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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/crypto/ccp/platform-access.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/crypto/ccp/platform-access.c')
-rw-r--r--drivers/crypto/ccp/platform-access.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/platform-access.c b/drivers/crypto/ccp/platform-access.c
new file mode 100644
index 0000000000..94367bc49e
--- /dev/null
+++ b/drivers/crypto/ccp/platform-access.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Platform Security Processor (PSP) Platform Access interface
+ *
+ * Copyright (C) 2023 Advanced Micro Devices, Inc.
+ *
+ * Author: Mario Limonciello <mario.limonciello@amd.com>
+ *
+ * Some of this code is adapted from drivers/i2c/busses/i2c-designware-amdpsp.c
+ * developed by Jan Dabros <jsd@semihalf.com> and Copyright (C) 2022 Google Inc.
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/errno.h>
+#include <linux/iopoll.h>
+#include <linux/mutex.h>
+
+#include "platform-access.h"
+
+#define PSP_CMD_TIMEOUT_US (500 * USEC_PER_MSEC)
+#define DOORBELL_CMDRESP_STS GENMASK(7, 0)
+
+/* Recovery field should be equal 0 to start sending commands */
+static int check_recovery(u32 __iomem *cmd)
+{
+ return FIELD_GET(PSP_CMDRESP_RECOVERY, ioread32(cmd));
+}
+
+static int wait_cmd(u32 __iomem *cmd)
+{
+ u32 tmp, expected;
+
+ /* Expect mbox_cmd to be cleared and ready bit to be set by PSP */
+ expected = FIELD_PREP(PSP_CMDRESP_RESP, 1);
+
+ /*
+ * Check for readiness of PSP mailbox in a tight loop in order to
+ * process further as soon as command was consumed.
+ */
+ return readl_poll_timeout(cmd, tmp, (tmp & expected), 0,
+ PSP_CMD_TIMEOUT_US);
+}
+
+int psp_check_platform_access_status(void)
+{
+ struct psp_device *psp = psp_get_master_device();
+
+ if (!psp || !psp->platform_access_data)
+ return -ENODEV;
+
+ return 0;
+}
+EXPORT_SYMBOL(psp_check_platform_access_status);
+
+int psp_send_platform_access_msg(enum psp_platform_access_msg msg,
+ struct psp_request *req)
+{
+ struct psp_device *psp = psp_get_master_device();
+ u32 __iomem *cmd, *lo, *hi;
+ struct psp_platform_access_device *pa_dev;
+ phys_addr_t req_addr;
+ u32 cmd_reg;
+ int ret;
+
+ if (!psp || !psp->platform_access_data)
+ 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;
+
+ mutex_lock(&pa_dev->mailbox_mutex);
+
+ if (check_recovery(cmd)) {
+ dev_dbg(psp->dev, "platform mailbox is in recovery\n");
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (wait_cmd(cmd)) {
+ dev_dbg(psp->dev, "platform mailbox is not done processing command\n");
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ /*
+ * Fill mailbox with address of command-response buffer, which will be
+ * used for sending i2c requests as well as reading status returned by
+ * PSP. Use physical address of buffer, since PSP will map this region.
+ */
+ req_addr = __psp_pa(req);
+ iowrite32(lower_32_bits(req_addr), lo);
+ iowrite32(upper_32_bits(req_addr), hi);
+
+ print_hex_dump_debug("->psp ", DUMP_PREFIX_OFFSET, 16, 2, req,
+ req->header.payload_size, false);
+
+ /* Write command register to trigger processing */
+ cmd_reg = FIELD_PREP(PSP_CMDRESP_CMD, msg);
+ iowrite32(cmd_reg, cmd);
+
+ if (wait_cmd(cmd)) {
+ ret = -ETIMEDOUT;
+ goto unlock;
+ }
+
+ /* Ensure it was triggered by this driver */
+ if (ioread32(lo) != lower_32_bits(req_addr) ||
+ ioread32(hi) != upper_32_bits(req_addr)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ /* Store the status in request header for caller to investigate */
+ cmd_reg = ioread32(cmd);
+ req->header.status = FIELD_GET(PSP_CMDRESP_STS, cmd_reg);
+ if (req->header.status) {
+ ret = -EIO;
+ goto unlock;
+ }
+
+ print_hex_dump_debug("<-psp ", DUMP_PREFIX_OFFSET, 16, 2, req,
+ req->header.payload_size, false);
+
+ ret = 0;
+
+unlock:
+ mutex_unlock(&pa_dev->mailbox_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(psp_send_platform_access_msg);
+
+int psp_ring_platform_doorbell(int msg, u32 *result)
+{
+ struct psp_device *psp = psp_get_master_device();
+ struct psp_platform_access_device *pa_dev;
+ u32 __iomem *button, *cmd;
+ int ret, val;
+
+ if (!psp || !psp->platform_access_data)
+ return -ENODEV;
+
+ pa_dev = psp->platform_access_data;
+ button = psp->io_regs + pa_dev->vdata->doorbell_button_reg;
+ cmd = psp->io_regs + pa_dev->vdata->doorbell_cmd_reg;
+
+ mutex_lock(&pa_dev->doorbell_mutex);
+
+ if (wait_cmd(cmd)) {
+ dev_err(psp->dev, "doorbell command not done processing\n");
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ iowrite32(FIELD_PREP(DOORBELL_CMDRESP_STS, msg), cmd);
+ iowrite32(PSP_DRBL_RING, button);
+
+ if (wait_cmd(cmd)) {
+ ret = -ETIMEDOUT;
+ goto unlock;
+ }
+
+ val = FIELD_GET(DOORBELL_CMDRESP_STS, ioread32(cmd));
+ if (val) {
+ if (result)
+ *result = val;
+ ret = -EIO;
+ goto unlock;
+ }
+
+ ret = 0;
+unlock:
+ mutex_unlock(&pa_dev->doorbell_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(psp_ring_platform_doorbell);
+
+void platform_access_dev_destroy(struct psp_device *psp)
+{
+ struct psp_platform_access_device *pa_dev = psp->platform_access_data;
+
+ if (!pa_dev)
+ return;
+
+ mutex_destroy(&pa_dev->mailbox_mutex);
+ mutex_destroy(&pa_dev->doorbell_mutex);
+ psp->platform_access_data = NULL;
+}
+
+int platform_access_dev_init(struct psp_device *psp)
+{
+ struct device *dev = psp->dev;
+ struct psp_platform_access_device *pa_dev;
+
+ pa_dev = devm_kzalloc(dev, sizeof(*pa_dev), GFP_KERNEL);
+ if (!pa_dev)
+ return -ENOMEM;
+
+ psp->platform_access_data = pa_dev;
+ pa_dev->psp = psp;
+ pa_dev->dev = dev;
+
+ pa_dev->vdata = (struct platform_access_vdata *)psp->vdata->platform_access;
+
+ mutex_init(&pa_dev->mailbox_mutex);
+ mutex_init(&pa_dev->doorbell_mutex);
+
+ dev_dbg(dev, "platform access enabled\n");
+
+ return 0;
+}