On Friday 26 October 2007, Jeff Garzik wrote: > Bartlomiej Zolnierkiewicz wrote: > > On Thursday 25 October 2007, Jeff Garzik wrote: > >> Store our hwif indices at probe time, in order to eliminate a needless > >> and ugly loop across all hwifs, searching for our pci device. > > > > It seems that we can simplify it even further and remove knowledge about > > hwifs altogether from suspend/resume methods. > > > >> Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx> > >> --- > >> drivers/ide/pci/sc1200.c | 76 +++++++++++++++++++++++++++++++--------------- > >> 1 files changed, 51 insertions(+), 25 deletions(-) > >> > >> diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c > >> index d2c8b55..17e58d6 100644 > >> --- a/drivers/ide/pci/sc1200.c > >> +++ b/drivers/ide/pci/sc1200.c > >> @@ -41,6 +41,8 @@ > >> #define PCI_CLK_66 0x02 > >> #define PCI_CLK_33A 0x03 > >> > >> +#define SC1200_IFS 4 > >> + > >> static unsigned short sc1200_get_pci_clock (void) > >> { > >> unsigned char chip_id, silicon_revision; > >> @@ -261,31 +263,32 @@ static void sc1200_set_pio_mode(ide_drive_t *drive, const u8 pio) > >> } > >> > >> #ifdef CONFIG_PM > >> -static ide_hwif_t *lookup_pci_dev (ide_hwif_t *prev, struct pci_dev *dev) > >> -{ > >> - int h; > >> - > >> - for (h = 0; h < MAX_HWIFS; h++) { > >> - ide_hwif_t *hwif = &ide_hwifs[h]; > >> - if (prev) { > >> - if (hwif == prev) > >> - prev = NULL; // found previous, now look for next match > >> - } else { > >> - if (hwif && hwif->pci_dev == dev) > >> - return hwif; // found next match > >> - } > >> - } > >> - return NULL; // not found > >> -} > >> - > >> typedef struct sc1200_saved_state_s { > >> __u32 regs[4]; > >> } sc1200_saved_state_t; > >> > >> +static unsigned int pack_hwif_idx(u8 *idx) > >> +{ > >> + return (((unsigned int) idx[0]) << 0) | > >> + (((unsigned int) idx[1]) << 8) | > >> + (((unsigned int) idx[2]) << 16) | > >> + (((unsigned int) idx[3]) << 24); > >> +} > >> + > >> +static ide_hwif_t *sc1200_hwif(struct pci_dev *pdev, unsigned int iface) > >> +{ > >> + unsigned int packed_hwifs, idx; > >> + > >> + packed_hwifs = (unsigned long) pci_get_drvdata(pdev); > >> + idx = (packed_hwifs >> (iface * 8)) & 0xff; > >> + > >> + return (idx == 0xff) ? NULL : &ide_hwifs[idx]; > >> +} > >> > >> static int sc1200_suspend (struct pci_dev *dev, pm_message_t state) > >> { > >> - ide_hwif_t *hwif = NULL; > >> + ide_hwif_t *hwif; > >> + int i; > >> > >> printk("SC1200: suspend(%u)\n", state.event); > >> > >> @@ -295,9 +298,14 @@ static int sc1200_suspend (struct pci_dev *dev, pm_message_t state) > >> // > >> // Loop over all interfaces that are part of this PCI device: > >> // > >> - while ((hwif = lookup_pci_dev(hwif, dev)) != NULL) { > >> + for (i = 0; i < SC1200_IFS; i++) { > >> sc1200_saved_state_t *ss; > >> unsigned int basereg, r; > >> + > >> + hwif = sc1200_hwif(dev, i); > >> + if (!hwif) > >> + continue; > >> + > >> // > >> // allocate a permanent save area, if not already allocated > >> // > >> @@ -310,7 +318,7 @@ static int sc1200_suspend (struct pci_dev *dev, pm_message_t state) > >> } > >> ss = (sc1200_saved_state_t *)hwif->config_data; > >> // > >> - // Save timing registers: this may be unnecessary if > >> + // Save timing registers: this may be unnecessary if > >> // BIOS also does it > >> // > >> basereg = hwif->channel ? 0x50 : 0x40; > > > > Please take a close look at the line above and the next three lines: > > > > for (r = 0; r < 4; ++r) { > > pci_read_config_dword (hwif->pci_dev, basereg + (r<<2), &ss->regs[r]); > > } > > > > It is highly obfuscated but the sc1200_suspend() reads 16 bytes from > > the offset 0x40 (for the primary port) and puts them in the corresponding > > struct sc1200_saved_state_s buffer, then it reads another 16 bytes from the > > offset 0x50 (for the secondary port) and puts it in the another buffer. > > > > In summary sc1200_suspend() reads 32 continuous bytes from offset 0x40 > > and the exactly reverse operation happens in sc1200_resume(). > > > > Given that and the fact that struct sc1200_save_state_s buffers are used > > _only_ by sc1200_{suspend,resume}() we may safely convert the code to use > > one buffer for both ports (the whole PCI device). We just need to bump > > the size of struct sc1200_saved_state_s (from 4 to 8 double-words) and use > > pci_{get,set}_drvdata() instead