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cciss: PCI power management reset for kexec

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The kexec kernel resets the CCISS hardware in three steps:

1. Use PCI power management states to reset the controller in the
   kexec kernel.

2. Clear the MSI/MSI-X bits in PCI configuration space so that MSI
   initialization in the kexec kernel doesn't fail.

3. Use the CCISS "No-op" message to determine when the controller
   firmware has recovered from the PCI PM reset.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Chip Coldwell 2009-02-16 13:11:56 +01:00 committed by Jens Axboe
parent c8cbec6bdf
commit 82eb03cfd8
1 changed files with 215 additions and 0 deletions
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215
drivers/block/cciss.c
View file

@ -3390,6 +3390,203 @@ static void free_hba(int i)
kfree(p);
}
/* Send a message CDB to the firmware. */
static __devinit int cciss_message(struct pci_dev *pdev, unsigned char opcode, unsigned char type)
{
typedef struct {
CommandListHeader_struct CommandHeader;
RequestBlock_struct Request;
ErrDescriptor_struct ErrorDescriptor;
} Command;
static const size_t cmd_sz = sizeof(Command) + sizeof(ErrorInfo_struct);
Command *cmd;
dma_addr_t paddr64;
uint32_t paddr32, tag;
void __iomem *vaddr;
int i, err;
vaddr = ioremap_nocache(pci_resource_start(pdev, 0), pci_resource_len(pdev, 0));
if (vaddr == NULL)
return -ENOMEM;
/* The Inbound Post Queue only accepts 32-bit physical addresses for the
CCISS commands, so they must be allocated from the lower 4GiB of
memory. */
err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
if (err) {
iounmap(vaddr);
return -ENOMEM;
}
cmd = pci_alloc_consistent(pdev, cmd_sz, &paddr64);
if (cmd == NULL) {
iounmap(vaddr);
return -ENOMEM;
}
/* This must fit, because of the 32-bit consistent DMA mask. Also,
although there's no guarantee, we assume that the address is at
least 4-byte aligned (most likely, it's page-aligned). */
paddr32 = paddr64;
cmd->CommandHeader.ReplyQueue = 0;
cmd->CommandHeader.SGList = 0;
cmd->CommandHeader.SGTotal = 0;
cmd->CommandHeader.Tag.lower = paddr32;
cmd->CommandHeader.Tag.upper = 0;
memset(&cmd->CommandHeader.LUN.LunAddrBytes, 0, 8);
cmd->Request.CDBLen = 16;
cmd->Request.Type.Type = TYPE_MSG;
cmd->Request.Type.Attribute = ATTR_HEADOFQUEUE;
cmd->Request.Type.Direction = XFER_NONE;
cmd->Request.Timeout = 0; /* Don't time out */
cmd->Request.CDB[0] = opcode;
cmd->Request.CDB[1] = type;
memset(&cmd->Request.CDB[2], 0, 14); /* the rest of the CDB is reserved */
cmd->ErrorDescriptor.Addr.lower = paddr32 + sizeof(Command);
cmd->ErrorDescriptor.Addr.upper = 0;
cmd->ErrorDescriptor.Len = sizeof(ErrorInfo_struct);
writel(paddr32, vaddr + SA5_REQUEST_PORT_OFFSET);
for (i = 0; i < 10; i++) {
tag = readl(vaddr + SA5_REPLY_PORT_OFFSET);
if ((tag & ~3) == paddr32)
break;
schedule_timeout_uninterruptible(HZ);
}
iounmap(vaddr);
/* we leak the DMA buffer here ... no choice since the controller could
still complete the command. */
if (i == 10) {
printk(KERN_ERR "cciss: controller message %02x:%02x timed out\n",
opcode, type);
return -ETIMEDOUT;
}
pci_free_consistent(pdev, cmd_sz, cmd, paddr64);
if (tag & 2) {
printk(KERN_ERR "cciss: controller message %02x:%02x failed\n",
opcode, type);
return -EIO;
}
printk(KERN_INFO "cciss: controller message %02x:%02x succeeded\n",
opcode, type);
return 0;
}
#define cciss_soft_reset_controller(p) cciss_message(p, 1, 0)
#define cciss_noop(p) cciss_message(p, 3, 0)
static __devinit int cciss_reset_msi(struct pci_dev *pdev)
{
/* the #defines are stolen from drivers/pci/msi.h. */
#define msi_control_reg(base) (base + PCI_MSI_FLAGS)
#define PCI_MSIX_FLAGS_ENABLE (1 << 15)
int pos;
u16 control = 0;
