crypto: ccp - Validate that platform access mailbox registers are declared

Some platforms might support platform access doorbell but not mailbox.
Add an extra guard to ensure this doesn't cause accesses to wrong ranges
if a consumer calls psp_send_platform_access_msg().

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/ccp/platform-access.c b/drivers/crypto/ccp/platform-access.c
index 939c924fc38321a3eb3bd4f54ea23445804df673..94367bc49e35b869dc5093a918c21f325459fce6 100644 (file)
--- a/drivers/crypto/ccp/platform-access.c
+++ b/drivers/crypto/ccp/platform-access.c
@@ -67,6 +67,11 @@ int psp_send_platform_access_msg(enum psp_platform_access_msg msg,
                return -ENODEV;
 
        pa_dev = psp->platform_access_data;
+
+       if (!pa_dev->vdata->cmdresp_reg || !pa_dev->vdata->cmdbuff_addr_lo_reg ||
+           !pa_dev->vdata->cmdbuff_addr_hi_reg)
+               return -ENODEV;
+
        cmd = psp->io_regs + pa_dev->vdata->cmdresp_reg;
        lo = psp->io_regs + pa_dev->vdata->cmdbuff_addr_lo_reg;
        hi = psp->io_regs + pa_dev->vdata->cmdbuff_addr_hi_reg;