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Diffstat (limited to 'arch/x86/pci/pcbios.c')
-rw-r--r--arch/x86/pci/pcbios.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c
new file mode 100644
index 00000000..da8fe053
--- /dev/null
+++ b/arch/x86/pci/pcbios.c
@@ -0,0 +1,455 @@
+/*
+ * BIOS32 and PCI BIOS handling.
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <asm/pci_x86.h>
+#include <asm/pci-functions.h>
+#include <asm/cacheflush.h>
+
+/* BIOS32 signature: "_32_" */
+#define BIOS32_SIGNATURE (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
+
+/* PCI signature: "PCI " */
+#define PCI_SIGNATURE (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
+
+/* PCI service signature: "$PCI" */
+#define PCI_SERVICE (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
+
+/* PCI BIOS hardware mechanism flags */
+#define PCIBIOS_HW_TYPE1 0x01
+#define PCIBIOS_HW_TYPE2 0x02
+#define PCIBIOS_HW_TYPE1_SPEC 0x10
+#define PCIBIOS_HW_TYPE2_SPEC 0x20
+
+int pcibios_enabled;
+
+/* According to the BIOS specification at:
+ * http://members.datafast.net.au/dft0802/specs/bios21.pdf, we could
+ * restrict the x zone to some pages and make it ro. But this may be
+ * broken on some bios, complex to handle with static_protections.
+ * We could make the 0xe0000-0x100000 range rox, but this can break
+ * some ISA mapping.
+ *
+ * So we let's an rw and x hole when pcibios is used. This shouldn't
+ * happen for modern system with mmconfig, and if you don't want it
+ * you could disable pcibios...
+ */
+static inline void set_bios_x(void)
+{
+ pcibios_enabled = 1;
+ set_memory_x(PAGE_OFFSET + BIOS_BEGIN, (BIOS_END - BIOS_BEGIN) >> PAGE_SHIFT);
+ if (__supported_pte_mask & _PAGE_NX)
+ printk(KERN_INFO "PCI : PCI BIOS area is rw and x. Use pci=nobios if you want it NX.\n");
+}
+
+/*
+ * This is the standard structure used to identify the entry point
+ * to the BIOS32 Service Directory, as documented in
+ * Standard BIOS 32-bit Service Directory Proposal
+ * Revision 0.4 May 24, 1993
+ * Phoenix Technologies Ltd.
+ * Norwood, MA
+ * and the PCI BIOS specification.
+ */
+
+union bios32 {
+ struct {
+ unsigned long signature; /* _32_ */
+ unsigned long entry; /* 32 bit physical address */
+ unsigned char revision; /* Revision level, 0 */
+ unsigned char length; /* Length in paragraphs should be 01 */
+ unsigned char checksum; /* All bytes must add up to zero */
+ unsigned char reserved[5]; /* Must be zero */
+ } fields;
+ char chars[16];
+};
+
+/*
+ * Physical address of the service directory. I don't know if we're
+ * allowed to have more than one of these or not, so just in case
+ * we'll make pcibios_present() take a memory start parameter and store
+ * the array there.
