CC: [email protected]
CC: [email protected]
BCC: [email protected]
In-Reply-To: <[email protected]>
References: <[email protected]>
TO: Niklas Schnelle <[email protected]>
TO: Bjorn Helgaas <[email protected]>
TO: Jan Kiszka <[email protected]>
TO: Matthew Rosato <[email protected]>
TO: Pierre Morel <[email protected]>
CC: [email protected]
CC: [email protected]

Hi Niklas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on helgaas-pci/next]
[also build test WARNING on s390/features tip/x86/core v5.18-rc2 next-20220413]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    
https://github.com/intel-lab-lkp/linux/commits/Niklas-Schnelle/PCI-Rework-pci_scan_slot-and-isolated-PCI-functions/20220412-223307
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
:::::: branch date: 32 hours ago
:::::: commit date: 32 hours ago
config: x86_64-randconfig-c007-20220411 
(https://download.01.org/0day-ci/archive/20220414/[email protected]/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 
fe2478d44e4f7f191c43fef629ac7a23d0251e72)
reproduce (this is a W=1 build):
        wget 
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
        chmod +x ~/bin/make.cross
        # 
https://github.com/intel-lab-lkp/linux/commit/5cac6729750b7434ff5d6ae99469e9e54bc9fb6e
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review 
Niklas-Schnelle/PCI-Rework-pci_scan_slot-and-isolated-PCI-functions/20220412-223307
        git checkout 5cac6729750b7434ff5d6ae99469e9e54bc9fb6e
        # save the config file to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 
clang-analyzer 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>


clang-analyzer warnings: (new ones prefixed by >>)
           if (primary & WM831X_TCHDATA_INT)
           ^
   drivers/mfd/wm831x-irq.c:478:2: note: Loop condition is true.  Entering loop 
body
           for (i = 0; i < ARRAY_SIZE(wm831x_irqs); i++) {
           ^
   drivers/mfd/wm831x-irq.c:481:7: note: Assuming the condition is false
                   if (!(primary & wm831x_irqs[i].primary))
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:481:3: note: Taking false branch
                   if (!(primary & wm831x_irqs[i].primary))
                   ^
   drivers/mfd/wm831x-irq.c:488:7: note: Assuming the condition is false
                   if (!read[offset]) {
                       ^~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:488:3: note: Taking false branch
                   if (!read[offset]) {
                   ^
   drivers/mfd/wm831x-irq.c:510:7: note: Assuming the condition is false
                   if (*status & wm831x_irqs[i].mask)
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:510:3: note: Taking false branch
                   if (*status & wm831x_irqs[i].mask)
                   ^
   drivers/mfd/wm831x-irq.c:517:7: note: Assuming 'primary' is equal to 
WM831X_GP_INT
                   if (primary == WM831X_GP_INT &&
                       ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:517:7: note: Left side of '&&' is true
   drivers/mfd/wm831x-irq.c:518:7: note: Assuming the condition is false
                       wm831x->gpio_level_high[i - WM831X_IRQ_GPIO_1]) {
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:517:3: note: Taking false branch
                   if (primary == WM831X_GP_INT &&
                   ^
   drivers/mfd/wm831x-irq.c:528:7: note: 'primary' is equal to WM831X_GP_INT
                   if (primary == WM831X_GP_INT &&
                       ^~~~~~~
   drivers/mfd/wm831x-irq.c:528:7: note: Left side of '&&' is true
   drivers/mfd/wm831x-irq.c:529:7: note: Assuming the condition is true
                       wm831x->gpio_level_low[i - WM831X_IRQ_GPIO_1]) {
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mfd/wm831x-irq.c:528:3: note: Taking true branch
                   if (primary == WM831X_GP_INT &&
                   ^
   drivers/mfd/wm831x-irq.c:531:21: note: The result of the left shift is 
undefined due to shifting by '4294967295', which is greater or equal to the 
width of type 'int'
                           while (!(ret & 1 << (i - WM831X_IRQ_GPIO_1))) {
                                            ^  ~~~~~~~~~~~~~~~~~~~~~~~
   Suppressed 41 warnings (41 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   47 warnings generated.
