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* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
@ 2021-11-27 18:35 kernel test robot
  2021-11-29  9:39   ` kernel test robot
  0 siblings, 1 reply; 9+ messages in thread
From: kernel test robot @ 2021-11-27 18:35 UTC (permalink / raw)
  To: kbuild

[-- Attachment #1: Type: text/plain, Size: 18441 bytes --]

CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
In-Reply-To: <20211120000250.1663391-18-ben.widawsky@intel.com>
References: <20211120000250.1663391-18-ben.widawsky@intel.com>
TO: Ben Widawsky <ben.widawsky@intel.com>
TO: linux-cxl(a)vger.kernel.org
TO: linux-pci(a)vger.kernel.org
CC: Ben Widawsky <ben.widawsky@intel.com>
CC: Alison Schofield <alison.schofield@intel.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Ira Weiny <ira.weiny@intel.com>
CC: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
CC: Vishal Verma <vishal.l.verma@intel.com>

Hi Ben,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 53989fad1286e652ea3655ae3367ba698da8d2ff]

url:    https://github.com/0day-ci/linux/commits/Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
base:   53989fad1286e652ea3655ae3367ba698da8d2ff
:::::: branch date: 8 days ago
:::::: commit date: 8 days ago
config: x86_64-randconfig-c007-20211118 (https://download.01.org/0day-ci/archive/20211128/202111280254.IoqCZcvv-lkp(a)intel.com/config)
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/0day-ci/linux/commit/cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
        git checkout cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        # 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 <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   2 warnings generated.
   drivers/power/supply/bq256xx_charger.c:275:8: warning: Excessive padding in 'struct bq256xx_chip_info' (11 padding bytes, where 3 is optimal). 
   Optimal fields order: 
   bq256xx_regmap_config, 
   bq256xx_get_ichg, 
   bq256xx_get_iindpm, 
   bq256xx_get_vbatreg, 
   bq256xx_get_iterm, 
   bq256xx_get_iprechg, 
   bq256xx_get_vindpm, 
   bq256xx_set_ichg, 
   bq256xx_set_iindpm, 
   bq256xx_set_vbatreg, 
   bq256xx_set_iterm, 
   bq256xx_set_iprechg, 
   bq256xx_set_vindpm, 
   model_id, 
   bq256xx_def_ichg, 
   bq256xx_def_iindpm, 
   bq256xx_def_vbatreg, 
   bq256xx_def_iterm, 
   bq256xx_def_iprechg, 
   bq256xx_def_vindpm, 
   bq256xx_max_ichg, 
   bq256xx_max_vbatreg, 
   has_usb_detect, 
   consider reordering the fields or adding explicit padding members [clang-analyzer-optin.performance.Padding]
   struct bq256xx_chip_info {
   ~~~~~~~^~~~~~~~~~~~~~~~~~~
   drivers/power/supply/bq256xx_charger.c:275:8: note: Excessive padding in 'struct bq256xx_chip_info' (11 padding bytes, where 3 is optimal). Optimal fields order: bq256xx_regmap_config, bq256xx_get_ichg, bq256xx_get_iindpm, bq256xx_get_vbatreg, bq256xx_get_iterm, bq256xx_get_iprechg, bq256xx_get_vindpm, bq256xx_set_ichg, bq256xx_set_iindpm, bq256xx_set_vbatreg, bq256xx_set_iterm, bq256xx_set_iprechg, bq256xx_set_vindpm, model_id, bq256xx_def_ichg, bq256xx_def_iindpm, bq256xx_def_vbatreg, bq256xx_def_iterm, bq256xx_def_iprechg, bq256xx_def_vindpm, bq256xx_max_ichg, bq256xx_max_vbatreg, has_usb_detect, consider reordering the fields or adding explicit padding members
   struct bq256xx_chip_info {
   ~~~~~~~^~~~~~~~~~~~~~~~~~~
   drivers/power/supply/bq256xx_charger.c:1521:2: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
           ret = regmap_update_bits(bq->regmap, BQ256XX_CHARGER_CONTROL_1,
           ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/power/supply/bq256xx_charger.c:1521:2: note: Value stored to 'ret' is never read
           ret = regmap_update_bits(bq->regmap, BQ256XX_CHARGER_CONTROL_1,
           ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   2 warnings generated.
   drivers/hwmon/acpi_power_meter.c:879:2: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
           strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
           ^~~~~~
   drivers/hwmon/acpi_power_meter.c:879:2: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
           strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
           ^~~~~~
   drivers/hwmon/acpi_power_meter.c:880:2: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
           strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
           ^~~~~~
   drivers/hwmon/acpi_power_meter.c:880:2: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
           strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
           ^~~~~~
   2 warnings generated.
   drivers/usb/storage/freecom.c:449:2: warning: Value stored to 'result' is never read [clang-analyzer-deadcode.DeadStores]
           result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
           ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/usb/storage/freecom.c:449:2: note: Value stored to 'result' is never read
           result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
           ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/usb/storage/freecom.c:537:2: warning: Value stored to 'offset' is never read [clang-analyzer-deadcode.DeadStores]
           offset = 0;
           ^        ~
   drivers/usb/storage/freecom.c:537:2: note: Value stored to 'offset' is never read
           offset = 0;
           ^        ~
   1 warning generated.
   Suppressed 1 warnings (1 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.
   3 warnings generated.
   drivers/cxl/core/mbox.c:324:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           struct device *dev = &cxlmd->dev;
                          ^~~   ~~~~~~~~~~~
   drivers/cxl/core/mbox.c:324:17: note: Value stored to 'dev' during its initialization is never read
           struct device *dev = &cxlmd->dev;
                          ^~~   ~~~~~~~~~~~
   drivers/cxl/core/mbox.c:449:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           struct device *dev = &cxlmd->dev;
                          ^~~   ~~~~~~~~~~~
   drivers/cxl/core/mbox.c:449:17: note: Value stored to 'dev' during its initialization is never read
           struct device *dev = &cxlmd->dev;
                          ^~~   ~~~~~~~~~~~
   drivers/cxl/core/mbox.c:580:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           struct device *dev = cxlds->dev;
                          ^~~   ~~~~~~~~~~
   drivers/cxl/core/mbox.c:580:17: note: Value stored to 'dev' during its initialization is never read
           struct device *dev = cxlds->dev;
                          ^~~   ~~~~~~~~~~
   4 warnings generated.
   drivers/cxl/pci.c:42:16: warning: Value stored to 'end' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           unsigned long end = start;
                         ^~~   ~~~~~
   drivers/cxl/pci.c:42:16: note: Value stored to 'end' during its initialization is never read
           unsigned long end = start;
                         ^~~   ~~~~~
   drivers/cxl/pci.c:64:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           struct device *dev = cxlds->dev;
                          ^~~   ~~~~~~~~~~
   drivers/cxl/pci.c:64:17: note: Value stored to 'dev' during its initialization is never read
           struct device *dev = cxlds->dev;
                          ^~~   ~~~~~~~~~~
>> drivers/cxl/pci.c:483:3: warning: Value stored to 'size' is never read [clang-analyzer-deadcode.DeadStores]
                   size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
                   ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/cxl/pci.c:483:3: note: Value stored to 'size' is never read
                   size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
                   ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   Suppressed 1 warnings (1 with check filters).
   3 warnings generated.
   drivers/cxl/acpi.c:142:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
           struct device *dev = ctx->dev;
                          ^~~   ~~~~~~~~
   drivers/cxl/acpi.c:142:17: note: Value stored to 'dev' during its initialization is never read
           struct device *dev = ctx->dev;
                          ^~~   ~~~~~~~~
   drivers/cxl/acpi.c:399:14: warning: 3rd function call argument is an uninitialized value [clang-analyzer-core.CallAndMessage]
           root_port = devm_cxl_add_port(host, CXL_RESOURCE_NONE, root_port);
                       ^                                          ~~~~~~~~~
   drivers/cxl/acpi.c:386:2: note: 'root_port' declared without an initial value
           struct cxl_port *root_port;
           ^~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/cxl/acpi.c:388:29: note: Assuming the condition is false
           struct acpi_device *adev = ACPI_COMPANION(host);
                                      ^
   include/linux/acpi.h:43:30: note: expanded from macro 'ACPI_COMPANION'
   #define ACPI_COMPANION(dev)             to_acpi_device_node((dev)->fwnode)
                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/acpi/acpi_bus.h:418:3: note: expanded from macro 'to_acpi_device_node'
                   is_acpi_device_node(__to_acpi_device_node_fwnode) ?     \
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/cxl/acpi.c:388:29: note: '?' condition is false
           struct acpi_device *adev = ACPI_COMPANION(host);
                                      ^
   include/linux/acpi.h:43:30: note: expanded from macro 'ACPI_COMPANION'
   #define ACPI_COMPANION(dev)             to_acpi_device_node((dev)->fwnode)
                                           ^
   include/acpi/acpi_bus.h:418:3: note: expanded from macro 'to_acpi_device_node'
                   is_acpi_device_node(__to_acpi_device_node_fwnode) ?     \
                   ^
   drivers/cxl/acpi.c:392:2: note: Assuming 'rc' is 0
           if (rc)
           ^
   include/linux/compiler.h:56:45: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:58:52: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                      ^~~~
   drivers/cxl/acpi.c:392:2: note: '?' condition is false
           if (rc)
           ^
   include/linux/compiler.h:56:28: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ^
   include/linux/compiler.h:58:31: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                 ^
   drivers/cxl/acpi.c:392:6: note: 'rc' is 0
           if (rc)
               ^
   include/linux/compiler.h:56:47: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                                                 ^~~~
   include/linux/compiler.h:58:86: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                                                        ^~~~
   include/linux/compiler.h:69:3: note: expanded from macro '__trace_if_value'
           (cond) ?                                        \
            ^~~~
   drivers/cxl/acpi.c:392:2: note: '?' condition is false
           if (rc)
           ^
   include/linux/compiler.h:56:28: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ^
   include/linux/compiler.h:58:69: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                                       ^
   include/linux/compiler.h:69:2: note: expanded from macro '__trace_if_value'
           (cond) ?                                        \
           ^
   drivers/cxl/acpi.c:392:2: note: Taking false branch
           if (rc)
           ^
   include/linux/compiler.h:56:23: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                         ^
   drivers/cxl/acpi.c:396:2: note: '?' condition is false
           if (rc)
           ^
   include/linux/compiler.h:56:28: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ^
   include/linux/compiler.h:58:31: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                 ^
   drivers/cxl/acpi.c:396:6: note: 'rc' is 0
           if (rc)
               ^
   include/linux/compiler.h:56:47: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                                                 ^~~~

