From: Hector Martin marcan@marcan.st
[ Upstream commit 3d68bbb81b1a64e279180eee1ed0e2c590b5029e ]
We need to save/restore the TCR/TTBR registers, since they are lost on power gate.
Reviewed-by: Sven Peter sven@svenpeter.dev Signed-off-by: Hector Martin marcan@marcan.st Link: https://lore.kernel.org/r/20230113105029.26654-3-marcan@marcan.st Signed-off-by: Joerg Roedel jroedel@suse.de Stable-dep-of: cf5c1c87c239 ("iommu/dart: Fix apple_dart_device_group for PCI groups") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/apple-dart.c | 43 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c index 4f4a323be0d0f..2458416122f8d 100644 --- a/drivers/iommu/apple-dart.c +++ b/drivers/iommu/apple-dart.c @@ -121,6 +121,9 @@ struct apple_dart {
struct iommu_group *sid2group[DART_MAX_STREAMS]; struct iommu_device iommu; + + u32 save_tcr[DART_MAX_STREAMS]; + u32 save_ttbr[DART_MAX_STREAMS][DART_MAX_TTBR]; };
/* @@ -932,6 +935,45 @@ static const struct apple_dart_hw apple_dart_hw_t6000 = { .fmt = APPLE_DART2, };
+static __maybe_unused int apple_dart_suspend(struct device *dev) +{ + struct apple_dart *dart = dev_get_drvdata(dev); + unsigned int sid, idx; + + for (sid = 0; sid < DART_MAX_STREAMS; sid++) { + dart->save_tcr[sid] = readl_relaxed(dart->regs + DART_TCR(sid)); + for (idx = 0; idx < DART_MAX_TTBR; idx++) + dart->save_ttbr[sid][idx] = + readl(dart->regs + DART_TTBR(sid, idx)); + } + + return 0; +} + +static __maybe_unused int apple_dart_resume(struct device *dev) +{ + struct apple_dart *dart = dev_get_drvdata(dev); + unsigned int sid, idx; + int ret; + + ret = apple_dart_hw_reset(dart); + if (ret) { + dev_err(dev, "Failed to reset DART on resume\n"); + return ret; + } + + for (sid = 0; sid < DART_MAX_STREAMS; sid++) { + for (idx = 0; idx < DART_MAX_TTBR; idx++) + writel(dart->save_ttbr[sid][idx], + dart->regs + DART_TTBR(sid, idx)); + writel(dart->save_tcr[sid], dart->regs + DART_TCR(sid)); + } + + return 0; +} + +DEFINE_SIMPLE_DEV_PM_OPS(apple_dart_pm_ops, apple_dart_suspend, apple_dart_resume); + static const struct of_device_id apple_dart_of_match[] = { { .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 }, { .compatible = "apple,t6000-dart", .data = &apple_dart_hw_t6000 }, @@ -944,6 +986,7 @@ static struct platform_driver apple_dart_driver = { .name = "apple-dart", .of_match_table = apple_dart_of_match, .suppress_bind_attrs = true, + .pm = pm_sleep_ptr(&apple_dart_pm_ops), }, .probe = apple_dart_probe, .remove = apple_dart_remove,