   block/partitions/cmdline.c:84:3: warning: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   strncpy(new_subpart->name, partdef, length);
                   ^~~~~~~
   block/partitions/cmdline.c:84:3: note: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11
                   strncpy(new_subpart->name, partdef, length);
                   ^~~~~~~
   block/partitions/cmdline.c:143:2: warning: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           strncpy(newparts->name, bdevdef, length);
           ^~~~~~~
   block/partitions/cmdline.c:143:2: note: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11
           strncpy(newparts->name, bdevdef, length);
           ^~~~~~~
   block/partitions/cmdline.c:156:3: warning: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   strncpy(buf, bdevdef, length);
                   ^~~~~~~
   block/partitions/cmdline.c:156:3: note: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11
                   strncpy(buf, bdevdef, length);
                   ^~~~~~~
   block/partitions/cmdline.c:270:2: warning: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           strncpy(info->volname, subpart->name, label_min);
           ^~~~~~~
   block/partitions/cmdline.c:270:2: note: Call to function 'strncpy' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'strncpy_s' in case of C11
           strncpy(info->volname, subpart->name, label_min);
           ^~~~~~~
   block/partitions/cmdline.c:273:2: warning: Call to function 'snprintf' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'snprintf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
           ^~~~~~~~
   block/partitions/cmdline.c:273:2: note: Call to function 'snprintf' is 
insecure as it does not provide security checks introduced in the C11 standard. 
Replace with analogous functions that support length arguments or provides 
boundary checks such as 'snprintf_s' in case of C11
           snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
           ^~~~~~~~
   Suppressed 42 warnings (42 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   33 warnings generated.
   Suppressed 33 warnings (33 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   33 warnings generated.
   Suppressed 33 warnings (33 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   37 warnings generated.
   drivers/pci/probe.c:1013:4: warning: Call to function 'snprintf' is insecure 
as it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'snprintf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                           snprintf(addr, sizeof(addr), fmt,
                           ^~~~~~~~
   drivers/pci/probe.c:1013:4: note: Call to function 'snprintf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'snprintf_s' in case of C11
                           snprintf(addr, sizeof(addr), fmt,
                           ^~~~~~~~
   drivers/pci/probe.c:1447:2: warning: Call to function 'sprintf' is insecure 
as it does not provide bounding of the memory buffer or security checks 
introduced in the C11 standard. Replace with analogous functions that support 
length arguments or provides boundary checks such as 'sprintf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           sprintf(child->name,
           ^~~~~~~
   drivers/pci/probe.c:1447:2: note: Call to function 'sprintf' is insecure as 
it does not provide bounding of the memory buffer or security checks introduced 
in the C11 standard. Replace with analogous functions that support length 
arguments or provides boundary checks such as 'sprintf_s' in case of C11
           sprintf(child->name,
           ^~~~~~~
>> drivers/pci/probe.c:2867:3: warning: Value stored to 'nr_devs' is never read 
>> [clang-analyzer-deadcode.DeadStores]
                   nr_devs = pci_scan_slot(bus, devfn);
                   ^         ~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/probe.c:2867:3: note: Value stored to 'nr_devs' is never read
                   nr_devs = pci_scan_slot(bus, devfn);
                   ^         ~~~~~~~~~~~~~~~~~~~~~~~~~
   Suppressed 34 warnings (33 in non-user code, 1 with check filters).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   33 warnings generated.
   Suppressed 33 warnings (33 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   33 warnings generated.
   Suppressed 33 warnings (33 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use 
-system-headers to display errors from system headers as well.
   44 warnings generated.