vim +/size +483 drivers/cxl/pci.c

1d5a4159074bde Ben Widawsky 2021-04-07  454  
cfdf51e15fc822 Ben Widawsky 2021-11-19  455  #define CDPD(cxlds, which)                                                     \
cfdf51e15fc822 Ben Widawsky 2021-11-19  456  	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
cfdf51e15fc822 Ben Widawsky 2021-11-19  457  
cfdf51e15fc822 Ben Widawsky 2021-11-19  458  #define CDPDR(cxlds, which, sorb, lohi)                                        \
cfdf51e15fc822 Ben Widawsky 2021-11-19  459  	cxlds->device_dvsec +                                                  \
cfdf51e15fc822 Ben Widawsky 2021-11-19  460  		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
cfdf51e15fc822 Ben Widawsky 2021-11-19  461  
cfdf51e15fc822 Ben Widawsky 2021-11-19  462  static int wait_for_valid(struct cxl_dev_state *cxlds)
cfdf51e15fc822 Ben Widawsky 2021-11-19  463  {
cfdf51e15fc822 Ben Widawsky 2021-11-19  464  	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
cfdf51e15fc822 Ben Widawsky 2021-11-19  465  	const unsigned long timeout = jiffies + HZ;
cfdf51e15fc822 Ben Widawsky 2021-11-19  466  	bool valid;
cfdf51e15fc822 Ben Widawsky 2021-11-19  467  
cfdf51e15fc822 Ben Widawsky 2021-11-19  468  	do {
cfdf51e15fc822 Ben Widawsky 2021-11-19  469  		u64 size;
cfdf51e15fc822 Ben Widawsky 2021-11-19  470  		u32 temp;
cfdf51e15fc822 Ben Widawsky 2021-11-19  471  		int rc;
cfdf51e15fc822 Ben Widawsky 2021-11-19  472  
cfdf51e15fc822 Ben Widawsky 2021-11-19  473  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
cfdf51e15fc822 Ben Widawsky 2021-11-19  474  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  475  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  476  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19  477  		size = (u64)temp << 32;
cfdf51e15fc822 Ben Widawsky 2021-11-19  478  
cfdf51e15fc822 Ben Widawsky 2021-11-19  479  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
cfdf51e15fc822 Ben Widawsky 2021-11-19  480  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  481  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  482  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19 @483  		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
cfdf51e15fc822 Ben Widawsky 2021-11-19  484  
cfdf51e15fc822 Ben Widawsky 2021-11-19  485  		/*
cfdf51e15fc822 Ben Widawsky 2021-11-19  486  		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
cfdf51e15fc822 Ben Widawsky 2021-11-19  487  		 * Size high and Size Low registers are valid. Must be set
cfdf51e15fc822 Ben Widawsky 2021-11-19  488  		 * within 1 second of deassertion of reset to CXL device.
cfdf51e15fc822 Ben Widawsky 2021-11-19  489  		 */
cfdf51e15fc822 Ben Widawsky 2021-11-19  490  		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  491  		if (valid)
cfdf51e15fc822 Ben Widawsky 2021-11-19  492  			break;
cfdf51e15fc822 Ben Widawsky 2021-11-19  493  		cpu_relax();
cfdf51e15fc822 Ben Widawsky 2021-11-19  494  	} while (!time_after(jiffies, timeout));
cfdf51e15fc822 Ben Widawsky 2021-11-19  495  
cfdf51e15fc822 Ben Widawsky 2021-11-19  496  	return valid ? 0 : -ETIMEDOUT;
cfdf51e15fc822 Ben Widawsky 2021-11-19  497  }
cfdf51e15fc822 Ben Widawsky 2021-11-19  498  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-27 18:35 [PATCH 17/23] cxl: Cache and pass DVSEC ranges kernel test robot
@ 2021-11-29  9:39   ` kernel test robot
  0 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-11-29  9:39 UTC (permalink / raw)
  To: Ben Widawsky; +Cc: llvm, kbuild-all, linux-pci, linux-cxl

Hi Ben,

Thanks for your patch! Perhaps something to improve:

