState *phb = PCI_HOST_BRIDGE(s); uint32_t saddr = addr >> 2; trace_gt64120_write(addr, val); @@ -592,6 +635,7 @@ static void gt64120_writel(void *opaque, hwaddr addr, case GT_PCI0_CMD: case GT_PCI1_CMD: s->regs[saddr] = val & 0x0401fc0f; + gt64120_update_pci_cfgdata_mapping(s); break; case GT_PCI0_TOR: case GT_PCI0_BS_SCS10: @@ -632,15 +676,9 @@ static void gt64120_writel(void *opaque, hwaddr addr, saddr << 2, size, size << 1, val); break; case GT_PCI0_CFGADDR: - phb->config_reg = val & 0x80fffffc; - break; case GT_PCI0_CFGDATA: - if (!(s->regs[GT_PCI0_CMD] & 1) && (phb->config_reg & 0x00fff800)) { - val = bswap32(val); - } - if (phb->config_reg & (1u << 31)) { - pci_data_write(phb->bus, phb->config_reg, val, 4); - } + /* Mapped via in gt64120_pci_mapping() */ + g_assert_not_reached(); break; /* Interrupts */ @@ -698,7 +736,6 @@ static uint64_t gt64120_readl(void *opaque, hwaddr addr, unsigned size) { GT64120State *s = opaque; - PCIHostState *phb = PCI_HOST_BRIDGE(s); uint32_t val; uint32_t saddr = addr >> 2; @@ -883,17 +920,9 @@ static uint64_t gt64120_readl(void *opaque, /* PCI Internal */ case GT_PCI0_CFGADDR: - val = phb->config_reg; - break; case GT_PCI0_CFGDATA: - if (!(phb->config_reg & (1 << 31))) { - val = 0xffffffff; - } else { - val = pci_data_read(phb->bus, phb->config_reg, 4); - } - if (!(s->regs[GT_PCI0_CMD] & 1) && (phb->config_reg & 0x00fff800)) { - val = bswap32(val); - } + /* Mapped via in gt64120_pci_mapping() */ + g_assert_not_reached(); break; case GT_PCI0_CMD: @@ -1153,6 +1182,7 @@ static void gt64120_reset(DeviceState *dev) gt64120_isd_mapping(s); gt64120_pci_mapping(s); + gt64120_update_pci_cfgdata_mapping(s); } static void gt64120_realize(DeviceState *dev, Error **errp)