   drivers/pci/pci.c:286:9: warning: Call to function 'sscanf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'sscanf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
                         ^~~~~~
   drivers/pci/pci.c:286:9: note: Call to function 'sscanf' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'sscanf_s' in case of C11
                   ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
                         ^~~~~~
   drivers/pci/pci.c:312:8: warning: Call to function 'sscanf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'sscanf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
                 ^~~~~~
   drivers/pci/pci.c:312:8: note: Call to function 'sscanf' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'sscanf_s' in case of C11
           ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
                 ^~~~~~
   drivers/pci/pci.c:316:9: warning: Call to function 'sscanf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'sscanf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
                         ^~~~~~
   drivers/pci/pci.c:316:9: note: Call to function 'sscanf' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'sscanf_s' in case of C11
                   ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
                         ^~~~~~
   drivers/pci/pci.c:372:9: warning: Call to function 'sscanf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'sscanf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
                         ^~~~~~
   drivers/pci/pci.c:372:9: note: Call to function 'sscanf' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'sscanf_s' in case of C11
                   ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
                         ^~~~~~
   drivers/pci/pci.c:375:10: warning: Call to function 'sscanf' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'sscanf_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                           ret = sscanf(p, "%hx:%hx%n", &vendor, &device, 
&count);
                                 ^~~~~~
   drivers/pci/pci.c:375:10: note: Call to function 'sscanf' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'sscanf_s' in case of C11
                           ret = sscanf(p, "%hx:%hx%n", &vendor, &device, 
&count);
                                 ^~~~~~
   drivers/pci/pci.c:1783:2: warning: Call to function 'memcpy' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'memcpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           memcpy(state->config_space, dev->saved_config_space,
           ^
   include/linux/fortify-string.h:369:26: note: expanded from macro 'memcpy'
   #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/fortify-string.h:362:2: note: expanded from macro 
'__fortify_memcpy_chk'
           __underlying_##op(p, q, __fortify_size);                        \
           ^~~~~~~~~~~~~~~~~
   note: expanded from here
   include/linux/fortify-string.h:45:29: note: expanded from macro 
'__underlying_memcpy'
   #define __underlying_memcpy     __builtin_memcpy
                                   ^~~~~~~~~~~~~~~~
   drivers/pci/pci.c:1783:2: note: Call to function 'memcpy' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'memcpy_s' in case of C11
           memcpy(state->config_space, dev->saved_config_space,
           ^
   include/linux/fortify-string.h:369:26: note: expanded from macro 'memcpy'
   #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/fortify-string.h:362:2: note: expanded from macro 
'__fortify_memcpy_chk'
           __underlying_##op(p, q, __fortify_size);                        \
           ^~~~~~~~~~~~~~~~~
   note: expanded from here
   include/linux/fortify-string.h:45:29: note: expanded from macro 
'__underlying_memcpy'
   #define __underlying_memcpy     __builtin_memcpy
                                   ^~~~~~~~~~~~~~~~
   drivers/pci/pci.c:1789:3: warning: Call to function 'memcpy' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'memcpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
                   memcpy(cap, &tmp->cap, len);
                   ^
   include/linux/fortify-string.h:369:26: note: expanded from macro 'memcpy'
   #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/fortify-string.h:362:2: note: expanded from macro 
'__fortify_memcpy_chk'
           __underlying_##op(p, q, __fortify_size);                        \
           ^~~~~~~~~~~~~~~~~
   note: expanded from here
   include/linux/fortify-string.h:45:29: note: expanded from macro 
'__underlying_memcpy'
   #define __underlying_memcpy     __builtin_memcpy
                                   ^~~~~~~~~~~~~~~~
   drivers/pci/pci.c:1789:3: note: Call to function 'memcpy' is insecure as it 
does not provide security checks introduced in the C11 standard. Replace with 
analogous functions that support length arguments or provides boundary checks 
such as 'memcpy_s' in case of C11
                   memcpy(cap, &tmp->cap, len);
                   ^
   include/linux/fortify-string.h:369:26: note: expanded from macro 'memcpy'
   #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/fortify-string.h:362:2: note: expanded from macro 
'__fortify_memcpy_chk'
           __underlying_##op(p, q, __fortify_size);                        \
           ^~~~~~~~~~~~~~~~~
   note: expanded from here
   include/linux/fortify-string.h:45:29: note: expanded from macro 
'__underlying_memcpy'
   #define __underlying_memcpy     __builtin_memcpy
                                   ^~~~~~~~~~~~~~~~
   drivers/pci/pci.c:1813:2: warning: Call to function 'memcpy' is insecure as 
it does not provide security checks introduced in the C11 standard. Replace 
with analogous functions that support length arguments or provides boundary 
checks such as 'memcpy_s' in case of C11 
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
           memcpy(dev->saved_config_space, state->config_space,
           ^
   include/linux/fortify-string.h:369:26: note: expanded from macro 'memcpy'

vim +/nr_devs +2867 drivers/pci/probe.c

bccf90d6e063d27 Palmer Dabbelt  2017-06-23  2841  
1c02ea81006548a Mika Westerberg 2017-10-13  2842  /**
1c02ea81006548a Mika Westerberg 2017-10-13  2843   * 
pci_scan_child_bus_extend() - Scan devices below a bus
1c02ea81006548a Mika Westerberg 2017-10-13  2844   * @bus: Bus to scan for 
devices
1c02ea81006548a Mika Westerberg 2017-10-13  2845   * @available_buses: Total 
number of buses available (%0 does not try to
1c02ea81006548a Mika Westerberg 2017-10-13  2846   *                 extend 
beyond the minimal)
1c02ea81006548a Mika Westerberg 2017-10-13  2847   *
1c02ea81006548a Mika Westerberg 2017-10-13  2848   * Scans devices below @bus 
including subordinate buses. Returns new
1c02ea81006548a Mika Westerberg 2017-10-13  2849   * subordinate number 
including all the found devices. Passing
1c02ea81006548a Mika Westerberg 2017-10-13  2850   * @available_buses causes 
the remaining bus space to be distributed
1c02ea81006548a Mika Westerberg 2017-10-13  2851   * equally between 
hotplug-capable bridges to allow future extension of the
1c02ea81006548a Mika Westerberg 2017-10-13  2852   * hierarchy.