[auto build test WARNING on 53989fad1286e652ea3655ae3367ba698da8d2ff]

url:    https://github.com/0day-ci/linux/commits/Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
base:   53989fad1286e652ea3655ae3367ba698da8d2ff
config: x86_64-randconfig-c007-20211118 (https://download.01.org/0day-ci/archive/20211128/202111280254.IoqCZcvv-lkp@intel.com/config)
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/0day-ci/linux/commit/cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
         git remote add linux-review https://github.com/0day-ci/linux
         git fetch --no-tags linux-review Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
         git checkout cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
         # 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 <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)

 >> drivers/cxl/pci.c:483:3: warning: Value stored to 'size' is never read [clang-analyzer-deadcode.DeadStores]
                    size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
                    ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/size +483 drivers/cxl/pci.c

1d5a4159074bde Ben Widawsky 2021-04-07  454
cfdf51e15fc822 Ben Widawsky 2021-11-19  455  #define CDPD(cxlds, which)                                                     \
cfdf51e15fc822 Ben Widawsky 2021-11-19  456  	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
cfdf51e15fc822 Ben Widawsky 2021-11-19  457
cfdf51e15fc822 Ben Widawsky 2021-11-19  458  #define CDPDR(cxlds, which, sorb, lohi)                                        \
cfdf51e15fc822 Ben Widawsky 2021-11-19  459  	cxlds->device_dvsec +                                                  \
cfdf51e15fc822 Ben Widawsky 2021-11-19  460  		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
cfdf51e15fc822 Ben Widawsky 2021-11-19  461
cfdf51e15fc822 Ben Widawsky 2021-11-19  462  static int wait_for_valid(struct cxl_dev_state *cxlds)
cfdf51e15fc822 Ben Widawsky 2021-11-19  463  {
cfdf51e15fc822 Ben Widawsky 2021-11-19  464  	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
cfdf51e15fc822 Ben Widawsky 2021-11-19  465  	const unsigned long timeout = jiffies + HZ;
cfdf51e15fc822 Ben Widawsky 2021-11-19  466  	bool valid;
cfdf51e15fc822 Ben Widawsky 2021-11-19  467
cfdf51e15fc822 Ben Widawsky 2021-11-19  468  	do {
cfdf51e15fc822 Ben Widawsky 2021-11-19  469  		u64 size;
cfdf51e15fc822 Ben Widawsky 2021-11-19  470  		u32 temp;
cfdf51e15fc822 Ben Widawsky 2021-11-19  471  		int rc;
cfdf51e15fc822 Ben Widawsky 2021-11-19  472
cfdf51e15fc822 Ben Widawsky 2021-11-19  473  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
cfdf51e15fc822 Ben Widawsky 2021-11-19  474  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  475  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  476  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19  477  		size = (u64)temp << 32;
cfdf51e15fc822 Ben Widawsky 2021-11-19  478
cfdf51e15fc822 Ben Widawsky 2021-11-19  479  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
cfdf51e15fc822 Ben Widawsky 2021-11-19  480  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  481  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  482  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19 @483  		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
cfdf51e15fc822 Ben Widawsky 2021-11-19  484
cfdf51e15fc822 Ben Widawsky 2021-11-19  485  		/*
cfdf51e15fc822 Ben Widawsky 2021-11-19  486  		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
cfdf51e15fc822 Ben Widawsky 2021-11-19  487  		 * Size high and Size Low registers are valid. Must be set
cfdf51e15fc822 Ben Widawsky 2021-11-19  488  		 * within 1 second of deassertion of reset to CXL device.
cfdf51e15fc822 Ben Widawsky 2021-11-19  489  		 */
cfdf51e15fc822 Ben Widawsky 2021-11-19  490  		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  491  		if (valid)
cfdf51e15fc822 Ben Widawsky 2021-11-19  492  			break;
cfdf51e15fc822 Ben Widawsky 2021-11-19  493  		cpu_relax();
cfdf51e15fc822 Ben Widawsky 2021-11-19  494  	} while (!time_after(jiffies, timeout));
cfdf51e15fc822 Ben Widawsky 2021-11-19  495
cfdf51e15fc822 Ben Widawsky 2021-11-19  496  	return valid ? 0 : -ETIMEDOUT;
cfdf51e15fc822 Ben Widawsky 2021-11-19  497  }
cfdf51e15fc822 Ben Widawsky 2021-11-19  498

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
@ 2021-11-29  9:39   ` kernel test robot
  0 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-11-29  9:39 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 5008 bytes --]

Hi Ben,

Thanks for your patch! Perhaps something to improve:

[auto build test WARNING on 53989fad1286e652ea3655ae3367ba698da8d2ff]

url:    https://github.com/0day-ci/linux/commits/Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
base:   53989fad1286e652ea3655ae3367ba698da8d2ff
config: x86_64-randconfig-c007-20211118 (https://download.01.org/0day-ci/archive/20211128/202111280254.IoqCZcvv-lkp(a)intel.com/config)
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/0day-ci/linux/commit/cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
         git remote add linux-review https://github.com/0day-ci/linux
         git fetch --no-tags linux-review Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
         git checkout cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
         # 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 <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)

 >> drivers/cxl/pci.c:483:3: warning: Value stored to 'size' is never read [clang-analyzer-deadcode.DeadStores]
                    size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
                    ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/size +483 drivers/cxl/pci.c

1d5a4159074bde Ben Widawsky 2021-04-07  454
cfdf51e15fc822 Ben Widawsky 2021-11-19  455  #define CDPD(cxlds, which)                                                     \
cfdf51e15fc822 Ben Widawsky 2021-11-19  456  	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
cfdf51e15fc822 Ben Widawsky 2021-11-19  457
cfdf51e15fc822 Ben Widawsky 2021-11-19  458  #define CDPDR(cxlds, which, sorb, lohi)                                        \
cfdf51e15fc822 Ben Widawsky 2021-11-19  459  	cxlds->device_dvsec +                                                  \
cfdf51e15fc822 Ben Widawsky 2021-11-19  460  		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
cfdf51e15fc822 Ben Widawsky 2021-11-19  461
cfdf51e15fc822 Ben Widawsky 2021-11-19  462  static int wait_for_valid(struct cxl_dev_state *cxlds)
cfdf51e15fc822 Ben Widawsky 2021-11-19  463  {
cfdf51e15fc822 Ben Widawsky 2021-11-19  464  	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
cfdf51e15fc822 Ben Widawsky 2021-11-19  465  	const unsigned long timeout = jiffies + HZ;
cfdf51e15fc822 Ben Widawsky 2021-11-19  466  	bool valid;
cfdf51e15fc822 Ben Widawsky 2021-11-19  467
cfdf51e15fc822 Ben Widawsky 2021-11-19  468  	do {
cfdf51e15fc822 Ben Widawsky 2021-11-19  469  		u64 size;
cfdf51e15fc822 Ben Widawsky 2021-11-19  470  		u32 temp;
cfdf51e15fc822 Ben Widawsky 2021-11-19  471  		int rc;
cfdf51e15fc822 Ben Widawsky 2021-11-19  472
cfdf51e15fc822 Ben Widawsky 2021-11-19  473  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
cfdf51e15fc822 Ben Widawsky 2021-11-19  474  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  475  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  476  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19  477  		size = (u64)temp << 32;
cfdf51e15fc822 Ben Widawsky 2021-11-19  478
cfdf51e15fc822 Ben Widawsky 2021-11-19  479  		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
cfdf51e15fc822 Ben Widawsky 2021-11-19  480  					   &temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  481  		if (rc)
cfdf51e15fc822 Ben Widawsky 2021-11-19  482  			return -ENXIO;
cfdf51e15fc822 Ben Widawsky 2021-11-19 @483  		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
cfdf51e15fc822 Ben Widawsky 2021-11-19  484
cfdf51e15fc822 Ben Widawsky 2021-11-19  485  		/*
cfdf51e15fc822 Ben Widawsky 2021-11-19  486  		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
cfdf51e15fc822 Ben Widawsky 2021-11-19  487  		 * Size high and Size Low registers are valid. Must be set
cfdf51e15fc822 Ben Widawsky 2021-11-19  488  		 * within 1 second of deassertion of reset to CXL device.
cfdf51e15fc822 Ben Widawsky 2021-11-19  489  		 */
cfdf51e15fc822 Ben Widawsky 2021-11-19  490  		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
cfdf51e15fc822 Ben Widawsky 2021-11-19  491  		if (valid)
cfdf51e15fc822 Ben Widawsky 2021-11-19  492  			break;
cfdf51e15fc822 Ben Widawsky 2021-11-19  493  		cpu_relax();
cfdf51e15fc822 Ben Widawsky 2021-11-19  494  	} while (!time_after(jiffies, timeout));
cfdf51e15fc822 Ben Widawsky 2021-11-19  495
cfdf51e15fc822 Ben Widawsky 2021-11-19  496  	return valid ? 0 : -ETIMEDOUT;
cfdf51e15fc822 Ben Widawsky 2021-11-19  497  }
cfdf51e15fc822 Ben Widawsky 2021-11-19  498

