diff options
| author | Hook, Gary <Gary.Hook@amd.com> | 2019-07-09 15:07:29 +0000 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-07-26 22:08:04 +1000 |
| commit | 90773bc1ab407bc2198d7e9fc1c6d6b5ef27a24f (patch) | |
| tree | 2abf11361c6e0559b2ab903ff020f38cf5a928d7 /drivers/crypto/ccp | |
| parent | c4a89279086e9c98eba659d7665b1732e0d5e3e3 (diff) | |
crypto: ccp - module parameter to limit the number of enabled CCPs
Provide the ability to constrain the total number of enabled devices in
the system. Once max_devs devices have been configured, subsequently
probed devices are ignored.
The max_devs parameter may be zero, in which case all CCPs are disabled.
PSPs are always enabled and active.
Disabling the CCPs also disables DMA and RNG registration.
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/ccp')
| -rw-r--r-- | drivers/crypto/ccp/ccp-dev.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c index 352059d0c572..e58d69d4dd43 100644 --- a/drivers/crypto/ccp/ccp-dev.c +++ b/drivers/crypto/ccp/ccp-dev.c @@ -2,7 +2,7 @@ /* * AMD Cryptographic Coprocessor (CCP) driver * - * Copyright (C) 2013,2017 Advanced Micro Devices, Inc. + * Copyright (C) 2013,2019 Advanced Micro Devices, Inc. * * Author: Tom Lendacky <thomas.lendacky@amd.com> * Author: Gary R Hook <gary.hook@amd.com> @@ -20,6 +20,7 @@ #include <linux/delay.h> #include <linux/hw_random.h> #include <linux/cpu.h> +#include <linux/atomic.h> #ifdef CONFIG_X86 #include <asm/cpu_device_id.h> #endif @@ -27,11 +28,19 @@ #include "ccp-dev.h" +#define MAX_CCPS 32 + /* Limit CCP use to a specifed number of queues per device */ static unsigned int nqueues = 0; module_param(nqueues, uint, 0444); MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)"); +/* Limit the maximum number of configured CCPs */ +static atomic_t dev_count = ATOMIC_INIT(0); +static unsigned int max_devs = MAX_CCPS; +module_param(max_devs, uint, 0444); +MODULE_PARM_DESC(max_devs, "Maximum number of CCPs to enable (default: all; 0 disables all CCPs)"); + struct ccp_tasklet_data { struct completion completion; struct ccp_cmd *cmd; @@ -592,6 +601,13 @@ int ccp_dev_init(struct sp_device *sp) struct ccp_device *ccp; int ret; + /* + * Check how many we have so far, and stop after reaching + * that number + */ + if (atomic_inc_return(&dev_count) > max_devs) + return 0; /* don't fail the load */ + ret = -ENOMEM; ccp = ccp_alloc_struct(sp); if (!ccp) |