From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 3e1b6469f8324bee5927b063e2aca30d3e56b907 ]
Building lpddr2_nvm with clang can result in a giant stack usage in one function:
drivers/mtd/lpddr/lpddr2_nvm.c:399:12: error: stack frame size of 1144 bytes in function 'lpddr2_nvm_probe' [-Werror,-Wframe-larger-than=]
The problem is that clang decides to build a copy of the mtd_info structure on the stack and then do a memcpy() into the actual version. It shouldn't really do it that way, but it's not strictly a bug either.
As a workaround, use a static const version of the structure to assign most of the members upfront and then only set the few members that require runtime knowledge at probe time.
Fixes: 96ba9dd65788 ("mtd: lpddr: add driver for LPDDR2-NVM PCM memories") Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20200505140136.263461-1-arnd@arndb.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/lpddr/lpddr2_nvm.c | 35 ++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/drivers/mtd/lpddr/lpddr2_nvm.c b/drivers/mtd/lpddr/lpddr2_nvm.c index 2342277c9bcb0..5e36366d9b36d 100644 --- a/drivers/mtd/lpddr/lpddr2_nvm.c +++ b/drivers/mtd/lpddr/lpddr2_nvm.c @@ -408,6 +408,17 @@ static int lpddr2_nvm_lock(struct mtd_info *mtd, loff_t start_add, return lpddr2_nvm_do_block_op(mtd, start_add, len, LPDDR2_NVM_LOCK); }
+static const struct mtd_info lpddr2_nvm_mtd_info = { + .type = MTD_RAM, + .writesize = 1, + .flags = (MTD_CAP_NVRAM | MTD_POWERUP_LOCK), + ._read = lpddr2_nvm_read, + ._write = lpddr2_nvm_write, + ._erase = lpddr2_nvm_erase, + ._unlock = lpddr2_nvm_unlock, + ._lock = lpddr2_nvm_lock, +}; + /* * lpddr2_nvm driver probe method */ @@ -448,6 +459,7 @@ static int lpddr2_nvm_probe(struct platform_device *pdev) .pfow_base = OW_BASE_ADDRESS, .fldrv_priv = pcm_data, }; + if (IS_ERR(map->virt)) return PTR_ERR(map->virt);
@@ -459,22 +471,13 @@ static int lpddr2_nvm_probe(struct platform_device *pdev) return PTR_ERR(pcm_data->ctl_regs);
/* Populate mtd_info data structure */ - *mtd = (struct mtd_info) { - .dev = { .parent = &pdev->dev }, - .name = pdev->dev.init_name, - .type = MTD_RAM, - .priv = map, - .size = resource_size(add_range), - .erasesize = ERASE_BLOCKSIZE * pcm_data->bus_width, - .writesize = 1, - .writebufsize = WRITE_BUFFSIZE * pcm_data->bus_width, - .flags = (MTD_CAP_NVRAM | MTD_POWERUP_LOCK), - ._read = lpddr2_nvm_read, - ._write = lpddr2_nvm_write, - ._erase = lpddr2_nvm_erase, - ._unlock = lpddr2_nvm_unlock, - ._lock = lpddr2_nvm_lock, - }; + *mtd = lpddr2_nvm_mtd_info; + mtd->dev.parent = &pdev->dev; + mtd->name = pdev->dev.init_name; + mtd->priv = map; + mtd->size = resource_size(add_range); + mtd->erasesize = ERASE_BLOCKSIZE * pcm_data->bus_width; + mtd->writebufsize = WRITE_BUFFSIZE * pcm_data->bus_width;
/* Verify the presence of the device looking for PFOW string */ if (!lpddr2_nvm_pfow_present(map)) {