Message ID | 20230322210227.464-1-mario.limonciello@amd.com |
---|---|
Headers | show |
Series | Use CCP driver to handle PSP I2C arbitration | expand |
On Wed, Mar 22, 2023 at 04:02:25PM -0500, Mario Limonciello wrote: > Currently the PSP semaphore communication base address is discovered > by using an MSR that is not architecturally guaranteed for future > platforms. Also the mailbox that is utilized for communication with > the PSP may have other consumers in the kernel, so it's better to > make all communication go through a single driver. Fine by me, Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > --- > v5->v6: > * Drop now unnecessary asm/msr.h header > * Fix IS_REACHABLE > * Drop tags > * Fix status code handling for Cezanne > v4->v5: > * Pick up tags > v3->v4: > * Pick up tags > v1->v2: > * Fix Kconfig to use imply > * Use IS_REACHABLE > --- > drivers/i2c/busses/Kconfig | 2 +- > drivers/i2c/busses/i2c-designware-amdpsp.c | 175 +++----------------- > drivers/i2c/busses/i2c-designware-core.h | 1 - > drivers/i2c/busses/i2c-designware-platdrv.c | 1 - > include/linux/psp-platform-access.h | 1 + > 5 files changed, 27 insertions(+), 153 deletions(-) > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 25eb4e8fd22f..d53bf716f97d 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -566,9 +566,9 @@ config I2C_DESIGNWARE_PLATFORM > > config I2C_DESIGNWARE_AMDPSP > bool "AMD PSP I2C semaphore support" > - depends on X86_MSR > depends on ACPI > depends on I2C_DESIGNWARE_PLATFORM > + imply CRYPTO_DEV_SP_PSP > help > This driver enables managed host access to the selected I2C bus shared > between AMD CPU and AMD PSP. > diff --git a/drivers/i2c/busses/i2c-designware-amdpsp.c b/drivers/i2c/busses/i2c-designware-amdpsp.c > index 652e6b64bd5f..12870dc44bdb 100644 > --- a/drivers/i2c/busses/i2c-designware-amdpsp.c > +++ b/drivers/i2c/busses/i2c-designware-amdpsp.c > @@ -1,35 +1,20 @@ > // 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-platform-access.h> > #include <linux/psp.h> > -#include <linux/types.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 > > -struct psp_req_buffer_hdr { > - u32 total_size; > - u32 status; > -}; > - > enum psp_i2c_req_type { > PSP_I2C_REQ_ACQUIRE, > PSP_I2C_REQ_RELEASE, > @@ -41,119 +26,12 @@ 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_CMDRESP_RECOVERY, tmp); > -} > - > -static int psp_wait_cmd(struct psp_mbox __iomem *mbox) > -{ > - u32 tmp, expected; > - > - /* Expect mbox_cmd to be cleared and the response 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(&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_CMDRESP_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_CMDRESP_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; > -} > - > /* Helper to verify status returned by PSP */ > static int check_i2c_req_sts(struct psp_i2c_req *req) > { > @@ -173,22 +51,25 @@ 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; > > - return check_i2c_req_sts(req); > + 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 ret; > } > > static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type) > @@ -202,11 +83,11 @@ 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_cezanne, status, > (status != -EBUSY), > PSP_I2C_REQ_RETRY_DELAY_US, > PSP_I2C_REQ_RETRY_CNT * PSP_I2C_REQ_RETRY_DELAY_US, > @@ -381,7 +262,8 @@ 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; > + if (!IS_REACHABLE(CONFIG_CRYPTO_DEV_CCP_DD)) > + return -ENODEV; > > if (!dev) > return -ENODEV; > @@ -393,11 +275,10 @@ int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) > if (psp_i2c_dev) > return -EEXIST; > > - psp_i2c_dev = dev->dev; > + if (psp_check_platform_access_status()) > + return -EPROBE_DEFER; > > - ret = psp_mbox_probe(); > - if (ret) > - return ret; > + psp_i2c_dev = dev->dev; > > dev_info(psp_i2c_dev, "I2C bus managed by AMD PSP\n"); > > @@ -411,9 +292,3 @@ 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); > -} > diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h > index 050d8c63ad3c..c5d87aae39c6 100644 > --- a/drivers/i2c/busses/i2c-designware-core.h > +++ b/drivers/i2c/busses/i2c-designware-core.h > @@ -383,7 +383,6 @@ int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev); > > #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_AMDPSP) > int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev); > -void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev); > #endif > > int i2c_dw_validate_speed(struct dw_i2c_dev *dev); > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index 74182db03a88..89ad88c54754 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -214,7 +214,6 @@ static const struct i2c_dw_semaphore_callbacks i2c_dw_semaphore_cb_table[] = { > #ifdef CONFIG_I2C_DESIGNWARE_AMDPSP > { > .probe = i2c_dw_amdpsp_probe_lock_support, > - .remove = i2c_dw_amdpsp_remove_lock_support, > }, > #endif > {} > diff --git a/include/linux/psp-platform-access.h b/include/linux/psp-platform-access.h > index 1b661341d8f3..75da8f5f7ad8 100644 > --- a/include/linux/psp-platform-access.h > +++ b/include/linux/psp-platform-access.h > @@ -7,6 +7,7 @@ > > enum psp_platform_access_msg { > PSP_CMD_NONE = 0x0, > + PSP_I2C_REQ_BUS_CMD = 0x64, > }; > > struct psp_req_buffer_hdr { > -- > 2.34.1 >