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-20  0:02 ` [PATCH 17/23] cxl: Cache and pass DVSEC ranges Ben Widawsky
  2021-11-20  4:29     ` kernel test robot
  2021-11-22 17:00   ` Jonathan Cameron
@ 2021-11-26 11:37   ` Jonathan Cameron
  2 siblings, 0 replies; 9+ messages in thread
From: Jonathan Cameron @ 2021-11-26 11:37 UTC (permalink / raw)
  To: Ben Widawsky
  Cc: linux-cxl, linux-pci, Alison Schofield, Dan Williams, Ira Weiny,
	Vishal Verma

On Fri, 19 Nov 2021 16:02:44 -0800
Ben Widawsky <ben.widawsky@intel.com> wrote:

> CXL 1.1 specification provided a mechanism for mapping an address space
> of a CXL device. That functionality is known as a "range" and can be
> programmed through PCIe DVSEC. In addition to this, the specification
> defines an active bit which a device will expose through the same DVSEC
> to notify system software that memory is initialized and ready.
> 
> While CXL 2.0 introduces a more powerful mechanism called HDM decoders
> that are controlled by MMIO behind a PCIe BAR, the spec does allow the
> 1.1 style mapping to still be present. In such a case, when the CXL
> driver takes over, if it were to enable HDM decoding and there was an
> actively used range, things would likely blow up, in particular if it
> wasn't an identical mapping.
> 
> This patch caches the relevant information which the cxl_mem driver will
> need to make the proper decision and passes it along.
> 
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> ---
>  drivers/cxl/cxlmem.h |  19 +++++++
>  drivers/cxl/pci.c    | 126 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/pci.h    |  13 +++++
>  3 files changed, 158 insertions(+)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 3ef3c652599e..eac5528ccaae 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -89,6 +89,22 @@ struct cxl_mbox_cmd {
>   */
>  #define CXL_CAPACITY_MULTIPLIER SZ_256M
>  
> +/**
> + * struct cxl_endpoint_dvsec_info - Cached DVSEC info
> + * @mem_enabled: cached value of mem_enabled in the DVSEC, PCIE_DEVICE
> + * @ranges: Number of HDM ranges this device contains.
> + * @range.base: cached value of the range base in the DVSEC, PCIE_DEVICE
> + * @range.size: cached value of the range size in the DVSEC, PCIE_DEVICE
> + */
> +struct cxl_endpoint_dvsec_info {
> +	bool mem_enabled;
> +	int ranges;
> +	struct {
> +		u64 base;
> +		u64 size;
> +	} range[2];

kernel-doc wants documentation for range as well.

> +};

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-22 17:00   ` Jonathan Cameron
@ 2021-11-22 22:50     ` Ben Widawsky
  0 siblings, 0 replies; 9+ messages in thread
From: Ben Widawsky @ 2021-11-22 22:50 UTC (permalink / raw)
  To: Jonathan Cameron
  Cc: linux-cxl, linux-pci, Alison Schofield, Dan Williams, Ira Weiny,
	Vishal Verma

On 21-11-22 17:00:56, Jonathan Cameron wrote:
> On Fri, 19 Nov 2021 16:02:44 -0800
> Ben Widawsky <ben.widawsky@intel.com> wrote:
> 
> > CXL 1.1 specification provided a mechanism for mapping an address space
> > of a CXL device. That functionality is known as a "range" and can be
> > programmed through PCIe DVSEC. In addition to this, the specification
> > defines an active bit which a device will expose through the same DVSEC
> > to notify system software that memory is initialized and ready.
> > 
> > While CXL 2.0 introduces a more powerful mechanism called HDM decoders
> > that are controlled by MMIO behind a PCIe BAR, the spec does allow the
> > 1.1 style mapping to still be present. In such a case, when the CXL
> > driver takes over, if it were to enable HDM decoding and there was an
> > actively used range, things would likely blow up, in particular if it
> > wasn't an identical mapping.
> > 
> > This patch caches the relevant information which the cxl_mem driver will
> > need to make the proper decision and passes it along.
> > 
> > Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> 
> 0-day spotted issues in same code as me. See below.
> 
> This is another case where I'd treat failure as fatal.  Anything that fails
> is either dead, or non spec compliant so don't bother loading the driver
> if that happens. Fewer paths to test etc...

I disagree about treating failure as fatal. The failure here only forbids using
the memory on the device. I can envision firmware bugs or the like where these
things might fail, but the mailbox interfaces still work perfectly fine, or at
least fine enough to upgrade the firmware and try again.

Dan and I had talked about a modparam (or perhaps sysfs on some higher level,
like CXL bus) to control the length of the timeout, so that one doesn't have to
wait forever to deal with this usage. Figured we'd cross that bridge when we
came to it.