1c02ea81006548a Mika Westerberg 2017-10-13  2853   */
1c02ea81006548a Mika Westerberg 2017-10-13  2854  static unsigned int 
pci_scan_child_bus_extend(struct pci_bus *bus,
1c02ea81006548a Mika Westerberg 2017-10-13  2855                                
              unsigned int available_buses)
1c02ea81006548a Mika Westerberg 2017-10-13  2856  {
1c02ea81006548a Mika Westerberg 2017-10-13  2857        unsigned int 
used_buses, normal_bridges = 0, hotplug_bridges = 0;
1c02ea81006548a Mika Westerberg 2017-10-13  2858        unsigned int start = 
bus->busn_res.start;
5cac6729750b743 Niklas Schnelle 2022-04-12  2859        unsigned int devfn, 
cmax, max = start;
^1da177e4c3f415 Linus Torvalds  2005-04-16  2860        struct pci_dev *dev;
690f4304104f37e Jan Kiszka      2018-03-07  2861        int nr_devs;
^1da177e4c3f415 Linus Torvalds  2005-04-16  2862  
0207c356ef0e2ba Bjorn Helgaas   2009-11-04  2863        dev_dbg(&bus->dev, 
"scanning bus\n");
^1da177e4c3f415 Linus Torvalds  2005-04-16  2864  
^1da177e4c3f415 Linus Torvalds  2005-04-16  2865        /* Go find them, Rover! 
*/
5cac6729750b743 Niklas Schnelle 2022-04-12  2866        for (devfn = 0; devfn < 
256; devfn += 8)
690f4304104f37e Jan Kiszka      2018-03-07 @2867                nr_devs = 
pci_scan_slot(bus, devfn);
690f4304104f37e Jan Kiszka      2018-03-07  2868  
3e466e2d3a04c72 Bjorn Helgaas   2017-11-30  2869        /* Reserve buses for 
SR-IOV capability */
1c02ea81006548a Mika Westerberg 2017-10-13  2870        used_buses = 
pci_iov_bus_range(bus);
1c02ea81006548a Mika Westerberg 2017-10-13  2871        max += used_buses;
a28724b0fb909d2 Yu Zhao         2009-03-20  2872  
^1da177e4c3f415 Linus Torvalds  2005-04-16  2873        /*
^1da177e4c3f415 Linus Torvalds  2005-04-16  2874         * After performing 
arch-dependent fixup of the bus, look behind
^1da177e4c3f415 Linus Torvalds  2005-04-16  2875         * all PCI-to-PCI 
bridges on this bus.
^1da177e4c3f415 Linus Torvalds  2005-04-16  2876         */
74710ded8e16fc8 Alex Chiang     2009-03-20  2877        if (!bus->is_added) {
0207c356ef0e2ba Bjorn Helgaas   2009-11-04  2878                
dev_dbg(&bus->dev, "fixups for bus\n");
^1da177e4c3f415 Linus Torvalds  2005-04-16  2879                
pcibios_fixup_bus(bus);
74710ded8e16fc8 Alex Chiang     2009-03-20  2880                bus->is_added = 
1;
74710ded8e16fc8 Alex Chiang     2009-03-20  2881        }
74710ded8e16fc8 Alex Chiang     2009-03-20  2882  
1c02ea81006548a Mika Westerberg 2017-10-13  2883        /*
1c02ea81006548a Mika Westerberg 2017-10-13  2884         * Calculate how many 
hotplug bridges and normal bridges there
1c02ea81006548a Mika Westerberg 2017-10-13  2885         * are on this bus. We 
will distribute the additional available
1c02ea81006548a Mika Westerberg 2017-10-13  2886         * buses between 
hotplug bridges.
