diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-amdpsp.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-amdpsp.c | 205 |
1 files changed, 49 insertions, 156 deletions
diff --git a/drivers/i2c/busses/i2c-designware-amdpsp.c b/drivers/i2c/busses/i2c-designware-amdpsp.c index 8f36167bce62..63454b06e5da 100644 --- a/drivers/i2c/busses/i2c-designware-amdpsp.c +++ b/drivers/i2c/busses/i2c-designware-amdpsp.c @@ -1,41 +1,21 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/bitfield.h> -#include <linux/bits.h> #include <linux/i2c.h> -#include <linux/io-64-nonatomic-lo-hi.h> -#include <linux/psp-sev.h> -#include <linux/types.h> +#include <linux/pci.h> +#include <linux/psp-platform-access.h> +#include <linux/psp.h> #include <linux/workqueue.h> -#include <asm/msr.h> - #include "i2c-designware-core.h" -#define MSR_AMD_PSP_ADDR 0xc00110a2 -#define PSP_MBOX_OFFSET 0x10570 -#define PSP_CMD_TIMEOUT_US (500 * USEC_PER_MSEC) - #define PSP_I2C_RESERVATION_TIME_MS 100 -#define PSP_I2C_REQ_BUS_CMD 0x64 #define PSP_I2C_REQ_RETRY_CNT 400 #define PSP_I2C_REQ_RETRY_DELAY_US (25 * USEC_PER_MSEC) #define PSP_I2C_REQ_STS_OK 0x0 #define PSP_I2C_REQ_STS_BUS_BUSY 0x1 #define PSP_I2C_REQ_STS_INV_PARAM 0x3 -#define PSP_MBOX_FIELDS_STS GENMASK(15, 0) -#define PSP_MBOX_FIELDS_CMD GENMASK(23, 16) -#define PSP_MBOX_FIELDS_RESERVED GENMASK(29, 24) -#define PSP_MBOX_FIELDS_RECOVERY BIT(30) -#define PSP_MBOX_FIELDS_READY BIT(31) - -struct psp_req_buffer_hdr { - u32 total_size; - u32 status; -}; - enum psp_i2c_req_type { PSP_I2C_REQ_ACQUIRE, PSP_I2C_REQ_RELEASE, @@ -47,118 +27,13 @@ struct psp_i2c_req { enum psp_i2c_req_type type; }; -struct psp_mbox { - u32 cmd_fields; - u64 i2c_req_addr; -} __packed; - static DEFINE_MUTEX(psp_i2c_access_mutex); static unsigned long psp_i2c_sem_acquired; -static void __iomem *mbox_iomem; static u32 psp_i2c_access_count; static bool psp_i2c_mbox_fail; static struct device *psp_i2c_dev; -/* - * Implementation of PSP-x86 i2c-arbitration mailbox introduced for AMD Cezanne - * family of SoCs. - */ - -static int psp_get_mbox_addr(unsigned long *mbox_addr) -{ - unsigned long long psp_mmio; - - if (rdmsrl_safe(MSR_AMD_PSP_ADDR, &psp_mmio)) - return -EIO; - - *mbox_addr = (unsigned long)(psp_mmio + PSP_MBOX_OFFSET); - - return 0; -} - -static int psp_mbox_probe(void) -{ - unsigned long mbox_addr; - int ret; - - ret = psp_get_mbox_addr(&mbox_addr); - if (ret) - return ret; - - mbox_iomem = ioremap(mbox_addr, sizeof(struct psp_mbox)); - if (!mbox_iomem) - return -ENOMEM; - - return 0; -} - -/* Recovery field should be equal 0 to start sending commands */ -static int psp_check_mbox_recovery(struct psp_mbox __iomem *mbox) -{ - u32 tmp; - - tmp = readl(&mbox->cmd_fields); - - return FIELD_GET(PSP_MBOX_FIELDS_RECOVERY, tmp); -} - -static int psp_wait_cmd(struct psp_mbox __iomem *mbox) -{ - u32 tmp, expected; - - /* Expect mbox_cmd to be cleared and ready bit to be set by PSP */ - expected = FIELD_PREP(PSP_MBOX_FIELDS_READY, 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(&mbox->cmd_fields, tmp, (tmp == expected), - 0, PSP_CMD_TIMEOUT_US); -} - -/* Status equal to 0 means that PSP succeed processing command */ -static u32 psp_check_mbox_sts(struct psp_mbox __iomem *mbox) -{ - u32 cmd_reg; - - cmd_reg = readl(&mbox->cmd_fields); - - return FIELD_GET(PSP_MBOX_FIELDS_STS, cmd_reg); -} - -static int psp_send_cmd(struct psp_i2c_req *req) -{ - struct psp_mbox __iomem *mbox = mbox_iomem; - phys_addr_t req_addr; - u32 cmd_reg; - - if (psp_check_mbox_recovery(mbox)) - return -EIO; - - if (psp_wait_cmd(mbox)) - return -EBUSY; - - /* - * 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((void *)req); - writeq(req_addr, &mbox->i2c_req_addr); - - /* Write