of hwif->config_data. Then we can remove > > looping over interfaces completely from sc1200_{suspend,resume}()! :) > > May I assume you'll handle that task? :) It sounds like you have a far > better idea than mine, and my main goal -- fixing bugs and warning -- is > accomplished anyway with the merging of patch #3. Uh, OK... [PATCH] sc1200: remove pointless hwif lookup loop Save PCI regs values for both IDE ports in one buffer, in order to eliminate a needless and ugly loop across all hwifs, searching for our PCI device. Partially based on the previous patch by Jeff Garzik. Cc: Jeff Garzik <jeff@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> --- drivers/ide/pci/sc1200.c | 106 ++++++++++++++++------------------------------- 1 file changed, 37 insertions(+), 69 deletions(-) Index: b/drivers/ide/pci/sc1200.c =================================================================== --- a/drivers/ide/pci/sc1200.c +++ b/drivers/ide/pci/sc1200.c @@ -261,66 +261,39 @@ static void sc1200_set_pio_mode(ide_driv } #ifdef CONFIG_PM -static ide_hwif_t *lookup_pci_dev (ide_hwif_t *prev, struct pci_dev *dev) -{ - int h; - - for (h = 0; h < MAX_HWIFS; h++) { - ide_hwif_t *hwif = &ide_hwifs[h]; - if (prev) { - if (hwif == prev) - prev = NULL; // found previous, now look for next match - } else { - if (hwif && hwif->pci_dev == dev) - return hwif; // found next match - } - } - return NULL; // not found -} - -typedef struct sc1200_saved_state_s { - __u32 regs[4]; -} sc1200_saved_state_t; - +struct sc1200_saved_state { + u32 regs[8]; +}; static int sc1200_suspend (struct pci_dev *dev, pm_message_t state) { - ide_hwif_t *hwif = NULL; - printk("SC1200: suspend(%u)\n", state.event); + /* + * we only save state when going from full power to less + */ if (state.event == PM_EVENT_ON) { - // we only save state when going from full power to less + struct sc1200_saved_state *ss; + unsigned int r; - // - // Loop over all interfaces that are part of this PCI device: - // - while ((hwif = lookup_pci_dev(hwif, dev)) != NULL) { - sc1200_saved_state_t *ss; - unsigned int basereg, r; - // - // allocate a permanent save area, if not already allocated - // - ss = (sc1200_saved_state_t *)hwif->config_data; - if (ss == NULL) { - ss = kmalloc(sizeof(sc1200_saved_state_t), GFP_KERNEL); - if (ss == NULL) - return -ENOMEM; - hwif->config_data = (unsigned long)ss; - } - ss = (sc1200_saved_state_t *)hwif->config_data; - // - // Save timing registers: this may be unnecessary if - // BIOS also does it - // - basereg = hwif->channel ? 0x50 : 0x40; - for (r = 0; r < 4; ++r) { - pci_read_config_dword (hwif->pci_dev, basereg + (r<<2), &ss->regs[r]); - } + /* + * allocate a permanent save area, if not already allocated + */ + ss = (struct sc1200_saved_state *)pci_get_drvdata(dev); + if (ss == NULL) { + ss = kmalloc(sizeof(*ss), GFP_KERNEL); + if (ss == NULL) + return -ENOMEM; + pci_set_drvdata(dev, ss); } - } - /* You don't need to iterate over disks -- sysfs should have done that for you already */ + /* + * save timing registers + * (this may be unnecessary if BIOS also does it) + */ + for (r = 0; r < 8; r++) + pci_read_config_dword(dev, 0x40 + r * 4, &ss->regs[r]); + } pci_disable_device(dev); pci_set_power_state(dev, pci_choose_state(dev, state)); @@ -329,30 +302,25 @@ static int sc1200_suspend (struct pci_de static int sc1200_resume (struct pci_dev *dev) { - ide_hwif_t *hwif = NULL; - int i; + struct sc1200_saved_state *ss; + unsigned int r; + int i; i = pci_enable_device(dev); if (i) return i; - // - // loop over all interfaces that are part of this pci device: - // - while ((hwif = lookup_pci_dev(hwif, dev)) != NULL) { - unsigned int basereg, r; - sc1200_saved_state_t *ss = (sc1200_saved_state_t *)hwif->config_data; - - // - // Restore timing registers: this may be unnecessary if BIOS also does it - // - basereg = hwif->channel ? 0x50 : 0x40; - if (ss != NULL) { - for (r = 0; r < 4; ++r) { - pci_write_config_dword(hwif->pci_dev, basereg + (r<<2), ss->regs[r]); - } - } + ss = (struct sc1200_saved_state *)pci_get_drvdata(dev); + + /* + * restore timing registers + * (this may be unnecessary if BIOS also does it) + */ + if (ss) { + for (r = 0; r < 8; r++) + pci_write_config_dword(dev, 0x40 + r * 4, ss->regs[r]); } + return 0; } #endif - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html