Bug Summary

File:dev/pci/drm/i915/gt/uc/intel_guc_fw.c
Warning:line 126, column 22
Value stored to 'drm' during its initialization is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name intel_guc_fw.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -target-feature +retpoline-external-thunk -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/llvm16/lib/clang/16 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/legacy-dpm -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu13 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/inc -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc/pmfw_if -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D SUSPEND -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -o /home/ben/Projects/scan/2024-01-11-110808-61670-1 -x c /usr/src/sys/dev/pci/drm/i915/gt/uc/intel_guc_fw.c
1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2014-2019 Intel Corporation
4 *
5 * Authors:
6 * Vinit Azad <vinit.azad@intel.com>
7 * Ben Widawsky <ben@bwidawsk.net>
8 * Dave Gordon <david.s.gordon@intel.com>
9 * Alex Dai <yu.dai@intel.com>
10 */
11
12#include "gt/intel_gt.h"
13#include "gt/intel_gt_regs.h"
14#include "intel_guc_fw.h"
15#include "i915_drv.h"
16
17static void guc_prepare_xfer(struct intel_uncore *uncore)
18{
19 u32 shim_flags = GUC_ENABLE_READ_CACHE_LOGIC(1<<1) |
20 GUC_ENABLE_READ_CACHE_FOR_SRAM_DATA(1<<9) |
21 GUC_ENABLE_READ_CACHE_FOR_WOPCM_DATA(1<<10) |
22 GUC_ENABLE_MIA_CLOCK_GATING(1<<15);
23
24 if (GRAPHICS_VER_FULL(uncore->i915)(((&(uncore->i915)->__runtime)->graphics.ip.ver)
<< 8 | ((&(uncore->i915)->__runtime)->graphics
.ip.rel))
< IP_VER(12, 50)((12) << 8 | (50)))
25 shim_flags |= GUC_DISABLE_SRAM_INIT_TO_ZEROES(1<<0) |
26 GUC_ENABLE_MIA_CACHING(1<<2);
27
28 /* Must program this register before loading the ucode with DMA */
29 intel_uncore_write(uncore, GUC_SHIM_CONTROL((const i915_reg_t){ .reg = (0xc064) }), shim_flags);
30
31 if (IS_GEN9_LP(uncore->i915)(((&(uncore->i915)->__runtime)->graphics.ip.ver)
== 9 && ((&(uncore->i915)->__info)->is_lp
))
)
32 intel_uncore_write(uncore, GEN9LP_GT_PM_CONFIG((const i915_reg_t){ .reg = (0x138140) }), GT_DOORBELL_ENABLE(1<<0));
33 else
34 intel_uncore_write(uncore, GEN9_GT_PM_CONFIG((const i915_reg_t){ .reg = (0x13816c) }), GT_DOORBELL_ENABLE(1<<0));
35
36 if (GRAPHICS_VER(uncore->i915)((&(uncore->i915)->__runtime)->graphics.ip.ver) == 9) {
37 /* DOP Clock Gating Enable for GuC clocks */
38 intel_uncore_rmw(uncore, GEN7_MISCCPCTL((const i915_reg_t){ .reg = (0x9424) }),
39 0, GEN8_DOP_CLOCK_GATE_GUC_ENABLE(1 << 4));
40
41 /* allows for 5us (in 10ns units) before GT can go to RC6 */
42 intel_uncore_write(uncore, GUC_ARAT_C6DIS((const i915_reg_t){ .reg = (0xA178) }), 0x1FF);
43 }
44}
45
46static int guc_xfer_rsa_mmio(struct intel_uc_fw *guc_fw,
47 struct intel_uncore *uncore)
48{
49 u32 rsa[UOS_RSA_SCRATCH_COUNT64];
50 size_t copied;
51 int i;
52
53 copied = intel_uc_fw_copy_rsa(guc_fw, rsa, sizeof(rsa));
54 if (copied < sizeof(rsa))
55 return -ENOMEM12;
56
57 for (i = 0; i < UOS_RSA_SCRATCH_COUNT64; i++)
58 intel_uncore_write(uncore, UOS_RSA_SCRATCH(i)((const i915_reg_t){ .reg = (0xc200 + (i) * 4) }), rsa[i]);
59
60 return 0;
61}
62
63static int guc_xfer_rsa_vma(struct intel_uc_fw *guc_fw,
64 struct intel_uncore *uncore)
65{
66 struct intel_guc *guc = container_of(guc_fw, struct intel_guc, fw)({ const __typeof( ((struct intel_guc *)0)->fw ) *__mptr =
(guc_fw); (struct intel_guc *)( (char *)__mptr - __builtin_offsetof
(struct intel_guc, fw) );})
;
67
68 intel_uncore_write(uncore, UOS_RSA_SCRATCH(0)((const i915_reg_t){ .reg = (0xc200 + (0) * 4) }),
69 intel_guc_ggtt_offset(guc, guc_fw->rsa_data));
70
71 return 0;
72}
73
74/* Copy RSA signature from the fw image to HW for verification */
75static int guc_xfer_rsa(struct intel_uc_fw *guc_fw,
76 struct intel_uncore *uncore)
77{
78 if (guc_fw->rsa_data)
79 return guc_xfer_rsa_vma(guc_fw, uncore);
80 else
81 return guc_xfer_rsa_mmio(guc_fw, uncore);
82}
83
84/*
85 * Read the GuC status register (GUC_STATUS) and store it in the
86 * specified location; then return a boolean indicating whether
87 * the value matches either of two values representing completion
88 * of the GuC boot process.
89 *
90 * This is used for polling the GuC status in a wait_for()
91 * loop below.