1c02ea81006548a Mika Westerberg 2017-10-13  2887         */
1c02ea81006548a Mika Westerberg 2017-10-13  2888        
for_each_pci_bridge(dev, bus) {
1c02ea81006548a Mika Westerberg 2017-10-13  2889                if 
(dev->is_hotplug_bridge)
1c02ea81006548a Mika Westerberg 2017-10-13  2890                        
hotplug_bridges++;
1c02ea81006548a Mika Westerberg 2017-10-13  2891                else
1c02ea81006548a Mika Westerberg 2017-10-13  2892                        
normal_bridges++;
1c02ea81006548a Mika Westerberg 2017-10-13  2893        }
1c02ea81006548a Mika Westerberg 2017-10-13  2894  
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2895        /*
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2896         * Scan bridges that 
are already configured. We don't touch them
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2897         * unless they are 
misconfigured (which will be done in the second
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2898         * scan below).
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2899         */
1c02ea81006548a Mika Westerberg 2017-10-13  2900        
for_each_pci_bridge(dev, bus) {
1c02ea81006548a Mika Westerberg 2017-10-13  2901                cmax = max;
1c02ea81006548a Mika Westerberg 2017-10-13  2902                max = 
pci_scan_bridge_extend(bus, dev, max, 0, 0);
3374c545c27c535 Mika Westerberg 2018-05-28  2903  
3374c545c27c535 Mika Westerberg 2018-05-28  2904                /*
3374c545c27c535 Mika Westerberg 2018-05-28  2905                 * Reserve one 
bus for each bridge now to avoid extending
3374c545c27c535 Mika Westerberg 2018-05-28  2906                 * hotplug 
bridges too much during the second scan below.
3374c545c27c535 Mika Westerberg 2018-05-28  2907                 */
3374c545c27c535 Mika Westerberg 2018-05-28  2908                used_buses++;
3374c545c27c535 Mika Westerberg 2018-05-28  2909                if (cmax - max 
> 1)
3374c545c27c535 Mika Westerberg 2018-05-28  2910                        
used_buses += cmax - max - 1;
1c02ea81006548a Mika Westerberg 2017-10-13  2911        }
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2912  
4147c2fd9b12ae1 Mika Westerberg 2017-10-13  2913        /* Scan bridges that 
need to be reconfigured */
1c02ea81006548a Mika Westerberg 2017-10-13  2914        
for_each_pci_bridge(dev, bus) {
1c02ea81006548a Mika Westerberg 2017-10-13  2915                unsigned int 
buses = 0;
1c02ea81006548a Mika Westerberg 2017-10-13  2916  
1c02ea81006548a Mika Westerberg 2017-10-13  2917                if 
(!hotplug_bridges && normal_bridges == 1) {
3e466e2d3a04c72 Bjorn Helgaas   2017-11-30  2918  
1c02ea81006548a Mika Westerberg 2017-10-13  2919                        /*
1c02ea81006548a Mika Westerberg 2017-10-13  2920                         * 
There is only one bridge on the bus (upstream
1c02ea81006548a Mika Westerberg 2017-10-13  2921                         * 
port) so it gets all available buses which it
1c02ea81006548a Mika Westerberg 2017-10-13  2922                         * can 
then distribute to the possible hotplug
1c02ea81006548a Mika Westerberg 2017-10-13  2923                         * 
bridges below.
1c02ea81006548a Mika Westerberg 2017-10-13  2924                         */
1c02ea81006548a Mika Westerberg 2017-10-13  2925                        buses = 
available_buses;
1c02ea81006548a Mika Westerberg 2017-10-13  2926                } else if 
(dev->is_hotplug_bridge) {
3e466e2d3a04c72 Bjorn Helgaas   2017-11-30  2927  
1c02ea81006548a Mika Westerberg 2017-10-13  2928                        /*
1c02ea81006548a Mika Westerberg 2017-10-13  2929                         * 
Distribute the extra buses between hotplug
1c02ea81006548a Mika Westerberg 2017-10-13  2930                         * 
bridges if any.
