From: Robin Murphy robin.murphy@arm.com
commit da5fb9e1ad3fbf632dce735f1bdad257ca528499 upstream.
The original version of the IORT PMCG definition had an oversight wherein there was no way to describe the second register page for an implementation using the recommended RELOC_CTRS feature. Although the spec was fixed, and the final patches merged to ACPICA and Linux written against the new version, it seems that some old firmware based on the original revision has survived and turned up in the wild.
Add a check for the original PMCG definition, and avoid filling in the second memory resource with nonsense if so. Otherwise it is likely that something horrible will happen when the PMCG driver attempts to probe.
Reported-by: Michael Petlan mpetlan@redhat.com Fixes: 24e516049360 ("ACPI/IORT: Add support for PMCG") Cc: stable@vger.kernel.org # 5.2.x Signed-off-by: Robin Murphy robin.murphy@arm.com Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Link: https://lore.kernel.org/r/75628ae41c257fb73588f7bf1c4459160e04be2b.164391625... Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/arm64/iort.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -1361,9 +1361,17 @@ static void __init arm_smmu_v3_pmcg_init res[0].start = pmcg->page0_base_address; res[0].end = pmcg->page0_base_address + SZ_4K - 1; res[0].flags = IORESOURCE_MEM; - res[1].start = pmcg->page1_base_address; - res[1].end = pmcg->page1_base_address + SZ_4K - 1; - res[1].flags = IORESOURCE_MEM; + /* + * The initial version in DEN0049C lacked a way to describe register + * page 1, which makes it broken for most PMCG implementations; in + * that case, just let the driver fail gracefully if it expects to + * find a second memory resource. + */ + if (node->revision > 0) { + res[1].start = pmcg->page1_base_address; + res[1].end = pmcg->page1_base_address + SZ_4K - 1; + res[1].flags = IORESOURCE_MEM; + }
if (pmcg->overflow_gsiv) acpi_iort_register_irq(pmcg->overflow_gsiv, "overflow",