[PATCH v2 4/4] platform/x86/amd: pmc: Add an extra STB message for entering s2idle

From: Mario Limonciello
Date: Mon Aug 29 2022 - 09:30:05 EST


The `enter` callback is run right before the cores are put into HLT.
This will allow checking synchronization problems with other software
that writes into the STB.

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/platform/x86/amd/pmc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/platform/x86/amd/pmc.c b/drivers/platform/x86/amd/pmc.c
index fba42036682d..33300db461d1 100644
--- a/drivers/platform/x86/amd/pmc.c
+++ b/drivers/platform/x86/amd/pmc.c
@@ -41,6 +41,7 @@
#define AMD_PMC_STB_PMI_0 0x03E30600
#define AMD_PMC_STB_S2IDLE_PREPARE 0xC6000001
#define AMD_PMC_STB_S2IDLE_RESTORE 0xC6000002
+#define AMD_PMC_STB_S2IDLE_ENTER 0xC6000003

/* STB S2D(Spill to DRAM) has different message port offset */
#define STB_SPILL_TO_DRAM 0xBE
@@ -706,6 +707,16 @@ static void amd_pmc_s2idle_prepare(void)
dev_err(pdev->dev, "error writing to STB: %d\n", rc);
}

+static void amd_pmc_s2idle_enter(void)
+{
+ struct amd_pmc_dev *pdev = &pmc;
+ int rc;
+
+ rc = amd_pmc_write_stb(pdev, AMD_PMC_STB_S2IDLE_ENTER);
+ if (rc)
+ dev_err(pdev->dev, "error writing to STB: %d\n", rc);
+}
+
static void amd_pmc_s2idle_restore(void)
{
struct amd_pmc_dev *pdev = &pmc;
@@ -733,6 +744,7 @@ static void amd_pmc_s2idle_restore(void)

static struct acpi_s2idle_dev_ops amd_pmc_s2idle_dev_ops = {
.prepare = amd_pmc_s2idle_prepare,
+ .enter = amd_pmc_s2idle_enter,
.restore = amd_pmc_s2idle_restore,
};
#endif
--
2.34.1