1c02ea81006548a Mika Westerberg 2017-10-13  2931                         */
1c02ea81006548a Mika Westerberg 2017-10-13  2932                        buses = 
available_buses / hotplug_bridges;
3374c545c27c535 Mika Westerberg 2018-05-28  2933                        buses = 
min(buses, available_buses - used_buses + 1);
1c02ea81006548a Mika Westerberg 2017-10-13  2934                }
1c02ea81006548a Mika Westerberg 2017-10-13  2935  
1c02ea81006548a Mika Westerberg 2017-10-13  2936                cmax = max;
1c02ea81006548a Mika Westerberg 2017-10-13  2937                max = 
pci_scan_bridge_extend(bus, dev, cmax, buses, 1);
3374c545c27c535 Mika Westerberg 2018-05-28  2938                /* One bus is 
already accounted so don't add it again */
3374c545c27c535 Mika Westerberg 2018-05-28  2939                if (max - cmax 
> 1)
3374c545c27c535 Mika Westerberg 2018-05-28  2940                        
used_buses += max - cmax - 1;
1c02ea81006548a Mika Westerberg 2017-10-13  2941        }
^1da177e4c3f415 Linus Torvalds  2005-04-16  2942  
e16b46605960bd0 Keith Busch     2016-07-21  2943        /*
e16b46605960bd0 Keith Busch     2016-07-21  2944         * Make sure a hotplug 
bridge has at least the minimum requested
1c02ea81006548a Mika Westerberg 2017-10-13  2945         * number of buses but 
allow it to grow up to the maximum available
1c02ea81006548a Mika Westerberg 2017-10-13  2946         * bus number of there 
is room.
e16b46605960bd0 Keith Busch     2016-07-21  2947         */
1c02ea81006548a Mika Westerberg 2017-10-13  2948        if (bus->self && 
bus->self->is_hotplug_bridge) {
1c02ea81006548a Mika Westerberg 2017-10-13  2949                used_buses = 
max_t(unsigned int, available_buses,
1c02ea81006548a Mika Westerberg 2017-10-13  2950                                
   pci_hotplug_bus_size - 1);
1c02ea81006548a Mika Westerberg 2017-10-13  2951                if (max - start 
< used_buses) {
1c02ea81006548a Mika Westerberg 2017-10-13  2952                        max = 
start + used_buses;
a20c7f36bd3d20d Mika Westerberg 2017-10-13  2953  
a20c7f36bd3d20d Mika Westerberg 2017-10-13  2954                        /* Do 
not allocate more buses than we have room left */
a20c7f36bd3d20d Mika Westerberg 2017-10-13  2955                        if (max 
> bus->busn_res.end)
a20c7f36bd3d20d Mika Westerberg 2017-10-13  2956                                
max = bus->busn_res.end;
1c02ea81006548a Mika Westerberg 2017-10-13  2957  
1c02ea81006548a Mika Westerberg 2017-10-13  2958                        
dev_dbg(&bus->dev, "%pR extended by %#02x\n",
1c02ea81006548a Mika Westerberg 2017-10-13  2959                                
&bus->busn_res, max - start);
1c02ea81006548a Mika Westerberg 2017-10-13  2960                }
e16b46605960bd0 Keith Busch     2016-07-21  2961        }
e16b46605960bd0 Keith Busch     2016-07-21  2962  
^1da177e4c3f415 Linus Torvalds  2005-04-16  2963        /*
^1da177e4c3f415 Linus Torvalds  2005-04-16  2964         * We've scanned the 
bus and so we know all about what's on
^1da177e4c3f415 Linus Torvalds  2005-04-16  2965         * the other side of 
any bridges that may be on this bus plus
^1da177e4c3f415 Linus Torvalds  2005-04-16  2966         * any devices.
^1da177e4c3f415 Linus Torvalds  2005-04-16  2967         *
^1da177e4c3f415 Linus Torvalds  2005-04-16  2968         * Return how far we've 
got finding sub-buses.
^1da177e4c3f415 Linus Torvalds  2005-04-16  2969         */
0207c356ef0e2ba Bjorn Helgaas   2009-11-04  2970        dev_dbg(&bus->dev, "bus 
scan returning with max=%02x\n", max);
^1da177e4c3f415 Linus Torvalds  2005-04-16  2971        return max;
^1da177e4c3f415 Linus Torvalds  2005-04-16  2972  }
1c02ea81006548a Mika Westerberg 2017-10-13  2973  

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp
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