cxl: Provide debugfs access to PSL_DEBUG/XSL_DEBUG registers

Access to PSL/XSL_DEBUG registers on the adapter provides easy access
to the debug facilities provided by PSL/XSL. So this patch adds two
new files (debug, xsl-debug) to the cxl-adapter specific debugfs
folder located at /sys/kernel/debugfs/cxl/card<n>, which will provide
direct r/w access to corrosponding debug registers in the adapter
config-space.

Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/cxl.h

@@ -101,6 +101,7 @@ static const cxl_p1_reg_t CXL_XSL_DSNCTL    = {0x0168};
 /* PSL registers - CAIA 2 */
 static const cxl_p1_reg_t CXL_PSL9_CONTROL  = {0x0020};
 static const cxl_p1_reg_t CXL_XSL9_INV      = {0x0110};
+static const cxl_p1_reg_t CXL_XSL9_DBG      = {0x0130};
 static const cxl_p1_reg_t CXL_XSL9_DEF      = {0x0140};
 static const cxl_p1_reg_t CXL_XSL9_DSNCTL   = {0x0168};
 static const cxl_p1_reg_t CXL_PSL9_FIR1     = {0x0300};

drivers/misc/cxl/debugfs.c

@@ -66,6 +66,10 @@ void cxl_debugfs_add_adapter_regs_psl9(struct cxl *adapter, struct dentry *dir)
 			      _cxl_p1_addr(adapter, CXL_PSL9_FIR_MASK));
 	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL9_FIR_CNTL));
 	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL9_TRACECFG));
+	debugfs_create_io_x64("debug", 0600, dir,
+			      _cxl_p1_addr(adapter, CXL_PSL9_DEBUG));
+	debugfs_create_io_x64("xsl-debug", 0600, dir,
+			      _cxl_p1_addr(adapter, CXL_XSL9_DBG));
 }
 
 void cxl_debugfs_add_adapter_regs_psl8(struct cxl *adapter, struct dentry *dir)