> 
> > ---
> >  drivers/cxl/cxlmem.h |  19 +++++++
> >  drivers/cxl/pci.c    | 126 +++++++++++++++++++++++++++++++++++++++++++
> >  drivers/cxl/pci.h    |  13 +++++
> >  3 files changed, 158 insertions(+)
> > 
> > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> > index 3ef3c652599e..eac5528ccaae 100644
> > --- a/drivers/cxl/cxlmem.h
> > +++ b/drivers/cxl/cxlmem.h
> > @@ -89,6 +89,22 @@ struct cxl_mbox_cmd {
> >   */
> >  #define CXL_CAPACITY_MULTIPLIER SZ_256M
> >  
> > +/**
> > + * struct cxl_endpoint_dvsec_info - Cached DVSEC info
> > + * @mem_enabled: cached value of mem_enabled in the DVSEC, PCIE_DEVICE
> > + * @ranges: Number of HDM ranges this device contains.
> > + * @range.base: cached value of the range base in the DVSEC, PCIE_DEVICE
> > + * @range.size: cached value of the range size in the DVSEC, PCIE_DEVICE
> > + */
> > +struct cxl_endpoint_dvsec_info {
> > +	bool mem_enabled;
> > +	int ranges;
> > +	struct {
> > +		u64 base;
> > +		u64 size;
> > +	} range[2];
> > +};
> > +
> >  /**
> >   * struct cxl_dev_state - The driver device state
> >   *
> > @@ -117,6 +133,7 @@ struct cxl_mbox_cmd {
> >   * @active_persistent_bytes: sum of hard + soft persistent
> >   * @next_volatile_bytes: volatile capacity change pending device reset
> >   * @next_persistent_bytes: persistent capacity change pending device reset
> > + * @info: Cached DVSEC information about the device.
> >   * @mbox_send: @dev specific transport for transmitting mailbox commands
> >   *
> >   * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
> > @@ -147,6 +164,8 @@ struct cxl_dev_state {
> >  	u64 next_volatile_bytes;
> >  	u64 next_persistent_bytes;
> >  
> > +	struct cxl_endpoint_dvsec_info *info;
> > +
> >  	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
> >  };
> >  
> > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> > index f3872cbee7f8..b3f46045bf3e 100644
> > --- a/drivers/cxl/pci.c
> > +++ b/drivers/cxl/pci.c
> > @@ -452,8 +452,126 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> >  	return rc;
> >  }
> >  
> > +#define CDPD(cxlds, which)                                                     \
> > +	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
> 
> My usual grumble :)  I personally find macros like this a bit of a pain when
> reviewing.  I'd really like to see things spelled out in the code so I
> can immediately see what register we are dealing with even if it does
> seem rather repetitive in the code.

I understand. It's this or have every line look strange because of character
limits.  I agree that whomever writes this stuff can reason it out better, and
that makes it harder on reviewers. I don't mind changing it back, I'd like hear
any other opinions before I do though.

> 
> > +
> > +#define CDPDR(cxlds, which, sorb, lohi)                                        \
> > +	cxlds->device_dvsec +                                                  \
> > +		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
> > +
> > +static int wait_for_valid(struct cxl_dev_state *cxlds)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
> > +	const unsigned long timeout = jiffies + HZ;
> > +	bool valid;
> > +
> > +	do {
> > +		u64 size;
> > +		u32 temp;
> > +		int rc;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
> > +					   &temp);
> > +		if (rc)
> > +			return -ENXIO;
> > +		size = (u64)temp << 32;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
> > +					   &temp);
> > +		if (rc)
> > +			return -ENXIO;
> > +		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
> > +
> > +		/*
> > +		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
> > +		 * Size high and Size Low registers are valid. Must be set
> > +		 * within 1 second of deassertion of reset to CXL device.
> > +		 */
> > +		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
> > +		if (valid)
> > +			break;
> 
> I think there is a race here.  What if you read the high part, get garbage and then
> read the low part which is now valid...
> 
> Swap this around so you read this one first and it will be fine.
> 
> However given as 0-day pointed out, size isn't used, this is fine anyway
> (subject to removing the pointless code).
> 

Yes. I've fixed that. And you're right, size is potentially invalid in this case
even if it found the valid bit.

> > +		cpu_relax();
> > +	} while (!time_after(jiffies, timeout));
> > +
> > +	return valid ? 0 : -ETIMEDOUT;
> > +}
> > +
> > +static struct cxl_endpoint_dvsec_info *dvsec_ranges(struct cxl_dev_state *cxlds)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
> > +	struct cxl_endpoint_dvsec_info *info;
> > +	int hdm_count, rc, i;
> > +	u16 cap, ctrl;
> > +
> > +	rc = pci_read_config_word(pdev, CDPD(cxlds, CAP), &cap);
> > +	if (rc)
> > +		return ERR_PTR(-ENXIO);
> > +	rc = pci_read_config_word(pdev, CDPD(cxlds, CTRL), &ctrl);
> > +	if (rc)
> > +		return ERR_PTR(-ENXIO);
> > +
> > +	if (!(cap & CXL_DVSEC_PCIE_DEVICE_MEM_CAPABLE))
> > +		return ERR_PTR(-ENODEV);
> > +
> > +	/*
> > +	 * It is not allowed by spec for MEM.capable to be set and have 0 HDM
> > +	 * decoders. Therefore, the device is not considered CXL.mem capable.
> > +	 */
> > +	hdm_count = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_HDM_COUNT_MASK, cap);
> > +	if (!hdm_count || hdm_count > 2)
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	rc = wait_for_valid(cxlds);
> > +	if (rc)
> > +		return ERR_PTR(rc);
> > +
> > +	info = devm_kzalloc(cxlds->dev, sizeof(*info), GFP_KERNEL);
> > +	if (!info)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	info->mem_enabled = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_ENABLE, ctrl);
> > +
> > +	for (i = 0; i < hdm_count; i++) {
> > +		u64 base, size;
> > +		u32 temp;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, HIGH),
> > +					   &temp);
> > +		if (rc)
> > +			continue;
> > +		size = (u64)temp << 32;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, LOW),
> > +					   &temp);
> > +		if (rc)
> > +			continue;
> > +		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, HIGH),
> > +					   &temp);
> > +		if (rc)
> > +			continue;
> > +		base = (u64)temp << 32;
> > +
> > +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, LOW),
> > +					   &temp);
> > +		if (rc)
> > +			continue;
> > +		base |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_BASE_LOW_MASK;
> > +
> > +		info->range[i].base = base;
> > +		info->range[i].size = size;
> > +		info->ranges++;
> > +	}
> > +
> > +	return info;
> > +}
> > +
> > +#undef CDPDR
> > +
> >  static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >  {
> > +	struct cxl_endpoint_dvsec_info *info;
> >  	struct cxl_register_map map;
> >  	struct cxl_memdev *cxlmd;
> >  	struct cxl_dev_state *cxlds;
> > @@ -505,6 +623,14 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >  	if (rc)
> >  		return rc;
> >  
> > +	info = dvsec_ranges(cxlds);
> > +	if (IS_ERR(info))
> > +		dev_err(&pdev->dev,
> > +			"Failed to get DVSEC range information (%ld)\n",
> > +			PTR_ERR(info));
> > +	else
> > +		cxlds->info = info;
> > +
> >  	cxlmd = devm_cxl_add_memdev(cxlds);
> >  	if (IS_ERR(cxlmd))
> >  		return PTR_ERR(cxlmd);
> 
> 

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-20  0:02 ` [PATCH 17/23] cxl: Cache and pass DVSEC ranges Ben Widawsky
  2021-11-20  4:29     ` kernel test robot
@ 2021-11-22 17:00   ` Jonathan Cameron
  2021-11-22 22:50     ` Ben Widawsky
  2021-11-26 11:37   ` Jonathan Cameron
  2 siblings, 1 reply; 9+ messages in thread
From: Jonathan Cameron @ 2021-11-22 17:00 UTC (permalink / raw)
  To: Ben Widawsky
  Cc: linux-cxl, linux-pci, Alison Schofield, Dan Williams, Ira Weiny,
	Vishal Verma

On Fri, 19 Nov 2021 16:02:44 -0800
Ben Widawsky <ben.widawsky@intel.com> wrote:

> CXL 1.1 specification provided a mechanism for mapping an address space
> of a CXL device. That functionality is known as a "range" and can be
> programmed through PCIe DVSEC. In addition to this, the specification
> defines an active bit which a device will expose through the same DVSEC
> to notify system software that memory is initialized and ready.
> 
> While CXL 2.0 introduces a more powerful mechanism called HDM decoders
> that are controlled by MMIO behind a PCIe BAR, the spec does allow the
> 1.1 style mapping to still be present. In such a case, when the CXL
> driver takes over, if it were to enable HDM decoding and there was an
> actively used range, things would likely blow up, in particular if it
> wasn't an identical mapping.
> 
> This patch caches the relevant information which the cxl_mem driver will
> need to make the proper decision and passes it along.
> 
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>

0-day spotted issues in same code as me. See below.

