From 453eb94c7651e791c3cbc1bbf8880677a61342ca Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 26 May 2022 18:43:43 -0400 Subject: [PATCH] ppc: fix boot with sam460ex MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Recent changes to pcie_host corrected size of its internal region to match what it expects: only the low 28 bits are ever decoded. Previous code just ignored bit 29 (if size was 1 << 29) in the address which does not make much sense. We are now asserting on size > 1 << 28 instead, but PPC 4xx actually allows guest to configure different sizes, and some firmwares seem to set it to 1 << 29. This caused e.g. qemu-system-ppc -M sam460ex to exit with an assert when the guest writes a value to CFGMSK register when trying to map config space. This is done in the board firmware in ppc4xx_init_pcie_port() in roms/u-boot-sam460ex/arch/powerpc/cpu/ppc4xx/4xx_pcie.c It's not clear what the proper fix should be but for now let's force the size to 256MB, so anything outside the expected address range is ignored. Fixes: commit 1f1a7b2269 ("include/hw/pci/pcie_host: Correct PCIE_MMCFG_SIZE_MAX") Reviewed-by: BALATON Zoltan Tested-by: BALATON Zoltan Signed-off-by: Michael S. Tsirkin Acked-by: Cédric Le Goater Message-Id: <20220526224229.95183-1-mst@redhat.com> [danielhb: changed commit msg as BALATON Zoltan suggested] Signed-off-by: Daniel Henrique Barboza --- hw/ppc/ppc440_uc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/hw/ppc/ppc440_uc.c b/hw/ppc/ppc440_uc.c index 993e3ba955..a1ecf6dd1c 100644 --- a/hw/ppc/ppc440_uc.c +++ b/hw/ppc/ppc440_uc.c @@ -1180,6 +1180,14 @@ static void dcr_write_pcie(void *opaque, int dcrn, uint32_t val) case PEGPL_CFGMSK: s->cfg_mask = val; size = ~(val & 0xfffffffe) + 1; + /* + * Firmware sets this register to E0000001. Why we are not sure, + * but the current guess is anything above PCIE_MMCFG_SIZE_MAX is + * ignored. + */ + if (size > PCIE_MMCFG_SIZE_MAX) { + size = PCIE_MMCFG_SIZE_MAX; + } pcie_host_mmcfg_update(PCIE_HOST_BRIDGE(s), val & 1, s->cfg_base, size); break; case PEGPL_MSGBAH: -- 2.30.2