pos = pci_find_capability(pdev, PCI_CAP_ID_MSI);
if (pos) {
pci_read_config_word(pdev, msi_control_reg(pos), &control);
if (control & PCI_MSI_FLAGS_ENABLE) {
printk(KERN_INFO "cciss: resetting MSI\n");
pci_write_config_word(pdev, msi_control_reg(pos), control & ~PCI_MSI_FLAGS_ENABLE);
}
}
pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX);
if (pos) {
pci_read_config_word(pdev, msi_control_reg(pos), &control);
if (control & PCI_MSIX_FLAGS_ENABLE) {
printk(KERN_INFO "cciss: resetting MSI-X\n");
pci_write_config_word(pdev, msi_control_reg(pos), control & ~PCI_MSIX_FLAGS_ENABLE);
}
}
return 0;
}
/* This does a hard reset of the controller using PCI power management
* states. */
static __devinit int cciss_hard_reset_controller(struct pci_dev *pdev)
{
u16 pmcsr, saved_config_space[32];
int i, pos;
printk(KERN_INFO "cciss: using PCI PM to reset controller\n");
/* This is very nearly the same thing as
pci_save_state(pci_dev);
pci_set_power_state(pci_dev, PCI_D3hot);
pci_set_power_state(pci_dev, PCI_D0);
pci_restore_state(pci_dev);
but we can't use these nice canned kernel routines on
kexec, because they also check the MSI/MSI-X state in PCI
configuration space and do the wrong thing when it is
set/cleared. Also, the pci_save/restore_state functions
violate the ordering requirements for restoring the
configuration space from the CCISS document (see the
comment below). So we roll our own .... */
for (i = 0; i < 32; i++)
pci_read_config_word(pdev, 2*i, &saved_config_space[i]);
pos = pci_find_capability(pdev, PCI_CAP_ID_PM);
if (pos == 0) {
printk(KERN_ERR "cciss_reset_controller: PCI PM not supported\n");
return -ENODEV;
}
/* Quoting from the Open CISS Specification: "The Power
* Management Control/Status Register (CSR) controls the power
* state of the device. The normal operating state is D0,
* CSR=00h. The software off state is D3, CSR=03h. To reset
* the controller, place the interface device in D3 then to
* D0, this causes a secondary PCI reset which will reset the
* controller." */
/* enter the D3hot power management state */
pci_read_config_word(pdev, pos + PCI_PM_CTRL, &pmcsr);
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= PCI_D3hot;
pci_write_config_word(pdev, pos + PCI_PM_CTRL, pmcsr);
schedule_timeout_uninterruptible(HZ >> 1);
/* enter the D0 power management state */
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= PCI_D0;
pci_write_config_word(pdev, pos + PCI_PM_CTRL, pmcsr);
schedule_timeout_uninterruptible(HZ >> 1);
/* Restore the PCI configuration space. The Open CISS
* Specification says, "Restore the PCI Configuration
* Registers, offsets 00h through 60h. It is important to
* restore the command register, 16-bits at offset 04h,
* last. Do not restore the configuration status register,
* 16-bits at offset 06h." Note that the offset is 2*i. */
for (i = 0; i < 32; i++) {
if (i == 2 || i == 3)
continue;
pci_write_config_word(pdev, 2*i, saved_config_space[i]);
}
wmb();
pci_write_config_word(pdev, 4, saved_config_space[2]);
return 0;
}
/*
* This is it. Find all the controllers and register them. I really hate
* stealing all these major device numbers.
@ -3404,6 +3601,24 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
int dac, return_code;
InquiryData_struct *inq_buff = NULL;
if (reset_devices) {
/* Reset the controller with a PCI power-cycle */
if (cciss_hard_reset_controller(pdev) || cciss_reset_msi(pdev))
return -ENODEV;
/* Some devices (notably the HP Smart Array 5i Controller)
need a little pause here */
schedule_timeout_uninterruptible(30*HZ);
/* Now try to get the controller to respond to a no-op */
for (i=0; i<12; i++) {
if (cciss_noop(pdev) == 0)
break;
else
printk("cciss: no-op failed%s\n", (i < 11 ? "; re-trying" : ""));
}
}
i = alloc_cciss_hba();
if (i < 0)
return -1;