diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/mips/pci/msi-octeon.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c new file mode 100644 index 000000000..288b58b00 --- /dev/null +++ b/arch/mips/pci/msi-octeon.c @@ -0,0 +1,438 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005-2009, 2010 Cavium Networks + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/msi.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> + +#include <asm/octeon/octeon.h> +#include <asm/octeon/cvmx-npi-defs.h> +#include <asm/octeon/cvmx-pci-defs.h> +#include <asm/octeon/cvmx-npei-defs.h> +#include <asm/octeon/cvmx-sli-defs.h> +#include <asm/octeon/cvmx-pexp-defs.h> +#include <asm/octeon/pci-octeon.h> + +/* + * Each bit in msi_free_irq_bitmask represents a MSI interrupt that is + * in use. + */ +static u64 msi_free_irq_bitmask[4]; + +/* + * Each bit in msi_multiple_irq_bitmask tells that the device using + * this bit in msi_free_irq_bitmask is also using the next bit. This + * is used so we can disable all of the MSI interrupts when a device + * uses multiple. + */ +static u64 msi_multiple_irq_bitmask[4]; + +/* + * This lock controls updates to msi_free_irq_bitmask and + * msi_multiple_irq_bitmask. + */ +static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock); + +/* + * Number of MSI IRQs used. This variable is set up in + * the module init time. + */ +static int msi_irq_size; + +/** + * Called when a driver request MSI interrupts instead of the + * legacy INT A-D. This routine will allocate multiple interrupts + * for MSI devices that support them. A device can override this by + * programming the MSI control bits [6:4] before calling + * pci_enable_msi(). + * + * @dev: Device requesting MSI interrupts + * @desc: MSI descriptor + * + * Returns 0 on success. + */ +int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc) +{ + struct msi_msg msg; + u16 control; + int configured_private_bits; + int request_private_bits; + int irq = 0; + int irq_step; + u64 search_mask; + int index; + + /* + * Read the MSI config to figure out how many IRQs this device + * wants. Most devices only want 1, which will give + * configured_private_bits and request_private_bits equal 0. + */ + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + + /* + * If the number of private bits has been configured then use + * that value instead of the requested number. This gives the + * driver the chance to override the number of interrupts + * before calling pci_enable_msi(). + */ + configured_private_bits = (control & PCI_MSI_FLAGS_QSIZE) >> 4; + if (configured_private_bits == 0) { + /* Nothing is configured, so use the hardware requested size */ + request_private_bits = (control & PCI_MSI_FLAGS_QMASK) >> 1; + } else { + /* + * Use the number of configured bits, assuming the + * driver wanted to override the hardware request + * value. + */ + request_private_bits = configured_private_bits; + } + + /* + * The PCI 2.3 spec mandates that there are at most 32 + * interrupts. If this device asks for more, only give it one. + */ + if (request_private_bits > 5) + request_private_bits = 0; + +try_only_one: + /* + * The IRQs have to be aligned on a power of two based on the + * number being requested. + */ + irq_step = 1 << request_private_bits; + + /* Mask with one bit for each IRQ */ + search_mask = (1 << irq_step) - 1; + + /* + * We're going to search msi_free_irq_bitmask_lock for zero + * bits. This represents an MSI interrupt number that isn't in + * use. + */ + spin_lock(&msi_free_irq_bitmask_lock); + for (index = 0; index < msi_irq_size/64; index++) { + for (irq = 0; irq < 64; irq += irq_step) { + if ((msi_free_irq_bitmask[index] & (search_mask << irq)) == 0) { + msi_free_irq_bitmask[index] |= search_mask << irq; + msi_multiple_irq_bitmask[index] |= (search_mask >> 1) << irq; + goto msi_irq_allocated; + } + } + } +msi_irq_allocated: + spin_unlock(&msi_free_irq_bitmask_lock); + + /* Make sure the search for available interrupts didn't fail */ + if (irq >= 64) { + if (request_private_bits) { + pr_err("arch_setup_msi_irq: Unable to find %d free interrupts, trying just one", + 1 << request_private_bits); + request_private_bits = 0; + goto try_only_one; + } else + panic("arch_setup_msi_irq: Unable to find a free MSI interrupt"); + } + + /* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */ + irq += index*64; + irq += OCTEON_IRQ_MSI_BIT0; + + switch (octeon_dma_bar_type) { + case OCTEON_DMA_BAR_TYPE_SMALL: + /* When not using big bar, Bar 0 is based at 128MB */ + msg.address_lo = + ((128ul << 20) + CVMX_PCI_MSI_RCV) & 0xffffffff; + msg.address_hi = ((128ul << 20) + CVMX_PCI_MSI_RCV) >> 32; + break; + case OCTEON_DMA_BAR_TYPE_BIG: + /* When using big bar, Bar 0 is based at 0 */ + msg.address_lo = (0 + CVMX_PCI_MSI_RCV) & 0xffffffff; + msg.address_hi = (0 + CVMX_PCI_MSI_RCV) >> 32; + break; + case OCTEON_DMA_BAR_TYPE_PCIE: + /* When using PCIe, Bar 0 is based at 0 */ + /* FIXME CVMX_NPEI_MSI_RCV* other than 0? */ + msg.address_lo = (0 + CVMX_NPEI_PCIE_MSI_RCV) & 0xffffffff; + msg.address_hi = (0 + CVMX_NPEI_PCIE_MSI_RCV) >> 32; + break; + case OCTEON_DMA_BAR_TYPE_PCIE2: + /* When using PCIe2, Bar 0 is based at 0 */ + msg.address_lo = (0 + CVMX_SLI_PCIE_MSI_RCV) & 0xffffffff; + msg.address_hi = (0 + CVMX_SLI_PCIE_MSI_RCV) >> 32; + break; + default: + panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type"); + } + msg.data = irq - OCTEON_IRQ_MSI_BIT0; + + /* Update the number of IRQs the device has available to it */ + control &= ~PCI_MSI_FLAGS_QSIZE; + control |= request_private_bits << 4; + pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control); + + irq_set_msi_desc(irq, desc); + pci_write_msi_msg(irq, &msg); + return 0; +} + +int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + struct msi_desc *entry; + int ret; + + /* + * MSI-X is not supported. + */ + if (type == PCI_CAP_ID_MSIX) + return -EINVAL; + + /* + * If an architecture wants to support multiple MSI, it needs to + * override arch_setup_msi_irqs() + */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + + for_each_pci_msi_entry(entry, dev) { + ret = arch_setup_msi_irq(dev, entry); + if (ret < 0) + return ret; + if (ret > 0) + return -ENOSPC; + } + + return 0; +} + +/** + * Called when a device no longer needs its MSI interrupts. All + * MSI interrupts for the device are freed. + * + * @irq: The devices first irq number. There may be multple in sequence. + */ +void arch_teardown_msi_irq(unsigned int irq) +{ + int number_irqs; + u64 bitmask; + int index = 0; + int irq0; + + if ((irq < OCTEON_IRQ_MSI_BIT0) + || (irq > msi_irq_size + OCTEON_IRQ_MSI_BIT0)) + panic("arch_teardown_msi_irq: Attempted to teardown illegal " + "MSI interrupt (%d)", irq); + + irq -= OCTEON_IRQ_MSI_BIT0; + index = irq / 64; + irq0 = irq % 64; + + /* + * Count the number of IRQs we need to free by looking at the + * msi_multiple_irq_bitmask. Each bit set means that the next + * IRQ is also owned by this device. + */ + number_irqs = 0; + while ((irq0 + number_irqs < 64) && + (msi_multiple_irq_bitmask[index] + & (1ull << (irq0 + number_irqs)))) + number_irqs++; + number_irqs++; + /* Mask with one bit for each IRQ */ + bitmask = (1 << number_irqs) - 1; + /* Shift the mask to the correct bit location */ + bitmask <<= irq0; + if ((msi_free_irq_bitmask[index] & bitmask) != bitmask) + panic("arch_teardown_msi_irq: Attempted to teardown MSI " + "interrupt (%d) not in use", irq); + + /* Checks are done, update the in use bitmask */ + spin_lock(&msi_free_irq_bitmask_lock); + msi_free_irq_bitmask[index] &= ~bitmask; + msi_multiple_irq_bitmask[index] &= ~bitmask; + spin_unlock(&msi_free_irq_bitmask_lock); +} + +static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock); + +static u64 msi_rcv_reg[4]; +static u64 mis_ena_reg[4]; + +static void octeon_irq_msi_enable_pcie(struct irq_data *data) +{ + u64 en; + unsigned long flags; + int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0; + int irq_index = msi_number >> 6; + int irq_bit = msi_number & 0x3f; + + raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags); + en = cvmx_read_csr(mis_ena_reg[irq_index]); + en |= 1ull << irq_bit; + cvmx_write_csr(mis_ena_reg[irq_index], en); + cvmx_read_csr(mis_ena_reg[irq_index]); + raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags); +} + +static void octeon_irq_msi_disable_pcie(struct irq_data *data) +{ + u64 en; + unsigned long flags; + int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0; + int irq_index = msi_number >> 6; + int irq_bit = msi_number & 0x3f; + + raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags); + en = cvmx_read_csr(mis_ena_reg[irq_index]); + en &= ~(1ull << irq_bit); + cvmx_write_csr(mis_ena_reg[irq_index], en); + cvmx_read_csr(mis_ena_reg[irq_index]); + raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags); +} + +static struct irq_chip octeon_irq_chip_msi_pcie = { + .name = "MSI", + .irq_enable = octeon_irq_msi_enable_pcie, + .irq_disable = octeon_irq_msi_disable_pcie, +}; + +static void octeon_irq_msi_enable_pci(struct irq_data *data) +{ + /* + * Octeon PCI doesn't have the ability to mask/unmask MSI + * interrupts individually. Instead of masking/unmasking them + * in groups of 16, we simple assume MSI devices are well + * behaved. MSI interrupts are always enable and the ACK is + * assumed to be enough + */ +} + +static void octeon_irq_msi_disable_pci(struct irq_data *data) +{ + /* See comment in enable */ +} + +static struct irq_chip octeon_irq_chip_msi_pci = { + .name = "MSI", + .irq_enable = octeon_irq_msi_enable_pci, + .irq_disable = octeon_irq_msi_disable_pci, +}; + +/* + * Called by the interrupt handling code when an MSI interrupt + * occurs. + */ +static irqreturn_t __octeon_msi_do_interrupt(int index, u64 msi_bits) +{ + int irq; + int bit; + + bit = fls64(msi_bits); + if (bit) { + bit--; + /* Acknowledge it first. */ + cvmx_write_csr(msi_rcv_reg[index], 1ull << bit); + + irq = bit + OCTEON_IRQ_MSI_BIT0 + 64 * index; + do_IRQ(irq); + return IRQ_HANDLED; + } + return IRQ_NONE; +} + +#define OCTEON_MSI_INT_HANDLER_X(x) \ +static irqreturn_t octeon_msi_interrupt##x(int cpl, void *dev_id) \ +{ \ + u64 msi_bits = cvmx_read_csr(msi_rcv_reg[(x)]); \ + return __octeon_msi_do_interrupt((x), msi_bits); \ +} + +/* + * Create octeon_msi_interrupt{0-3} function body + */ +OCTEON_MSI_INT_HANDLER_X(0); +OCTEON_MSI_INT_HANDLER_X(1); +OCTEON_MSI_INT_HANDLER_X(2); +OCTEON_MSI_INT_HANDLER_X(3); + +/* + * Initializes the MSI interrupt handling code + */ +int __init octeon_msi_initialize(void) +{ + int irq; + struct irq_chip *msi; + + if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) { + return 0; + } else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) { + msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0; + msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1; + msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2; + msi_rcv_reg[3] = CVMX_PEXP_NPEI_MSI_RCV3; + mis_ena_reg[0] = CVMX_PEXP_NPEI_MSI_ENB0; + mis_ena_reg[1] = CVMX_PEXP_NPEI_MSI_ENB1; + mis_ena_reg[2] = CVMX_PEXP_NPEI_MSI_ENB2; + mis_ena_reg[3] = CVMX_PEXP_NPEI_MSI_ENB3; + msi = &octeon_irq_chip_msi_pcie; + } else { + msi_rcv_reg[0] = CVMX_NPI_NPI_MSI_RCV; +#define INVALID_GENERATE_ADE 0x8700000000000000ULL; + msi_rcv_reg[1] = INVALID_GENERATE_ADE; + msi_rcv_reg[2] = INVALID_GENERATE_ADE; + msi_rcv_reg[3] = INVALID_GENERATE_ADE; + mis_ena_reg[0] = INVALID_GENERATE_ADE; + mis_ena_reg[1] = INVALID_GENERATE_ADE; + mis_ena_reg[2] = INVALID_GENERATE_ADE; + mis_ena_reg[3] = INVALID_GENERATE_ADE; + msi = &octeon_irq_chip_msi_pci; + } + + for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_LAST; irq++) + irq_set_chip_and_handler(irq, msi, handle_simple_irq); + + if (octeon_has_feature(OCTEON_FEATURE_PCIE)) { + if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0, + 0, "MSI[0:63]", octeon_msi_interrupt0)) + panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt1, + 0, "MSI[64:127]", octeon_msi_interrupt1)) + panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt2, + 0, "MSI[127:191]", octeon_msi_interrupt2)) + panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt3, + 0, "MSI[192:255]", octeon_msi_interrupt3)) + panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed"); + + msi_irq_size = 256; + } else if (octeon_is_pci_host()) { + if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0, + 0, "MSI[0:15]", octeon_msi_interrupt0)) + panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt0, + 0, "MSI[16:31]", octeon_msi_interrupt0)) + panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt0, + 0, "MSI[32:47]", octeon_msi_interrupt0)) + panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed"); + + if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt0, + 0, "MSI[48:63]", octeon_msi_interrupt0)) + panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed"); + msi_irq_size = 64; + } + return 0; +} +subsys_initcall(octeon_msi_initialize); |