mmc: tegra: Mark 64-bit DMA broken on Tegra124

According to the TRM, the SD/MMC controller on Tegra124 supports 34-bit
addressing, but testing shows that this doesn't work. On a device which
has more than 2 GiB of RAM and LPAE enabled, buffer allocations can use
addresses above the 32-bit boundary.

One way to work around this would be to enable IOMMU physical to virtual
address translations for the SD/MMC controllers, but that's not easy to
implement without breaking existing use-cases. It's also not obvious why
34-bit addressing doesn't work as advertised. In order to fix this for
existing users, add the SDHCI_QUIRK2_BROKEN_64_BIT_DMA quirk for now.
Reported-by: Paul Kocialkowski <contact@paulk.fr>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-tegra.c

@@ -391,6 +391,31 @@ static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
 	.pdata = &sdhci_tegra114_pdata,
 };
 
+static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
+	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
+		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
+		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
+		  SDHCI_QUIRK_NO_HISPD_BIT |
+		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
+		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
+		   /*
+		    * The TRM states that the SD/MMC controller found on
+		    * Tegra124 can address 34 bits (the maximum supported by
+		    * the Tegra memory controller), but tests show that DMA
+		    * to or from above 4 GiB doesn't work. This is possibly
+		    * caused by missing programming, though it's not obvious
+		    * what sequence is required. Mark 64-bit DMA broken for
+		    * now to fix this for existing users (e.g. Nyan boards).
+		    */
+		   SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
+	.ops  = &tegra114_sdhci_ops,
+};
+
+static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
+	.pdata = &sdhci_tegra124_pdata,
+};
+
 static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
@@ -408,7 +433,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
 
 static const struct of_device_id sdhci_tegra_dt_match[] = {
 	{ .compatible = "nvidia,tegra210-sdhci", .data = &soc_data_tegra210 },
-	{ .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra114 },
+	{ .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra124 },
 	{ .compatible = "nvidia,tegra114-sdhci", .data = &soc_data_tegra114 },
 	{ .compatible = "nvidia,tegra30-sdhci", .data = &soc_data_tegra30 },
 	{ .compatible = "nvidia,tegra20-sdhci", .data = &soc_data_tegra20 },