This is another case where I'd treat failure as fatal.  Anything that fails
is either dead, or non spec compliant so don't bother loading the driver
if that happens. Fewer paths to test etc...

> ---
>  drivers/cxl/cxlmem.h |  19 +++++++
>  drivers/cxl/pci.c    | 126 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/pci.h    |  13 +++++
>  3 files changed, 158 insertions(+)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 3ef3c652599e..eac5528ccaae 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -89,6 +89,22 @@ struct cxl_mbox_cmd {
>   */
>  #define CXL_CAPACITY_MULTIPLIER SZ_256M
>  
> +/**
> + * struct cxl_endpoint_dvsec_info - Cached DVSEC info
> + * @mem_enabled: cached value of mem_enabled in the DVSEC, PCIE_DEVICE
> + * @ranges: Number of HDM ranges this device contains.
> + * @range.base: cached value of the range base in the DVSEC, PCIE_DEVICE
> + * @range.size: cached value of the range size in the DVSEC, PCIE_DEVICE
> + */
> +struct cxl_endpoint_dvsec_info {
> +	bool mem_enabled;
> +	int ranges;
> +	struct {
> +		u64 base;
> +		u64 size;
> +	} range[2];
> +};
> +
>  /**
>   * struct cxl_dev_state - The driver device state
>   *
> @@ -117,6 +133,7 @@ struct cxl_mbox_cmd {
>   * @active_persistent_bytes: sum of hard + soft persistent
>   * @next_volatile_bytes: volatile capacity change pending device reset
>   * @next_persistent_bytes: persistent capacity change pending device reset
> + * @info: Cached DVSEC information about the device.
>   * @mbox_send: @dev specific transport for transmitting mailbox commands
>   *
>   * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
> @@ -147,6 +164,8 @@ struct cxl_dev_state {
>  	u64 next_volatile_bytes;
>  	u64 next_persistent_bytes;
>  
> +	struct cxl_endpoint_dvsec_info *info;
> +
>  	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
>  };
>  
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index f3872cbee7f8..b3f46045bf3e 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -452,8 +452,126 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
>  	return rc;
>  }
>  
> +#define CDPD(cxlds, which)                                                     \
> +	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET

My usual grumble :)  I personally find macros like this a bit of a pain when
reviewing.  I'd really like to see things spelled out in the code so I
can immediately see what register we are dealing with even if it does
seem rather repetitive in the code.

> +
> +#define CDPDR(cxlds, which, sorb, lohi)                                        \
> +	cxlds->device_dvsec +                                                  \
> +		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
> +
> +static int wait_for_valid(struct cxl_dev_state *cxlds)
> +{
> +	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
> +	const unsigned long timeout = jiffies + HZ;
> +	bool valid;
> +
> +	do {
> +		u64 size;
> +		u32 temp;
> +		int rc;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
> +					   &temp);
> +		if (rc)
> +			return -ENXIO;
> +		size = (u64)temp << 32;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
> +					   &temp);
> +		if (rc)
> +			return -ENXIO;
> +		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
> +
> +		/*
> +		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
> +		 * Size high and Size Low registers are valid. Must be set
> +		 * within 1 second of deassertion of reset to CXL device.
> +		 */
> +		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
> +		if (valid)
> +			break;

I think there is a race here.  What if you read the high part, get garbage and then
read the low part which is now valid...

Swap this around so you read this one first and it will be fine.

However given as 0-day pointed out, size isn't used, this is fine anyway
(subject to removing the pointless code).

> +		cpu_relax();
> +	} while (!time_after(jiffies, timeout));
> +
> +	return valid ? 0 : -ETIMEDOUT;
> +}
> +
> +static struct cxl_endpoint_dvsec_info *dvsec_ranges(struct cxl_dev_state *cxlds)
> +{
> +	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
> +	struct cxl_endpoint_dvsec_info *info;
> +	int hdm_count, rc, i;
> +	u16 cap, ctrl;
> +
> +	rc = pci_read_config_word(pdev, CDPD(cxlds, CAP), &cap);
> +	if (rc)
> +		return ERR_PTR(-ENXIO);
> +	rc = pci_read_config_word(pdev, CDPD(cxlds, CTRL), &ctrl);
> +	if (rc)
> +		return ERR_PTR(-ENXIO);
> +
> +	if (!(cap & CXL_DVSEC_PCIE_DEVICE_MEM_CAPABLE))
> +		return ERR_PTR(-ENODEV);
> +
> +	/*
> +	 * It is not allowed by spec for MEM.capable to be set and have 0 HDM
> +	 * decoders. Therefore, the device is not considered CXL.mem capable.
> +	 */
> +	hdm_count = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_HDM_COUNT_MASK, cap);
> +	if (!hdm_count || hdm_count > 2)
> +		return ERR_PTR(-EINVAL);
> +
> +	rc = wait_for_valid(cxlds);
> +	if (rc)
> +		return ERR_PTR(rc);
> +
> +	info = devm_kzalloc(cxlds->dev, sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return ERR_PTR(-ENOMEM);
> +
> +	info->mem_enabled = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_ENABLE, ctrl);
> +
> +	for (i = 0; i < hdm_count; i++) {
> +		u64 base, size;
> +		u32 temp;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, HIGH),
> +					   &temp);
> +		if (rc)
> +			continue;
> +		size = (u64)temp << 32;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, LOW),
> +					   &temp);
> +		if (rc)
> +			continue;
> +		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, HIGH),
> +					   &temp);
> +		if (rc)
> +			continue;
> +		base = (u64)temp << 32;
> +
> +		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, LOW),
> +					   &temp);
> +		if (rc)
> +			continue;
> +		base |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_BASE_LOW_MASK;
> +
> +		info->range[i].base = base;
> +		info->range[i].size = size;
> +		info->ranges++;
> +	}
> +
> +	return info;
> +}
> +
> +#undef CDPDR
> +
>  static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  {
> +	struct cxl_endpoint_dvsec_info *info;
>  	struct cxl_register_map map;
>  	struct cxl_memdev *cxlmd;
>  	struct cxl_dev_state *cxlds;
> @@ -505,6 +623,14 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	if (rc)
>  		return rc;
>  
> +	info = dvsec_ranges(cxlds);
> +	if (IS_ERR(info))
> +		dev_err(&pdev->dev,
> +			"Failed to get DVSEC range information (%ld)\n",
> +			PTR_ERR(info));
> +	else
> +		cxlds->info = info;
> +
>  	cxlmd = devm_cxl_add_memdev(cxlds);
>  	if (IS_ERR(cxlmd))
>  		return PTR_ERR(cxlmd);