+ */
+
+static struct {
+ unsigned long address;
+ unsigned short segment;
+} bios32_indirect = { 0, __KERNEL_CS };
+
+/*
+ * Returns the entry point for the given service, NULL on error
+ */
+
+static unsigned long bios32_service(unsigned long service)
+{
+ unsigned char return_code; /* %al */
+ unsigned long address; /* %ebx */
+ unsigned long length; /* %ecx */
+ unsigned long entry; /* %edx */
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __asm__("lcall *(%%edi); cld"
+ : "=a" (return_code),
+ "=b" (address),
+ "=c" (length),
+ "=d" (entry)
+ : "0" (service),
+ "1" (0),
+ "D" (&bios32_indirect));
+ local_irq_restore(flags);
+
+ switch (return_code) {
+ case 0:
+ return address + entry;
+ case 0x80: /* Not present */
+ printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
+ return 0;
+ default: /* Shouldn't happen */
+ printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
+ service, return_code);
+ return 0;
+ }
+}
+
+static struct {
+ unsigned long address;
+ unsigned short segment;
+} pci_indirect = { 0, __KERNEL_CS };
+
+static int pci_bios_present;
+
+static int __devinit check_pcibios(void)
+{
+ u32 signature, eax, ebx, ecx;
+ u8 status, major_ver, minor_ver, hw_mech;
+ unsigned long flags, pcibios_entry;
+
+ if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
+ pci_indirect.address = pcibios_entry + PAGE_OFFSET;
+
+ local_irq_save(flags);
+ __asm__(
+ "lcall *(%%edi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=d" (signature),
+ "=a" (eax),
+ "=b" (ebx),
+ "=c" (ecx)
+ : "1" (PCIBIOS_PCI_BIOS_PRESENT),
+ "D" (&pci_indirect)
+ : "memory");
+ local_irq_restore(flags);
+
+ status = (eax >> 8) & 0xff;
+ hw_mech = eax & 0xff;
+ major_ver = (ebx >> 8) & 0xff;
+ minor_ver = ebx & 0xff;
+ if (pcibios_last_bus < 0)
+ pcibios_last_bus = ecx & 0xff;
+ DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
+ status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
+ if (status || signature != PCI_SIGNATURE) {
+ printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
+ status, signature);
+ return 0;
+ }
+ printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
+ major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
+#ifdef CONFIG_PCI_DIRECT
+ if (!(hw_mech & PCIBIOS_HW_TYPE1))
+ pci_probe &= ~PCI_PROBE_CONF1;
+ if (!(hw_mech & PCIBIOS_HW_TYPE2))
+ pci_probe &= ~PCI_PROBE_CONF2;
+#endif
+ return 1;
+ }
+ return 0;
+}
+
+static int pci_bios_read(unsigned int seg, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 *value)
+{
+ unsigned long result = 0;
+ unsigned long flags;
+ unsigned long bx = (bus << 8) | devfn;
+
+ WARN_ON(seg);
+ if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
+ return -EINVAL;
+
+ raw_spin_lock_irqsave(&pci_config_lock, flags);
+
+ switch (len) {
+ case 1:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=c" (*value),
+ "=a" (result)
+ : "1" (PCIBIOS_READ_CONFIG_BYTE),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ /*
+ * Zero-extend the result beyond 8 bits, do not trust the
+ * BIOS having done it:
+ */
+ *value &= 0xff;
+ break;
+ case 2:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=c" (*value),
+ "=a" (result)
+ : "1" (PCIBIOS_READ_CONFIG_WORD),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ /*
+ * Zero-extend the result beyond 16 bits, do not trust the
+ * BIOS having done it:
+ */
+ *value &= 0xffff;
+ break;
+ case 4:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=c" (*value),
+ "=a" (result)
+ : "1" (PCIBIOS_READ_CONFIG_DWORD),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return (int)((result & 0xff00) >> 8);
+}
+
+static int pci_bios_write(unsigned int seg, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 value)
+{
+ unsigned long result = 0;
+ unsigned long flags;
+ unsigned long bx = (bus << 8) | devfn;
+
+ WARN_ON(seg);
+ if ((bus > 255) || (devfn > 255) || (reg > 255))
+ return -EINVAL;
+
+ raw_spin_lock_irqsave(&pci_config_lock, flags);
+
+ switch (len) {
+ case 1:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=a" (result)
+ : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
+ "c" (value),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ break;
+ case 2:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=a" (result)
+ : "0" (PCIBIOS_WRITE_CONFIG_WORD),
+ "c" (value),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ break;
+ case 4:
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=a" (result)
+ : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
+ "c" (value),
+ "b" (bx),
+ "D" ((long)reg),
+ "S" (&pci_indirect));
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return (int)((result & 0xff00) >> 8);
+}
+
+
+/*
+ * Function table for BIOS32 access
+ */
+
+static const struct pci_raw_ops pci_bios_access = {
+ .read = pci_bios_read,
+ .write = pci_bios_write
+};
+
+/*
+ * Try to find PCI BIOS.
+ */
+
+static const struct pci_raw_ops * __devinit pci_find_bios(void)
+{
+ union bios32 *check;
+ unsigned char sum;
+ int i, length;
+
+ /*
+ * Follow the standard procedure for locating the BIOS32 Service
+ * directory by scanning the permissible address range from
+ * 0xe0000 through 0xfffff for a valid BIOS32 structure.
