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authorPhilippe Mathieu-Daudé <f4bug@amsat.org>2021-06-24 21:22:19 +0200
committerPhilippe Mathieu-Daudé <f4bug@amsat.org>2021-07-02 17:34:55 +0200
commit711ef3373135f879459ece3b3c756b615334b404 (patch)
treea3754696362a8fb5860831b8ad92f7443229be9d /hw
parent300491f988f649fced2ffd5c46c1bc911fee0e60 (diff)
downloadqemu-711ef3373135f879459ece3b3c756b615334b404.zip
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So it seems safe to assume the datasheet is incomplete or outdated regarding the address constraints.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 <balaton@eik.bme.hu> Suggested-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20210624202747.1433023-4-f4bug@amsat.org> Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Diffstat (limited to 'hw')
-rw-r--r--hw/pci-host/bonito.c4
1 files changed, 2 insertions, 2 deletions
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