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Usable regions are those that are not reserved or protected. The extracted region is stored in GetGspStaticInfoReply and exposed via usable_fb_region() API for use by the memory subsystem. Cc: Nikola Djukic Signed-off-by: Joel Fernandes --- drivers/gpu/nova-core/gsp/commands.rs | 13 +++++++++- drivers/gpu/nova-core/gsp/fw/commands.rs | 30 ++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs index bf9e3086565f..44f8b08683f9 100644 --- a/drivers/gpu/nova-core/gsp/commands.rs +++ b/drivers/gpu/nova-core/gsp/commands.rs @@ -186,10 +186,13 @@ fn init(&self) -> impl Init { } } -/// The reply from the GSP to the [`GetGspInfo`] command. +/// The reply from the GSP to the [`GetGspStaticInfo`] command. pub(crate) struct GetGspStaticInfoReply { gpu_name: [u8; 64], bar1_pde_base: u64, + /// First usable FB region `(base, size)` for memory allocation. + #[expect(dead_code)] + usable_fb_region: Option<(u64, u64)>, } impl MessageFromGsp for GetGspStaticInfoReply { @@ -204,6 +207,7 @@ fn read( Ok(GetGspStaticInfoReply { gpu_name: msg.gpu_name_str(), bar1_pde_base: msg.bar1_pde_base(), + usable_fb_region: msg.first_usable_fb_region(), }) } } @@ -235,6 +239,13 @@ pub(crate) fn gpu_name(&self) -> core::result::Result<&str, GpuNameError> { pub(crate) fn bar1_pde_base(&self) -> u64 { self.bar1_pde_base } + + /// Returns the usable FB region `(base, size)` for driver allocation which is + /// already retrieved from the GSP. + #[expect(dead_code)] + pub(crate) fn usable_fb_region(&self) -> Option<(u64, u64)> { + self.usable_fb_region + } } /// Send the [`GetGspInfo`] command and awaits for its reply. diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs index f069f4092911..976eca5a59c4 100644 --- a/drivers/gpu/nova-core/gsp/fw/commands.rs +++ b/drivers/gpu/nova-core/gsp/fw/commands.rs @@ -122,6 +122,36 @@ impl GspStaticConfigInfo { pub(crate) fn bar1_pde_base(&self) -> u64 { self.0.bar1PdeBase } + + /// Extract the first usable FB region from GSP firmware data. + /// + /// Returns the first region suitable for driver memory allocation as a `(base, size)` tuple. + /// Usable regions are those that: + /// - Are not reserved for firmware internal use. + /// - Are not protected (hardware-enforced access restrictions). + /// - Support compression (can use GPU memory compression for bandwidth). + /// - Support ISO (isochronous memory for display requiring guaranteed bandwidth). + pub(crate) fn first_usable_fb_region(&self) -> Option<(u64, u64)> { + let fb_info = &self.0.fbRegionInfoParams; + for i in 0..fb_info.numFBRegions as usize { + if let Some(reg) = fb_info.fbRegion.get(i) { + // Skip malformed regions where limit < base. + if reg.limit < reg.base { + continue; + } + // Filter: not reserved, not protected, supports compression and ISO. + if reg.reserved == 0 + && reg.bProtected == 0 + && reg.supportCompressed != 0 + && reg.supportISO != 0 + { + let size = reg.limit - reg.base + 1; + return Some((reg.base, size)); + } + } + } + None + } } // SAFETY: Padding is explicit and will not contain uninitialized data. -- 2.34.1