From: Philippe Mathieu-Daudé Date: Thu, 24 Jun 2021 19:22:19 +0000 (+0200) Subject: hw/pci-host/bonito: Allow PCI config accesses smaller than 32-bit X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=711ef3373135f879459ece3b3c756b615334b404;p=qemu.git hw/pci-host/bonito: Allow PCI config accesses smaller than 32-bit When running the official PMON firmware for the Fuloong 2E, we see 8-bit and 16-bit accesses to PCI config space: $ qemu-system-mips64el -M fuloong2e -bios pmon_2e.bin \ -trace -trace bonito\* -trace pci_cfg\* pci_cfg_write vt82c686b-pm 05:4 @0x90 <- 0xeee1 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x4d2, size: 2 pci_cfg_write vt82c686b-pm 05:4 @0xd2 <- 0x1 pci_cfg_write vt82c686b-pm 05:4 @0x4 <- 0x1 pci_cfg_write vt82c686b-isa 05:0 @0x4 <- 0x7 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x81, size: 1 pci_cfg_read vt82c686b-isa 05:0 @0x81 -> 0x0 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x81, size: 1 pci_cfg_write vt82c686b-isa 05:0 @0x81 <- 0x80 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x83, size: 1 pci_cfg_write vt82c686b-isa 05:0 @0x83 <- 0x89 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x85, size: 1 pci_cfg_write vt82c686b-isa 05:0 @0x85 <- 0x3 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x5a, size: 1 pci_cfg_write vt82c686b-isa 05:0 @0x5a <- 0x7 bonito_spciconf_small_access PCI config address is smaller then 32-bit, addr: 0x85, size: 1 pci_cfg_write vt82c686b-isa 05:0 @0x85 <- 0x1 Also this is what the Linux kernel does since it supports the Bonito north bridge: https://elixir.bootlin.com/linux/v2.6.15/source/arch/mips/pci/ops-bonito64.c#L85 So it seems safe to assume the datasheet is incomplete or outdated regarding the address constraints. This problem was exposed by commit 911629e6d3773a8adeab48b ("vt82c686: Fix SMBus IO base and configuration registers"). Reported-by: BALATON Zoltan Suggested-by: Jiaxun Yang Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20210624202747.1433023-4-f4bug@amsat.org> Tested-by: BALATON Zoltan --- diff --git a/hw/pci-host/bonito.c b/hw/pci-host/bonito.c index 751fdcec68..a57e81e3a9 100644 --- a/hw/pci-host/bonito.c +++ b/hw/pci-host/bonito.c @@ -187,7 +187,7 @@ FIELD(BONGENCFG, PCIQUEUE, 12, 1) #define BONITO_PCICONF_FUN_MASK 0x700 /* [10:8] */ #define BONITO_PCICONF_FUN_OFFSET 8 #define BONITO_PCICONF_REG_MASK_DS (~3) /* Per datasheet */ -#define BONITO_PCICONF_REG_MASK 0xFC +#define BONITO_PCICONF_REG_MASK_HW 0xff /* As seen running PMON */ #define BONITO_PCICONF_REG_OFFSET 0 @@ -466,7 +466,7 @@ static uint32_t bonito_sbridge_pciaddr(void *opaque, hwaddr addr) BONITO_PCICONF_IDSEL_OFFSET; devno = ctz32(idsel); funno = (cfgaddr & BONITO_PCICONF_FUN_MASK) >> BONITO_PCICONF_FUN_OFFSET; - regno = (cfgaddr & BONITO_PCICONF_REG_MASK) >> BONITO_PCICONF_REG_OFFSET; + regno = (cfgaddr & BONITO_PCICONF_REG_MASK_HW) >> BONITO_PCICONF_REG_OFFSET; if (idsel == 0) { error_report("error in bonito pci config address 0x" TARGET_FMT_plx