^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-20  0:02 ` [PATCH 17/23] cxl: Cache and pass DVSEC ranges Ben Widawsky
@ 2021-11-20  4:29     ` kernel test robot
  2021-11-22 17:00   ` Jonathan Cameron
  2021-11-26 11:37   ` Jonathan Cameron
  2 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-11-20  4:29 UTC (permalink / raw)
  To: Ben Widawsky, linux-cxl, linux-pci
  Cc: llvm, kbuild-all, Ben Widawsky, Alison Schofield, Dan Williams,
	Ira Weiny, Jonathan Cameron, Vishal Verma

[-- Attachment #1: Type: text/plain, Size: 3171 bytes --]

Hi Ben,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 53989fad1286e652ea3655ae3367ba698da8d2ff]

url:    https://github.com/0day-ci/linux/commits/Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
base:   53989fad1286e652ea3655ae3367ba698da8d2ff
config: riscv-buildonly-randconfig-r001-20211119 (attached as .config)
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
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
        git checkout cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/cxl/pci.c:469:7: warning: variable 'size' set but not used [-Wunused-but-set-variable]
                   u64 size;
                       ^
   1 warning generated.


vim +/size +469 drivers/cxl/pci.c

   454	
   455	#define CDPD(cxlds, which)                                                     \
   456		cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
   457	
   458	#define CDPDR(cxlds, which, sorb, lohi)                                        \
   459		cxlds->device_dvsec +                                                  \
   460			CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
   461	
   462	static int wait_for_valid(struct cxl_dev_state *cxlds)
   463	{
   464		struct pci_dev *pdev = to_pci_dev(cxlds->dev);
   465		const unsigned long timeout = jiffies + HZ;
   466		bool valid;
   467	
   468		do {
 > 469			u64 size;
   470			u32 temp;
   471			int rc;
   472	
   473			rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
   474						   &temp);
   475			if (rc)
   476				return -ENXIO;
   477			size = (u64)temp << 32;
   478	
   479			rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
   480						   &temp);
   481			if (rc)
   482				return -ENXIO;
   483			size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
   484	
   485			/*
   486			 * Memory_Info_Valid: When set, indicates that the CXL Range 1
   487			 * Size high and Size Low registers are valid. Must be set
   488			 * within 1 second of deassertion of reset to CXL device.
   489			 */
   490			valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
   491			if (valid)
   492				break;
   493			cpu_relax();
   494		} while (!time_after(jiffies, timeout));
   495	
   496		return valid ? 0 : -ETIMEDOUT;
   497	}
   498	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 37677 bytes --]

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 17/23] cxl: Cache and pass DVSEC ranges
@ 2021-11-20  4:29     ` kernel test robot
  0 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-11-20  4:29 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 3254 bytes --]

Hi Ben,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 53989fad1286e652ea3655ae3367ba698da8d2ff]

url:    https://github.com/0day-ci/linux/commits/Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
base:   53989fad1286e652ea3655ae3367ba698da8d2ff
config: riscv-buildonly-randconfig-r001-20211119 (attached as .config)
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
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Ben-Widawsky/Add-drivers-for-CXL-ports-and-mem-devices/20211120-080513
        git checkout cfdf51e15fc8229a494ee59d05bc7459ab5eecd8
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/cxl/pci.c:469:7: warning: variable 'size' set but not used [-Wunused-but-set-variable]
                   u64 size;
                       ^
   1 warning generated.


vim +/size +469 drivers/cxl/pci.c

   454	
   455	#define CDPD(cxlds, which)                                                     \
   456		cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
   457	
   458	#define CDPDR(cxlds, which, sorb, lohi)                                        \
   459		cxlds->device_dvsec +                                                  \
   460			CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
   461	
   462	static int wait_for_valid(struct cxl_dev_state *cxlds)
   463	{
   464		struct pci_dev *pdev = to_pci_dev(cxlds->dev);
   465		const unsigned long timeout = jiffies + HZ;
   466		bool valid;
   467	
   468		do {
 > 469			u64 size;
   470			u32 temp;
   471			int rc;
   472	
   473			rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
   474						   &temp);
   475			if (rc)
   476				return -ENXIO;
   477			size = (u64)temp << 32;
   478	
   479			rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
   480						   &temp);
   481			if (rc)
   482				return -ENXIO;
   483			size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
   484	
   485			/*
   486			 * Memory_Info_Valid: When set, indicates that the CXL Range 1
   487			 * Size high and Size Low registers are valid. Must be set
   488			 * within 1 second of deassertion of reset to CXL device.
   489			 */
   490			valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
   491			if (valid)
   492				break;
   493			cpu_relax();
   494		} while (!time_after(jiffies, timeout));
   495	
   496		return valid ? 0 : -ETIMEDOUT;
   497	}
   498	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 37677 bytes --]

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH 17/23] cxl: Cache and pass DVSEC ranges
  2021-11-20  0:02 [PATCH 00/23] Add drivers for CXL ports and mem devices Ben Widawsky
@ 2021-11-20  0:02 ` Ben Widawsky
  2021-11-20  4:29     ` kernel test robot
                     ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: Ben Widawsky @ 2021-11-20  0:02 UTC (permalink / raw)
  To: linux-cxl, linux-pci
  Cc: Ben Widawsky, Alison Schofield, Dan Williams, Ira Weiny,
	Jonathan Cameron, Vishal Verma

CXL 1.1 specification provided a mechanism for mapping an address space
of a CXL device. That functionality is known as a "range" and can be
programmed through PCIe DVSEC. In addition to this, the specification
defines an active bit which a device will expose through the same DVSEC
to notify system software that memory is initialized and ready.

While CXL 2.0 introduces a more powerful mechanism called HDM decoders
that are controlled by MMIO behind a PCIe BAR, the spec does allow the
1.1 style mapping to still be present. In such a case, when the CXL
driver takes over, if it were to enable HDM decoding and there was an
actively used range, things would likely blow up, in particular if it
wasn't an identical mapping.

This patch caches the relevant information which the cxl_mem driver will
need to make the proper decision and passes it along.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
 drivers/cxl/cxlmem.h |  19 +++++++
 drivers/cxl/pci.c    | 126 +++++++++++++++++++++++++++++++++++++++++++
 drivers/cxl/pci.h    |  13 +++++
 3 files changed, 158 insertions(+)

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 3ef3c652599e..eac5528ccaae 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -89,6 +89,22 @@ struct cxl_mbox_cmd {
  */
 #define CXL_CAPACITY_MULTIPLIER SZ_256M
 
+/**
+ * struct cxl_endpoint_dvsec_info - Cached DVSEC info
+ * @mem_enabled: cached value of mem_enabled in the DVSEC, PCIE_DEVICE
+ * @ranges: Number of HDM ranges this device contains.
+ * @range.base: cached value of the range base in the DVSEC, PCIE_DEVICE
+ * @range.size: cached value of the range size in the DVSEC, PCIE_DEVICE
+ */
+struct cxl_endpoint_dvsec_info {
+	bool mem_enabled;
+	int ranges;
+	struct {
+		u64 base;
+		u64 size;
+	} range[2];
+};
+
 /**
  * struct cxl_dev_state - The driver device state
  *
@@ -117,6 +133,7 @@ struct cxl_mbox_cmd {
  * @active_persistent_bytes: sum of hard + soft persistent
  * @next_volatile_bytes: volatile capacity change pending device reset
  * @next_persistent_bytes: persistent capacity change pending device reset
+ * @info: Cached DVSEC information about the device.
  * @mbox_send: @dev specific transport for transmitting mailbox commands
  *
  * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
@@ -147,6 +164,8 @@ struct cxl_dev_state {
 	u64 next_volatile_bytes;
 	u64 next_persistent_bytes;
 
