[PATCH v4 5/6] partitions/tegra: Support gpt_sector= command line option

Dmitry Osipenko
2020-05-15T01:43:06Z

The gpt_sector=<sector> causes the GPT partition parser to look at the
specified sector for a valid GPT header if the GPT is not found at the
beginning or the end of a block device. This is needed by Tegra-based
devices that have TegraPT and GPT placed in inaccessible by kernel
locations. The GPT entry duplicates TegraPT partitions.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
block/partitions/check.h | 1 +
block/partitions/core.c | 1 +
block/partitions/efi.c | 6 ++++++
block/partitions/tegra.c | 38 ++++++++++++++++++++++++++++++++++++++
4 files changed, 46 insertions(+)

diff --git a/block/partitions/check.h b/block/partitions/check.h
index ffa01cc4b0b0..ff07435b3ac3 100644
--- a/block/partitions/check.h
+++ b/block/partitions/check.h
@@ -67,5 +67,6 @@ int osf_partition(struct parsed_partitions *state);
int sgi_partition(struct parsed_partitions *state);
int sun_partition(struct parsed_partitions *state);
int sysv68_partition(struct parsed_partitions *state);
+int tegra_partition_gpt(struct parsed_partitions *state);
int tegra_partition(struct parsed_partitions *state);
int ultrix_partition(struct parsed_partitions *state);
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 0b4720372f07..ece70f15f24d 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -83,6 +83,7 @@ static int (*check_part[])(struct parsed_partitions *) = {
sysv68_partition,
#endif
#ifdef CONFIG_TEGRA_PARTITION
+ tegra_partition_gpt,
tegra_partition,
#endif
NULL
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index 48e4c2aeeded..f3b26be2bd6e 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -98,6 +98,12 @@ static int force_gpt;
static int __init
force_gpt_fn(char *str)
{
+ /* This check allows to parse "gpt gpt_sector=" properly since
+ * "gpt" overlaps with "gpt_sector", see tegra_gpt_sector_fn().
+ */
+ if (force_gpt)
+ return 0;
+
force_gpt = 1;
return 1;
}
diff --git a/block/partitions/tegra.c b/block/partitions/tegra.c
index d1b84fff362c..c2dae0f32c2a 100644
--- a/block/partitions/tegra.c
+++ b/block/partitions/tegra.c
@@ -30,6 +30,7 @@
#include <soc/tegra/common.h>
#include <soc/tegra/partition.h>

+#include "efi.h"
#include "check.h"

#define TEGRA_PT_SECTOR_SIZE(ptp) ((ptp)->logical_sector_size / SZ_512)
@@ -563,3 +564,40 @@ int tegra_partition(struct parsed_partitions *state)

return ret;
}
+
+/*
+ * This allows a kernel command line option 'gpt_sector=<sector>' to
+ * enable GPT header lookup at a non-standard location. This option
+ * is given to kernel by a proprietary bootloader, which is used by
+ * *most* (but not all) of NVIDIA Tegra-based devices.
+ */
+static sector_t tegra_gpt_sector;
+static int __init tegra_gpt_sector_fn(char *str)
+{
+ WARN_ON(kstrtoull(str, 10, &tegra_gpt_sector) < 0);
+ return 1;
+}
+__setup("gpt_sector=", tegra_gpt_sector_fn);
+
+int tegra_partition_gpt(struct parsed_partitions *state)
+{
+ int ret = 0;
+
+#ifdef CONFIG_EFI_PARTITION
+ struct tegra_partition_table_parser ptp = {};
+
+ if (!soc_is_tegra() || !tegra_boot_sdmmc || !tegra_gpt_sector)
+ return 0;
+
+ ptp.state = state;
+
+ ptp.boot_offset = tegra_partition_table_emmc_boot_offset(&ptp);
+ if (ptp.boot_offset < 0)
+ return 0;
+
+ force_gpt_sector = tegra_gpt_sector;
+ ret = efi_partition(ptp.state);
+ force_gpt_sector = 0;
+#endif
+ return ret;
+}
--
2.26.0