diff options
author | Vaibhav Jain <vaibhav@linux.vnet.ibm.com> | 2018-02-15 21:19:24 +0530 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-03-13 15:50:26 +1100 |
commit | 94322ed8e857e3b2a33cf75118051af9baaa110f (patch) | |
tree | 0f4e6b8b5a5cb61192a2242ca4a56ef2b2e6a9d8 /drivers/misc/cxl | |
parent | 02b63b420223db3e33e19cc0aaf346371e8efe48 (diff) | |
download | linux-94322ed8e857e3b2a33cf75118051af9baaa110f.tar.bz2 |
cxl: Check if PSL data-cache is available before issue flush request
PSL9D doesn't have a data-cache that needs to be flushed before
resetting the card. However when cxl tries to flush data-cache on such
a card, it times-out as PSL_Control register never indicates flush
operation complete due to missing data-cache. This is usually
indicated in the kernel logs with this message:
"WARNING: cache flush timed out"
To fix this the patch checks PSL_Debug register CDC-Field(BIT:27)
which indicates the absence of a data-cache and sets a flag
'no_data_cache' in 'struct cxl_native' to indicate this. When
cxl_data_cache_flush() is called it checks the flag and if set bails
out early without requesting a data-cache flush operation to the PSL.
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>
Diffstat (limited to 'drivers/misc/cxl')
-rw-r--r-- | drivers/misc/cxl/cxl.h | 4 | ||||
-rw-r--r-- | drivers/misc/cxl/native.c | 11 | ||||
-rw-r--r-- | drivers/misc/cxl/pci.c | 19 |
3 files changed, 27 insertions, 7 deletions
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index 4f015da78f28..4949b8d5a748 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -369,6 +369,9 @@ static const cxl_p2n_reg_t CXL_PSL_WED_An = {0x0A0}; #define CXL_PSL_TFC_An_AE (1ull << (63-30)) /* Restart PSL with address error */ #define CXL_PSL_TFC_An_R (1ull << (63-31)) /* Restart PSL transaction */ +/****** CXL_PSL_DEBUG *****************************************************/ +#define CXL_PSL_DEBUG_CDC (1ull << (63-27)) /* Coherent Data cache support */ + /****** CXL_XSL9_IERAT_ERAT - CAIA 2 **********************************/ #define CXL_XSL9_IERAT_MLPID (1ull << (63-0)) /* Match LPID */ #define CXL_XSL9_IERAT_MPID (1ull << (63-1)) /* Match PID */ @@ -669,6 +672,7 @@ struct cxl_native { irq_hw_number_t err_hwirq; unsigned int err_virq; u64 ps_off; + bool no_data_cache; /* set if no data cache on the card */ const struct cxl_service_layer_ops *sl_ops; }; diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c index 1b3d7c65ea3f..98f867fcef24 100644 --- a/drivers/misc/cxl/native.c +++ b/drivers/misc/cxl/native.c @@ -353,8 +353,17 @@ int cxl_data_cache_flush(struct cxl *adapter) u64 reg; unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT); - pr_devel("Flushing data cache\n"); + /* + * Do a datacache flush only if datacache is available. + * In case of PSL9D datacache absent hence flush operation. + * would timeout. + */ + if (adapter->native->no_data_cache) { + pr_devel("No PSL data cache. Ignoring cache flush req.\n"); + return 0; + } + pr_devel("Flushing data cache\n"); reg = cxl_p1_read(adapter, CXL_PSL_Control); reg |= CXL_PSL_Control_Fr; cxl_p1_write(adapter, CXL_PSL_Control, reg); diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 9bc30c20b66b..35f486912ddc 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -456,6 +456,7 @@ static int init_implementation_adapter_regs_psl9(struct cxl *adapter, u64 chipid; u32 phb_index; u64 capp_unit_id; + u64 psl_debug; int rc; rc = cxl_calc_capp_routing(dev, &chipid, &phb_index, &capp_unit_id); @@ -510,6 +511,16 @@ static int init_implementation_adapter_regs_psl9(struct cxl *adapter, cxl_p1_write(adapter, CXL_PSL9_DEBUG, 0xC000000000000000ULL); } + /* + * Check if PSL has data-cache. We need to flush adapter datacache + * when as its about to be removed. + */ + psl_debug = cxl_p1_read(adapter, CXL_PSL9_DEBUG); + if (psl_debug & CXL_PSL_DEBUG_CDC) { + dev_dbg(&dev->dev, "No data-cache present\n"); + adapter->native->no_data_cache = true; + } + return 0; } @@ -1448,10 +1459,8 @@ int cxl_pci_reset(struct cxl *adapter) /* * The adapter is about to be reset, so ignore errors. - * Not supported on P9 DD1 */ - if ((cxl_is_power8()) || (!(cxl_is_power9_dd1()))) - cxl_data_cache_flush(adapter); + cxl_data_cache_flush(adapter); /* pcie_warm_reset requests a fundamental pci reset which includes a * PERST assert/deassert. PERST triggers a loading of the image @@ -1934,10 +1943,8 @@ static void cxl_pci_remove_adapter(struct cxl *adapter) /* * Flush adapter datacache as its about to be removed. - * Not supported on P9 DD1. */ - if ((cxl_is_power8()) || (!(cxl_is_power9_dd1()))) - cxl_data_cache_flush(adapter); + cxl_data_cache_flush(adapter); cxl_deconfigure_adapter(adapter); |