cxl: Abstract the differences between the PSL and XSL

The XSL (Translation Service Layer) is a stripped down version of the
PSL (Power Service Layer) used in some cards such as the Mellanox CX4.

Like the PSL, it implements the CAIA architecture, but has a number of
differences, mostly in it's implementation dependent registers. This
adds an ops structure to abstract these differences to bring initial
support for XSL CAPI devices.

The XSL does not implement the optional architected SERR register,
however while it treats it as a reserved register and should work with
no special treatment, attempting to access it will cause the XSL_FEC
(First Error Capture) register to be filled out, preventing it from
capturing any subsequent errors. Therefore, this patch also prevents the
kernel from trying to set up the SERR register so that the FEC register
may still be useful, and to save one interrupt.

The XSL also uses a special DMA cxl mode, which uses a slightly
different init sequence for the CAPP and PHB. The kernel support for
this will be in a future patch once the corresponding support has been
merged into skiboot.

Co-authored-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 25 insertions, 10 deletions

diff --git a/drivers/misc/cxl/debugfs.c b/drivers/misc/cxl/debugfs.c
index 5751899e0c17..ec7b8a017439 100644
--- a/drivers/misc/cxl/debugfs.c
+++ b/drivers/misc/cxl/debugfs.c
@@ -51,6 +51,19 @@ static struct dentry *debugfs_create_io_x64(const char *name, umode_t mode,
 	return debugfs_create_file(name, mode, parent, (void __force *)value, &fops_io_x64);
 }
 
+void cxl_debugfs_add_adapter_psl_regs(struct cxl *adapter, struct dentry *dir)
+{
+	debugfs_create_io_x64("fir1", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR1));
+	debugfs_create_io_x64("fir2", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR2));
+	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR_CNTL));
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_TRACE));
+}
+
+void cxl_debugfs_add_adapter_xsl_regs(struct cxl *adapter, struct dentry *dir)
+{
+	debugfs_create_io_x64("fec", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_XSL_FEC));
+}
+
 int cxl_debugfs_adapter_add(struct cxl *adapter)
 {
 	struct dentry *dir;
@@ -65,13 +78,10 @@ int cxl_debugfs_adapter_add(struct cxl *adapter)
 		return PTR_ERR(dir);
 	adapter->debugfs = dir;
 
-	debugfs_create_io_x64("fir1",     S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR1));
-	debugfs_create_io_x64("fir2",     S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR2));
-	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR_CNTL));
 	debugfs_create_io_x64("err_ivte", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_ErrIVTE));
 
-	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_TRACE));
-
+	if (adapter->native->sl_ops->debugfs_add_adapter_sl_regs)
+		adapter->native->sl_ops->debugfs_add_adapter_sl_regs(adapter, dir);
 	return 0;
 }
 
@@ -80,6 +90,14 @@ void cxl_debugfs_adapter_remove(struct cxl *adapter)
 	debugfs_remove_recursive(adapter->debugfs);
 }
 
+void cxl_debugfs_add_afu_psl_regs(struct cxl_afu *afu, struct dentry *dir)
+{
+	debugfs_create_io_x64("fir", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_FIR_SLICE_An));
+	debugfs_create_io_x64("serr", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SERR_An));
+	debugfs_create_io_x64("afu_debug", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_AFU_DEBUG_An));
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SLICE_TRACE));
+}
+
 int cxl_debugfs_afu_add(struct cxl_afu *afu)
 {
 	struct dentry *dir;
@@ -94,18 +112,15 @@ int cxl_debugfs_afu_add(struct cxl_afu *afu)
 		return PTR_ERR(dir);
 	afu->debugfs = dir;
 
-	debugfs_create_io_x64("fir",        S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_FIR_SLICE_An));
-	debugfs_create_io_x64("serr",       S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SERR_An));
-	debugfs_create_io_x64("afu_debug",  S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_AFU_DEBUG_An));
 	debugfs_create_io_x64("sr",         S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SR_An));
-
 	debugfs_create_io_x64("dsisr",      S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DSISR_An));
 	debugfs_create_io_x64("dar",        S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DAR_An));
 	debugfs_create_io_x64("sstp0",      S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_SSTP0_An));
 	debugfs_create_io_x64("sstp1",      S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_SSTP1_An));
 	debugfs_create_io_x64("err_status", S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_ErrStat_An));
 
-	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SLICE_TRACE));
+	if (afu->adapter->native->sl_ops->debugfs_add_afu_sl_regs)
+		afu->adapter->native->sl_ops->debugfs_add_afu_sl_regs(afu, dir);
 
 	return 0;
 }