From 390fd5929f52bdfb9dfcc03820041ba556780f4a Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Fri, 28 Aug 2015 09:37:36 +0200 Subject: [PATCH] cxl: Set up and enable PSL Timebase This patch configures the PSL Timebase function and enables it, after the CAPP has been initialized by OPAL. Acked-by: Ian Munsie Signed-off-by: Philippe Bergheaud Signed-off-by: Michael Ellerman --- drivers/misc/cxl/cxl.h | 5 ++++ drivers/misc/cxl/pci.c | 57 +++++++++++++++++++++++++++++++++++++++++- 2 files changed, 61 insertions(+), 1 deletion(-) diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index d6566c60bcb0..1c30ef77073d 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -83,8 +83,10 @@ static const cxl_p1_reg_t CXL_PSL_AFUSEL = {0x00B0}; /* 0x00C0:7EFF Implementation dependent area */ static const cxl_p1_reg_t CXL_PSL_FIR1 = {0x0100}; static const cxl_p1_reg_t CXL_PSL_FIR2 = {0x0108}; +static const cxl_p1_reg_t CXL_PSL_Timebase = {0x0110}; static const cxl_p1_reg_t CXL_PSL_VERSION = {0x0118}; static const cxl_p1_reg_t CXL_PSL_RESLCKTO = {0x0128}; +static const cxl_p1_reg_t CXL_PSL_TB_CTLSTAT = {0x0140}; static const cxl_p1_reg_t CXL_PSL_FIR_CNTL = {0x0148}; static const cxl_p1_reg_t CXL_PSL_DSNDCTL = {0x0150}; static const cxl_p1_reg_t CXL_PSL_SNWRALLOC = {0x0158}; @@ -152,6 +154,9 @@ static const cxl_p2n_reg_t CXL_PSL_WED_An = {0x0A0}; #define CXL_PSL_SPAP_Size_Shift 4 #define CXL_PSL_SPAP_V 0x0000000000000001ULL +/****** CXL_PSL_Control ****************************************************/ +#define CXL_PSL_Control_tb 0x0000000000000001ULL + /****** CXL_PSL_DLCNTL *****************************************************/ #define CXL_PSL_DLCNTL_D (0x1ull << (63-28)) #define CXL_PSL_DLCNTL_C (0x1ull << (63-29)) diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 6ca7c3d0ef9b..02c85160bfe9 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -370,6 +370,55 @@ static int init_implementation_adapter_regs(struct cxl *adapter, struct pci_dev return 0; } +#define TBSYNC_CNT(n) (((u64)n & 0x7) << (63-6)) +#define _2048_250MHZ_CYCLES 1 + +static int cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev) +{ + u64 psl_tb; + int delta; + unsigned int retry = 0; + struct device_node *np; + + if (!(np = pnv_pci_get_phb_node(dev))) + return -ENODEV; + + /* Do not fail when CAPP timebase sync is not supported by OPAL */ + of_node_get(np); + if (! of_get_property(np, "ibm,capp-timebase-sync", NULL)) { + of_node_put(np); + pr_err("PSL: Timebase sync: OPAL support missing\n"); + return 0; + } + of_node_put(np); + + /* + * Setup PSL Timebase Control and Status register + * with the recommended Timebase Sync Count value + */ + cxl_p1_write(adapter, CXL_PSL_TB_CTLSTAT, + TBSYNC_CNT(2 * _2048_250MHZ_CYCLES)); + + /* Enable PSL Timebase */ + cxl_p1_write(adapter, CXL_PSL_Control, 0x0000000000000000); + cxl_p1_write(adapter, CXL_PSL_Control, CXL_PSL_Control_tb); + + /* Wait until CORE TB and PSL TB difference <= 16usecs */ + do { + msleep(1); + if (retry++ > 5) { + pr_err("PSL: Timebase sync: giving up!\n"); + return -EIO; + } + psl_tb = cxl_p1_read(adapter, CXL_PSL_Timebase); + delta = mftb() - psl_tb; + if (delta < 0) + delta = -delta; + } while (cputime_to_usecs(delta) > 16); + + return 0; +} + static int init_implementation_afu_regs(struct cxl_afu *afu) { /* read/write masks for this slice */ @@ -1053,9 +1102,12 @@ static struct cxl *cxl_alloc_adapter(void) return NULL; } +#define CXL_PSL_ErrIVTE_tberror (0x1ull << (63-31)) + static int sanitise_adapter_regs(struct cxl *adapter) { - cxl_p1_write(adapter, CXL_PSL_ErrIVTE, 0x0000000000000000); + /* Clear PSL tberror bit by writing 1 to it */ + cxl_p1_write(adapter, CXL_PSL_ErrIVTE, CXL_PSL_ErrIVTE_tberror); return cxl_tlb_slb_invalidate(adapter); } @@ -1108,6 +1160,9 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev) if ((rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON))) goto err; + if ((rc = cxl_setup_psl_timebase(adapter, dev))) + goto err; + if ((rc = cxl_register_psl_err_irq(adapter))) goto err; -- GitLab