command register to trigger processing */ - cmd_reg = FIELD_PREP(PSP_MBOX_FIELDS_CMD, PSP_I2C_REQ_BUS_CMD); - writel(cmd_reg, &mbox->cmd_fields); - - if (psp_wait_cmd(mbox)) - return -ETIMEDOUT; - - if (psp_check_mbox_sts(mbox)) - return -EIO; - - return 0; -} +static int (*_psp_send_i2c_req)(struct psp_i2c_req *req); /* Helper to verify status returned by PSP */ static int check_i2c_req_sts(struct psp_i2c_req *req) @@ -179,22 +54,36 @@ static int check_i2c_req_sts(struct psp_i2c_req *req) } } -static int psp_send_check_i2c_req(struct psp_i2c_req *req) +/* + * Errors in x86-PSP i2c-arbitration protocol may occur at two levels: + * 1. mailbox communication - PSP is not operational or some IO errors with + * basic communication had happened. + * 2. i2c-requests - PSP refuses to grant i2c arbitration to x86 for too long. + * + * In order to distinguish between these in error handling code all mailbox + * communication errors on the first level (from CCP symbols) will be passed + * up and if -EIO is returned the second level will be checked. + */ +static int psp_send_i2c_req_cezanne(struct psp_i2c_req *req) { - /* - * Errors in x86-PSP i2c-arbitration protocol may occur at two levels: - * 1. mailbox communication - PSP is not operational or some IO errors - * with basic communication had happened; - * 2. i2c-requests - PSP refuses to grant i2c arbitration to x86 for too - * long. - * In order to distinguish between these two in error handling code, all - * errors on the first level (returned by psp_send_cmd) are shadowed by - * -EIO. - */ - if (psp_send_cmd(req)) - return -EIO; + int ret; + + ret = psp_send_platform_access_msg(PSP_I2C_REQ_BUS_CMD, (struct psp_request *)req); + if (ret == -EIO) + return check_i2c_req_sts(req); - return check_i2c_req_sts(req); + return ret; +} + +static int psp_send_i2c_req_doorbell(struct psp_i2c_req *req) +{ + int ret; + + ret = psp_ring_platform_doorbell(req->type, &req->hdr.status); + if (ret == -EIO) + return check_i2c_req_sts(req); + + return ret; } static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type) @@ -208,11 +97,11 @@ static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type) if (!req) return -ENOMEM; - req->hdr.total_size = sizeof(*req); + req->hdr.payload_size = sizeof(*req); req->type = i2c_req_type; start = jiffies; - ret = read_poll_timeout(psp_send_check_i2c_req, status, + ret = read_poll_timeout(_psp_send_i2c_req, status, (status != -EBUSY), PSP_I2C_REQ_RETRY_DELAY_US, PSP_I2C_REQ_RETRY_CNT * PSP_I2C_REQ_RETRY_DELAY_US, @@ -387,7 +276,10 @@ static const struct i2c_lock_operations i2c_dw_psp_lock_ops = { int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) { - int ret; + struct pci_dev *rdev; + + if (!IS_REACHABLE(CONFIG_CRYPTO_DEV_CCP_DD)) + return -ENODEV; if (!dev) return -ENODEV; @@ -399,11 +291,18 @@ int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) if (psp_i2c_dev) return -EEXIST; - psp_i2c_dev = dev->dev; + /* Cezanne uses platform mailbox, Mendocino and later use doorbell */ + rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0)); + if (rdev->device == 0x1630) + _psp_send_i2c_req = psp_send_i2c_req_cezanne; + else + _psp_send_i2c_req = psp_send_i2c_req_doorbell; + pci_dev_put(rdev); - ret = psp_mbox_probe(); - if (ret) - return ret; + if (psp_check_platform_access_status()) + return -EPROBE_DEFER; + + psp_i2c_dev = dev->dev; dev_info(psp_i2c_dev, "I2C bus managed by AMD PSP\n"); @@ -417,9 +316,3 @@ int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) return 0; } - -/* Unmap area used as a mailbox with PSP */ -void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev) -{ - iounmap(mbox_iomem); -} |