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, 39 insertions, 14 deletions

diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index efe8af9d7c7e..e80d8f7d4dcb 100644
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c
@@ -795,26 +795,38 @@ static int native_get_irq_info(struct cxl_afu *afu, struct cxl_irq_info *info)
 	return 0;
 }
 
-static irqreturn_t native_handle_psl_slice_error(struct cxl_context *ctx,
-						u64 dsisr, u64 errstat)
+void cxl_native_psl_irq_dump_regs(struct cxl_context *ctx)
 {
 	u64 fir1, fir2, fir_slice, serr, afu_debug;
 
 	fir1 = cxl_p1_read(ctx->afu->adapter, CXL_PSL_FIR1);
 	fir2 = cxl_p1_read(ctx->afu->adapter, CXL_PSL_FIR2);
 	fir_slice = cxl_p1n_read(ctx->afu, CXL_PSL_FIR_SLICE_An);
-	serr = cxl_p1n_read(ctx->afu, CXL_PSL_SERR_An);
 	afu_debug = cxl_p1n_read(ctx->afu, CXL_AFU_DEBUG_An);
 
-	dev_crit(&ctx->afu->dev, "PSL ERROR STATUS: 0x%016llx\n", errstat);
 	dev_crit(&ctx->afu->dev, "PSL_FIR1: 0x%016llx\n", fir1);
 	dev_crit(&ctx->afu->dev, "PSL_FIR2: 0x%016llx\n", fir2);
-	dev_crit(&ctx->afu->dev, "PSL_SERR_An: 0x%016llx\n", serr);
+	if (ctx->afu->adapter->native->sl_ops->register_serr_irq) {
+		serr = cxl_p1n_read(ctx->afu, CXL_PSL_SERR_An);
+		dev_crit(&ctx->afu->dev, "PSL_SERR_An: 0x%016llx\n", serr);
+	}
 	dev_crit(&ctx->afu->dev, "PSL_FIR_SLICE_An: 0x%016llx\n", fir_slice);
 	dev_crit(&ctx->afu->dev, "CXL_PSL_AFU_DEBUG_An: 0x%016llx\n", afu_debug);
+}
+
+static irqreturn_t native_handle_psl_slice_error(struct cxl_context *ctx,
+						u64 dsisr, u64 errstat)
+{
+
+	dev_crit(&ctx->afu->dev, "PSL ERROR STATUS: 0x%016llx\n", errstat);
 
-	dev_crit(&ctx->afu->dev, "STOPPING CXL TRACE\n");
-	cxl_stop_trace(ctx->afu->adapter);
+	if (ctx->afu->adapter->native->sl_ops->psl_irq_dump_registers)
+		ctx->afu->adapter->native->sl_ops->psl_irq_dump_registers(ctx);
+
+	if (ctx->afu->adapter->native->sl_ops->debugfs_stop_trace) {
+		dev_crit(&ctx->afu->dev, "STOPPING CXL TRACE\n");
+		ctx->afu->adapter->native->sl_ops->debugfs_stop_trace(ctx->afu->adapter);
+	}
 
 	return cxl_ops->ack_irq(ctx, 0, errstat);
 }
@@ -892,6 +904,9 @@ static irqreturn_t native_slice_irq_err(int irq, void *data)
 	struct cxl_afu *afu = data;
 	u64 fir_slice, errstat, serr, afu_debug;
 
+	/*
+	 * slice err interrupt is only used with full PSL (no XSL)
+	 */
 	WARN(irq, "CXL SLICE ERROR interrupt %i\n", irq);
 
 	serr = cxl_p1n_read(afu, CXL_PSL_SERR_An);
@@ -908,23 +923,33 @@ static irqreturn_t native_slice_irq_err(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+void cxl_native_err_irq_dump_regs(struct cxl *adapter)
+{
+	u64 fir1, fir2;
+
+	fir1 = cxl_p1_read(adapter, CXL_PSL_FIR1);
+	fir2 = cxl_p1_read(adapter, CXL_PSL_FIR2);
+
+	dev_crit(&adapter->dev, "PSL_FIR1: 0x%016llx\nPSL_FIR2: 0x%016llx\n", fir1, fir2);
+}
+
 static irqreturn_t native_irq_err(int irq, void *data)
 {
 	struct cxl *adapter = data;
-	u64 fir1, fir2, err_ivte;
+	u64 err_ivte;
 
 	WARN(1, "CXL ERROR interrupt %i\n", irq);
 
 	err_ivte = cxl_p1_read(adapter, CXL_PSL_ErrIVTE);
 	dev_crit(&adapter->dev, "PSL_ErrIVTE: 0x%016llx\n", err_ivte);
 
-	dev_crit(&adapter->dev, "STOPPING CXL TRACE\n");
-	cxl_stop_trace(adapter);
-
-	fir1 = cxl_p1_read(adapter, CXL_PSL_FIR1);
-	fir2 = cxl_p1_read(adapter, CXL_PSL_FIR2);
+	if (adapter->native->sl_ops->debugfs_stop_trace) {
+		dev_crit(&adapter->dev, "STOPPING CXL TRACE\n");
+		adapter->native->sl_ops->debugfs_stop_trace(adapter);
+	}
 
-	dev_crit(&adapter->dev, "PSL_FIR1: 0x%016llx\nPSL_FIR2: 0x%016llx\n", fir1, fir2);
+	if (adapter->native->sl_ops->err_irq_dump_registers)
+		adapter->native->sl_ops->err_irq_dump_registers(adapter);
 
 	return IRQ_HANDLED;
 }