| Upstream-Status: Backport [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8e3f9da608f14cfebac2659d8dd8737b79d01308] |
| Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> |
| |
| From a8f3e351c07c48774be2a45e184b9f08dc92f1db Mon Sep 17 00:00:00 2001 |
| From: Sudeep Holla <sudeep.holla@arm.com> |
| Date: Wed, 13 Apr 2022 15:43:19 +0100 |
| Subject: [PATCH] UPSTREAM: firmware: arm_ffa: Handle compatibility with |
| different firmware versions |
| |
| The driver currently just support v1.0 of Arm FFA specification. It also |
| expects the firmware implementation to match the same and bail out if it |
| doesn't match. This is causing issue when running with higher version of |
| firmware implementation(e.g. v1.1 which will released soon). |
| |
| In order to support compatibility with different firmware versions, let |
| us add additional checks and find the compatible version the driver can |
| work with. |
| |
| Link: https://lore.kernel.org/r/20211013091127.990992-1-sudeep.holla@arm.com |
| Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org> |
| Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> |
| (cherry picked from commit 8e3f9da608f14cfebac2659d8dd8737b79d01308) |
| Change-Id: I7bc9a3b172a9067bfd4e9bb9d50b4729e915b5a5 |
| Bug: 168585974 |
| --- |
| drivers/firmware/arm_ffa/driver.c | 37 ++++++++++++++++++++++++++----- |
| 1 file changed, 32 insertions(+), 5 deletions(-) |
| |
| diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c |
| index c9fb56afbcb4..6e0c883ab708 100644 |
| --- a/drivers/firmware/arm_ffa/driver.c |
| +++ b/drivers/firmware/arm_ffa/driver.c |
| @@ -167,6 +167,28 @@ struct ffa_drv_info { |
| |
| static struct ffa_drv_info *drv_info; |
| |
| +/* |
| + * The driver must be able to support all the versions from the earliest |
| + * supported FFA_MIN_VERSION to the latest supported FFA_DRIVER_VERSION. |
| + * The specification states that if firmware supports a FFA implementation |
| + * that is incompatible with and at a greater version number than specified |
| + * by the caller(FFA_DRIVER_VERSION passed as parameter to FFA_VERSION), |
| + * it must return the NOT_SUPPORTED error code. |
| + */ |
| +static u32 ffa_compatible_version_find(u32 version) |
| +{ |
| + u32 compat_version; |
| + u16 major = MAJOR_VERSION(version), minor = MINOR_VERSION(version); |
| + u16 drv_major = MAJOR_VERSION(FFA_DRIVER_VERSION); |
| + u16 drv_minor = MINOR_VERSION(FFA_DRIVER_VERSION); |
| + |
| + if ((major < drv_major) || (major == drv_major && minor <= drv_minor)) |
| + return version; |
| + |
| + pr_info("Firmware version higher than driver version, downgrading\n"); |
| + return FFA_DRIVER_VERSION; |
| +} |
| + |
| static int ffa_version_check(u32 *version) |
| { |
| ffa_value_t ver; |
| @@ -180,15 +202,20 @@ static int ffa_version_check(u32 *version) |
| return -EOPNOTSUPP; |
| } |
| |
| - if (ver.a0 < FFA_MIN_VERSION || ver.a0 > FFA_DRIVER_VERSION) { |
| - pr_err("Incompatible version %d.%d found\n", |
| - MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0)); |
| + if (ver.a0 < FFA_MIN_VERSION) { |
| + pr_err("Incompatible v%d.%d! Earliest supported v%d.%d\n", |
| + MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0), |
| + MAJOR_VERSION(FFA_MIN_VERSION), |
| + MINOR_VERSION(FFA_MIN_VERSION)); |
| return -EINVAL; |
| } |
| |
| - *version = ver.a0; |
| - pr_info("Version %d.%d found\n", MAJOR_VERSION(ver.a0), |
| + pr_info("Driver version %d.%d\n", MAJOR_VERSION(FFA_DRIVER_VERSION), |
| + MINOR_VERSION(FFA_DRIVER_VERSION)); |
| + pr_info("Firmware version %d.%d found\n", MAJOR_VERSION(ver.a0), |
| MINOR_VERSION(ver.a0)); |
| + *version = ffa_compatible_version_find(ver.a0); |
| + |
| return 0; |
| } |
| |
| -- |
| 2.17.1 |
| |