NVIDIA Tegra consumer devices have EMMC storage that has GPT entry at a
non-standard location. Support looking up GPT entry at a special sector
to enable such devices.
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
block/partitions/Kconfig | 8 +++++
block/partitions/Makefile | 1 +
block/partitions/check.h | 2 ++
block/partitions/core.c | 3 ++
block/partitions/efi.c | 9 +++++
block/partitions/tegra.c | 75 +++++++++++++++++++++++++++++++++++++++
6 files changed, 98 insertions(+)
create mode 100644 block/partitions/tegra.c
diff --git a/block/partitions/Kconfig b/block/partitions/Kconfig
index 278593b8e4e9..5db25e7efbb7 100644
--- a/block/partitions/Kconfig
+++ b/block/partitions/Kconfig
@@ -267,3 +267,11 @@ config CMDLINE_PARTITION
help
Say Y here if you want to read the partition table from bootargs.
The format for the command line is just like mtdparts.
+
+config TEGRA_PARTITION
+ bool "NVIDIA Tegra Partition support" if PARTITION_ADVANCED
+ default y if ARCH_TEGRA
+ depends on EFI_PARTITION && MMC_BLOCK && (ARCH_TEGRA || COMPILE_TEST)
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by NVIDIA Tegra machines.
diff --git a/block/partitions/Makefile b/block/partitions/Makefile
index a7f05cdb02a8..83cb70c6d08d 100644
--- a/block/partitions/Makefile
+++ b/block/partitions/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_IBM_PARTITION) += ibm.o
obj-$(CONFIG_EFI_PARTITION) += efi.o
obj-$(CONFIG_KARMA_PARTITION) += karma.o
obj-$(CONFIG_SYSV68_PARTITION) += sysv68.o
+obj-$(CONFIG_TEGRA_PARTITION) += tegra.o
diff --git a/block/partitions/check.h b/block/partitions/check.h
index d5b28e309d64..bd4b66443cf4 100644
--- a/block/partitions/check.h
+++ b/block/partitions/check.h
@@ -22,6 +22,7 @@ struct parsed_partitions {
int limit;
bool access_beyond_eod;
char *pp_buf;
+ sector_t force_gpt_sector;
};
typedef struct {
@@ -67,4 +68,5 @@ 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_forced_gpt(struct parsed_partitions *state);
int ultrix_partition(struct parsed_partitions *state);
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 9265936df77e..bbfbb1621581 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -82,6 +82,9 @@ static int (*check_part[])(struct parsed_partitions *) = {
#endif
#ifdef CONFIG_SYSV68_PARTITION
sysv68_partition,
+#endif
+#ifdef CONFIG_TEGRA_PARTITION
+ tegra_partition_forced_gpt,
#endif
NULL
};
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index aaa3dc487cb5..4ad151176204 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -619,6 +619,15 @@ static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
if (!good_agpt && force_gpt)
good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
+ /*
+ * The force_gpt_sector is used by NVIDIA Tegra partition parser in
+ * order to convey a non-standard location of the GPT entry for lookup.
+ * By default force_gpt_sector is set to 0 and has no effect.
+ */
+ if (!good_agpt && force_gpt && state->force_gpt_sector)
+ good_agpt = is_gpt_valid(state, state->force_gpt_sector,
+ &agpt, &aptes);
+
/* The obviously unsuccessful case */
if (!good_pgpt && !good_agpt)
goto fail;
diff --git a/block/partitions/tegra.c b/block/partitions/tegra.c
new file mode 100644
index 000000000000..4937e9f62398
--- /dev/null
+++ b/block/partitions/tegra.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "tegra-partition: " fmt
+
+#include <linux/blkdev.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/sizes.h>
+
+#include <linux/mmc/blkdev.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
+
+#include <soc/tegra/common.h>
+
+#include "check.h"
+
+static const struct of_device_id tegra_sdhci_match[] = {
+ { .compatible = "nvidia,tegra20-sdhci", },
+ { .compatible = "nvidia,tegra30-sdhci", },
+ { .compatible = "nvidia,tegra114-sdhci", },
+ { .compatible = "nvidia,tegra124-sdhci", },
+ {}
+};
+
+int tegra_partition_forced_gpt(struct parsed_partitions *state)
+{
+ struct gendisk *disk = state->disk;
+ struct block_device *bdev = disk->part0;
+ struct mmc_card *card = mmc_bdev_to_card(bdev);
+ int ret, boot_offset;
+
+ if (!soc_is_tegra())
+ return 0;
+
+ /* filter out unrelated and untested boot sources */
+ if (!card || card->ext_csd.rev < 3 ||
+ !mmc_card_is_blockaddr(card) ||
+ mmc_card_is_removable(card->host) ||
+ bdev_logical_block_size(bdev) != SZ_512 ||
+ !of_match_node(tegra_sdhci_match, card->host->parent->of_node)) {
+ pr_debug("%s: unexpected boot source\n", disk->disk_name);
+ return 0;
+ }
+
+ /*
+ * eMMC storage has two special boot partitions in addition to the
+ * main one. NVIDIA's bootloader linearizes eMMC boot0->boot1->main
+ * accesses, this means that the partition table addresses are shifted
+ * by the size of boot partitions. In accordance with the eMMC
+ * specification, the boot partition size is calculated as follows:
+ *
+ * boot partition size = 128K byte x BOOT_SIZE_MULT
+ *
+ * This function returns number of sectors occupied by the both boot
+ * partitions.
+ */
+ boot_offset = card->ext_csd.raw_boot_mult * SZ_128K /
+ SZ_512 * MMC_NUM_BOOT_PARTITION;
+
+ /*
+ * The fixed GPT entry address is calculated like this:
+ *
+ * gpt_sector = ext_csd.sectors_num - ext_csd.boot_sectors_num - 1
+ *
+ * This algorithm is defined by NVIDIA and used by Android devices.
+ */
+ state->force_gpt_sector = get_capacity(disk);
+ state->force_gpt_sector -= boot_offset + 1;
+
+ ret = efi_partition(state);
+ state->force_gpt_sector = 0;
+
+ return ret;
+}
--
2.32.0
