xref: /linux/drivers/gpu/nova-core/firmware/gsp.rs (revision eee8227dd18868bb16dbf72e2ab11d1a9008b874)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 use core::mem::size_of_val;
4 
5 use kernel::{
6     device,
7     dma::{
8         DataDirection,
9         DmaAddress, //
10     },
11     kvec,
12     prelude::*,
13     scatterlist::{
14         Owned,
15         SGTable, //
16     },
17 };
18 
19 use crate::{
20     dma::DmaObject,
21     firmware::riscv::RiscvFirmware,
22     gpu::{
23         Architecture,
24         Chipset, //
25     },
26     gsp::GSP_PAGE_SIZE,
27     num::FromSafeCast,
28 };
29 
30 /// Ad-hoc and temporary module to extract sections from ELF images.
31 ///
32 /// Some firmware images are currently packaged as ELF files, where sections names are used as keys
33 /// to specific and related bits of data. Future firmware versions are scheduled to move away from
34 /// that scheme before nova-core becomes stable, which means this module will eventually be
35 /// removed.
36 mod elf {
37     use core::mem::size_of;
38 
39     use kernel::bindings;
40     use kernel::str::CStr;
41     use kernel::transmute::FromBytes;
42 
43     /// Newtype to provide a [`FromBytes`] implementation.
44     #[repr(transparent)]
45     struct Elf64Hdr(bindings::elf64_hdr);
46     // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
47     unsafe impl FromBytes for Elf64Hdr {}
48 
49     #[repr(transparent)]
50     struct Elf64SHdr(bindings::elf64_shdr);
51     // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
52     unsafe impl FromBytes for Elf64SHdr {}
53 
54     /// Tries to extract section with name `name` from the ELF64 image `elf`, and returns it.
55     pub(super) fn elf64_section<'a, 'b>(elf: &'a [u8], name: &'b str) -> Option<&'a [u8]> {
56         let hdr = &elf
57             .get(0..size_of::<bindings::elf64_hdr>())
58             .and_then(Elf64Hdr::from_bytes)?
59             .0;
60 
61         // Get all the section headers.
62         let mut shdr = {
63             let shdr_num = usize::from(hdr.e_shnum);
64             let shdr_start = usize::try_from(hdr.e_shoff).ok()?;
65             let shdr_end = shdr_num
66                 .checked_mul(size_of::<Elf64SHdr>())
67                 .and_then(|v| v.checked_add(shdr_start))?;
68 
69             elf.get(shdr_start..shdr_end)
70                 .map(|slice| slice.chunks_exact(size_of::<Elf64SHdr>()))?
71         };
72 
73         // Get the strings table.
74         let strhdr = shdr
75             .clone()
76             .nth(usize::from(hdr.e_shstrndx))
77             .and_then(Elf64SHdr::from_bytes)?;
78 
79         // Find the section which name matches `name` and return it.
80         shdr.find(|&sh| {
81             let Some(hdr) = Elf64SHdr::from_bytes(sh) else {
82                 return false;
83             };
84 
85             let Some(name_idx) = strhdr
86                 .0
87                 .sh_offset
88                 .checked_add(u64::from(hdr.0.sh_name))
89                 .and_then(|idx| usize::try_from(idx).ok())
90             else {
91                 return false;
92             };
93 
94             // Get the start of the name.
95             elf.get(name_idx..)
96                 .and_then(|nstr| CStr::from_bytes_until_nul(nstr).ok())
97                 // Convert into str.
98                 .and_then(|c_str| c_str.to_str().ok())
99                 // Check that the name matches.
100                 .map(|str| str == name)
101                 .unwrap_or(false)
102         })
103         // Return the slice containing the section.
104         .and_then(|sh| {
105             let hdr = Elf64SHdr::from_bytes(sh)?;
106             let start = usize::try_from(hdr.0.sh_offset).ok()?;
107             let end = usize::try_from(hdr.0.sh_size)
108                 .ok()
109                 .and_then(|sh_size| start.checked_add(sh_size))?;
110 
111             elf.get(start..end)
112         })
113     }
114 }
115 
116 /// GSP firmware with 3-level radix page tables for the GSP bootloader.
117 ///
118 /// The bootloader expects firmware to be mapped starting at address 0 in GSP's virtual address
119 /// space:
120 ///
121 /// ```text
122 /// Level 0:  1 page, 1 entry         -> points to first level 1 page
123 /// Level 1:  Multiple pages/entries  -> each entry points to a level 2 page
124 /// Level 2:  Multiple pages/entries  -> each entry points to a firmware page
125 /// ```
126 ///
127 /// Each page is 4KB, each entry is 8 bytes (64-bit DMA address).
128 /// Also known as "Radix3" firmware.
129 #[pin_data]
130 pub(crate) struct GspFirmware {
131     /// The GSP firmware inside a [`VVec`], device-mapped via a SG table.
132     #[pin]
133     fw: SGTable<Owned<VVec<u8>>>,
134     /// Level 2 page table whose entries contain DMA addresses of firmware pages.
135     #[pin]
136     level2: SGTable<Owned<VVec<u8>>>,
137     /// Level 1 page table whose entries contain DMA addresses of level 2 pages.
138     #[pin]
139     level1: SGTable<Owned<VVec<u8>>>,
140     /// Level 0 page table (single 4KB page) with one entry: DMA address of first level 1 page.
141     level0: DmaObject,
142     /// Size in bytes of the firmware contained in [`Self::fw`].
143     pub(crate) size: usize,
144     /// Device-mapped GSP signatures matching the GPU's [`Chipset`].