+ */
+
+ for (check = (union bios32 *) __va(0xe0000);
+ check <= (union bios32 *) __va(0xffff0);
+ ++check) {
+ long sig;
+ if (probe_kernel_address(&check->fields.signature, sig))
+ continue;
+
+ if (check->fields.signature != BIOS32_SIGNATURE)
+ continue;
+ length = check->fields.length * 16;
+ if (!length)
+ continue;
+ sum = 0;
+ for (i = 0; i < length ; ++i)
+ sum += check->chars[i];
+ if (sum != 0)
+ continue;
+ if (check->fields.revision != 0) {
+ printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
+ check->fields.revision, check);
+ continue;
+ }
+ DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
+ if (check->fields.entry >= 0x100000) {
+ printk("PCI: BIOS32 entry (0x%p) in high memory, "
+ "cannot use.\n", check);
+ return NULL;
+ } else {
+ unsigned long bios32_entry = check->fields.entry;
+ DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
+ bios32_entry);
+ bios32_indirect.address = bios32_entry + PAGE_OFFSET;
+ set_bios_x();
+ if (check_pcibios())
+ return &pci_bios_access;
+ }
+ break; /* Hopefully more than one BIOS32 cannot happen... */
+ }
+
+ return NULL;
+}
+
+/*
+ * BIOS Functions for IRQ Routing
+ */
+
+struct irq_routing_options {
+ u16 size;
+ struct irq_info *table;
+ u16 segment;
+} __attribute__((packed));
+
+struct irq_routing_table * pcibios_get_irq_routing_table(void)
+{
+ struct irq_routing_options opt;
+ struct irq_routing_table *rt = NULL;
+ int ret, map;
+ unsigned long page;
+
+ if (!pci_bios_present)
+ return NULL;
+ page = __get_free_page(GFP_KERNEL);
+ if (!page)
+ return NULL;
+ opt.table = (struct irq_info *) page;
+ opt.size = PAGE_SIZE;
+ opt.segment = __KERNEL_DS;
+
+ DBG("PCI: Fetching IRQ routing table... ");
+ __asm__("push %%es\n\t"
+ "push %%ds\n\t"
+ "pop %%es\n\t"
+ "lcall *(%%esi); cld\n\t"
+ "pop %%es\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=a" (ret),
+ "=b" (map),
+ "=m" (opt)
+ : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
+ "1" (0),
+ "D" ((long) &opt),
+ "S" (&pci_indirect),
+ "m" (opt)
+ : "memory");
+ DBG("OK ret=%d, size=%d, map=%x\n", ret, opt.size, map);
+ if (ret & 0xff00)
+ printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
+ else if (opt.size) {
+ rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
+ if (rt) {
+ memset(rt, 0, sizeof(struct irq_routing_table));
+ rt->size = opt.size + sizeof(struct irq_routing_table);
+ rt->exclusive_irqs = map;
+ memcpy(rt->slots, (void *) page, opt.size);
+ printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
+ }
+ }
+ free_page(page);
+ return rt;
+}
+EXPORT_SYMBOL(pcibios_get_irq_routing_table);
+
+int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
+{
+ int ret;
+
+ __asm__("lcall *(%%esi); cld\n\t"
+ "jc 1f\n\t"
+ "xor %%ah, %%ah\n"
+ "1:"
+ : "=a" (ret)
+ : "0" (PCIBIOS_SET_PCI_HW_INT),
+ "b" ((dev->bus->number << 8) | dev->devfn),
+ "c" ((irq << 8) | (pin + 10)),
+ "S" (&pci_indirect));
+ return !(ret & 0xff00);
+}
+EXPORT_SYMBOL(pcibios_set_irq_routing);
+
+void __init pci_pcbios_init(void)
+{
+ if ((pci_probe & PCI_PROBE_BIOS)
+ && ((raw_pci_ops = pci_find_bios()))) {
+ pci_bios_present = 1;
+ }
+}
+
generated by cgit (git 2.34.1) at 2024-12-20 10:20:44 +0000