+	struct cxl_endpoint_dvsec_info *info;
+
 	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
 };
 
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index f3872cbee7f8..b3f46045bf3e 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -452,8 +452,126 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
 	return rc;
 }
 
+#define CDPD(cxlds, which)                                                     \
+	cxlds->device_dvsec + CXL_DVSEC_PCIE_DEVICE_##which##_OFFSET
+
+#define CDPDR(cxlds, which, sorb, lohi)                                        \
+	cxlds->device_dvsec +                                                  \
+		CXL_DVSEC_PCIE_DEVICE_RANGE_##sorb##_##lohi##_OFFSET(which)
+
+static int wait_for_valid(struct cxl_dev_state *cxlds)
+{
+	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	const unsigned long timeout = jiffies + HZ;
+	bool valid;
+
+	do {
+		u64 size;
+		u32 temp;
+		int rc;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, HIGH),
+					   &temp);
+		if (rc)
+			return -ENXIO;
+		size = (u64)temp << 32;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, 0, SIZE, LOW),
+					   &temp);
+		if (rc)
+			return -ENXIO;
+		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
+
+		/*
+		 * Memory_Info_Valid: When set, indicates that the CXL Range 1
+		 * Size high and Size Low registers are valid. Must be set
+		 * within 1 second of deassertion of reset to CXL device.
+		 */
+		valid = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID, temp);
+		if (valid)
+			break;
+		cpu_relax();
+	} while (!time_after(jiffies, timeout));
+
+	return valid ? 0 : -ETIMEDOUT;
+}
+
+static struct cxl_endpoint_dvsec_info *dvsec_ranges(struct cxl_dev_state *cxlds)
+{
+	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	struct cxl_endpoint_dvsec_info *info;
+	int hdm_count, rc, i;
+	u16 cap, ctrl;
+
+	rc = pci_read_config_word(pdev, CDPD(cxlds, CAP), &cap);
+	if (rc)
+		return ERR_PTR(-ENXIO);
+	rc = pci_read_config_word(pdev, CDPD(cxlds, CTRL), &ctrl);
+	if (rc)
+		return ERR_PTR(-ENXIO);
+
+	if (!(cap & CXL_DVSEC_PCIE_DEVICE_MEM_CAPABLE))
+		return ERR_PTR(-ENODEV);
+
+	/*
+	 * It is not allowed by spec for MEM.capable to be set and have 0 HDM
+	 * decoders. Therefore, the device is not considered CXL.mem capable.
+	 */
+	hdm_count = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_HDM_COUNT_MASK, cap);
+	if (!hdm_count || hdm_count > 2)
+		return ERR_PTR(-EINVAL);
+
+	rc = wait_for_valid(cxlds);
+	if (rc)
+		return ERR_PTR(rc);
+
+	info = devm_kzalloc(cxlds->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	info->mem_enabled = FIELD_GET(CXL_DVSEC_PCIE_DEVICE_MEM_ENABLE, ctrl);
+
+	for (i = 0; i < hdm_count; i++) {
+		u64 base, size;
+		u32 temp;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, HIGH),
+					   &temp);
+		if (rc)
+			continue;
+		size = (u64)temp << 32;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, SIZE, LOW),
+					   &temp);
+		if (rc)
+			continue;
+		size |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, HIGH),
+					   &temp);
+		if (rc)
+			continue;
+		base = (u64)temp << 32;
+
+		rc = pci_read_config_dword(pdev, CDPDR(cxlds, i, BASE, LOW),
+					   &temp);
+		if (rc)
+			continue;
+		base |= temp & CXL_DVSEC_PCIE_DEVICE_MEM_BASE_LOW_MASK;
+
+		info->range[i].base = base;
+		info->range[i].size = size;
+		info->ranges++;
+	}
+
+	return info;
+}
+
+#undef CDPDR
+
 static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
+	struct cxl_endpoint_dvsec_info *info;
 	struct cxl_register_map map;
 	struct cxl_memdev *cxlmd;
 	struct cxl_dev_state *cxlds;
@@ -505,6 +623,14 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		return rc;
 
+	info = dvsec_ranges(cxlds);
+	if (IS_ERR(info))
+		dev_err(&pdev->dev,
+			"Failed to get DVSEC range information (%ld)\n",
+			PTR_ERR(info));
+	else
+		cxlds->info = info;
+
 	cxlmd = devm_cxl_add_memdev(cxlds);
 	if (IS_ERR(cxlmd))
 		return PTR_ERR(cxlmd);
diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h
index a4b506bb37d1..2a48cd65bf59 100644
--- a/drivers/cxl/pci.h
+++ b/drivers/cxl/pci.h
@@ -15,6 +15,19 @@
 
 /* CXL 2.0 8.1.3: PCIe DVSEC for CXL Device */
 #define CXL_DVSEC_PCIE_DEVICE					0
+#define   CXL_DVSEC_PCIE_DEVICE_CAP_OFFSET			0xA
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_CAPABLE			BIT(2)
+#define     CXL_DVSEC_PCIE_DEVICE_HDM_COUNT_MASK		GENMASK(5, 4)
+#define   CXL_DVSEC_PCIE_DEVICE_CTRL_OFFSET			0xC
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_ENABLE			BIT(2)
+#define   CXL_DVSEC_PCIE_DEVICE_RANGE_SIZE_HIGH_OFFSET(i)	0x18 + (i * 0x10)
+#define   CXL_DVSEC_PCIE_DEVICE_RANGE_SIZE_LOW_OFFSET(i)	0x1C + (i * 0x10)
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_INFO_VALID		BIT(0)
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_ACTIVE			BIT(1)
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_SIZE_LOW_MASK		GENMASK(31, 28)
+#define   CXL_DVSEC_PCIE_DEVICE_RANGE_BASE_HIGH_OFFSET(i)	0x20 + (i * 0x10)
+#define   CXL_DVSEC_PCIE_DEVICE_RANGE_BASE_LOW_OFFSET(i)	0x24 + (i * 0x10)
+#define     CXL_DVSEC_PCIE_DEVICE_MEM_BASE_LOW_MASK		GENMASK(31, 28)
 
 /* CXL 2.0 8.1.4: Non-CXL Function Map DVSEC */
 #define CXL_DVSEC_FUNCTION_MAP					2
-- 
2.34.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2021-11-29  9:40 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-27 18:35 [PATCH 17/23] cxl: Cache and pass DVSEC ranges kernel test robot
2021-11-29  9:39 ` kernel test robot
2021-11-29  9:39   ` kernel test robot
  -- strict thread matches above, loose matches on Subject: below --
2021-11-20  0:02 [PATCH 00/23] Add drivers for CXL ports and mem devices Ben Widawsky
2021-11-20  0:02 ` [PATCH 17/23] cxl: Cache and pass DVSEC ranges Ben Widawsky
2021-11-20  4:29   ` kernel test robot
2021-11-20  4:29     ` kernel test robot
2021-11-22 17:00   ` Jonathan Cameron
2021-11-22 22:50     ` Ben Widawsky
2021-11-26 11:37   ` Jonathan Cameron

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