145     pub(crate) signatures: DmaObject,
146     /// GSP bootloader, verifies the GSP firmware before loading and running it.
147     pub(crate) bootloader: RiscvFirmware,
148 }
149 
150 impl GspFirmware {
151     /// Loads the GSP firmware binaries, map them into `dev`'s address-space, and creates the page
152     /// tables expected by the GSP bootloader to load it.
153     pub(crate) fn new<'a>(
154         dev: &'a device::Device<device::Bound>,
155         chipset: Chipset,
156         ver: &'a str,
157     ) -> impl PinInit<Self, Error> + 'a {
158         pin_init::pin_init_scope(move || {
159             let firmware = super::request_firmware(dev, chipset, "gsp", ver)?;
160 
161             let fw_section = elf::elf64_section(firmware.data(), ".fwimage").ok_or(EINVAL)?;
162 
163             let size = fw_section.len();
164 
165             // Move the firmware into a vmalloc'd vector and map it into the device address
166             // space.
167             let fw_vvec = VVec::with_capacity(fw_section.len(), GFP_KERNEL)
168                 .and_then(|mut v| {
169                     v.extend_from_slice(fw_section, GFP_KERNEL)?;
170                     Ok(v)
171                 })
172                 .map_err(|_| ENOMEM)?;
173 
174             Ok(try_pin_init!(Self {
175                 fw <- SGTable::new(dev, fw_vvec, DataDirection::ToDevice, GFP_KERNEL),
176                 level2 <- {
177                     // Allocate the level 2 page table, map the firmware onto it, and map it into
178                     // the device address space.
179                     VVec::<u8>::with_capacity(
180                         fw.iter().count() * core::mem::size_of::<u64>(),
181                         GFP_KERNEL,
182                     )
183                     .map_err(|_| ENOMEM)
184                     .and_then(|level2| map_into_lvl(&fw, level2))
185                     .map(|level2| SGTable::new(dev, level2, DataDirection::ToDevice, GFP_KERNEL))?
186                 },
187                 level1 <- {
188                     // Allocate the level 1 page table, map the level 2 page table onto it, and map
189                     // it into the device address space.
190                     VVec::<u8>::with_capacity(
191                         level2.iter().count() * core::mem::size_of::<u64>(),
192                         GFP_KERNEL,
193                     )
194                     .map_err(|_| ENOMEM)
195                     .and_then(|level1| map_into_lvl(&level2, level1))
196                     .map(|level1| SGTable::new(dev, level1, DataDirection::ToDevice, GFP_KERNEL))?
197                 },
198                 level0: {
199                     // Allocate the level 0 page table as a device-visible DMA object, and map the
200                     // level 1 page table onto it.
201 
202                     // Level 0 page table data.
203                     let mut level0_data = kvec![0u8; GSP_PAGE_SIZE]?;
204 
205                     // Fill level 1 page entry.
206                     let level1_entry = level1.iter().next().ok_or(EINVAL)?;
207                     let level1_entry_addr = level1_entry.dma_address();
208                     let dst = &mut level0_data[..size_of_val(&level1_entry_addr)];
209                     dst.copy_from_slice(&level1_entry_addr.to_le_bytes());
210 
211                     // Turn the level0 page table into a [`DmaObject`].
212                     DmaObject::from_data(dev, &level0_data)?
213                 },
214                 size,
215                 signatures: {
216                     let sigs_section = match chipset.arch() {
217                         Architecture::Turing
218                             if matches!(chipset, Chipset::TU116 | Chipset::TU117) =>
219                         {
220                             ".fwsignature_tu11x"
221                         }
222                         Architecture::Turing => ".fwsignature_tu10x",
223                         // GA100 uses the same firmware as Turing
224                         Architecture::Ampere if chipset == Chipset::GA100 => ".fwsignature_tu10x",
225                         Architecture::Ampere => ".fwsignature_ga10x",
226                         Architecture::Ada => ".fwsignature_ad10x",
227                     };
228 
229                     elf::elf64_section(firmware.data(), sigs_section)
230                         .ok_or(EINVAL)
231                         .and_then(|data| DmaObject::from_data(dev, data))?
232                 },
233                 bootloader: {
234                     let bl = super::request_firmware(dev, chipset, "bootloader", ver)?;
235 
236                     RiscvFirmware::new(dev, &bl)?
237                 },
238             }))
239         })
240     }
241 
242     /// Returns the DMA handle of the radix3 level 0 page table.
243     pub(crate) fn radix3_dma_handle(&self) -> DmaAddress {
244         self.level0.dma_handle()
245     }
246 }
247 
248 /// Build a page table from a scatter-gather list.
249 ///
250 /// Takes each DMA-mapped region from `sg_table` and writes page table entries
251 /// for all 4KB pages within that region. For example, a 16KB SG entry becomes
252 /// 4 consecutive page table entries.
253 fn map_into_lvl(sg_table: &SGTable<Owned<VVec<u8>>>, mut dst: VVec<u8>) -> Result<VVec<u8>> {
254     for sg_entry in sg_table.iter() {
255         // Number of pages we need to map.
256         let num_pages = usize::from_safe_cast(sg_entry.dma_len()).div_ceil(GSP_PAGE_SIZE);
257 
258         for i in 0..num_pages {
259             let entry = sg_entry.dma_address()
260                 + (u64::from_safe_cast(i) * u64::from_safe_cast(GSP_PAGE_SIZE));
261             dst.extend_from_slice(&entry.to_le_bytes(), GFP_KERNEL)?;
262         }
263     }
264 
265     Ok(dst)
266 }
267