Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/13599
-gerrit
commit 467201b87c26f93334a93e5ff0a2b33e06cb7c75 Author: Duncan Laurie dlaurie@chromium.org Date: Tue Jan 26 16:22:53 2016 -0800
chromeos: Make vbnv_flash driver safe for CAR usage
This modifies the vbnv_flash driver to make it safe for use in cache-as-ram by handling the global variables safely.
To make this cleaner all of the variables were moved into one structure and referenced from there.
BUG=chrome-os-partner:47915 BRANCH=glados TEST=build and boot on chell using following patches to test backup and restore of vbnv_cmos into flash
Change-Id: I3a17fa51cfd754455502ac2e5f181dae35967f2a Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: 48876561fa4fb61e1ec8f92596c5610d97135201 Original-Change-Id: Id9fda8467edcc55e5ed760ddab197ab97d1f3d25 Original-Signed-off-by: Duncan Laurie dlaurie@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/324121 Original-Reviewed-by: Aaron Durbin adurbin@chromium.org --- src/vendorcode/google/chromeos/vbnv_flash.c | 105 ++++++++++++++++------------ 1 file changed, 62 insertions(+), 43 deletions(-)
diff --git a/src/vendorcode/google/chromeos/vbnv_flash.c b/src/vendorcode/google/chromeos/vbnv_flash.c index ea5d9f3..88f39b0 100644 --- a/src/vendorcode/google/chromeos/vbnv_flash.c +++ b/src/vendorcode/google/chromeos/vbnv_flash.c @@ -11,10 +11,9 @@ * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. - * - * TODO: Make this CAR-friendly in case we use it on x86 some day. */
+#include <arch/early_variables.h> #include <assert.h> #include <console/console.h> #include <spi_flash.h> @@ -27,20 +26,26 @@
#define BLOB_SIZE VB2_NVDATA_SIZE
-/* FMAP descriptor of the NVRAM area */ -static struct region_device nvram_region; +struct vbnv_flash_ctx { + /* VBNV flash is initialized */ + int initialized; + + /* Offset of the current nvdata in SPI flash */ + int blob_offset;
-/* offset of the current nvdata in SPI flash */ -static int blob_offset = -1; + /* Offset of the topmost nvdata blob in SPI flash */ + int top_offset;
-/* Offset of the topmost nvdata blob in SPI flash */ -static int top_offset; + /* SPI flash handler used when saving data */ + struct spi_flash *flash;
-/* cache of the current nvdata */ -static uint8_t cache[BLOB_SIZE]; + /* FMAP descriptor of the NVRAM area */ + struct region_device region;
-/* spi_flash struct used when saving data */ -static struct spi_flash *spi_flash = NULL; + /* Cache of the current nvdata */ + uint8_t cache[BLOB_SIZE]; +}; +static struct vbnv_flash_ctx vbnv_flash CAR_GLOBAL;
/* * This code assumes that flash is erased to 1-bits, and write operations can @@ -57,20 +62,16 @@ static inline int can_overwrite(uint8_t current, uint8_t new) return (current & new) == new; }
-static inline int is_initialized(void) -{ - return blob_offset >= 0; -} - static int init_vbnv(void) { + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); uint8_t buf[BLOB_SIZE]; uint8_t empty_blob[BLOB_SIZE]; int offset; int i;
- if (vboot_named_region_device("RW_NVRAM", &nvram_region) || - region_device_sz(&nvram_region) < BLOB_SIZE) { + if (vboot_named_region_device("RW_NVRAM", &ctx->region) || + region_device_sz(&ctx->region) < BLOB_SIZE) { printk(BIOS_ERR, "%s: failed to locate NVRAM\n", __func__); return 1; } @@ -80,7 +81,7 @@ static int init_vbnv(void) empty_blob[i] = erase_value();
offset = 0; - top_offset = region_device_sz(&nvram_region) - BLOB_SIZE; + ctx->top_offset = region_device_sz(&ctx->region) - BLOB_SIZE;
/* * after the loop, offset is supposed to point the blob right before @@ -88,8 +89,8 @@ static int init_vbnv(void) * empty blob, or the base of the region if the nvram has never been * used. */ - for (i = 0; i <= top_offset; i += BLOB_SIZE) { - if (rdev_readat(&nvram_region, buf, i, BLOB_SIZE) < 0) { + for (i = 0; i <= ctx->top_offset; i += BLOB_SIZE) { + if (rdev_readat(&ctx->region, buf, i, BLOB_SIZE) < 0) { printk(BIOS_ERR, "failed to read nvdata\n"); return 1; } @@ -99,12 +100,13 @@ static int init_vbnv(void) }
