[PATCH 2/5] firmware: memconsole: Probe via coreboot bus

From: Samuel Holland
Date: Wed Jan 24 2018 - 20:41:37 EST


Remove the ad-hoc coreboot table search. Now the driver will only be
probed when the necessary coreboot table entry has already been found.

Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---
drivers/firmware/google/memconsole-coreboot.c | 49 ++++++++++-----------------
1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/drivers/firmware/google/memconsole-coreboot.c b/drivers/firmware/google/memconsole-coreboot.c
index 52738887735c..b29e10757bfb 100644
--- a/drivers/firmware/google/memconsole-coreboot.c
+++ b/drivers/firmware/google/memconsole-coreboot.c
@@ -15,9 +15,9 @@
* GNU General Public License for more details.
*/

+#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/platform_device.h>

#include "memconsole.h"
#include "coreboot_table.h"
@@ -73,18 +73,19 @@ static ssize_t memconsole_coreboot_read(char *buf, loff_t pos, size_t count)
return done;
}

-static int memconsole_coreboot_init(phys_addr_t physaddr)
+static int memconsole_probe(struct coreboot_device *dev)
{
struct cbmem_cons __iomem *tmp_cbmc;

- tmp_cbmc = memremap(physaddr, sizeof(*tmp_cbmc), MEMREMAP_WB);
+ tmp_cbmc = memremap(dev->cbmem_ref.cbmem_addr,
+ sizeof(*tmp_cbmc), MEMREMAP_WB);

if (!tmp_cbmc)
return -ENOMEM;

/* Read size only once to prevent overrun attack through /dev/mem. */
cbmem_console_size = tmp_cbmc->size_dont_access_after_boot;
- cbmem_console = memremap(physaddr,
+ cbmem_console = memremap(dev->cbmem_ref.cbmem_addr,
cbmem_console_size + sizeof(*cbmem_console),
MEMREMAP_WB);
memunmap(tmp_cbmc);
@@ -93,26 +94,11 @@ static int memconsole_coreboot_init(phys_addr_t physaddr)
return -ENOMEM;

memconsole_setup(memconsole_coreboot_read);
- return 0;
-}
-
-static int memconsole_probe(struct platform_device *pdev)
-{
- int ret;
- struct lb_cbmem_ref entry;
-
- ret = coreboot_table_find(CB_TAG_CBMEM_CONSOLE, &entry, sizeof(entry));
- if (ret)
- return ret;
-
- ret = memconsole_coreboot_init(entry.cbmem_addr);
- if (ret)
- return ret;

return memconsole_sysfs_init();
}

-static int memconsole_remove(struct platform_device *pdev)
+static int memconsole_remove(struct coreboot_device *dev)
{
memconsole_exit();

@@ -122,28 +108,27 @@ static int memconsole_remove(struct platform_device *pdev)
return 0;
}

-static struct platform_driver memconsole_driver = {
+static struct coreboot_driver memconsole_driver = {
.probe = memconsole_probe,
.remove = memconsole_remove,
- .driver = {
+ .drv = {
.name = "memconsole",
},
+ .tag = CB_TAG_CBMEM_CONSOLE,
};

-static int __init platform_memconsole_init(void)
+static void coreboot_memconsole_exit(void)
{
- struct platform_device *pdev;
-
- pdev = platform_device_register_simple("memconsole", -1, NULL, 0);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
-
- platform_driver_register(&memconsole_driver);
+ coreboot_driver_unregister(&memconsole_driver);
+}

- return 0;
+static int __init coreboot_memconsole_init(void)
+{
+ return coreboot_driver_register(&memconsole_driver);
}

-module_init(platform_memconsole_init);
+module_exit(coreboot_memconsole_exit);
+module_init(coreboot_memconsole_init);

MODULE_AUTHOR("Google, Inc.");
MODULE_LICENSE("GPL");
--
2.13.6