[PATCH v2 2/5] firmware: google: memconsole: Use devm_memremap()

[Stephen Boyd]

Use the devm version of memremap so that we can delete the unmapping
code in driver remove, but more importantly so that we can unmap this
memory region if memconsole_sysfs_init() errors out for some reason.

Cc: Wei-Ning Huang <wnhu...@chromium.org>
Cc: Julius Werner <jwer...@chromium.org>
Cc: Brian Norris <briannor...@chromium.org>
Cc: Samuel Holland <sam...@sholland.org>
Cc: Guenter Roeck <gro...@chromium.org>
Signed-off-by: Stephen Boyd <swb...@chromium.org>
---

Quoting Stephen Boyd (2019-05-10 11:01:48)
> diff --git a/drivers/firmware/google/memconsole-coreboot.c 
> b/drivers/firmware/google/memconsole-coreboot.c
> index 86331807f1d5..0b29b27b86f5 100644
> --- a/drivers/firmware/google/memconsole-coreboot.c
> +++ b/drivers/firmware/google/memconsole-coreboot.c
> @@ -85,7 +85,7 @@ static int memconsole_probe(struct coreboot_device *dev)
>  
>         /* Read size only once to prevent overrun attack through /dev/mem. */
>         cbmem_console_size = tmp_cbmc->size_dont_access_after_boot;
> -       cbmem_console = memremap(dev->cbmem_ref.cbmem_addr,
> +       cbmem_console = devm_memremap(&dev->dev, dev->cbmem_ref.cbmem_addr,

Whoops, this returns an error pointer now. Here's an updated patch.

 drivers/firmware/google/memconsole-coreboot.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/google/memconsole-coreboot.c 
b/drivers/firmware/google/memconsole-coreboot.c
index 86331807f1d5..cc3797f1ba85 100644
--- a/drivers/firmware/google/memconsole-coreboot.c
+++ b/drivers/firmware/google/memconsole-coreboot.c
@@ -85,13 +85,13 @@ static int memconsole_probe(struct coreboot_device *dev)
 
        /* Read size only once to prevent overrun attack through /dev/mem. */
        cbmem_console_size = tmp_cbmc->size_dont_access_after_boot;
-       cbmem_console = memremap(dev->cbmem_ref.cbmem_addr,
+       cbmem_console = devm_memremap(&dev->dev, dev->cbmem_ref.cbmem_addr,
                                 cbmem_console_size + sizeof(*cbmem_console),
                                 MEMREMAP_WB);
        memunmap(tmp_cbmc);
 
-       if (!cbmem_console)
-               return -ENOMEM;
+       if (IS_ERR(cbmem_console))
+               return PTR_ERR(cbmem_console);
 
        memconsole_setup(memconsole_coreboot_read);
 
@@ -102,9 +102,6 @@ static int memconsole_remove(struct coreboot_device *dev)
 {
        memconsole_exit();
 
-       if (cbmem_console)
-               memunmap(cbmem_console);
-
        return 0;
 }
 

base-commit: e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd
prerequisite-patch-id: b7c2a1e21fb108364f0e8cfaf1970cbc7903c750
-- 
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