/* reread the nvdata and write it to the cache */ - if (rdev_readat(&nvram_region, cache, offset, BLOB_SIZE) < 0) { + if (rdev_readat(&ctx->region, ctx->cache, offset, BLOB_SIZE) < 0) { printk(BIOS_ERR, "failed to read nvdata\n"); return 1; }
- blob_offset = offset; + ctx->blob_offset = offset; + ctx->initialized = 1;
return 0; } @@ -122,15 +124,19 @@ static void vbnv_is_erasable(void) * * TODO: Check by calling can_erase implemented by each spi flash driver */ - assert(!(region_device_offset(&nvram_region) % spi_flash->sector_size)); - assert(!(region_device_sz(&nvram_region) % spi_flash->sector_size)); + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); + + assert(!(region_device_offset(&ctx->region) % ctx->flash->sector_size)); + assert(!(region_device_sz(&ctx->region) % ctx->flash->sector_size)); }
static int vbnv_flash_probe(void) { - if (!spi_flash) { - spi_flash = spi_flash_probe(CONFIG_BOOT_MEDIA_SPI_BUS, 0); - if (!spi_flash) { + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); + + if (!ctx->flash) { + ctx->flash = spi_flash_probe(CONFIG_BOOT_MEDIA_SPI_BUS, 0); + if (!ctx->flash) { printk(BIOS_ERR, "failed to probe spi flash\n"); return 1; } @@ -140,16 +146,25 @@ static int vbnv_flash_probe(void) */ vbnv_is_erasable(); } + + /* + * Handle the case where spi_flash_probe returns a CAR_GLOBAL + * in early execution on x86 but then later is moved to RAM. + */ + ctx->flash = car_get_var_ptr(ctx->flash); + return 0; }
static int erase_nvram(void) { + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); + if (vbnv_flash_probe()) return 1;
- if (spi_flash->erase(spi_flash, region_device_offset(&nvram_region), - region_device_sz(&nvram_region))) { + if (ctx->flash->erase(ctx->flash, region_device_offset(&ctx->region), + region_device_sz(&ctx->region))) { printk(BIOS_ERR, "failed to erase nvram\n"); return 1; } @@ -160,33 +175,37 @@ static int erase_nvram(void)
void read_vbnv_flash(uint8_t *vbnv_copy) { - if (!is_initialized()) + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); + + if (!ctx->initialized) if (init_vbnv()) return; /* error */ - memcpy(vbnv_copy, cache, BLOB_SIZE); + + memcpy(vbnv_copy, ctx->cache, BLOB_SIZE); }
void save_vbnv_flash(const uint8_t *vbnv_copy) { + struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash); int new_offset; int i;
- if (!is_initialized()) + if (!ctx->initialized) if (init_vbnv()) return; /* error */
/* Bail out if there have been no changes. */ - if (!memcmp(vbnv_copy, cache, BLOB_SIZE)) + if (!memcmp(vbnv_copy, ctx->cache, BLOB_SIZE)) return;
- new_offset = blob_offset; + new_offset = ctx->blob_offset;
/* See if we can overwrite the current blob with the new one */ for (i = 0; i < BLOB_SIZE; i++) { - if (!can_overwrite(cache[i], vbnv_copy[i])) { + if (!can_overwrite(ctx->cache[i], vbnv_copy[i])) { /* unable to overwrite. need to use the next blob */ new_offset += BLOB_SIZE; - if (new_offset > top_offset) { + if (new_offset > ctx->top_offset) { if (erase_nvram()) return; /* error */ new_offset = 0; @@ -196,12 +215,12 @@ void save_vbnv_flash(const uint8_t *vbnv_copy) }
if (!vbnv_flash_probe() && - !spi_flash->write(spi_flash, - region_device_offset(&nvram_region) + new_offset, - BLOB_SIZE, vbnv_copy)) { + !ctx->flash->write(ctx->flash, + region_device_offset(&ctx->region) + new_offset, + BLOB_SIZE, vbnv_copy)) { /* write was successful. safely move pointer forward */ - blob_offset = new_offset; - memcpy(cache, vbnv_copy, BLOB_SIZE); + ctx->blob_offset = new_offset; + memcpy(ctx->cache, vbnv_copy, BLOB_SIZE); } else { printk(BIOS_ERR, "failed to save nvdata\n"); }