92 */
93static inline bool_Bool guc_ready(struct intel_uncore *uncore, u32 *status)
94{
95 u32 val = intel_uncore_read(uncore, GUC_STATUS((const i915_reg_t){ .reg = (0xc000) }));
96 u32 uk_val = REG_FIELD_GET(GS_UKERNEL_MASK, val)((u32)((typeof((0xFF << 8)))(((val) & ((0xFF <<
8))) >> (__builtin_ffsll((0xFF << 8)) - 1))))
;
97
98 *status = val;
99 return uk_val == INTEL_GUC_LOAD_STATUS_READY;
100}
101
102static int guc_wait_ucode(struct intel_uncore *uncore)
103{
104 u32 status;
105 int ret;
106
107 /*
108 * Wait for the GuC to start up.
109 * NB: Docs recommend not using the interrupt for completion.
110 * Measurements indicate this should take no more than 20ms
111 * (assuming the GT clock is at maximum frequency). So, a
112 * timeout here indicates that the GuC has failed and is unusable.
113 * (Higher levels of the driver may decide to reset the GuC and
114 * attempt the ucode load again if this happens.)
115 *
116 * FIXME: There is a known (but exceedingly unlikely) race condition
117 * where the asynchronous frequency management code could reduce
118 * the GT clock while a GuC reload is in progress (during a full
119 * GT reset). A fix is in progress but there are complex locking
120 * issues to be resolved. In the meantime bump the timeout to
121 * 200ms. Even at slowest clock, this should be sufficient. And
122 * in the working case, a larger timeout makes no difference.
123 */
124 ret = wait_for(guc_ready(uncore, &status), 200)({ const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll
* (((200) * 1000))); long wait__ = ((10)); int ret__; assertwaitok
(); for (;;) { const _Bool expired__ = ktime_after(ktime_get_raw
(), end__); ; __asm volatile("" : : : "memory"); if (((guc_ready
(uncore, &status)))) { ret__ = 0; break; } if (expired__)
{ ret__ = -60; break; } usleep_range(wait__, wait__ * 2); if
(wait__ < ((1000))) wait__ <<= 1; } ret__; })
;
125 if (ret) {
126 struct drm_device *drm = &uncore->i915->drm;
Value stored to 'drm' during its initialization is never read
127
128 drm_info(drm, "GuC load failed: status = 0x%08X\n", status)do { } while(0);
129 drm_info(drm, "GuC load failed: status: Reset = %d, "do { } while(0)
130 "BootROM = 0x%02X, UKernel = 0x%02X, "do { } while(0)
131 "MIA = 0x%02X, Auth = 0x%02X\n",do { } while(0)
132 REG_FIELD_GET(GS_MIA_IN_RESET, status),do { } while(0)
133 REG_FIELD_GET(GS_BOOTROM_MASK, status),do { } while(0)
134 REG_FIELD_GET(GS_UKERNEL_MASK, status),do { } while(0)
135 REG_FIELD_GET(GS_MIA_MASK, status),do { } while(0)
136 REG_FIELD_GET(GS_AUTH_STATUS_MASK, status))do { } while(0);
137
138 if ((status & GS_BOOTROM_MASK(0x7F << 1)) == GS_BOOTROM_RSA_FAILED(0x50 << 1)) {
139 drm_info(drm, "GuC firmware signature verification failed\n")do { } while(0);
140 ret = -ENOEXEC8;
141 }
142
143 if (REG_FIELD_GET(GS_UKERNEL_MASK, status)((u32)((typeof((0xFF << 8)))(((status) & ((0xFF <<
8))) >> (__builtin_ffsll((0xFF << 8)) - 1))))
== INTEL_GUC_LOAD_STATUS_EXCEPTION) {
144 drm_info(drm, "GuC firmware exception. EIP: %#x\n",do { } while(0)
145 intel_uncore_read(uncore, SOFT_SCRATCH(13)))do { } while(0);
146 ret = -ENXIO6;
147 }
148 }
149
150 return ret;
151}
152
153/**
154 * intel_guc_fw_upload() - load GuC uCode to device
155 * @guc: intel_guc structure
156 *
157 * Called from intel_uc_init_hw() during driver load, resume from sleep and
158 * after a GPU reset.
159 *
160 * The firmware image should have already been fetched into memory, so only
161 * check that fetch succeeded, and then transfer the image to the h/w.
162 *
163 * Return: non-zero code on error
164 */
165int intel_guc_fw_upload(struct intel_guc *guc)
166{
167 struct intel_gt *gt = guc_to_gt(guc);
168 struct intel_uncore *uncore = gt->uncore;
169 int ret;
170
171 guc_prepare_xfer(uncore);
172
173 /*
174 * Note that GuC needs the CSS header plus uKernel code to be copied
175 * by the DMA engine in one operation, whereas the RSA signature is
176 * loaded separately, either by copying it to the UOS_RSA_SCRATCH
177 * register (if key size <= 256) or through a ggtt-pinned vma (if key
178 * size > 256). The RSA size and therefore the way we provide it to the
179 * HW is fixed for each platform and hard-coded in the bootrom.
180 */
181 ret = guc_xfer_rsa(&guc->fw, uncore);
182 if (ret)
183 goto out;
184
185 /*
186 * Current uCode expects the code to be loaded at 8k; locations below
187 * this are used for the stack.
188 */
189 ret = intel_uc_fw_upload(&guc->fw, 0x2000, UOS_MOVE(1<<4));
190 if (ret)
191 goto out;
192
193 ret = guc_wait_ucode(uncore);
194 if (ret)
195 goto out;
196
197 intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_RUNNING);
198 return 0;
199
200out:
201 intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_LOAD_FAIL);
202 return ret;
203}